Recommendation? Scales coming off help

C

canuck cutler

Joined
Oct 27, 2015
Messages
17
This is my 3rd knife I have made. It's the first with a full metal tang. So it's my first crack at doing scales.

This knife is just a beater knife, it's a proof of concept. I am going to use it a lot and see if and how it fails.

Here is the knife


And here is my problem.



The scales have pulled away at the points.

I sanded the mating surfaces with 60 grit
Cleaned the metal with varsol
Glued with gorilla glue epoxy

Long story short, I was cleaning off my work bench of greasy tools. I used varsol to clean the tools.
A few days later when I was putting the scales on, I had everything laid out ready to glue and I grabbed the varsol to give the blank one last cleaning. I had the acetone out and sitting there, but in my excitement I subcontiously grabbed the wrong one. Didn't think of my mistake until after it was all together.

Would the varsol prevent a good adhesion and cause this problem?

My main concern is water getting in. Can I just use crazy glue to fill the the tiny gap?
 
I can't imagine it would have slid back with pins in there. I could be wrong but it looks more to me like some squeeze out that didn't get cleaned off
 
Geoff Flato said:
I can't imagine it would have slid back with pins in there. I could be wrong but it looks more to me like some squeeze out that didn't get cleaned off
Click to expand...

You are correct. I'm not worried about the squeeze out. It's the piece of paper that I slid between the wood and the blade
 
Varsol is mineral spirits? Not a good prep cleaner for glue up. Will leave a residue like acetone. Alcohol is the best bet for cleaning prior to glue up. The epoxy was a 5 or 15 minute type? Those are also not great, most of us use a 24 hour structural epoxy. How flat were the scales and liners before glue up? How flat was the tang? Is it possible there was a gap there from the start and you just didn't get it filled with epoxy?

As for filling with CA glue to prevent water intrusion, that should work fine.
 
If it's your knife then it's your call. If it's going to someone else then in my opinion the only acceptable fix is to pull the scales off and redo it. I hear people say all the time to just CA it or mix sanding dust with epoxy and shove it in there but that's not the best way to do it. If it's already separating them it's likely to continue. Looks good though!
 
kuraki said:
Varsol is mineral spirits? Not a good prep cleaner for glue up. Will leave a residue like acetone. Alcohol is the best bet for cleaning prior to glue up. The epoxy was a 5 or 15 minute type? Those are also not great, most of us use a 24 hour structural epoxy. How flat were the scales and liners before glue up? How flat was the tang? Is it possible there was a gap there from the start and you just didn't get it filled with epoxy?

As for filling with CA glue to prevent water intrusion, that should work fine.
Click to expand...

So this is the exact information I was looking for. I used 5 min epoxy. I cannot find a source for anything else in canada. I can order some good stuff from the states. But the cost would be hundreds of dollars. I produce a couple knives a year.
I can't find any 15min epoxy. I bought some Devcon and had good results, but now the cheapest I can find it for is like 45 bucks. So I went with gorilla hoping it would be comparable.
 
Matt R said:
If it's your knife then it's your call. If it's going to someone else then in my opinion the only acceptable fix is to pull the scales off and redo it. I hear people say all the time to just CA it or mix sanding dust with epoxy and shove it in there but that's not the best way to do it. If it's already separating them it's likely to continue. Looks good though!
Click to expand...

I agree, I would never sell a knife with these issues. I just want to keep it for myself and protect it as best as possible and find a way to prevent this issue in the future
 
Josh Rider said:
How hard did you clamp the scales down?
You may have clamped too tight and squeezed the epoxy out.
Click to expand...

How hard should the clamps be? I used this style.



Hard to say how much force they produce.
Probably too much.
Should I use a spring style clamp instead? This is my first knife with scales and it may seem like an easy thing to do, but for a first timer their are a lot of things that can go wrong.
 
