Laminating G10 to Black Ash Burl

Langadune

Langadune

Joined
Apr 19, 2012
Messages
212
I've tried this twice now and must be missing something. I'm trying "glue" some red G10 spacers to stabilized Black Ash Burl scales. I scuffed up the mating surfaces aggressively and epoxied them with Bob Smith Slow-Cure epoxy, clamping them together with spring clamps. On the first try the scales and G10 pulled apart pretty easily. Second try, I did the same thing except I didn't clamps them, I used a chunk of 2x4 as weight (not too heavy really). Same thing again. The pieces peeled apart rather easily.

Is there anything that seems obviously to anyone here that I'm not doing right?
 
You might want to just give CA glue a shot.

I normally use epoxy, but when I have trouble, CA has saved the day.
 
Langadune said:
That's too simple to work!!!!
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LOL that's what I thought.

I was gluing stacks of G10 liners together on a recent project, and no matter how I prepped them, the darn epoxy was just peeling like it was going out of style.

Then I switched to a drop of CA, and I didn't even get the darned things lined up before they were perma-bonded. I tried to break them apart and ended up cracking the G10 instead.

I did a several year long research project on adhesive bonding in my old career, especially epoxies, and it's still somewhat of a black art at certain times.
 
Well. It's definitely worth a try. I guess I was a little concerned because these are for chef-style knives and I wasn't sure if moisture would eventually break down the bond.
 
What I did on a couple knives I've been working on recently is to use the CA glue to laminate the 2 pieces together as Ian suggested. Then prior to gluing the now laminated scales to the knife, I used a 3/16th drill bit and drilled 8 or 10 holes all the way through the liner and into wood. Making sure to stay shallow and in the center of the scale to be sure to eliminate the possibility of exposing epoxy when shaping the handle.

I'm just learning myself and whether this is the proper method I can't say. It did however allow the epoxy to bond to both pieces of the laminate.

Chris
 
I do laminates fairly often and have been fortunate enough to not have a failure (yet) Here are some things I do

1.) I take a drill bit and make tiny chamfers all across the materials that will be bonded. These little divots are a nice place for epoxy to grab. Then take a small drill bit and drill holes all the way though the liner and into the wood. For this step make sure that you know where the edges of you handle are so you don't end up with a big divot visible. Learned this one the hard way :o

2.) sand to about 120 and then clean the material vigorously with soap and water and then with acetone. I think one reason alot of bonds fail is because alot of dust and gunk sticks to the material even when it looks clean. A chemically clean surface is a must.

3.) Make sure your surface is dry. Some epoxies can bond wet but Im not sure if yours can.

3.) use clamps and make sure that you don't squeeze too tight or all the epoxy will get pushed out of the joint.

4.) I use west systems G flex and have been super happy with it. I would suggest giving it a try.

5.) Cure at 70 degrees and wait at least 24 hours before working on it. If its cold where you are your epoxy may not be fully cured. Keep in mind that each 20 degree drop in temperature doubles cure time.

I hope this helps. If you are using mechanical fasteners you can use super glue and be fine. Maybe Andy Roy can chime in and give some advice. He's the king of laminate handles afterall :thumbup:
 
Thanks guys. Sounds like CA is a way to go. I'll be trying tonight. Salalon, good idea about drilling through the liner for adhesion. KalEl, I've been cleaning them, but not with acetone, that might be a big factor.

I feel better about epoxy, but it hasn't been working the way I'd like. The brand I've been using may not be the best, I've been getting it from USAKM. I have some System Three coming but it's a few days out. Think I'll try the CA on a pairs of scales and see how I feel about it.
 
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I haven't had a problem with epoxy (west systems). I flatten them with about 80 grit and clean with acetone and they stay snug together.
 
I use medium viscocity CA glue to accomplish this. It sets when there is no oxygen, so be prepared, and quick. Spray the outside with instaset and pop the sclaes from the clamps in 15 minutes to continue work.
 
I use Loctite Speedbonder... have ever since reading a review of the stuff here from Matthew Gregory.

I make sure the surfaces are FLAT and CLEAN. (most guys think G10 comes flat, but none of the stuff I've bought was). I've found this stuff works best with a pretty smooth surface.

You spray the pieces to be bonded with the activator, let them sit 3-5 minutes, then put the adhesive on one of the parts and put them together.

It's at fixture strength in 3 minutes. This stuff is very strong. :thumbup:
 
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KalEl said:
I do laminates fairly often and have been fortunate enough to not have a failure (yet) Here are some things I do

1.) I take a drill bit and make tiny chamfers all across the materials that will be bonded. These little divots are a nice place for epoxy to grab. Then take a small drill bit and drill holes all the way though the liner and into the wood. For this step make sure that you know where the edges of you handle are so you don't end up with a big divot visible. Learned this one the hard way :o

2.) sand to about 120 and then clean the material vigorously with soap and water and then with acetone. I think one reason alot of bonds fail is because alot of dust and gunk sticks to the material even when it looks clean. A chemically clean surface is a must.

