Butane recovery

I have instructions for extracting pure essential oil from plant material using butane. The problem I have with it is that at the end, the butane is vented. I just don't feel right about venting unburned hydrocarbons into the atmosphere. I've been looking at glass lab equipment (distillation tubes, connectors, etc). I have no background in chemistry, but it seems to me it shouldn't be too difficult to put something together using standard glass lab equipment to capture, distill and reuse the butane. Butane boils at 31 degrees Fahrenheit and is heavier than air. At the end of the process, the oil is scraped from the bottom of a drying dish. Does anyone have any suggestions on how to put something like this together? Thanks

Posted by GlobalVillageIdiot 8 years ago

Essential oil/Alchohol/Solvent purification and separation

Hi,I have a lot of impure essential oil that has a lot of water in it and was thinking about ways to get some of the water out. Would salting out with Epsom salts work? I've seen an Instructable where a nonpolar solvent is used to extract nepecatalone https://www.instructables.com/id/DIY-Kitty-Crack%3a--ultra-potent-catnip-extract/ would one be able to use a solvent that is immiscible (I swear that's a word) in water to get the constituents that are not water soluble out of the water?Also can common solvents (I'm thinking alcohol, acetone, and toulene) be salted out to increase the concentration? Would this work with dilute hydrochloric acid?-mitch

Posted by fearofsquirrels 9 years ago

what can be used to thin Dap Kwik Seal Plus for spray coating

I am trying to figure out what solvent would be safe and suitable to thin Dap Kwik Seal plus enough to be applied to a latex coated foam surface via a HVLP sprayer. does anyone have any thoughts on this?

Posted by lunchbox739 7 months ago

what could I use for.....

Hello! For a project that i will transform into an instructable I would need a color with following properties: - Stick to metal - Possible to remove using solvents - Water resistant - possibly sprayable - Protect sprayed material from direct contact with water. (not long term.. half an hour is enough.. ) - NOT heat resistant. if heated the color should be damaged and come off the metal without the use of any solvents. - must be as dark as possible any Idea of what could be used? Thanks!

Posted by sharkyenergy 3 years ago

Cleaning the oil for a vacuum pump

Was too lazy to do an Instructable about it and think a lot of pics or even videos won't help much if you know what I mean ;) Some of us use rotary vane pumps not for the purpose of evacuating refrigeration systems but for all sorts of fun and experiments. This means quite soon or often we face the problem of the oil taking in a lot of water or even worse particles and solvent fumes. I don't know about you but I was getting sick and tired of replacing the expensive oil every few weeks or sometimes even days if something got too wrong. There are many different blends of compressor oil out there that will work very well in our rotary vane pumps. The main difference is whyt the oil is designed for. Some are perfect for aircon systems, others for the work with solvent fumes and there are even those special oils that bind moisture. Unless you really need to evacuted special gases or solvents basically any low viscosity oil will do us just fine! So instead of paying 20 bucks for special compressor or even vacuum pump oil we can select the cheap everyday oil. Well, not exactly... We also want to be able to recycle our oil to save even more money. That means we don't want an oil that binds to water to keep it out of harms way. We also don't want any oil that has special coating abilities for example these oils claiming to reduce wear and tear on your engine. But any other low viscosity mineral oil or if you prefer synthetic oil will do - just stay away from silicone based oils!! If you have not used your pump for a few days you can often see a slude at the bottom of the viewing glass. If the rest of the oil is clear you can simply drain this worst bit and top up with fresh oil if required. This simple procedure saves you a lot of oil already, at least if your pump has some rest every now and then. Once your oil looks wasted it is time for the recycling and cleaning: Release the oil into a high glass jar or these facy spaghetti glasses. Fill with fresh oil and give it a short run. Release this oil as well and wait for it to properly drain. You now have the inside of your pump nice and clean again, time to fill one last time with fresh oil to keep using the pump. The filthy oil we now have in our jar should be covered with some fine cloth or filter paper and placed somewhere warm. After a week or two the oil, filth and water will have seperated and you pump, drain or siphon out the now clean oil for further use. Don't be too exact here trying to get all the oil out, just remove what you can without risking to suck in the filth from the bottom. Simply leave the rest in the jar and add the next oil change to it for the same recycling process. Solvents.... In some cases we will work with solvents and that means the oil might bind to them. Acetone for example is quite nasty here and can change the oil itself by breaking down certain components. In most cases it means the viscosity will be reduced, which is not really too bad for us. What is bad however is the fact that these solvents often refuse to fully seperate or evaporate. Once the oil looks clean do a smell test and if it smells like solvent then for sure there is solvent in it. Next step to confirm is to do a lube test. Simply place on some smooth metal or glass and smear it with your finger - a drop is enough here. If it feels sticky on the surface, gives you a rubber like feeling when sliding over the surface or is far less "slippery" than the fresh oil you also have a problem. I found that filling this contaminated oil into a proper container and applying a strong vacuum will remove all solvent residue in a very short time. Downside is that the oil in the pump is contaminated again, so it pays off to collect solvent contaminated oil seperately and once you got enough for several refills use the pump to get rid of the solvent. When done do another smear and smell test, if still smelly repeat if no longer smelly but still the same bad feeling on the surface: Discard as the oil might be broken down by the solvent.

