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Trouble With Epoxy

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Jonathan Stanley
Posts: 117
Member
Topic starter
 

Okay, so here's the situation.

When I went to the Spring Piney Woods hammer in about a month ago J.R. Cook was very nice and let me forge a blade with him during one of his demonstrations.

I thought that since I did not win the raffle for the J.R. Cook knife at the hammer in, that I would try to make one like it. So I asked J.R. Cook if I could use the design and he said sure.

I have been wanting to to finish the knife since I got back home but one thing has been holding me back... I don't have access to any nickle silver or mild steel for the guard. So after several weeks I finally decided that if I were going to improve my skill in knife making that I was just going to have to do the best I could with what I had. So I took a old piece of brass that was lying around and use it for the guard. I cut/ground it to shape and thought "Well I think I'll just stick the handle, guard , and blade all together with a little bit of epoxy to get the over all shape and balance of the knife, and then I could take it apart and do the finishing touches... BAD idea.

I glued it together and it went well. I got the balance and shape right, but then when I tried to pull it apart it didn't work... the epoxy held like steel. I took a hammer and tried to gently whack it apart but that only dented the weak brass.

My question is,

How do I pull the knife apart?

is there a way to weaken the epoxy?

I am desperate and will try about anything right now because this is a special knife to me. I made it at my first hammer in, J.R. Cook and Brion Tomberlin helped me with it, the handle wood is the first piece of stabilized wood I have ever worked with, the wood is also a gift from Jim Clow, and a whole lot of other reasons.

Any help would be GREATLY appreciated.

Thanks,

Jonathan

Jonathan Stanley

Apprentice Smith

 
Posted : 21/05/2012 8:38 pm
Posts: 209
Estimable Member Journeyman Bladesmith (5yr)
 

Jonathan

We all have seemingly good ideas that sometimes turn out bad. I know I have had my share of them. Some epoxies will weaken with heat. The problem is some require more heat than others and the heat may ruin the wood.

Could you tell us what brand of epoxy you used and how much of it you used?

Brian

 
Posted : 21/05/2012 9:43 pm
BrionTomberlin
Posts: 1675
Member
 

I have been there Johnathan. There are a couple of ways I know of to get the handle off.

You can use mineral oil or baby oil in a mason jar. Then place the jar in a pot with water coming up just about a 1/2" below the lip of the jar. Then you heat the water to a gentle boil. This will warm the oil and hopefully loosen the epoxy. This may take 20-30 minutes and you need to check it frequently. I do not know how this will affect stabilized wood. Works on ivory.

Another way, since you already have dings on the guard is to use a piece of wood. place one end against the face of the guard on one side and tap the other end with a small hammer. The Japanese use a similar tool to take down swords if they get stuck. You may have to clamp the blade in a vise when you do this and be very careful when you do this. I do this sometimes after press fitting a guard and it is on GOOD. I tape the blade and hold it with my left hand, the thumb and forefinger hold the wood piece against the guard. I then use the right hand to gently hammer on the other end of the wood with a small hammer. This usually works just fine. Just go slow.

Normally I use super glue for test fitting. Just a few drops and it will break loose easily.

Good luck.

Brion

Brion Tomberlin

Anvil Top Custom Knives

ABS Mastersmith

 
Posted : 21/05/2012 9:48 pm
Jonathan Stanley
Posts: 117
Member
Topic starter
 

Thanks guys!

In answer to your question, Mr. Brian I use a super glue brand of epoxy. I usually get a 2500 pounds per square inch, five minute set epoxy. For knives that have a lot of pieces I might use a thirty minute setting epoxy so I have a little more time to put things together. Most people say that 5 minute epoxy is just too fast but I am only 13 and am still having to deal with the fact that my speed in everything is way to fast.(which, 9 times out of 10, tends to get me in trouble) <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//wink.gi f' class='bbc_emoticon' alt=';)' />

Mr. Brion,

What is mineral oil? I'm not sure I know what your talking about. Would water work?

Jonathan Stanley

Apprentice Smith

 
Posted : 22/05/2012 8:00 am
Steve Culver
Posts: 827
Prominent Member Master Bladesmith/ABS Instructor
 

Jonathan,

You can get mineral oil in the pharmacy. I've never used it as Brion described, so don't have any other recommendations there. But, I doubt that water would work as well.

I have also used a leather mallet to remove stuck guards without marring them.

 
Posted : 22/05/2012 11:17 am
Posts: 233
Member
 

The only time I had to remove a handle that was epoxied on I heated the recosso with a plumbers torch. It did not go that well. I got the handle off and if I had known that this customers knife had such a poor construction in the first place I would never have agreed to work on it. I would try some other method first if I were you.

The knife I'm referring to had about an inch long tang that was maybe a quarter inch wide. I think that is the only reason I was able to use that method and be successfull. All I could bring myself to do was to put the knife back together and return it to the owner. Needless to say I no longer work on anyone else's knives.

 
Posted : 22/05/2012 7:56 pm
Posts: 11
Member
 

I haven't used the mineral oil trick on stabilized wood, but have on a piece of bocote and had some success with it. Took 45 mins. or so. Like brion said you just have to keep checking to see when it will come loose.

 
Posted : 22/05/2012 9:18 pm
BrionTomberlin
Posts: 1675
Member
 

Like Steve said Johnathan, you can get mineral oil at a pharmacy or in the pharmacy department at Wal Mart. It does take a while and you have to keep checking on it. Personally I would try the wood trick first and see if I could get it loose. There is one area that you have to be careful about and that is to not hit the wood block too hard. Just go easy and take your time.

The mineral oil does work as I have used it with success, don't ask. Basically ask your Mom about a double boiler as that is what the setup is. Water might work but I do not know for sure. Baby oil also has mineral oil as it's main ingredient, but your handle material will smell like babies.

