Handle Epoxy

J

John Nord

Joined
Jan 13, 2020
Messages
7
Can anyone tell me what the best epoxy is for gluing on brass knife handles. I have been engraving 12 ga brass handle scales and pinning and epoxying them on. I use 330 epoxy and i have tried devcon 5 min epoxy. After drying it seems to turn loose from knife blank slightly in some areas. My preparation of the blank is thoroughly cleaning the brass and the blank handle. Drilling depressions all over both sides of the insides of the brass to give more glue surface, and ruffing up the blank handle the best i can on a hardened knife.
Sure like to hear from some experts
 
i am not an expert, but what do you mean by 'turn loose" ? is the brass curling away from the blade ? i dont know what 12 ga is, but it sounds too thick to bend. how do you rough up the blade/ handle ? 120 grit is what most people use. you might be squeezing all of the epoxy out of the joint if you are peening it before it cures. another thing to consider is the faster an epoxy sets, the weaker the bond is. they all take 24 hours to fully cure at room temp, but the quicker epoxies are not as good at grabbing or strength in my experience. i would suggest the 120 grit rough up, clamping the scales on and curing the epoxy before peening, and making sure your clamps for attaching the scales only hold hand tight. if you clamp harder than you can squeeze with your fingers, you might squeeze out too much epoxy. also be careful sanding. brass and copper scales and spacers heat up much faster than other handle materials. its easy to get them too hot, and the epoxy grip totally releases.
 
john april said:
i am not an expert, but what do you mean by 'turn loose" ? is the brass curling away from the blade ? i dont know what 12 ga is, but it sounds too thick to bend. how do you rough up the blade/ handle ? 120 grit is what most people use. you might be squeezing all of the epoxy out of the joint if you are peening it before it cures. another thing to consider is the faster an epoxy sets, the weaker the bond is. they all take 24 hours to fully cure at room temp, but the quicker epoxies are not as good at grabbing or strength in my experience. i would suggest the 120 grit rough up, clamping the scales on and curing the epoxy before peening, and making sure your clamps for attaching the scales only hold hand tight. if you clamp harder than you can squeeze with your fingers, you might squeeze out too much epoxy. also be careful sanding. brass and copper scales and spacers heat up much faster than other handle materials. its easy to get them too hot, and the epoxy grip totally releases.
Click to expand...
 
All of that information sounds good. 12ga is approx 1/8” thick. The scales do not need to bend, because they go on flat. I ruff up the blank handle with 80 grit on both sides. I also degrease everything. The 330 is a 15 minute epoxy. It cures in 24 hrs. But i leave it linger undisturbed. I drill shallow holes in brass to retain glue but i may be tightening clamps way to tight. Thank you
 
I drill shallow holes all over the insides of the brass. It is also ruffed up with 80 grit.
I cut slots in the pins before epoxying them in place. Anywhere there is not a pin, like up near the blade, there appears a small separation, sometimes. Lately i have been brading pins so everything stays tight. That seems to work. I just thought that epoxy pins and scales was how it was done. Not always braded.
 
Hmmm... that is weird.
Questions:

are the materials on both sides of the joint dead flat?
Do you clamp in such a way that you push non-flat surfaces into contact?
Do you heat the joined materials, or do they experience significant temperature changes?
Do you cure the epoxy at room temperature?
Is the epoxy new, or is it old?
Do you mix in correct ratios, and get the two parts mixed THOROUGHLY?
 
I am a engraver. The epoxy is less than 6 months old. Its great epoxy. I will double check everything i do. I suppose i am clamping to tight and maybe bending center of scales downward, causing ends to turn up. I thought there might be a better epoxy than what i am using. But it has always done a great job on my other items.
However, i did not realize that clamps should only be hand tight. I think i get them to tight, squeezing glue out and possibly bending scales. I will try to lighten that up. Thank you.
 
The way to solve these issues forever is to use Corby bolts. They come in many metal types, and sizes from 1/8" to 3/8". When finished they look just like a standard rivet. If you are an engraver, you can even engrave the heads after finishing.

If you are using plain rivets, these steps will assure a strong epoxy bond (the same steps are still wise for Corby bolts).Drill lots of holes through the tang ( besides the rivet holes.
Sand the back of the scales flat with 100 grit.
Making a lot of divots in the back of the scales with a drill or ball burr in a Dremel is a good idea.
Use slow cure 24 hour epoxy.
nly clamp hard enough to hold in place.


I use the cheap, small, weak plastic clamps from HF for scales. Screw clamps and strong clamps will cause epoxy starvation.
 
If you are properly peening your pin heads, there is no use whatsoever for epoxy. I believe he is installing scales on folding knives.
 
You must log in or register to reply here.
Back
Top