Posted by Downunder35m 1 year ago


I have a bag of dried cayenne peppers lying around here somewhere. Is there any way i can extract the oils to make a kind of spicy fire liquid? What solvents (isopropyl? denatured alcohol? acetone?) would dissolve the oils? Thanks.

Posted by John Smith 10 years ago

Removing rust from a motorbike's fuel tank?

My dad has got a yamaha xs650 but the fuel tanks got rust in it. What solvents can I put in to remove the rust without removing the tank or messing up the fuel? The pics are of 1)in the tank 2)The motorbike 3)a blurry pic of inside the tank

Posted by thermoelectric 10 years ago

Nylon and substitutes on a cold bed

It's been some time and I made progress with Nylon. Aldi had some cheap craft glue with methanol as the solvent - this stuff works great for PLA, ABS AND Nylon. The common problem with nylon is that it has no real adhesion to anything, except cardboard and bakelite. Cardboard makes a clean up nightmare and bakelite is not always easy to find, especially not the right type. So I tried various glues, paints and primers but none was really suited for all printing needs. And the cleanup of the bed is imoprtant too as I did not want to spend hours scrubbing with acetone or similar nasty solvents. After the first great succes with the clear Aldi craft glue I checked the local 2$ shops and carft stores and found similar glueswith methanol as a solvent. Since not everyone is lucky enough to get these specials I will tell you what to look out for if you try clear craft glue: Don't buy anything that can be cleaned up with water - you want methanol or ethanol as the solvent in the glue! Do a test with the glue on something that usually does not bind well to cheap glue, like glass and blister packs. Let the glue dry and peel it off - it should be a clear film that is quite strong and barely streches when you pull it. It almost feels like hard paper. All good so far? Check if the nylon, pla or abs really sticks to it: Spread a very thin layer on a piece of cardboard and let dry. Add another, thicker layer and let dry again. Now hold it under your nozzle and extrude a bit of filament while moving the cardboard around. Let cool and check how good it sticks. In a perfect world the cool plastic should peel the papaer off with the glue. Time to prepare your print bed the same way and to start printing ;) Just use a very thin first layer and for the first layer much lower speeds than usual. I print nylon with 60mm/s and the first layer at just 25mm/s, any faster and the first layer does not look right. ABS and PLA are much more forgiving here.

Posted by Downunder35m 2 years ago

Film Adhesion? (How do I get old camera reel film to stick to itself in a clean way?)

I need some kind of clear glue to get old camera film, the kind you find on reels, to stick together. I was thinking of finding a volatile solvent and pouring that over two pieces on top of each other. Anyone know what old camera film dissolves in?? Thanks, -Josh

Posted by T3h_Muffinator 11 years ago

Ultrasound Cleaning

For maintenance purposes, I would like to construct an ultrasound cleaning tank. Preferably an encapsulated ultrasound transducer and generator that could be used in an old solvent cleaning tank which now should not be used. From reading a little about the subject, its application would find a wide use as a clean and environmentally friendly solution in many industrial and domestic applications. Is it feasable and cost effective to build a generator and an encapsulated transducer, and are there any websites to go to to find out more?

Posted by brianeggar 11 years ago

Etching, staining, or wildly coloring plastic

I own too much plastic, that I use regularly, but want to decorate. Is there a SAFE method to chemically or otherwise "mottle" plastic with colors? Not looking to use paints, as those will just peel off. I know that plastics react to some solvents and such, but is there anything that you could 'wash' plastic with that would just outwardly alter the appearance? If I could get an "oil on water", or even just a "camo" sort of effect, that would be wonderful! (I tried searches for what to AVOID using around plastics without risking such an effect, but can't get the right search parameters...) Thanks for any ideas! I'd really prefer not to have to throw stuff out.

