Hardening a Knife?

I have this really cheap-y bowie knife I bought on a whim that I hadn't really used before now.  At first I was all happy because I had a giant bowie knife to swing at trees, but then I started to realize just how cheap-y it is: with a hard swing and something(dead tree, for example) the blade tends to bend a little..just wondering, is there any way to harden steel that would be plausible for this knife?  The blade needs work anyway so if I can harden the steel I'll just add that to the list of things....I mean I can deal with a cheap-y handle and a cheap-y guard but a cheap-y blade is kind of a problem...

Topic by retrogamer9000   |  last reply


Epoxy Hardener?

I needed to use some Marine-TEX epoxy for a project I'm currently working on, and found that I've misplaced the little vial of hardener. Are there any other hardeners I can use for this epoxy? I've quite the collection of various epoxies and hardeners, but I'm not sure if any other hardener will work with the Marine-TEX epoxy resin. Help anyone?

Question by LiquidLightning   |  last reply


How to harden cardboard

Hi everyone!  I want to make the initial of a name as a door decoration for my first granddaughter.  The letter is made of cardboard and I want to make it stiff so it doesn't bend with time.  I am going to use wool thread to cover it.  Appreciate any help given!!

Topic by Elisa Martinez   |  last reply


Cutting Hardened Steel

So here's my situation... I've lost the key to my U-lock - I'm fairly certain it fell out of my pocket while I was sitting - somewhere :/... Any recommendations on how to cut it? After chewing up 1 hacksaw blade to it's dull tomb, I'm fairly certain it's made from hardened steel. Bugger. From past expirience, bolt cutters don't play nice with hardened steel :p Recommendations? oh, and it's a decent lock - picking isn't an option :/

Topic by trebuchet03   |  last reply


a way to harden styrofoam? Answered

I have been working on a metal mechanical iris for a while now and have been looking for a few things, but one thing that has me scratching my head is having a base, or cam wheel. its just a circle with grooves in it. i decided to use plain styrofoam for this so it will be lightweight and easy to cut, but when i tried it the cam wheel easily crumbled with enough force applied. is there any way to harden styrofoam with a spray or something of that sort? it needs to be somewhat slidey, so it can move well, so nothing like a rubber spray.

Question by imBobertRobert   |  last reply


Can liquid starch make cardboard really stiff and hard?

Especially thin cardboard? 

Question by coolcarl89   |  last reply


Is there anything that can make thin layers or pieces of cardboard hard as a rock or metal beside poly/epoxy resin?

I want to make the cardboard as hard and unbendable as possible. With concrete? With foam coat? What else is there? 

Question by coolcarl89   |  last reply


Metal for blades and hardening techniques

Hey y'all!  need some 2 cents on another instructable...  so, i recently posted an instructable on how to make your own machete, and i have received some feedback on using tool steel, and quenching the metal before final sharpening to keep an edge longer.   does anyone have any expertise on what type of steel/metal i should get, where i could get it, and how i could go about quenching the metal? any help would be much appreciated!

Topic by Trollinwater   |  last reply


How to harden a 'rubber bone'? Answered

A few weeks ago I was digging a new garden and I uncovered an old beef rib bone buried next to a rusty tin can. I presume one of my dogs put them there several years ago. The bone had developed a nice patina, infused with a reddish-brown color, most likely from the rusty can. It would work perfectly as scales (handles) for an old hunting knife of mine if I could flatten it out somewhat.  Remembering an old trick from my youth, I have been soaking it in white vinegar and it has softened nicely without losing the patina. From my past experience I know it will re-harden if I allow it to dry out, but it will be more porous and brittle. My thought was to dry it then coat it liberally with super glue or to soak it in a clear acrylic paint for several days to fill the pores. I am looking for any ideas or suggestions that will help me in this project, whether they be ways to make my ideas better or something entirely different. Thanks.

