A gap showed up between the scale and tang

I like how Nick wheeler goes so far as to file the tang to put keyways for the epoxy to lock onto.

I think he even files on his pins :)
 
I just finished putting together a large camp knife with 1/4 mosaic pins and I used a Dremel tool with a fiberglass cutting wheel to cut slots in the tang in a cross-hatch fashion to grip the G-flex epoxy. I drilled a couple extra 1/4 inch holes in the tang also. I have not had a knife come apart yet but I know it's always possible. I like Corby bolts also but sometimes I want a mosaic pin for a little "jewelry" on the knife. Larry
 
Teppojutsu said:
On the epoxy packages don't they tell you about shrinkage?
I know while thumbing through my Brownell catalog they have tons of epoxy like acraglass and I believe they list the shrinkage factor not sure on this though .
Click to expand...

It may say on the package, it's very possible I overlooked it.

It makes sense, most anything that goes through a liquid to solid transformation is going to shrink I would guess, just never occurred to me before.
 
Ive had that happen on a lot of my first batch of knives. Actually about 12 out of 20 of my first knives that happened to.
I took several measures at once and have not seen it since.
I have had good epoxy holds to the original surface of the steel like you have pictured here. But I dont trust it so I always grind the surface down on my flat platen. I always grind the surface down and clean with acetone and denatured alcohol right before glue up so that there is not a chance for any oxidation to form.
I switched from west systems 205/207 to west systems g-flex.
I stopped clamping tight. I just snug up the clamps while the pins hold it in position.
Pay extra careful attention when you are clamping the scales. Is the clamp "bending" the scales to fit flatter to the tang? You cannot compensate for slightly non parallel surfaces by clamping tighter. I found this single factor to be the cause of most of my earlier failures.
 
Hengelo_77 said:
I did clean everything well with acetone. I aplie quite a bit of acetone, then whipe it off with clean textile (cotton) to remove the solved grease, fat and dirt.
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ACETONE is not what you want to use. It leaves an oily residue. Use denatured alcohol to clean with. If you do not have that then use dawn and hot water and wash until it is spotless.


Bead blast the area under the tang and the handles really is great for bonding.

What I would do with that knife is use "Insta Cure" ca glue. It is like water and will wick up into the space. Then clamp and apply "Insta Set" to kick the reaction.

Then use "Un Cure Debonder" to clean up the overflow.

It will look good as new.

Every knife maker should have:

Insta Cure
Insta Cure+ which is thicker
Insta Bond
Uncure debonder.
 
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AVigil said:
ACETONE is not what you want to use. It leaves an oily residue. Use denatured alcohol to clean with. If you do not have that then use dawn and hot water and wash until it is spotless.
.
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West Systems actually recommends using acetone (or alcohol) to prep before bonding.
 
Roamad said:
West Systems actually recommends using acetone (or alcohol) to prep before bonding.
Click to expand...

West Systems is WRONG. There is to much unpure acetone out there to be trusted. It is easy to see the residue it leaves, for that reasons those who know do not recommend acetone
 
West Systems was probably right when they first started saying that, but I think the reality is that the acetone available today isn't particularly pure for this application. If you doubt it, smear some on a glass window and see. Mine is junk.

The problem with alcohol is it isn't a very good solvent. Since acetone cuts oils and contaminates so well, but leaves a film behind of its own, I start with it and then use 91% Isopropyl alcohol after the acetone to get the film. Seems to work okay.
 
I always clean ALL surfaces being bonded with acetone, then clean again with denatured alcohol. To my knowledge, I've never had one of my knives have a bonding failure using that method. In my own testing, it takes some serious destruction to break that bond. G-flex is the only epoxy I've ever used or have experience with.
 
AVigil said:
West Systems is WRONG. There is to much unpure acetone out there to be trusted. It is easy to see the residue it leaves, for that reasons those who know do not recommend acetone
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This is absolutely true
When we do structural joints on curtain wall (Glass building where the only thing holding the glass is structural silicone )

Adam and Nate are correct if it leaves residue on glass it contains impuritys.

Also some solvents including acetone and denatured alcohol can release things found in dirty rags as well so test your paper towels or rags the same way .

Usually leaves some kind of residues from breaking down the stuff in the paper towels.


I would stick to cleaning with acetone then decreasing with denatured as well

As isopropyl contains other stuff in it to make it taste bad so people don't try and drink it .
Also isopropyl contains a lot of water :) denatured is best in my opinion.

But for removing stuck on shit the acetone works very well.