Posted by Dragon Maze 9 years ago


Over the years I've done a lot of things that didn't work out well, and I try learn something from them  hoping to avoid similar problems in the future. I think ibles  needs a place to share these 'educational moments'  to help others avoid pitfalls and to console with laughter anyone who is sitting amidst the ruins of their own project.   So here's the  place to share.    I'll go first........... My first dramatic failure at about age 8 - Gluing glitter onto balloons. Not a good idea. The glue popped the balloon (I think it was 'airplane glue' ) The result was glue and glitter everywhere (including in my eyes) and a lot of unhappiness. Then there was the hot glue surprise -  Using a glue gun to close drip irrigation holes in a garden hose.  It plugged the holes and worked just fine in the overcast cool spring weather. Then a rare sunny day  heated the hose, and all those plugs melted and the holes started jetting water.  I hadn't realized how hot a green hose in the sun could get. And I have made some just plain stupid moves - like spending hours pulling all the shreds of paper out of the toothed wheels on the paper shredder.... you know how they get sucked inside.  After getting it all clear I thought I might as well lubricate the thing with spray silicon stuff.  So far so good. And then I was so excited to see how it much better it would work, I turned it on.  Flash of flame, slightly singed eyebrows, and a TOTALLY dead smoking shredder.  Ummm.... it's really worthwhile to let solvents totally evaporate before turning on electrical things.

Posted by mole1 3 years ago

Heated print beds - are they overrated gimmicks?

For years now I use my old, trusty Mega Prusa with the bare basics in terms of hardware. But basically every new printer out there comes with heated print beds and most users "upgrade" to one to get better quality prints. So I started to to check the reprap forums and other websites to find out why a heated would be a "must have". Quite a simple task you might think, but not so for someone who prints every material on a cold bed with success... What are the official pro statements for a heated bed? 1. Better bed adhesion of course. 2. Less warping of parts. 3. Far less problems with layer seperation. 4. Better print results. And of course there are a few more but not worth listing them. Why do I think most of the four statements are actually unrelated to using a heated bed? Bed adhesion is a matter of print material and surface of the bed / bed preperation, like tape, glue and such. If you filament peels off a cold bed with no adhesion at all it simply means the surface is either unclean or unsuited for the print material. Warping of parts happens because the material shrinks when it cools down, a heated bed is only able to keep a certain height of the print warm. Higher prints won't have any benefit in terms of better layer adhesion with a heated bed. Same goes for seperating layers. Unlike the common believe a heated bed does not fix this problem - it only masks it! Layers seperate because there is not enough bonging between them. This can be due to insuffient extrusion width, too high print layers, wrong print temperature and of course wrong z-axis stepping and wrong extrusion multiplicator. And how good a print comes out of your printer depends on a good calibration and proper print settings - again a heated bed only masks problems ;) Ok, so heated beds are nonsense, right? Well, wrong again ;) They take a lot of worry out of the daily print life to start with. Especially prints with big foot print will benefit, although PLA should never be a problem on a cold bed. If you print long parts in ABS or even Nylon you can have a hard time forcing the plastic to stay on the bed all around the print. A heated bed, with the right settings of course, can make sure your print keeps the shape until it is high enough so the bottom part won't be affected by shrinking anymore. My opinion on how to get the best results... Manage to print on a cold bed first! Smaller parts don't need a heated bed anyway, so use them to improve on your skills of finding the perfect bed material / coating! You will find that once you have really optimised your printer and settings most parts won't need a heated bed anymore. Once you are really happy with the result of smaller prints on a cold bed try something bigger and pay close attention to any problems on the way. For example a big print might start out perfectly but after about 5-10mm of print height you see the part starts to warp and slowly peels of the print bed - especially long parts or thin areas are affected. The infill also affects how a parts reacts during the cooling, so try the same problem print with solid infill as well as only 15% infill to compare - you can stop the print once the problem is identified, don't waste filament. Now comes the magic of the heated bed... You want the temp as low as possible but still high enough to prevent the warping! Why go low if high would help more?? Simply said: If the bed is too hot the part stays soft for a long time, which can badly affect layer bonding and shape. Imagine you squish the plastic on an already "hard" layer - the plastic is pressed flat to be within the set specs. Now if the the layer is still too hot and soft the plastic will push the lower layer in - which of course will expand outwards. So the layer can actually end up to be lower than it should be - layer will still peel ;) Start with around 50° C for ABS and turn the heat down gradually every 10 layers or 25 if you print really thin layers. If the part still prefers to warp go 10 degrees higher. But again: If the stuff would not stick properly on a cold bed work on that first! How do I print on a cold bed and claim it works fine? To be honest, with a lot of time spent on trying, calibrating and finding the right "magic" to put on the glass to make things stick. Nylon, if the part is big, can still be a frustrating task unless cardboard or Bakelite is used but I still prefer the glass bed. I no longer bother with tapes as it can be costly and I hate changing the entire setup just because I use a different material ;) As said, the main key is a proper calibration of hard- and software! If your prints look messy and you spend as much time cleaning your parts as printing them you know what I mean ;) At the moment my "bed magic" is a clear craft glue with methanol as a solvent, mine is from Aldi but similar products can be found in every craft store. The bed is sanded with 600 grid diamond blocks to be as flat as possible and to provide a bigger surface area for the glue. When mostly printing Nylon is first clean the bed with alcohol and put a layer of plastic primer on it before re-applying the glue. With the right temp settings this glue surface can be reused several times with increasing bond to the part. Once the glue start peeling off the bed it cut the area clean and apply another coat just in the spot. A single bottle of craft glue, diluted down by 20%, lasted now about 3 rolls of filament - not too bad for a 2$ investment LOL Seriously though, squeeky clean your glass bed using alcohol and / or acetone and play with different types of craft glue. You want the stuff that is clear and uses either methanol or ethanol as the solvent, don't bother with water based glues! If the glue sticks well to your part but peels off the bed easily try a layer of plastic primer on the bed first - do this outside! However, if your printer is only capable of using PLA anyway you might not want to bother at all and stick to tape ;)