Brion

Brion Tomberlin

Anvil Top Custom Knives

ABS Mastersmith

 
Posted : 22/05/2012 10:01 pm
Posts: 209
Estimable Member Journeyman Bladesmith (5yr)
 

Jonathan

Different epoxies react to heat differently. Acraglas is a tough epoxy and has to get really hot to start breaking down. the epoxy that you used I do not think will require a lot of heat. I would suggest mixing up some, letting it set up, then trying some of the methods mentioned here to see if the epoxy will soften before you try it on your knife. Ideally, you would have a piece of the stabilized wood that you sawed from the handle that you can experiment with as well to see how it reacts with the oil.

I would also contact the person you got the stabilized wood from and find out if it will take the heat and oil.

Brian

 
Posted : 23/05/2012 8:26 pm
Jonathan Stanley
Posts: 117
Member
Topic starter
 

I decided to try some of y'all ideas today so I went to the barn and got to work.

First I wrapped the blade and clamped it in the vice as tight as possible. Then I took a piece of scrap wood and a hammer, and hammered on the knife handle until the wood I was using to hammer with just split into tinny little pieces. So I went back inside to try the boiling process. I quickly found that we don't have enough mineral oil for the process. So I got online to get a rough estimate on hoe much it would cost. The cheapest half gallon I could find was at wall mart and it was almost $30.00.

Any body around here got a plan C ? <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//blink.gi f' class='bbc_emoticon' alt=':blink:' />

Jonathan Stanley

Apprentice Smith

 
Posted : 24/05/2012 5:47 pm
Posts: 7
Active Member Apprentice Bladesmith (5yr)
 

|quoted:

I decided to try some of y'all ideas today so I went to the barn and got to work.

First I wrapped the blade and clamped it in the vice as tight as possible. Then I took a piece of scrap wood and a hammer, and hammered on the knife handle until the wood I was using to hammer with just split into tinny little pieces. So I went back inside to try the boiling process. I quickly found that we don't have enough mineral oil for the process. So I got online to get a rough estimate on hoe much it would cost. The cheapest half gallon I could find was at wall mart and it was almost $30.00.

Any body around here got a plan C ? <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//blink.gi f' class='bbc_emoticon' alt=':blink:' />

Jonathan,

Here is a plan "c" for you if your happy with the overal fit of the componets. Leave the handle on and consider shaping the gaurd, if it is not to dinged up. Make sure the blade and the wood are protected by tape, layout some guide lines and file/sand to desired shape. You will want to make some drawing of potential ideas and after selecting one refer to it often! This is how I saved a coulpe back in the early 70s when I accidentally dinged some, oops made a confession. Remember great skill comes from experience and learn from your mistakes.

 
Posted : 25/05/2012 3:34 am
BrionTomberlin
Posts: 1675
Member
 

Another thing Johnathan and this is a hard one. Sometimes you just have to knock the handle off. I usually use a hammer and the anvil and knock it off. This will destroy the handle. One of those lessons learned. It really hurts when you have to do this to a $60 piece of ironwood, but sometimes it is neccessary.

I also noticed you said you you hammered on the handle material. When you use a piece of wood and hit it with the hammer do it on the face of the guard up next to the ricasso. You will probably have to alternate sides.

Also you should not need near a half gallon of mineral oil. I have two pints and they were like $3.00 each at Wal Mart.

Stephen makes a very good point. If you are satisfied with the fit and can correct the dings in the guard face, then go ahead and finish the knife. Most of the time my final shaping and finishing is done after the knife is glued up. We call them design opportunities.

Brion

Brion Tomberlin

Anvil Top Custom Knives

ABS Mastersmith

 
Posted : 25/05/2012 9:56 pm
Jonathan Stanley
Posts: 117
Member
Topic starter
 

Thanks guys!

I think I will have to look a little harder for that mineral oil.

If all else fails I will try to work the design to match the dents.

By the way Mr. Brion, that's what i meant to say. I hammered on the guard not the handle material.

Jonathan Stanley

Apprentice Smith

 
Posted : 26/05/2012 9:05 pm
BrionTomberlin
Posts: 1675
Member
 

Like I said Johnathan, design opportunties. I would give the mineral oil a try and see.

Brion

Brion Tomberlin

Anvil Top Custom Knives

ABS Mastersmith

 
Posted : 26/05/2012 9:23 pm
Posts: 0
New Member Guest
 

Jonathon

Epoxy degrades in heat by first softening - called the glass transition, normally under the boiling point of water althro sometimes about and then burning at much higher temperatures. Certain oil will "plasticize" it - make it softer. I normally gently heat but soaking it the right solvent will soften it too. Mineral oil is a good choice because it's one of the not-nasty ones. Water will not work. (Explanations on request)

For Brion mostly. The oil swells the polymer, making it softer and shifting the glass transition down. In that gun bedding compound you also have some other stuff to drive the glass transition up, and if you use the filler and a reinforcing agent that is also a thermal insulator, so it will take more heat. Even hot, it should be stiffer.

"In answer to your question, Mr. Brian I use a super glue brand of epoxy"

However, I am a little worries about the superglue brand of epoxy you mention. Do you still have the glue? If you really used superglue, those are not epoxies. If it was a 2 part epoxy with that brand name, you're okay but if it wa really a "superglue," those are cyanoacrylates and they act different. One they need more heat to soften, they stink when they do and often give off white vapors - don't breathe, and acetone will soften it. If you don't have acetone around as a solvent, then check your mother's or sister's nail polish remover. Often that contents mostly acetone.

Hope that helps,

Kevin

 
Posted : 27/05/2012 7:31 am
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