Just my 2

. Also if you hit it with a white rag and alcohol and it comes up not white it's not clean just had to put that out there as obvious as it sounds ;)
 
SOMETIMES,... wood that naturally has a lot of oil will not adhere with epoxy. I don't know if that is an issue with the koa veneer you used.

I like how you used it for spacer material. It looks nice.

- Paul Meske, AKA lonepine
 
Dishwashing liquid will clean a blade well for epoxy but I am always in the shop when I am ready to epoxy so I have been holding my breath and squirting a little carb cleaner on a cloth and wiping the blade before glue-up. It evaporates so quickly and completely degreases the blade and so it works well but you have to wear nitrile gloves to protect your skin. I clean the blade with acetone first but there is always a little residue. I use G-flex and glue on scales by putting a little weight on the scale and letting gravity hold the tang to the scale instead on using clamps which sometimes squeeze out too much epoxy. My method is slow because I only epoxy one scale at a time but I stress less about getting a tight fit against the guard or bolster. I am not saying that this is the best way to do it but rather just the way I do it. Larry
 
Hengelo: I usually use epoxy glue from Lidl superstore chain, this one. You surely already seen it there. It is very strong and fast cured so You have to be quick. I clean tang with acetone AND this cleaner. No residue remains. Both of them tested by myself. ;)

Hope it will help.
 
LARRYZ10 said:
Dishwashing liquid will clean a blade well for epoxy but I am always in the shop when I am ready to epoxy so I have been holding my breath and squirting a little carb cleaner on a cloth and wiping the blade before glue-up. It evaporates so quickly and completely degreases the blade and so it works well but you have to wear nitrile gloves to protect your skin. I clean the blade with acetone first but there is always a little residue. I use G-flex and glue on scales by putting a little weight on the scale and letting gravity hold the tang to the scale instead on using clamps which sometimes squeeze out too much epoxy. My method is slow because I only epoxy one scale at a time but I stress less about getting a tight fit against the guard or bolster. I am not saying that this is the best way to do it but rather just the way I do it. Larry
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Correct.me if i. Wrong Larry but doesn't carb cleaner actually have something to lube the carburetor in it?

I remember sometime trying to coat one of.my guns .
Everyone recommended break cleaner and said carb cleaner contains something to lube the carbs with .
I never researched it i could be wrong

I know when I degreases my guns for any kind of coating
I clean with brake cleaner then then when it's all evaporated off I wipe it down again using ultra clean microfiber (no lint to get in the paint) and nitrile gloves
 
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Nathan the Machinist said:
I'll touch on the obvious stuff:
Did you clean both surfaces well with solvents first?
Are you using a good quality epoxy such as Acraglas?
Is your epoxy fresh, was it measured out and mixed very thoroughly?
Did you over clamp it and squeeze the epoxy to thin?
Click to expand...

That's all!! :thumbup: the mill skin should not be the culprit. Also be careful when removing the glue residues from the front... useing too much solvent there could weaken the glue as far as it wicks, swollen the wood, and then the wood will shrink away from the tang
 
Hengelo_77 said:
Thnx for the input.
Here is a pic of the tang before glue up.
I used four hidden pinns (in the middle row of holes), two massive pins and tho with thread to give the epoxy more to hold on to.
What do you think of my idea of "hardening skinn" in the deeper parts of the roling skinn being a barrier between the epoxy and steel?

Should I have had holes closer to the end of the scales as well?

IMG_20160305_114941_zpst4m9flkx.jpg
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I use Dremel with small disc cutter to make some slots in steel close to edge of tang / REd in picture / .In wood I drill shallow hole , in your case through both . Next , when you mix epoxy becomes white and that is air trapped inside .Live some time to become clear , put epoxy on wood and wait some time epoxy to soak in wood / that s way we use slow curing epoxy / next put another coat epoxy on wood scales and on tang and stick together everything .I use vice to hold handle till dried /over night/ and quite strong pressure to squeeze out excess epoxy .Of course everything has to be clear, I have used all sorts of epoxy and never have a problem .....I have a small knife that I made twenty years ago and epoxy hold as first day ..............
2gt0u2v.jpg
 
stezann said:
Also be careful when removing the glue residues from the front... useing too much solvent there could weaken the glue as far as it wicks, swollen the wood, and then the wood will shrink away from the tang
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That might be the problem.
I remember using quite a bit of acetone to remove squized out epoxy from the front of the scale/ricasso area

So if not clean with plenty of acetone, how should I clean the squized out epoxy?
How do you guys do it?
 
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