Question by Burf   |  last reply


How Do I Harden This Rock-Pick ? Answered

After seasons of cracking rocks my nice rock-pick, it was rounded and dull. A grinder put a new point on it  ....   but it is Now a soft tip.... see the picture. Do I need to heat it red and stab it into the butt region of  a slave or will cow blood suffice. If there is a reasonable tip hardening method please let me know.. A

Question by iceng   |  last reply


is there any way to harden floral foam? Answered

I am making some molds and stuff from floral foam, and I wan't to know if there is a way to harden it and make it heavy.  Some of the things I'm making will have to take handling and painting without chipping, breaking, or crushing.  I use floral foam because it's easy to use, so I can make models in the first place.  I'm not looking for another medium, but how to change it once the model is made.  Also, I cannot use anything expensive or that must be bought online.  Preferrably something like paper-mache, but that will not stick out from small crevices in the model. 

Question by jduffy54   |  last reply


Any ideas for hardening plumber's putty? Answered

I want to mold it, harden it, sand it, gift it.

Question by JeanDuke   |  last reply


Keeping rosin (pine sap) hardened?

I just finished making a prop for halloween that involves melting down pine sap to make rosin. Everything went as planned except it slowly becomes misshapen if it is above 70 F  does anyone know of a way to keep the rosin hard?

Question by bravoechonovember1   |  last reply


Are there other ways to harden earth clays? Answered

I do not have access to a kiln nor do i have the money to buy one. Are there other ways to harden the clay that will make it as hard or nearly as hard as a kiln would? I thought air drying would make it resonably hard, but nope it shatters WAY TOO easily. EDIT: I should have noted that I live in the heart of LA in an apartment so I can't really make a kiln, but it seeming like i need to kiln it or buy some oven clay(I forogt the name) 

Question by Zergling_pack   |  last reply


Hardening Play Doh Kinda Stuff

Hi There! I need some kind of stuff, that acts like Play Doh at first and after a while gets really hard without any heat or preassure ore anything applied. Since I don't exactly know what I'm looking for or how to call, I haven't been able to search anywhere... I need to use a small amount on a hinge on my headphones. The hinge looks kinda like this: |     | |     | |-T-|    |  /   \ with the T part able to rotate. The little horizontal part is kinda broken, so that the T sometimes slips out, which is kinda annyoing while listening to music ;) I don't want to glue it in, because then it won't be able to rotate anymore. So if you have any idea how to call the stuff I'm looking for, or even better, got a recipe how to do it myself, I would really appreciate it! Thank you very much!

Topic by Rabenvogel   |  last reply



what is the time and temperature for hardening earth clay?

Earth clay is for doing tiles of dimension 15*15*2

Question by GAVIYAAM   |  last reply


Any ideas for using hardened plumber's putty? Answered

I bought a tub of this to fix my sink and only used a tad.  Despite it saying "Will not separate, harden, or crack" it does all that.  Unfortunately, they don't give warranties with this stuff, so I was left with a life time's supply of plumber's putty that is hardening as I speak.  Please, if you have ANY ideas on how to use this or soften it, do pass them along.  Thanks!  :)    =^..^=