Yeah, spring clamps are best for this. I've used the standard style on nearly all my knives without any trouble. The key to good glue up is #1 flat surfaces #2 clean surfaces #3 good adhesive and don't squeeze it all out. Past that, the handle material can pull and move with humidity changes but if you've got 1, 2 and 3 right, it can make up for a lot of other variables.

Here is a Canadian supplier with T-88. I'm sure there are more, this was just a quick google find.
https://www.aircraftspruce.ca/catalog/wppages/t88gluegun.php
 
canuck cutler said:
You are correct. I'm not worried about the squeeze out. It's the piece of paper that I slid between the wood and the blade
Click to expand...
I missed that, my bad.
As for epoxy, I'm in Canada and we have many sources. Lee Valley sells west systems and a couple others.
I normally use loctite-hysol e-120hp which is about the best stuff on the market. Acklands-grainger sells it, but most independent industrial suppliers can order it in for you for $18-25 a tube
 
I would skip the Gorilla glue epoxy. Haven't had a good experience with it. It doesn't have much shear strength in my experience.
Is the wood used for the scales stabilized? Could it have warped from humidity change?

I also like to mechanicaly retain my scales as well as glue them. What I usually do is peen the handle pins or use flared tubing. Some people also use Corby bolts or loveless type fasteners.If they come off after all that, then I am doing something way wrong.
 
As a repair for the existing problem, flow thin CA in the cracks. Let dry overnight and repeat as needed. Lightly sand the excess resin off and you are good to go.

Clamp scales as lightly as possible. The clamps you used are far too strong, and squeezed all the glue out of the joint.
 
Okay, so this time I can bandaid the knife with crazy glue. Just to prevent water from getting between the scales.

Next time around I will
Clean with isopropyl alcohol
Use loctite-hysol e-120hp
Use Spring clamps only

Thanks guys.
 
Mr. Stacy Apelt has often recommended using a light spring clamp on knives glued up with epoxy because of the problem of starving the joint of epoxy. This is wisdom attested to by many fine knife makers. I have butted in on many of these discussions to offer my method of getting sound epoxy joints. I will epoxy only one side at a time mainly because I like bolsters and I want a tight bolster joint.. If the scales that im using are flat then I put the knife on a marble pastry board covered with wax paper and I epoxy the one side and set a can of soup on top of the knife to provide a gravity hold while the epoxy cures. I then drill the pin holes and repeat on the other side. I have done this for the last several years with good results in my opinion. I know that this is not scientific but it works for me and I am proud of the knives that I make. This method may work well for you as well. Larry

VgYxILLm.jpg
 
Well first thing is the Hysol from loctite someone else recommended is great, having said that if you look around a bit on Knife Dogs, the owner of USA Knifemaker did a thorough test on different epoxies and Gorilla glue did superb, in fact the straight brown Gorilla Glue, not the epoxy was one of the two best performers--so I don't think your Gorilla Glue epoxy was an issue for you, those clamps you use are actually probably fine also, unless you just pumped the hell out of them to squeeze the life out of your scales--I to do recommend the spring clamps someone posted a pic of, and are what I use--filling in the gap you have with CA glue is fine, and you don't need to add any sawdust or other to it--I would recommend Gap Filling medium consistency CA glue--it's easy to find-I always look on Amazon. Good luck with your knives, your off to a good start IMO
 
Bill DeShivs said:
Larry- any particular kind of soup?;)
Click to expand...
My first inclination is to go with something thick and hearty, though I don't want to risk squeeze out. I suppose if I go with a low calorie or "light" soup, there's less chance I'll want to eat it before the epoxy cures.

Decisions, decisions...
 
The key to successful scale fit is make sure the scale, liners and knife are DEAD FLAT. And rough with 50 grit and do not contaminate the surfaces.

I have been testing "Clear Gorilla Glue" and holds a strong bond like epoxy and is easy to work with. A good alternative for those who do not or can not get expensive epoxy. To be honest it is probably ounce to ounce more expensive, but you only have to fork out $6 and will get many knives from it.
 
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