Cheyenne

You can get by with the resin and hardener only. If you want Dye, you can purchase that seperatly for $6.00. Flock is just a filler material that you can mix with the Acraglas for filling large voids when bedding rifles. It is kind of like adding fiberglass to concrete to add strength -- but it is not needed for knives.

The release agent is again designed for the gun bedding. It is designed to keep something from bonding to something else. Although there are times where it could be used in knifemaking, most people use vasaline.

Check out this link from Brownells for Acraglas instructions.

AcraGlas instructions

Brian

Just the Acragas, not all of the other stuff. Sorry about that, didn't think about it giving you the rifle bedding kit option. The release agent is used on a rifle action to keep the Acraglas from adhering to it, when glass bedding the action into a rifle stock. It would work well on a blade tang, if you are building a take-down knife. Other than that, you don't need it.

Something that bears mentioning about Acraglass is....it is NOT mixed as typical epoxy is mixed. Acraglass is mixed 4 parts resin, to 1 part hardener. When I first started using it, I purchased a batch of the graduated mixing cups...by the time I had used them up, I had it down "by eye".

Some folks have gotten themselves in the habit of mixing the standard 50/50 epoxies with a tad more hardener, hoping to make it "kick" faster... DO NOT do that with acraglass! If you add too much hardener to acraglass, it will reach the consistency of jell-O, and never get any harder. I've gotten myself in the habit of sitting the mixing cup next to the knife I just put a handle on...there's always a bit left over...and if it cures correctly, I know everything is good.

Personally, when it comes to dyes being used in acraglass, I will only use the dry (powdered) variety. I experimented a few times with using liquid dyes, and never had good results. I like the powdered dyes that K&G sells.

Thanks Brian and Steve. <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' /> I will get it ordered.

I use the West System epoxy. I appreciate the calibrated pumps.

It's a marine epoxy, and if you think of it - it's meant to hold boats together and as the coat that adheres the fiberglass sheets to hulls!

It's UV resistant and impervious to solvents and cleaners that one might find around a marine installation.

And the excess just wipes off with denatured alcohol for nearly an hour after application.

I have no desire to use anything else.

I have used devcon but ran into the problems Ed mentioned. I do use Loc Tite quick epoxy for bedding stag handles after the pith is taken out. I also have been using Loc Tite regular epoxy and have not had problems, BUT, I will be getting the Acraglass post haste. Thanks guys.

Brion

Thanks Karl,

I think John White also uses the West Systems epoxy. I've heard that it is really good stuff. West Systems

The message here is that knifemakers should be using high performance epoxies and not the household varieties.

|quoted:

Thanks Karl,

I think John White also uses the West Systems epoxy. I've heard that it is really good stuff. West Systems

The message here is that knifemakers should be using high performance epoxies and not the household varieties.

GREAT INFO.. IM JUST GETTIN STARTED INTO KNIFE MAKING, STILL IGNORANT OF ALOT ABOUT KMING...GLAD TO KNOW ABOUT THE GOOD EPOXIES. SO FAR IVE USED JB WELD.. ONLY 3 KNIVES UNDER MY BELT. I WILL SWITCH IMMEDIATELY.. THANKS

I'm curious about thoughts/experiences of using JB Weld.. I have been using it for a long time with excellent results.. I like the paste like consistency and when I need to get it to flow into a tang hole I just heat it up a bit with a heat gun and it flows right in.. I add a touch of black powdered dye to it as well..

I'm in full agreement with the acraglas. Besides having as good as or better adhesion than other epoxies, it is much tougher due to the increased amount of resin. This plus the longevity (I was told 100 years) of the finished glue joint is a huge plus over most epoxies.

One thing to remember with it is to keep it warm. It doesn't set well below 60 degrees and shouldn't be stored in an unheated area during the winter.

Gary

Epoxies are actually a pretty complex subject but commonly used enough that most of them work just fine. This may be more than you want to know but I've spent a bit of my career working with them and other thermosetting materials...

All epoxies consist of a chemical with a 3 atom ring consisting of 2 carbons and an oxygen. The hardener or iniatitor is really a material that reacts with the ring and forms a chain. These are often amines, containing nitrogen groups, but sometimes it can be a sulfur compound. Since amines are also what you smell with rotting meat and spoiled fish, they are unpleasant. One molecule of amine reacts with one epoxy ring. Now different vendors use different compounds and different mixes of compounds to develop the properties they want to emphasize. One can consist a cured epoxy as a 3-D mesh and often the manufacturers use compounds with more than one amine group attached so they encourage this. Let me break this up in some sections so I can tie it back to making wood stick to metal.

Curing - one of the big properties you can control with proper selection of parts is the rate of cure. Now, normally a slower cure at a given temperature means a stronger material because you make more little chains to hook together to form that network. In a properly cured material, it is often referred to as approaching an infinite molecular weight, which translates into the epoxy is all connected together in one big molecule. The cure rate happens because of the chemicals picked in the initiator and the temperature. If your shop is 110 F in the summer, 2 hour epoxy cures much faster than in winter at 40F. (That's my garage) That's why they tell you a temperature range. Another reason if you get too cold, you can crystallize the material out of solution and then you have the wrong ratios and get a bad cure if at all. You can change the time of cure by increasing the temperature if you need to. The amount of amine is important as it needs to be equal or slightly amine right. Now, the amine ratio depends on epoxy so if you material is filled, or has tougheners added you might be mixing 1:2 or 1:4. Tougheners are normally rubbery materials and added to the epoxy they form little pockets that make the material less brittle and more flexible. Because the ratio is so important, I weigh them out rather than use volumes. Most commercial systems have some slop figured in but for the absolute best, weigh and post cure.

Post cure - After the material is cured, in most system you have full mechanical strength at 85% degree of cure or so. Solvent resistance etc may not track as close and often commercial materials are post cured by heating at a temperature about the Tg. The Tg is the glass transition temperature and it's where a epoxy or any thermoset goes from hard to rubbery. For example, epoxies have Tg valuess about 50-60 C, tire rubber about -40 C, silicon rubbers at -60 C, etc. All of them are hard below and rubbery above, which lets you remove a chisel from an epoxied-on handle by heating above this softening point and pulling it apart. For System 3 epoxy, I like to cure for 2 hours at RT and then post cure for 4-6 hours at 60 C.

Physical properties - the whole selection process of what particular epoxy and what blend of amines to use is to drive first strength and then other properties to the best mix. Like with steels, manufacturers compromise depending on whether you want max strength, clarity, solvent (water) resistance, etc. That's why the different formulas. One property is age life and that's where I have a little trouble with that 100 year claim. One, it's predicted and I know how that's done and there are weakness, but secondly and more importantly, it depends on use and environment and that is very different in a high end rifle versus a fishing or pocket knife. It' actaully a huge field of stuff in aerospace.

The crap they add to the epoxy, the fillers, are also important but that gets more complicated...

I attached the first of a series of articles I did on epoxies below. The others are available on request but are pretty specialized and large files.

Hopefully this helps. Basically, the answer comes down to it depends.

Physical