Question by happi cat #71   |  last reply


"Sonic" drilling or cutting

If we look up sonic drills today we usually get some fancy machines driving pipes in the ground, preferably softer ground.But the term includes all types of machines that use sonic vibrations to advance through a media.With the ancient and claimed to have never existed technologies in mind I did some digging...In the food industry vibrating knifes are quite common, same for "air knifes" on softer food.Even in the meat industry they find more and more uses now.Ultrasonic cutting or welding is the same thing and included in "sonic".Same for some experimental sub sonic drilling methods currently being tested.The general idea might be as old as using vibrating equippment to compact stuff, like concrete, bricks and so on.What you can compact by vibration you can also make "fluid" by vibration.Industrial feeder systems utilise this to the extreme by even making light and fine particles like flour move like water without causing any dusting.What all the techniques have in common that a suitable tool or tool head is used and that it is attempted to use the most suitable vibration frequency for the job.Anyone operating an ultrasonic welder knows the pain of finetuning for a new electrode or just new part to be welded.What does that tell us now that makes the understanding easier?Take a bottle of ketchup, preferably one that is still quite full.Turn it upside down and noothing comes out.Shake it a bit and you are either lucky or drowned in red.But hold it at an angle and start tapping it and the red sauce flows out easily.What it true for most newtonian fluids is in some way also true for non-newtonian fluids.Ever mixed corn starch and water to make these funny experiments with it?Hit it hard and it reacts really hard and is not sticky at all.Leave your hand resting on it and in sinks in and sticks to it.Stirring it very slowly is easy, go faster and you get stuck.You can do similar things with by using an external source for vibrations.For example a vibration speaker mounted to a smal cup of the goo.If you place sand on a sloped piece of plastic or sheet metal then at a low angle it will pile up easy and stay.Start vibrating the plate and the sand will start to flow off.Works fine with a vibration source mounted to a piece of steel bar or rod and a bucket of sand too.Trying to press it into the sand requires a lot of force, especially once you are a bit deeper.Let it vibrate properly and it slides rights down.If we can do the simple stuff as well as really complicated stuff in the industry then what about other materials?So far we use vibrations to make things move out of the way, compact things, transport them or to heat them up for welding plus some cutting applications.Considering the variety one might wonder why no one tries it for "difficult" materials.Machined surface can be found throughout ancient history.Finding "machined things" were vibrations was clearly used is a bit harder.The great walls are not a perfect example here as the views differ quite a bit on how they could have been created.But if we leave things melting them or a secret concret like recipe for creating for example granite then vibrations start to make some sense.You find some interesting videos on youtube where people use speakers, wires and rocks to confirm you can actually "machine" them by vibrations.Especially granite has some quite musical properties, big boulders as well as smaller ones produce destinct sounds when you hit them hard.Tests and measurements were made on granite and other hard rocks to check how fast sound travels in them , how it is refeclted and where the sound comes out or affects the surface the most.Lets just say every sample gave different results.Shape, density and dimensions affect not just the resonant frequency but also where and how the sound travels in the rock.What if??We can use a simple speaker, a plate and some rice to see how patterns form under various frequencies.Works with sand or other granules as well.The interesting patterns are the so called harmoncis.Here we see clear and destinct patters, sometimes with extremely fine lines and areas of softly vibrating granules.Some people say these harmonic frequencies have all special meanings and uses.We mainly used them to avoid problems.Imagine your new TV would not have a housing tested to be stable with all frequencies the speakers can produce.All of a sudden your back of the TV might start to rattle ;)Same for car engines.Harmonic vibrations are eliminated wherever possible.Otherwise they could multiply and affect other things in the engine or around it.Simply put it means we have various options to detect and measure vibrations on a surface or in a system.Back in the day every half decent backup generator had a mechanical indicator for the frequency of the supplied electricity.A set of tiny forks with the desired on painted red and several on either side of it.These forks were designed to get into harmonic and therfor quite intense vibrations at their set frequency.If the one for 50Hz looked blurry then all was good ;)The same principle god be applied on a big boulder of granite.Place the "vibration meter" at the desired spot and start moving around the vibration source on the surface until you find a spot that causes maximum response on the meter.Best thing here is that if you then place that surface area onto another peice of fixed in place granite both pieces will start to loose substance if vibrations are applied.The fine sediment forming is then usable as an indicator where to move the vibration source to continue once the effect literally wears off.Is it feasable?Well, if we trust mainstream science then the answer is no.A huge amount of vibration energy would be required for such a hard material, despite ancient proof that says otherwise.Semi industrial test also seemed to confirm the theory as only with very high amplitudes (loudness) and while automatically adjusting for the resonant frequency changes a measurable amount of material was removed.I struggle a bit with that as for the testing tool heads made from hardened steel or carbide were used.And that with little or no regards on how the head and tool itself affects the output.I mean in terms of having the max possible movement happening right t the tool contact surface!There is a huge difference between applying a vibration to a tool and using a system, tool and tool head DESIGNED to work at the desired frequency!Otherwise we wouldn't need a computer to design and test a horn for welding purposes or shade a knife spefically so that the vibration go along the right axis and in the right direction.You not break a hard thing with a very soft thing unless it travels fast enough to become harder as the target!This complicated explanation basically just confirms that if you hit water at a too high speed then it will just break you into pieces instead of offering a soft splashPlease do not jump of bridges or such to confirm this yourself!!If that is really true and science says it is, then how about the other way around?Works fine too, or we wouldn't have pressure washers or water cutters.Now for the part where I hope some really smart people leave helpful comments:If we can cut steel with just a stream of water, then I ask:Isn't for example copper much harder than water?Steel is much harder than copper but water cuts through it.The answer here it simple or complicated, depending on how you want to expain how it works.Comes down to speed and pressure plus the right nozzle shape to prevent a beam expansion.But then water is indeed "harder than steel".Questions:Lets say we would use a copper pipe that in lenght, thickness, hardness and diameter is optimised to transmit a frequency so the pipe end sees the max vibration like a feed horn for ultrasonic welding.Not to hard to calculate these days :)Now imagine said "main frequency" would be optimised for the pipe but also be a harmonic frequency of the rock to be worked on.The pipe end would deform quickly, abrasion does the rest and it fails before even making a decent sratch that is not copper metal on granite.No matter how hard we press nothing good enough will ever happen.BUT: If we would add more hormainc frequencies to feed our pipe we can multiply the amplitude quite easy!Just try with a sound generator from your app store, needs 2 or more channels to be usable.Pick for example 400hZ on one and 800Hz on another, then finetune around these number to hear how the tone changes ;)My theory goes like this:If all "working frequencies" would just harmonics of the resonant frequency of the granite, then they can be tuned so the effect on the pipe end is minimised.The overlaying frequencies however should result in the same effect a water cutter has: The pipe becomes ultra hard.The better the match and the more you have to get it right the harder the pipe will be.Adding now a "drilling frequency" or multiple could be used to drive these harmonics slightly out of phase.Like with the sound generator on your phone we end up with a pulsating sound, or vibration.While the pipe still vibrates at the same "hardening" mix the drilling frequency creates a peak like a jackhammer.Try it by using the heaphone output on a small speaker and placing some light and tiny things into the cone.The will violently jump around during these pulsing tones.For a drilling system the output can be mechanically maximised by utilising a pitchfork design.A head holds the vibration speakers and the tynes are tuned good enough to the frequency of the speakers.Always two would have to operate in sync though as otherwise the pitchfork movement that transfers the sound down the center bar won't work.This head could then be desgined to act as a holder for a quick change of work out pipes that are no longer long enough for tuning.I guesstimate that a well tuned design would result in a copper pipe being able to drill at least 10 to 15cm into solid granite before it wears off too much.And we are talking here about just a few mm to get the thing out of tune!But would dare to desing such a thing just to confirm a theory that no one ever really dared to test? ;)And if friction welding works as good as ultrasonic welding, then what would happen if we try this with the right frequencies and vibrations instead of wasting tons of energy?