Posted by Downunder35m 2 years ago

Looking for a cheap compressor with a high pressure rating or for airbrush use?

Today a friend of mine asked me if I know a way to reduce the noise level of his compressor in the work shed. With the current heat he prefers to work in the evening and nights, which does not make his neighbours too happy. His main use for several airbrush guns and sometimes for mormal airtools or the big spray gun for an undercoat or similar. So his main concern is oil in the airline and the actual flow rate is of second concern as he has an old 25kg propane cyclinder as an additional air tank. For relative low air volumes I would suggest an old fridge compressor. With a thicker pipe at the outlet that is filled with stainless steel wool most of the oil stays in the compressor. That is if this pipe is a) long enough b) upright c) of sufficient diameter so there is enough for the oil to avoid it being pushed up A second, standard oil seperator will be enough for the oil level required for airbrush stuff - and most other things too. If there is no pressure regulator on the airbrush system it is best to add a small air tank and shut off valve for it. In our case however a fridge compressor would be just enough to keep the bigger airbrush gun running but not to fill the tank at the same time. Not to mention the problem of fluctuating pressure levels. Since we already had a tank and pressure shut off connected to the loud compressor it was only a matter of finding something that keeps the neighbours happy. The first thing we did was to check how often the compressor comes on and how long it runs till the tank is back to pressure. With that and the stated air volume on the compressor we guesstimated that something a bit bigger than the compressor of a window airconditioner should be sufficient. The search begins.... If you don't know what to look for I give you a few hints: Older airconditioners often run on R22 or R12 - both use quite high system pressures which is a bonus, but more on that later. As a rule of thumb for these compressors you cans say: the bigger the higher the flow rate. At the local wreckers and scrap yards we found a few units but noticed the bigger ones often used three phases and not just one :( So we opted for the R22 compressor of a 4.5kW unit. Keep in mind the 4.5kW is for the entire system, so the quite massive fans can be removed from the sum. Usually the compressor alone is the 2.5 - 3kW range. Ok, we found the big thing but how does this help us? First things first ;) The oil was removed as the housing stating the original oil amount. This allowed us to use an oil rated for air use that has little to no water absorption qualities - you don't want water in your compressor. With the usual heat the water should be no problem anyway. Next was a pressure test to make sure the thing actually still works, so we added some plumping in the form of standard connectors to the inlet and outlet. We got well above 200PSI and abondoned the test at this stage as it was more than enough already. The air volume seemd to be well more than expected too so let'S move to the next stage. A fridge or aircon compressor always needs to have a certain amount of oil in it as it will otherwise seize and overheat quickly. But they are also designed so that the oil mixes with the refrigerant to cool all moving parts. So the biggest hurdle is to make sure the oil stays where it should stay and won't enter or get lost in the tank. Only real option for this to use something to catch the oil that is capable of releasing it into the compressor once it shuts off. Now there are several options for this so I start with the most basic: A "catch can" will get most of the oil, especially if filled with stainless steel wool or similar. Downside is that you have to find a way to get it back into the compressor. A step better is a thicker pipe filled with stainless steel wool to catch the oil. If placed upright and the outgoing pipe can be bend a bit upwards you have a good chance that most of the oil will sweep through the valves and get back down into the compressor housing. But only too often the cheap or even free compressor is better than expected and the oil won't get back into the housing as the vlaves are just too good. The last and IMHO best option is a pressurised return system. Most compressors for bigger aircons have a seperate filling port or sealed off piece of pipe. In this case you can do a simple check to see if they are usable for our purposes. Open the port of pipe and use a simple bike bump or similar to get some pressure in it. With a dedicated oil filling port you are best off but they are hard to find. The air you pump in should come out of the high pressure side - you might need a little pressure to overcome the valves. If you hear any bubbling in the housing (use a pipe on your ear or a sensitive microphone) it means you are going through the oil inside the compressor - perfect! You might not hear any bubbling but the port or pipe is still usable. Get ready with your fingers and start the compressor. The fill pipe should be sucking air in, same for the service port if there is one. A dedicated oil port should not suck but instead force some oil up if you cover the high pressure outlet. I assume all is good and no oil is splashing out