Epoxy

Tom Militano

Tom Militano

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I remember reading, a short while back, a discussion on the different epoxies that makers were using. I'm not even sure what forum it was on. I've been using acraglas for many years and today I was reminded of why I use it. I had epoxied a stabilized piece of giraffe leg bone on one side of a knife yesterday and when I checked it today I dropped it on a concrete floor with no damage, luckily. It took a chip out of it in a place that was going to be ground off anyway. There were no pins in it yet, just epoxy, and it never came close to popping off. Great stuff.
Tom
 
I have 2 worker knives that I made...er...put together from beaters at a flea market. The scales on both are held in place by epoxy and epoxy only. One is Defcon 5 min and the other is their 24 hour stuff...so far no problems.
 
Tom: I had a real interesting discussion with Frank Brownell a few months back. I mentioned that I appreciated the quality of their acraglass and he stated that there are lots of folks making epoxy from simialr stuff that they use. The quality or dependability of the acraglass comes from the technique (spell that care, knowledge etc.) that Brownells devotes to putting it together for us. I have been using it since it came out and have never had a problem other than those caused by me. Brownells is one outfit that I have a lot of appreciation for.
 
No doubt about it, it's great stuff. I'm not sure it holds any better than JB Weld but it is easier to keep the seams from showing. A lot of the things I do are a result of making things before they had the huge selection of parts for handguns. Many years ago before night sights were easilyy obtained, I molded front sights for 45's from Acraglass and Lithium Tridide (spelling) That I got from a friend who worked in one of the local college Labs. I never had one fail. I've even used it to bed stocks, can you imagine that. I used it to bed a sword sheath once. Made me nervous as hell because I routed an oversize slot in the two halves of the sheath, coated the blade in release agent, filled the slots with Acraglass and, coated the flats with the stuff and sandwithched the whole thing and clamped. I wasn't sure the blade would come out but the next morning I gave it a tug and out it came. The sheath needless to asy, was a prefect fit. It is also the only wooden sheath I've ever made that does not stain carbon blades.

Yes it's cheating but it worked! :D
 
I use Acraglas for the majority of my work and occasionally JB Weld too.

I agree with Ed that Brownell's is a fine company and I have always has GREAT service from them.

If you use Acraglas you will never have any question of strength.
 
I've always used J-B Weld with great success, but it is a bland color. I always tint it dark grey/black with black iron oxide, and find the dark hairline blends in well. If you were sing white Micarta etc, you might want to use something else. It works well for my style of knife, and thats the key I think. there are many acceptable epoxies, but they have to work with your selection of materials and methods.
 
No question that Brownells are great to do business with.

I've said this many times, but I've found that surface preparation is far more important than the epoxy used, IMHO. Even 5 minute epoxy has 1500 PSI holding capacity. In other words if your knife tang has about 3 square inches of surface area, you can support over 2 tons with that epoxy. More often, maybe always, bonding failures are at the surface, expecially the metal/epoxy surface. I etch most of my tangs before epoxying and that eliminates any problem there. If the fit is good, nothing is going to get into that bond.

Another problem can be created however if you clamp the parts very tightly. You can squeze most of the epoxy out of the joint. I use firm hand pressure, and am able to get no line fits just by being certain the parts are flat and even. If you don't oversize your pin holes, you'll squeegee off the epoxy as you push in the pins. If you don't brush your pin surfaces, the epoxy won't hold them. If your fingers are oily, you'll contaminate the pins. Etc., etc...

Yet another problem pops up in how you handle the epoxy. I don't allow any oils or waxes anywhere near where I epoxy things. NONE!! My drill press is rusty because I don't want oil in the handle holes or on the tangs. Also, I use Brownells epoxy mixing pads which are the world's most expensive paper, but they never contaminate the epoxy. Many papers are waxed or have other coatings which can contaminate epoxy and cause it to fail, sometimes long after it sets up.

OK, I've vented. I'm better now... :)
 
I used it when I was making and bedding rifle stocks. I started using acraglas gel towards the end though, because it didn't run as bad. I like the regular acraglas for knifes though. Brownell's is a great company to do business with.
 
Right now I'm useing Devcon 5 minit, 2 ton, and JB weld and some supper glue, depending on the aplication. I haven't tried acraglas yet, But from what I've heard, I'm dying to give it a go.

I had a lot of seperations when I was in high school makeing knife shaped objects(read junk), probly due to the reasons Jerry Hossom stated. Now I no longer trust any epoxy, and relie on a macanicle bond. On full tang I eigther use Loveless type bolts, corbys or pien the pins. On the rare hidden tang where I don't use a pin, I use JB weld. In most cases I am useing epoxy for a seal and little else.

I still don't completely trust epoxy, and useing a macanicle faster is just added insurance to me. I have seen anouther maker's knives literly come apart from relieing on epoxy for handle strength.
 
The epoxy you use works best when you blend the type of epoxy with the nature of the handle material. Sheep horn is very micro-porous, the slow cure time for acraglas allows plenty of time for the epoxy to soak into the sheep horn for a strong bond. I fill the cavity for the tang in the sheep horn with acraglas and stir and wait, then stir again before setting the tang into the tang place.
 
The main reason I use any of the stuff be it 5 min.
or 30 min or any brand
(though I think the 30 will last longer as Ed said, soak time).
is for the seal. I always and or ether
use external/internal pins, barbs,dovetail, or end biscuits.
the man made stuff I trust is my stuff, the way I put
em together, yes mechanical all the way, and still you
don't have to have any pins showing.
even if silver soldered, I normally will pin it.
heat expands different materials at different rates
this is cause for failure alone, let alone expansion
and shrinking of natural materials.
  I try not to leave anything to chance,
Mother nature has a way of trying to reclaiming her self.
 
Jerry has hit the nail square on...
I joined a LOT of things with 5 minutes epoxy. The only separations are due to improper surface finish.
Glue together two mirror like surface and you'll be able to separate them with your fingers.
Most natural material are far less resistant than epoxy and, if properly epoxied together will never, ever, come apart if not due to fracture of the weakest material.
In the case of two metals, the weakest material will be epoxy, obviously, but you'll need an awesome amount of force and leverage, and you'll see that epoxy fails, but doesn't detach from the surfaces.
Obviously if there is also a strong mechanical bond, with proper pins and dovetailing, all helps.
The difference between making a custom knife and making a production one is that you aren't happy with what simply meets the requirements or just works. You want the best you can do. :D

Anyway, there's no need to keep your drill press rusty. I oil mine regularly. You just need denatured ethil alcohol (where does that damn "h" go, anyway? :) ) to clean perfectly the handle before epoxying. You have to degrease the knife anyway, after all.
Rough grinding and etching will do the trick.
 
if anyone wishes to use the harder rock type material
as a grip.. such as jasper..jade..ect.. the epoxy must be
specialized... it must bond at the molecular level in the
rock... their is a special epoxy made to bond rock to metal..
its called 330... its fairly cheap..easily mixed..and works
verrry well..just thought id share this in case you ever need
to use some..dm

http://www.ccsilver.com/supplies/epoxies/epoxies.html
 
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