need advice on how to glue this up

U

Uhurungus

Joined
Jan 8, 2015
Messages
62
steel tang
brass liner
wood scales with brass divider

there is some debate on whether or not epoxy is the best option when dealing with brass. JB weld is one option i hear. anyone have the definitive answer?

IMG_20150421_190954_018_zpstflwojfq.jpg
[/URL][/IMG]

IMG_20150421_191005_977_zpsq5hwkdzu.jpg
[/URL][/IMG]
 
For brass I like JB weld. I have done silver solder but found it took way to long and was not satisfactory. Epoxy works but again, I feel JB is the best for metal on metal.
 
JB Weld will certainly hold - providing the surface prep is done correctly. Most any other good epoxy such as West System or Raka will also hold just fine on brass.

I tend to provide a good tooth in the metal by using 36 grit belt to abrad the surface good. Be sure to degrease the surface of everything good with alcohol just before gluing everything up.

Also drilling a few holes thru the brass can provide a good bite for the epoxy. Where I've used a spacer between two sections of the handle scale I often will drill a hole and use a brass rod to provide extra strength, and to help hold everything in alignment while epoxy is curing.

Good luck, and remember, surface prep is everything with epoxy gluing.

Ken H>
 
update: used Devcon 2 ton epoxy and glued all wood to the brass. waited 36 hours for cure. set 1 piece to the grinder to take off the edges and everything fell apart. grabbed the other piece and i could just peel the brass liner away from the wood with my fingers.

i cleaned everything with acetone before i glued and scratched up all the brass with a 60g belt by hand to roughen it up.

and thoughts?
 
There are a couple of possible explanations for your issue. First, and most likely, you got the brass too hot on the grinder and melted the epoxy. This is very easy to do, as standard epoxy's melting point is in the neighborhood of 200 F. The second is that you didn't mix your epoxy well enough in the first place. I have done both. Now when I put small spacers like that in a handle, I bond them to the wood or fiber spacer with CA, then put the whole thing on a fiber backer with G-Flex. CA has a melting point of ~500F, so much harder to mess up, although still possible. Those little pieces of metal can get hot in a hurry.

It took me while to get this stuff dialed. My advice, avoid excess metal as much as possible, the less you have to grind it down, the less heat you have to deal with. If using epoxy, I'd just shape with files rather than the grinder. If you do use the grinder, stick with new sharp belts, grind just a quick swipe at a time, and stay on the coarser side.

If you go with CA, 3M CA is the way to go. The gorilla glue is garbage, it's brittle and crumbles if you look at it funny. I haven't tried JB weld, it has a temp rating of 600F for short term so that's pretty good, I might have to give it a shot.
 
yeah the one that i put on the grinder definitely got too hot. but the other one didn't. i'll try it again mixing it longer this time and i'll cut back some of the metal spacer first too.
 
make sure the epoxy hardens in a nice and warm room. If cold it doesn't harden well or at all. makes a huge difference
 
I have read bad reviews about devcon 2 ton for knife making. I've heard quite often that it fails. The guys are right about surface prep, mixing, and overheating as well.

Many makers use west system G flex, or acraglas epoxy.
 
i tried it again, warmer, better mixed, cleaned surface with alcohol and better scratched up.

same result. going to move on with no liners, need to get past this hump.
 
Uhurungus said:
i tried it again, warmer, better mixed, cleaned surface with alcohol and better scratched up.

same result. going to move on with no liners, need to get past this hump.
Click to expand...
G-flex, rough to 36 grit or so. Use some of the resin to actually wet sand all the mating surfaces. Try some hidden pins running laterally through the brass divider, wood bolster and seated in the guard.

I'd probably even use a few small all-thread pins hidden in about 1/8 of each scale near the middle where you won't dig into them...

I did a copper on spalted maple knife for a fellow a few years ago using this method. He uses it very frequently and has never had a problem... It is mainly in the prep work. Properly applied, good West systems epoxy and the like will stick anything to anything. Better still is some form of mechanical attachment running through the pieces...

Cheers, good luck. Traditional metal liners are cool as heck in my book...
-Eric
 
I've found that CA glue works very well (as mentioned above). I've gotten it at Hobby Town here in Portland - USAknifemaker.com also carries the same brand, BSI I think. I've had one fail when sanding the handle with Devcon. I threw the rest of it away and went and got BSI's Slow Cure epoxy -also sold at usaknifemaker- and it seems to be good stuff.

I think that Ken-H's advice is rock solid. I've done it that way a couple times and it worked VERY well. I actually used CA glue instead of epoxy for that and found that it took a good deal of force to break them apart.(I tested on a piece that was trimmed off during shaping.
 
You must log in or register to reply here.
Back
Top