of the open pipe or port. Add a small amount of oil with a syringe or similar into the port/pipe. If you see an oil mist coming out of the high side it is bad news. Clean outlet air is good. To get the oil back from the catch pipe or can we have to add a hose or pipe with a needle valve. It needs to be adjusted so that there is only a very little airflow (or oil mist) coming out. This regulated outlet is now being connect to the port/pipe with a bit of suction that we found earlier. Now every time the compressor runs the collected oil is forced back into the compressor :) Please double check the port/pipe used is not directly connected to the intake port! The last thing you want is a puddle of oil going into the cylinder and damaging it! They are designed to move gas but not liquid! If in doubt use a hardened sttel nail or similar to create a small puncture in the top of the compressor housing if there is nothing else to use. Check first if the material sound very thick, if so it might help to drill with a 5 or 6mm drill first - only about 1mm to make sure you won't enter the housing and conimate it with metal shavings! Once you have a small puncture hole of about 2mm in diameter get some 2 component metal repair glue mix and add a suitable connection for the collecting pipe/can. If you feel up to it you can of course use a blow torch and solder the connection on. Now we have the compressor working with a oil return system that also gives up very little to no oil at all in our system. You might now think you are good to go but you should at least add a decent and fine filter to the air inlet ;) The compressor noise of a bigger system can still be an issue if thicker pipes are used that allow the noise to travel out. Keep in mind they usually run in a fully closed system.... As we only need to match the noise level of the compressor itself a solid steel can like an old fire extinguisher in the 1kg rage is a good way out. Fill it with filter wool and a fine filter pad after adding some hose connectors either end. You can misuse the trigger nozzle and keep it to seal the top if you braze a connector on it. If the intake here is about 5 times larger than the pipe connection to the compressor itself the air flow going into the thing is low enough for a cheap paper air filter can or box if you have a quite dusty enviroment to work with. The real trick is to have a hose or pipe on the inside of the fire extinguisher connected to the compressor pipe connection. A garden hose is great here as is reduces the noise quite good and is dirt cheap. Make a lot of about 2mm sized holes in this pipe and close the other end of it off. Now the compressor will suck it through the small holes and the soft garden hose reduces the noise, the surrounding padding brings it down to basically nothing. The special case of clean air for airbrush.... If you read this for the sole purpose of airbrush use then this chapter is just for you, all other might want to skip it. The two things you don't want to enter your gun is oil or water. Both are a common thing in normal compressors due to lubrication and pressure difference resulting in condensation of the humidity in the intake air. Oil free compressors of good quality can cost quite a few bucks and often require ongoing replacement of membranes or piston seals. A refrigeration compressor with the above modifications already provides clean enough air for most airbrush users if a proper tank is used to store enough of the compressed air. So you might just want to add a basic oil filter or very fine paper filter close to the regulator. For very detailed work with very sensitive paints you might want to build a filter box containing of several layers of oil absorbent paper. This stuff is often used in the industry to clean up minor oil spills and bind oil very well. A PVC pipe (pressure rated please) with 5-8 layers of filter screens should last about a lifetime before the filters need changing if the diameter is in the 10-15cm range. That leaves us with the dreaded problem of condensation and water contamination. Depending on the type of paint and gun used a small amount of water vapour is usually no problem. Solvent based paints usally show their disliking by unwanted drops or run offs caused by water droplets. Of course you just go and buy a professional dehumidifier and accept the ongoing replacement costs for the cartridges... But if you are in a climated that has above 30% humidity for most of the year than you will have to remove the water one way or the other. A big enough storage tank for the air that is upright usually helps to release any condensated water prior to usage. But if you use a homemade tank you might want to avoid this problem completely and forget about water in the system altogehter. Silaca gel is the answer here, specifically the indicating variety that changes color once "full". A spaghetti glas or similar should be big enough unless you are in a very humid climate - is so just use multiple in a row. The air intake side for the compressor has to go through the silica gel to be effictive. This mean we need two holes in the lid. One with a pipe or hose going all the way to the botom - that is the air intake side. The other right on the lid - this is the air outlet side which continues to the compressor intake. With