Topic by Downunder35m 


dose metal explode when you put it in the micro wave? Answered

I want to temper my home made steel knife in the micro wave as my oven is currently out of action. Will the metal just heat up or will it explode??? Will it heat up to fast and cause to much pressure on the steel resulting in a crack or a warped knife??? Should i heat up the knife with a blow torch first???  Are there any good ways of doing this??? Please help me!!! :2(

Question by henster22   |  last reply


How to harden fabric without using comercial products?

I need to harden fabric for a costume. Do you know any common or at least natural things I could achieve that with?

Question by Fypsigon   |  last reply


How can you get Play-Doh to harden?

My son made me a ring out of Play-Doh and I would like to know how I would go about hardening it so that I may wear it?

Question by kimzgreatlife   |  last reply


How to remove hardened epoxy from a USB drive?

I tried to make a USB thumb drive and messed it up. It was quick drying epoxy so it's set really hard. I've tried scraping it off - works but takes too long. I don't know what heating it will do to the USB drive. Any ideas on how to take it off?

Question by Kottravai   |  last reply



how do you make the african magazine harden to where they are just like a bead?

I tried using modpodge on beads and covering with clear nailpolish but it does not harden the bead.  It is still plyable not hard enough for a bead. 

Question by lala74   |  last reply




Is there anything that can harden thin layers of cardboard, inside AND out, permanently?

This is for a sculpture project where I am building sculptures out of cardboard. 

Question by coolcarl89   |  last reply


Will hot ethanol eat through flame hardened PVA glue?