3.) Make sure your surface is dry. Some epoxies can bond wet but Im not sure if yours can.

3.) use clamps and make sure that you don't squeeze too tight or all the epoxy will get pushed out of the joint.

4.) I use west systems G flex and have been super happy with it. I would suggest giving it a try.

5.) Cure at 70 degrees and wait at least 24 hours before working on it. If its cold where you are your epoxy may not be fully cured. Keep in mind that each 20 degree drop in temperature doubles cure time.

I hope this helps. If you are using mechanical fasteners you can use super glue and be fine. Maybe Andy Roy can chime in and give some advice. He's the king of laminate handles afterall :thumbup:
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Good advice, Hunter. I also use the "divot then drill-through" technique and it works like a charm. Epoxy is indeed a black art - and the characteristics of different epoxies vary all over the map. I'd recommend sticking with epoxies that are tried-and-true in the community - like Gflex and Acraglas.

TedP
 
BTW- The last cleaning step should either be sandblasting or cleaning with Alcohol (denatured is best). I had heard that Acetone left a bit of oily residue and always thought that was crap. I couldn't find any solid info about it online, so I did a test...

I took a piece of steel and surface ground it clean with a brand new belt. I wiped 1/2 of it down with Acetone, then let it sit outside (in the Northwest weather). The side I wiped down with Acetone would bead up water, the other side rusted evenly over the entire surface.

So now I wipe down surfaces to be bonded with Acetone to remove Sharpie marks and such, then with alcohol to make sure it's clean.
 
I rub the epoxy hard into both surfaces with a metal rod. That, clean non-glossy surfaces, and a high quality epoxy (Acraglas, West Systems, etc) will do the job.
 
I did some testing a while back with both epoxy and CA, bonding micarta to steel. I found that when the surfaces were prepared with a belt or sandpaper the strength of the bond was pretty low. I was able to pop them apart with just hand strength (the pieces were in a lap joint).

The exact same setup with the surfaces prepared by sandblasting was like night and day. All of a sudden I needed to use big channel locks to break the pieces apart. If you're able to get access to a sandblaster I highly recommend using one, I was surprised how much I ended up using the one in the shared shop I work from.

EDIT: this experience is not directly applicable to your situation, but I think the same principle will hold true. Maximizing the glue surface area by sandblasting seems to add a lot of strength to the joint.
 
I had mentioned a study I'd worked on regarding adhesive bonding with epoxies, we found that sandblasting was the best surface treatment overall as far as ease of application and repeatability.

We finally settled on one of these for our process (preparing 1"^2 of 316ss for bonding), it is in a league of its own:

http://www.crystalmarkinc.com/product/micro-sandblasters-ev-2

It is also $$$$, and probably not at all practical for most makers. You could think of it as the airbrush of sandblasters. You can get very fine grit, but very high surface area finishes with it by using aggressive media in a fine micron size. They use them for cleaning fossils, preparing medical devices, all kinds of stuff.

You could actually see the epoxy creeping through the surface and wetting via capillary action on these really fine blasted finishes, and that is with a thixotropic paste.

One of these units is on my list for Knifemaking for sure, it will just be some time before I'm able to purchase one.

Not only can you do amazing surface prep for gluing, you can get ultra fine, ultra uniform beadblast type finishes with it as well.



Basically the above blaster with a multi-bath ultrasonic cleaning process and then isopropanol vapor degrease was the highest bond strength we were able to achieve with any of the epoxies we were studying.

On some materials and substrates, the ultrasonic was important to shake loose any grit particles stuck to the surface, it could sometimes have a large effect on bond strength vs. a hand scrub using the same high strength cleaners.



As for right now, I try to put a very thorough multidirectional finish on with sandpaper or scotchbrite, and just clean the heck out of it the best I can.
 
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Very cool Ian! looks like a fun toy!

In my head for some reason I had it that coarser grit would make more surface area, but your comment made me re-think that an realize it didn't make sense! Good to know.
 
NickWheeler said:
BTW- The last cleaning step should either be sandblasting or cleaning with Alcohol (denatured is best). I had heard that Acetone left a bit of oily residue and always thought that was crap. I couldn't find any solid info about it online, so I did a test...

I took a piece of steel and surface ground it clean with a brand new belt. I wiped 1/2 of it down with Acetone, then let it sit outside (in the Northwest weather). The side I wiped down with Acetone would bead up water, the other side rusted evenly over the entire surface.

So now I wipe down surfaces to be bonded with Acetone to remove Sharpie marks and such, then with alcohol to make sure it's clean.
Click to expand...

Nick, that sparked a memory. I had to search, but look at post #92.

http://www.bladeforums.com/forums/showthread.php?t=337504
 
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