the color change in the silica gel we can estimate how much usage we have left until we have to heat it up to remove the water. If this color change happens quite fast from the bottom to the top, let's say within three days or less than you really need to use more jars with silica gel in a row or a longer one - like using a long and clear acrylic pipe instead. Of course you can always just cut holes and "viewing glasses" along the length to a PVC pipe.... No matter how wet your climate is you want to get at least 100 hours of compressor run time before you need to recharge the silica gel. This brings us to the recharging.... Once the color changes and you only have about one quarter left to the top you want to get the water out of the gel and re-use it. To do this you simply heat it up in your oven to around 120-150°C - the supplier should state the max temp for this. If you use a gas oven or one with limited accuracy here it is best to stay within the 120° range. You need to stir and mix the gel or use something big enough like an oven tray. But be aware that these little balls are like glass! The roll and bounce like no tomorrow! IMHO it best to use an old cooking pot that has no plastic handles for this and not to overfill it. This allows for easy mixing without making a mess that might cause a bad trpping hazard on your kitchen floor tiles! Once the gel is back to original colr it is time to let it cool of to a safe temperature and to fill it back into our canister or pipe. Tanks and shut off systems.... We have a refrigeration compressor working for us, and since it was for R22 we can use much higher pressures as a simple compressor from the hardware store. The low pressure side is used to 70PSI or around 5Bar of pressure in normal working conditions. The high side often works at pressure in the range of 200-300PSI or 14-20Bar! The tank we used is a big propane tank that was restamped at some stage in his life for the use of LPG - so it was tested to quite high pressures. The lower pressure limit is what keeps the stored gas liquid at the given temperature. For Propane at an imaginary 30°C this would around 155PSI or 10Bar. The stamped test pressure, although outdated, showed 600PSI or around 40Bar of pressure with no problems - and the thing was thick in the walls... The old shut off switch from an old air compressor was adjustable after removing the safety cap with a bit of force and the help of few cold beer. With a little tank attached we adjusted it to turn the compressor off at 250PSI or around 17Bar of pressure. If your tank is old or has no test pressure stamped on do your own test in a safe location. Make sure the area is secured so there is no chance of debris from a brusting tank can go anywhere - this includes to chain down the tank itself ;) Use the aircon compressor to fill it up to 300PSI or 20Bar of pressure - this should be tolerated with ease by any propane or LPG tank. Shut the valves and let it rest for a day or so. It is best to do this in the early morning so the heat from the day will slightly increase the pressure. At the end you still want to have a working tank and no major pressure losses. All of our mods on this tank were done without actually harming the tank. This was possible as the original valve had a release port for filling purposes - as it standard on most refillable ones. Here we removed the valve and added a pressure guage instead - better to know what is happening than to assume things. As this "port" had a seperate connection to the bottom of the brass valve we added as T-connection to allow for the connection to the compressor. Just be be really sure a thin piece of copper tubing was brazed to the exit hole of this port so all incoming air will be going down and away from the outlet connection with the big shut off valve on top - which we use to actually isolate and close the tank when not it use. Last thing required was something to connect the pressure shut off switch and regulator to. That was the only major expense on this project as we had no old BBQ hose or similar to get a suitable connector to the tank. We bought a simple adapter for the use of smaller hoses and cut the unwanted bits off we there was only the bottle conntector with the nut left. After removing the rubber ring we brazed piece of copper pipe onto it. Here we drilled holes and fitted severy connectors. First for the pressure switch, then for the connection to the pressure regulator and two standard ones with a ball valve for air hose connections. One air hose connection female, the other male so a standard compressor can be connected as well or "backfilled" for additional and mobile storage use. As we wanted to avoid any reduction in the safety and burst pressure no release valve was added at the bottom on the tank. The added silica gel filter stage was used instead so no water will get into the system to begin with. Additionally, and painfully for me and me friend, the inside of the tank was coated with a layer of acrylic paint to prevent and rust as it was free from it when we checked it at the beginning. This involved filling a suitable amount of paint into it, closing the top while keeping the thread clean and then to move the tank around to cover the inside evenly. If you do this be prepared for some weird movements with your friends