I'm still working on this solar thing and it's coming along pretty well, am starting in on the final piecing of things together. One old problem that has resurfaced tho is the sealing of the boiler. I was using a metal epoxy similar to Quicksteel, which handled the ethanol ok but is going soft and cracking off, I think due to the regular heating > 80C. So I'm once again looking around for other options. What I'm trying now is wood glue, which I assume is just PVA, run over a flame so that it becomes hard. It seals the ends of the flattened copper pipe well, and doesn't immediately fail on contact with ethanol. Is it likely to hold up, do you think? I'm kind of assuming it won't, but it'd be great if it did. cheers Daniel.

Topic by SolarFlower_org   |  last reply


What is the most effect way of removing hardened duct tape adhesive from car paint and glass without causing damage?

My car window regulator broke so I had to hold up my window with thick black duct tape. It baked in the sun and the adhesive hardened on the car paint and glass. What is the most effective and safe manner in which to remove this hardened duct tape adhesive without damaging the car paint or window?

Question by nisvara   |  last reply


how do you make a knife? Answered

Well i am thinking on making a knife n=but i don't know what ible to use help me!!!

Question by knife maker   |  last reply


What should i do with all of my old hack saw blades?

I have lots of small broken hacksaw blades and I want to do something with them along the line of making weapons or knife attachments or stuff like that!!!  Hope that you all have some good ideas!!! Ps The cut on my thumb is not from a hack saw. I got bitten!!! :2)

Question by henster22   |  last reply


Will hardened lead antimony balls wear out quickly in a ball mill?

I've read that regular soft lead balls can wear out extremely quickly and contaminate mixtures in a ball mill, but what about these hardened lead antimony balls? I don't really fancy the idea of breathing in a lot of lead dust after a couple hours of milling. http://www.pyrocreations.com/inc/sdetail/11961 Would it be a good idea to get the lead balls from this website (found under "ball mills and media") for my ball mill (for making potentially explosive chemicals)? I've considered getting brass balls, but they are unbelievably expensive. I've also considered getting a brass bar and cutting it, but that's not cheap either and I don't know where to get a brass bar. Plus, apparently brass wears down quickly too, so it seems like a lot of trouble when I can just get lead balls, as long as they don't wear out too badly.

Question by Ke-Bob   |  last reply


epoxy gone wrong! can i start over?

I was working on a belt buckle with colored epoxy, but i screwed up mixing in the hardener. so it's still wet in some places and then it hardened real ugly in others. is there anything i can do about it or should i start over?

Topic by yokotei   |  last reply


Custom Flashdrive shell Question

I've got a couple flash drives with broken cases, but the drive itself still works. I was wondering if anyone happens to know if the drive would survive temperatures high enough to harden modeling clay.  This would involve about an hour at 300 degrees Farenheit in an oven for hardening.

Topic by Great Wight Ninja   |  last reply



is there a way to make a soft object hard (e.g. soft plastic)? Answered

Some thing that you could brush on and let it harden?

Question by animan1   |  last reply



underwater sparkler

Is this real?CLICK HEREfor some reason i cant add the video if anyone wants to try, calcium chloride is basically water hardener

Topic by budsiskos   |  last reply


Casting Resin issue?

I'm trying to cast some resin claws for a halloween/convention costume I'm trying to make ( it isn't a Wolverine one .. more a VERY twisted, evil, and blood thirsty Mad Hatter character ) and running into a bit of trouble. I'm following the 5 drops of hardener per 1 oz of resin that is stated on the resin can's instructions. It also says it's supposed to set hard enough to support objects at 40 minutes. I mixed a 2oz batch of resin ( 10 drops of hardener ) and poured it into a rubber latex lined plaster mold that I had sprayed with mold release. I put a bolt down partly into the resin so I can later attach a wire to it and left it alone for about an hour to an hour and a half. I came back to check on it and the bolt was still able to be moved/removed with NO resistance. I figured the mix was bad and threw it out, but noticed it was the consistancy of slime. Did I mess it up and not wait long enough, or did I not add enough hardener or what ? Any suggestions would be great!

Question by Myrr   |  last reply


How would i harden printer ink to stand up to lots of handling (on a plastic-type substance)?

