Epoxy Problem

Michael, how do you deal with that stuff, since it's mixed by weight?? Mix enough to register on a kitchen-quality scale or what?
 
fitzo said:
Michael, how do you deal with that stuff, since it's mixed by weight?? Mix enough to register on a kitchen-quality scale or what?
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I use a formula that i learned in all my years in the Engineering field called SWAG. Stupid wild ass guess.

The instructions on the tub says "a little more part A than part B"
I visually try to put a little more part "A" than part "B" on my mixing plate and hope. It seems to be very forgiving because i have never had anything loosen up on me. I also color the epoxy almost 100% of the time and that doesnt seem to effect it either.
When i use brick red spacer i us a little brown and red powdered tempura and i can match the color almost exact.

Michael
 
Cool, good info to know, Mike! Thanks.

I got some I haven't used yet and have been trying to decide if I'd SWAG or try the tech approach and weigh it. :D
 
I mix my small epoxy batches in small measuring glasses I get at wally world.
It's a 4 oz measuring glass by Gemco.
It's clear glass and has all kinds of graduation marks. Ozs, tbs,tsp,and ml
You can easily mix 1to1 2to1 3to1 etc. an any amount you need.
I wipe out all the extra epoxy with paper towels then clean it with paper towels soaked with mineral spirits. They last forever of you don't drop them.
They're cheap too.
Do not throw the wet paper towel in the garbage. Lay them open out until the mineral spirits evaporate to prevent fires.
 
I didn't catch what type of scales you are using. Some oily woods and plastics do not do well with most eopies. Industrial Formulators makes G2 which is very good on oily woods. I'll add my voice to the "24 hour epoxy" crowd as well. Lastly, epoxy shouldn't cause warping. How good is the fit between tang and scales before clamping?
 
Another thing you can check out on system three's web page are the extra supplies they sell. They have disposibleplastic measuring cups, very handy. Also all their epoxies are either a 2 to 1 or 1 to1 mix by volume.

WS
 
Could it be that the material you are using for scales is not stable enough? In the past I've had trouble with materials warping that I had not allowed sufficient time to adjust to a differant cliamate.

I had it happen one time with some mammoth Ivory on a set of slip-joint frames. Warped the liners and all. In your case the scales would be the only thing lifting. I've learned to let my ivories dry at least a year and then it takes three weeks to do a final fit on a knife to prevent warpage.
 
Michael

I have only ever had one batch of epoxy "go bad" such that it never set, even after something like a week. I think that the bottles got roasted in my garage over one summer. The only other time I have seen epoxy not set was when my friend tried to glue a piece back on his model airplane using two parts from the same tube :rolleyes:

To know if the epoxy in the joint has set, without disturbing it and possibly weakening it, keep the unused part with the applicator around. When the applicator is firmly stuck to the mixing surface, the epoxy in your joint should be set too.

Phil
 
:) I use the K&G and have never had any problem with it. I just use plastic spoons and eyeball the amount. After putting the knife together I put it under a 100watt light bulb for a little while and then into a heated box around 90 degrees over night. Oh yea, after roughing the surfaces up with 60G and cleaning with acetone.
 
Good move
That's the right way. keep it warm as long as you can.
One other good thing about using a premium epoxy is that you have access to ALL the technical data. I see here in this thread that there is some mixing
of the terms set and cure. They do not interchange. The cure goes on for days and even weeks after the set. There is a MINIMUM cure temperature. Find out what it is from the epoxy maker. If the temperature falls below
the minimum cure temp. the cure ends. Raising the temp will not restart the cure. It's done and you lost the maximum strength the product could have given you.
I can aslo guarantee you that MR. Holbrooks epoxies are stronger than those that of you that do not use heat.
 
Someone said not to clamp too tight. I even bought some of the "no twist" clamps to rack them tight! What I discovered was that I was squezeing all the epoxy out of the joint.
Now I make sure of the fit and clamp with spring clamps only. Made a world of difference.
Lynn
 
Michael I'd suspect the epoxy is too old. Everything you're doing should result in a good bind. I've had epoxy that was a few months old go weak, so I'd consider a fresh batch, expecially if it happens again after you've checked out all the other ideas. I too use long-set stuff, the local Ace hardware has a 90-minute version that after 24 hours of curing will not come loose. No matter the brand of epoxy, I always leave it clamped 24 hours.

Good luck! There's hardly anything worse than grinding off a failed handle... :barf:
 
GrassHoppa; Did you glue them together in your cold shop then bring them in the warm house???? Bring it with you the next time you come over and we will experiment in my warm shop.
 
Your scales are changing with time, heat from grinding, etc in my opinion, or your surfaces are not flat. Think about it: if you have a perfectly flat surface on the blade handle and the scales, nothing should "lift". Work to get your surfaces flat before gluing. I say this ONLY because it has happened to me as well in the past. If your handle material is indeed lifting, then the scales are changing dimensions as they are heated up. This is a problem for me too with some handle materials....particularly with stag, bone, & wood that has not dried down. I have some materials that I grind on and they naturally get heated up in the grinding process...they will appear flat after grinding, but be warm or hot to the touch...when cooling down they will bow up on me...this could be your problem. When this happens I just let them cool down and take my time flattening them on out...got to force myself to slow down. I have found some woods require a long time to dry out as well.....got some beautiful olive wood from the Blade Show a few years ago...every piece bowed up on me...now I let it "season" for a year before I even work it.

Best of luck!
 
On some hard to glue woods it helps to do a wash and rubdown with acetone.
let the acetone evaporate before gluing, of course.
It removes the oils from the gluing surface of the wood.
I've done this with teak and was satisfied with the results
 
Well I have only made two knives so I'm not sure I should even be responding yet but I ran into the same problem with 5 min epoxy. My problem was that as I was trying to get everything aligned and the pins in place the epoxy had hardened enough that when I put pressure with the clamps, the epoxy was too thick to squeeze out everywhere leaving a thicker spot of epoxy and the handle 'lifted'. If I were to guess I would say that is what is happening because only two things could cause this. One, the handle is lifted from the get-go (what I think) or the handle is moving enough to push the clamp out of the way which I would think would require much more force than a little moisture warping the wood. Of course if after the epoxy is allowed to set overnight and it is flat and then once you start working the wood the handle pops up, I would say you let the handle get too hot and caused the epoxy to fail (yes I had just about everything possible go wrong in my first two knives :cool: ). Hope I might have been able to help. Good luck!
 
i'm using moose as handle material, the fit is great before the gluing and the handles arent actually popping up they're just lifting when shoeshine it witha shop roll.... the roll catches the edge and lifts it where it dind't bond right... well today i'm going out to get some better epoxy from the hardware store... the longest setting stuff they have... then i'llglue both handles up and see what tomorrow brings. thanks for the info guys it really helped
 
For mixing epoxy I use a medical medicine cup that I get from Brownells it holds 1 oz and has several different sets of measurements on it. works great and if you wash it out with vinager thy can be used over again. There number is 800 741 0015. If you don't have there catalog you need it. Gib
 
Thanks, Gib, for the tip! I gotta order some more Dichropan anyway so I'll get me some of those. :)
 
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