LOL Once we were sure all ust be covered by paint at least three times we released the exxess paint and allowed the inside to dry with the assistance of some air forced to go in with a length of pipe. This was repeated 3 times... Then another two just for the bottom third of it where there might be some moisture after all... Now you don't want to remove the brass valve with everything connected to it just to turn the tank over to releae the collected water. Instead we made sure the added pipe on the former relese port would go all the way to the bottom of the tank. If any water collection is suspected only the connection to the compressor needs an additional valve for the disconnection so the water will be force back out here. To make this easy and fast we used standard quick connectors and a piece of flexible airhose rated to 20bar of pressure for the connection to the compressor. We checked the performance of the moisture removal and oil removal only for a few hours of running time while priming some surface for later use. The compressor oil used was very smelly to say it nice but nothing coul be smelled in the first paper filter after the pressure regulator. To check for remaining moisture levels (65% humidity in the house) we used a 10m length of clear PVC tubing going through an ice bath. After 30 minutes of moderate air release there was no condensation on the inside of the tubing visible. Of course if you only need it for air supply and don't care about a bit of moisture and oil you can keep it simple ;) Benefits of doing such a stupid thing: For starters noise and the peace of mind that you can do a lot of airbrushing until the compressor needs to kick in again. Then of course the benefit of an almost silent system compared to a standard compressor - something you can actually tolerate while doing art. But the real deal is knowing YOU did it and you did it for cheap. Warnings and some advise... I know, it should be at the very beginning but I just hope you read till the end ;) If the compressor fails from overheating you are up for a new one. This means the tan size should be within the limits of what the compressor can handle - same for what you actually use on air. You want an empty tank to be filled before the compressor feels hot to touch - quite warm is fine but if you can't leave your hand on it then it is too hot. Same story for the usage. There is no point in using a tiny 10 liter storage tank if you need that capacity every few minutes. The compressor would only have little pauses and overheat quickly. You want a good balance of usage time before the tank goes below supply pressure and running time of the compressor to get it to full pressure again. This brings us to the safety of high pressures. Where possible only copper tubing or sufficiently rate hoses should be used, the later as short as possible to avoid them acting like a whip if something goes wrong. When it comes to the safety of the tank you want to make sure to stay withing it's rated limits. All benefits of a compressor capable of producing over 500PSI otr close to 35Bar is wasted if your tank and pressure regulator can't handle it. This must not mean that you try to use a gas cylinder of unknow age and pressure rating and assume it will work! If in doubt use a lower shut off pressure and stay within the limits of normal air compressors - which is around 120PSI or 8Bar. Never, ever use a tank that is compromised by inside rust or bad corrosion on the outside! If you don't know how to braze copper tubing, pipes and connectors then check out some of the great Instructables about it! Whenever you know you won't use any compressed air for more than a few hours close all valves especially the ones going back to the compressor on the high pressure side! Some compressors really don't like a huge pressure difference constantly pushing on the reed valves. If your tank is big enough to allow for more than one hour of operation before the compressor has to top it up you might want to consider a one way valve right on the compressor outlet. This will prevent any massive pressures going onto the valves - especially helpful for modern compressors that only rely on the sealing capabilities of the clyinders or rotary system used. One thing you should always consider is a pressure relief valve rated for about 50PSI more than your tank pressure - it can be added to the pipe ;) If the shut off valve ever fails the relief valve gives you the ease of mind that it will blow before your tank does. Maintenance... If modded correctly the compressor should stay in the compressor and the compressor itself should not overheat from use. Having said that your compressor might force out a little more than your best catch system can handle. If that becomes a problem it might help to use an oil with a lower viscosity. If all fails it just means you need to top up oil once the last last paper filter is filthy or use slightly more to begin with so the intervals are longer. The silica gel, if used should be recharged before all of it is wasted - no point in adding it if you use it once full of water. If no gel is used there will be water in the storage tank. Even with the added paint and a good air filter it is possible that nasty things grow in there. Making sure the tank is emptied of any water after long uses