Lacquer or Varnish to finish a guitar?

Hi, I've just had an artist do some work on one of my acoustic guitars. Its done straight onto the sanded bare wood using sharpie, all I have to do is give it a finish to stop the design getting damaged and to give it a glossy shine. A lot of people recommend Lacquer but what type should I use? Nitrocellulose? Poly? Others say Varnish but I've heard it can become tarnished from sweat and heat. This coat needs to stay on indefinitely as I cant sand it down again to apply a new coat without removing the art. Please help!

Question by Boba Jett   |  last reply


slow drying art paint varnish? Answered

Can any artist help me find an art paint varnish (clear, matt)  that has a longer drying time? I have nothing to compare with but I'm thinking of ways to mix luminous powder for watches. I really have no idea about varnishes in general so any pointers or websites will be helpful. I need the mix to stay wet and workable for at least 15 to 30 minutes. I am looking at Winsor & Newton varnishes. Any other suggestions and options would greatly help me.

Question by phillyj   |  last reply


French polishing a turned item.? Answered

Hello, How would I go about french polishing a turned item. The problem associated with it is that the sanding and polishing (assuming I polish on the lathe) will both be accross the grain which is generally considered the less preferable option. Any advice would be greatly appreciated. Thanks in advance.

Question by alexhalford   |  last reply


Tips and tricks for UV curing glue, resin and coatings

Only a few years ago your only option to repair certain plastics, glass or even a broken crystal was epoxy based resin or the good old superglue.You might have already tried one of the 5-seconds-repair pens or tried your own UV curing nail polish art at home.For the later you might be lucky as the resins used here are optimised for the purpose and lights you get with them.Sadly even the best nail polish is no substitude for a glue as the material properties need to be different.One of the most common complaints when it comes to using some UV glue, like Kafuter or similar is that it never comes with instructions.Sould be straight forward but it is not free of problems.For example almost all commercail UV curing glues that you can buy require quite stirct procedures and for the light the right wavelenth(s).Resins and coatings can be even more painful here as they might also require you to stick to the correct temperature.Let's start with one thing you might have encountered already...The glue is definately cured and rock hard but the surface tacky and smeary.Quite annoying if you want to fix a piece of jewellery and can't prevent it from collecting dirt and dust...The next thing you might have encountered is that despite having transparent materials it seems to be impossible to cure the clue.Both problems come down to wavelenght and exposure.UV curing glue is prevented from curing in the presence of oxygen - a factor utilised for example in resin based 3D printers.Uncovered glue is exposed to the oxygen in the air and won't cure easy.The glue or resin below this layer however with fully cure with ease in the absence of oxygen.For the second problem consider that not all materials that you can see through will let UVC light pass through ;)Bonding strenght is another complaint I hear a lot...Be aware that certain things just are no good for UV curing glues or resins.Take the molds you get for that purpose: on the material the glue won't bond!Teflon is another prime candidate here.But in a lot of cases it comes down to surface preparation.Don't be afriad to sand the surface!Not only will the surface area increase but the scratch marks will be invisible once filled anyways.Use sandpaper on your fingernails, then go over with clear nail polish -mirror finish ;)With curing often a problem consider to fully cover the glue.A bit of clear sticky tape, food wrapping foil....If that is not an option then eliminate the oxygen.You can use a container filled with inert (for the glue) gas like CO2 or just place a burning candle in it until it goes out....Either way the amount of oxygen should then be low enough to cure the surface of your glue.Not always is any of the above an option.Then you can still try more power and a lover wavelength.Mercury based lamps for example provide a very broad and powerful light that in most cases will cure within seconds.For a proper surface cure you need a wavelength of 265nm or lower.LED's offering this exist but at prices well out of range for the hobby user.A mercury lamp under high pressure is nothing for short term use and the limited lifespan does not always justify the costs of buying them.Like with most things in life certain inventions can have a dual purpose.Quality germicidal lamp systems for examples often state to go as low or even lower than 265nm.And they come at a fraction of the cost you have with a broadband mercury lamp.Even cheaper is the fre weather forecast.If the sun is siad to be strong enough so you need protection than even the worst glue will fully cure in seconds outside in the sun - tackfree!Don't be fooled and protect yourself!!These tiny LED lamps for your glue stick, the curing thingies for your nailpolish and everything else using UV light comes with warnings.For very good reasons!It might be hidden in the fineprint but you can not really see UV light.The blueish-purple glow you see is on the high end of what comes out and by that in the visible range of your eye.Just because a LED only gives a faint glow you see does not mean the UV light wouldn blind you if you could see it!Even worse for fluoroscent lamps or open cruning systems like those for your nailpolish.Reflected UV light is still UV light and you can still NOT see it!Stories of people getting sunburnt from germicidal lamps in a butcher shop or other people going blind from checking money as their living have a true base...In most cases lamps used well past their lifespan or simply the wrong type of lamp but still: the damage came from UVC light...If you just love creating your own artwork or jewellery with UV curing resins and glues than protect yourself.Proper sunglasses with a stated UV protection for example or just black nitrile gloves for your hands...

Topic by Downunder35m 


preserving wood outside? Answered

I just scrounged a big round slab of a tree from a firewood seller. It is still green and about 32" across and 8" thick. My question is, how can I make it last a long time out in the weather all the time. I am using it as a knife and axe throwing target. I don't really want to spend a lot of money putting expensive varnish or wood preservatives on it! Any cheap recipes out there? Thanks, Triumphman.

Question by triumphman   |  last reply


How to stretch holes in a steel frame?