Hello fellow instructable'r,I have been trying to make my own custom guitar picks and, so far, have been extremely surprised with my results. First, i wondered if it was possible for a guitar pick to even run through my printer (regular load in front, print to front) without jamming it. I found out that i could. Then, i tried printing a NIN (Nine Inch Nails) logo on it and it worked. My only problem is that i can't get the ink to dry and become durable enough to let me touch it and not take ink off/ make fingerprints on it. For now, i have put tape over the side i printed on, but is there any way that you know of that i can make the ink more permanent? I was thinking of maybe using clear coat spray or that clear top coat for nail polish. Just so you guys know, i used a yellow dunlop tortex .73mm pick.Thanks,-Nick

Topic by tubbychick3n   |  last reply


how to build a vibrating platform?

I need to eliminate the air bubbles which form when pouring plaster of Paris into rubber moulds. so i thought i could eliminate this through low vibration as the plaster is being poured and eventually starts to harden.

Question by    |  last reply


i HAVE INSTRUCTIONS USING PLASTICINE SEVERAL TIME. i HAVE NOT BEEN ABLE TO FIND A PRODUCT ACTUALLY CALLED THAT.

IS THIS MODELING CLAY? IF NOT, WHAT EXACTLY IS IT AND WHERE DO I GET IT? I NEED IT TO BE SELF DRYING/HARDENING.

Question by theLilyLady   |  last reply


Cheap casting compound?

I´m on a budget and looking for a compound that can either be poured into a mould like plaster or is at least very soft and hardens in a short time without massive shrinking. (low temperature melting metals -> too heavy, plaster -> not rigid and hard enough, epoxy -> too expensive)

Question by Fypsigon   |  last reply


How should I make a level, mosaic table?

I'm thinking about making a mosaic table from broken ceramic lamps. If I want to fill in the empty space to create a level surface, what should I use? And how long does it take to harden?

Question by    |  last reply


Flexibility in Polyster Resin, which palsticizer?

I want to make a mixer of unsaturated polyster resin, cobalt, hardener and want to add some plasticizer to get the flexibility in finish product like a paper, which plasticizer shud be added and in what ratio. Can this be mix by a wood rod or a mixer is required.?

Question by mpoddar   |  last reply


Homemade epoxy alternative?

Hey all, I need epoxt for many reasons, and for many reasons I cannon get/use it. So I am wondering... Does anyone know of a good homemade solution that is comparable to epoxy? It needs to harden to a really solid finish. Thanks!

Question by I_am_Canadian   |  last reply


Lost wax casting help

I'm doing lost wax casting for a glass mold. I'm using parrafin wax to get the shape of it, but I was wondering what i could use to melt the wax out of the plaster of Paris once it's hardened. Also any advice regarding the whole lost wax process would be helpful!

Topic by Ehamby1219   |  last reply


The indestructable bike lock! ...Idea

The indestructable bike lock: the forum topic that was posted undeniably just to annoy the future patenters!So I had this weird idea for a product come out of nowhere. Y'know how aluminum is supposed to make cutting wheels on an angle grinder gum up, stick, and shatter - when trying to cut it, that is? I was wondering, what if a company engineered a special type of aluminum alloy or a similar material that would do just that: gum up abrasive cutting wheels and make them stick/bind and shatter. Then like with layers of plywood, it would be sandwiched together with hardened steel, in the shape of a U-lock bike lock, making it: Impossible to cut through with a hacksaw, reciprocating saw, TCT bladed portaband , because it's hardened and would wreck the teeth. Impossible to cut through with an angle grinder or rotary tool with an abrasive wheel because the aluminum would gum it up. Impossible to cut through it with bolt cutters - obviously... Impossible to freeze it with freezing gas? I don't know. I heard that's what thieves do. Maybe that aluminum alloy would be a super-insulator and wouldn't allow the hardened steel layer to freeze and become more brittle?I think it might just be invincible until the portable cordless battery powered waterjet is invented!Thoughts?

Topic by Yonatan24   |  last reply


would it be possible to bulk up gold flake for scrap ? Answered

Would it be possible to bulk up gold leaf/flake of a high purity with a resin/hardener to scrap ? as the jeweller will take a filing to test  would the bulking agent be minimal to detect  because it not being an alloy/metal ? love a bit of knowledge about this before i buy 30 kg of gold flake/leaf ;-P thanks   MAGIXO

Question by magixo   |  last reply