and again before the next use is good practise. If no pressure gauge is used on the tank you must make sure the shut off valve is always working fine and within set parameters. I strongly recommend using a gauge and if not to perform a pressure check of the system every now and then to confirm all is within parameters of normal operation. A compressor constantly running means you either use far too much air or you have a leak - same story if the compressos kicks in after some of forgetting to shut it off and close the valves. If you keep the above in mind the salvaged compressor should work just fine for many years to come. Troubleshooting and alternatives.... You put everything together the right way, double checked and something is till not right? Maybe my crystal ball helps me to find something... 1. Always oil coming through the catch system. It usually means you use too much of it. A salvaged compressor, if the refrigent was removed legally from the system should still have a "correct" level of oil inside. Too much oil would mean is being pumped through the system at an excessive rate. Very thin compressor oils tend to do that in the compressor is misude like we do. Changing to standard mineral oil can help here. As a last resort you can use a pressure gauge or good judgement to allow more flow through the needle valve from the catch system back to the compressor. Too much backflow here would mean we loose system pressure to the set level of this needle valve! 2. The R22 rated compressor seems to be unable to produce enough pressure. First do a leak test using soapy water to rule out any leaks. Do a back pressure test on the ports. If you can push air through them in the reverse way with ease it means the valves are damaged making the compressor useless. You need to replace it. A regular cause with our type of usage is a constand back pressure from the storage tank to the compressor. To prevent this it might help to mount an electric solenoid between the compressor and storage tank. Such valve should be off when the pressure switch is engaged and on when the pressure switch is disengaged. This prevents the coil from overheating but requires a "normally off" type of valve. A good source at the wreckers are cars with LPG systems installed, they usually have suitable 12V valves somewhere on or near the tank and filler cap. 3. I am using several kg of silica gel but still get a lot of water in my storage tank. Going overboard in a humid climate can be a good thing here but if moisture makes it into the tank even with great amounts of silica gel there are only two causes: a) the tube or cylinder used is not long enough or not wide enough to allow the absorption of all the moisture going through. b) the flow rate is too high and the temperatures are too. For the first the solution is obvious enough. The second is related to the first for the diameter and lenght but temperatures constantly above the 30°C while operating somehow limits what the gel can do. Using a cooling coil on the intake side or simply putting the gel containers in icy water will help to a great deal here. If that is not an option than I suggest to layer the gel and to seperate it with fine paper filter screens. This will slow and even out the airflow allowing for more contact time with the gel. 4. The compressor gets very noisy after some time. If "some time" means more than 30-45 minutes you simply have it running too much and it overheats. If the noise increases too much when reaching the shut off pressure it can mean the pressure is too high for it. 5. Can I use multiple compressors from smaller units or refrigerators to get enough air volume? Of course you can but it might mean you have to lower your pressure expectations. Consider that each individual compressor would get the back pressure from all other compressors running while it's outlet valve is closed. To avoid premature failure you want to make sure the compressors are shut off at a lowver pressure. 6. I don't want to use a big tank but require a good airflow for airbrush. Two or three fridge compressors working one after the other with a small tank to keep the output pressure even can allow for about 30 minutes runtime per compressor. With three it gives one hour for the the first to cool off and should be enough for ongoing work. Downside is you need to make some sort of automatic switch to "rotate" to compressor working. Last words.... Is you find any spelling mistakes you can keep them. However, if you use them in any way to make a profit with them I kindly ask for 10% of your earning from it ;) Why did I not make an Instructable out of all this? Well the day was very hot, the beer very cold and my mobile phone at home, so I did not take any pics. To top it up the whole thing is now in a seperate box for additional noise reduction so it can be used in the same room where the guy is working. Of course he just used a nailgun for the job without any regard of access or at least easy view of the two pressure gauges. Typical if you have a great idea and the cold beer tells you to forget all about screws or hinges ROFL Only comment was: You created it and it works fine, why would need more than the pipe connections for the gel and regulator? Maybe he will reconsider when the service is due....

Posted by Downunder35m 1 year ago