I ran into a glitch in rehabing an old park bench.  The wooden slats were rotted out, so I'm saving the wrought iron end frames and fitting them with new poplar slats.  I included a mid-project picture below of one of the end frames. I don't know if you can notice from the picture, the holes in the frame for mounting the slats were not in a straight line, but rather haphazardly.  So each board needs to be custom-drilled to match the mounting holes in the frames. Problem is, I originally measured the distance between the bolts on one of the old slats and used that measurement to drill ALL the new (expensive) hardwood boards.  I had made the careless assumption that the holes in the frames would be in a straight line. Never assume good workmanship! After drilling the slats, I applied about 5 coats of clear urethane spar varnish.  The new slats look supreme, and I don't want to zorkk them up by drilling a second hole in each board to match the stupid end frames.  So the only way out of the quagmire I can see is to drill the frame to match the boards.  OK! Problem is, most of the new holes in the frames would intersect the old holes, and I know that drilling an intersecting hole is problematic, especially in 3/16" steel.  So I need advice on how to stretch holes in steel into an oval shape.  I'm thinking some sort of router bit, or a grinding bit that I could use with a hand drill. Suggestions?  Thanks.

Question by LesB   |  last reply


PVC pipes and winding Tesla coils....

There are still people out there playing with high voltage.And one big problem when it comes to Tesla coils is winding the secondary coil.Now, I won't go into the details and options of the actual winding part, instead I would like to share some tricks that might make things easier for your project.Whether you wind fully by hand or make use of some mechanical winder, magnet wire is a very slippery thing on PVC.For that reason and some others we usually wind as tight and close as possible.Any leftover spaces that you find after the winding is finnished will severly compromise the overall tension of the wire in this region if fixed.Next problem is what many call aging.No matter how good you coat your coil with varnish or paint it will start to degrade over time.I found a simple fix for these problems :)Well, not really that simple but I am too lazy today to make a full Instructable for just an addition that everyone can make in a few minutes....Let me start with idea behind it all:I noticed that no matter how thick the pipe or wire is that there is little to no chance at all to get any of the coating material through the wire and all the way down to the PVC.One coil failed after I abused it so I did some cuts and had a close look with a magnifying glass.The coil itself was really good covered but it was like a sleeve that sits on the PVC with nothing on the underside of the wire except for a few single spots.Some people will now say to just a much thinner mix for the coating to allow the stuff to sweep through but that does not always work.One big issue I noticed is that not all paints or varnishes actually stick to PVC.Especially those non smelling eco friendly ones most places now sell.This means when the coil expands due to the vibrations and heat the wire can simply rattle off the varnish or the coating itself can crack under the stress.So I thought there must be a way to fix this right at the winding stage....PVC is a good insulator too!So why not use PVC instead of messing with other things?My first attempt here works quite well with thin wire and goes like this:Go outside with your winding rig and have a bottle of PVC primer and a little brush or sponge ready as well as some gloves.If you have use a friend, if you have none make a small rig to hold the sponge right in front of your winding area.The key is to keep the sponge wet with the primer so it will wet the pipe properly.Best is to have the speed and distance set so the surface just starts to dry off under the wire.The primer will cause the PVC to soften, so the wire slightly sinks into the surface.An automatic winding rig is best here as it allows for consistency.There is no too much or too little here is nothing drips terribly and your wire sticks without fully sinking in.Once done you can cover the winding with your prefered coating.For thicker wire, lets say 0.3mm or thicker, I now use a similar way but with more preperations:Using some very rough sandpaper on a belt or vibrating sander I create a small pile of PVC dust.If you prefer some fancy color you can use ABS plasic here too and it dissolves in a similar way.The resulting mix should be free of lumps and of even color, if in doubt use more primer.Consistency should be a bit thinner than honey, if yours is too thin you can add more ABS/PVC or let the primer evaporate off while stirring it every now and then.To get a good start I do a few turns dry first with quite a big spacing.When approaching the actual start of the winding area I use some stick tape to make the last alignment and start to apply the mix onto the first bit of the winding area.Some lint free cloth with a bit of primer is used to wipe off any excess towards the still uncovered part of the pipe.Every time the mix on the pipe dries out too fast a brush with some primer is use to wet it.Every time the excess runs out a bit more mix is applied onto the wound area.The key is to only have a small area in front of the winding covered with mix with the most is on the winding and "cleaned" off towards the empty area.This way the entire wire is covered by PVC all around.To finnish off you simply use a brush and paint the mix onto the rotating coil until you have an even finnish.What are the downsides?The primer stinks and is certainly not healthy to breathe in. So good ventilation is a must have and it works better in colder temeratures as it gives you more time.It might require some test runs with braided fishing line or similar to get a feeling for how much mix or primer you need to apply and how much max tesion you can use to preven the wire from sinking in.Any benefits?IMHO using this method makes it possible to get a proper bond between the PVC pipe and the wire.And by using PVC or ABS as the coating there is little to no change material properties.This in return gives far less chances for vibrations or wire expansions that result in failing insulations.The whole thing just is one piece of PVC with the wire embedded in it instead of having a wire on top of the PVC with some coating above. ;)Are there alternatives to the PVC primer?If Acetone is much cheaper than you can use it but the same safety measures apply and the mix might dry a bit quicker.What if I need a break or stop the winding for one reason or another?Simply wipe off all access and stop with just enough tension on the wire so you can star again with no problems.Then start by wetting and applying the mix and continue winding as before.

Topic by Downunder35m   |  last reply