Gorilla glue vs Epoxy?!?!?!

Pedro G.

Well-Known Member
I was wondering if there is a difference between gorilla blue and epoxy?
I have a bottle of gorilla glue and a bottle of 5 minute epoxy.... well it says 5 minute epoxy but it says it takes 24 hrs to completely dry.....
I don't know which is better for knife handles and what is the difference. I only bought the epoxy because thats what I see most knife makers use but when i tried it and i waited like 3 hrs, then I tried to saw off the mild steel pins on the handle with a hacksaw which shook the whole knife and the glue came appart so i stuck it back together with a pair of locking pliers and im hoping that in 16 or so more hrs it finishes drying..... sorry for the long story but my question is what is the difference between gorilla glue and epoxy and which is better(of the ones I have because I can't afford anything else atm. :)

Thank you,
Pedro :)
 
if 5 minute epoxy takes 16 hours to cure, it's gone bad. I know the package will say full cure in 24 hours but it should take just an hour or so in real life for 5 minute stuff.
Epoxy will go bad with time. So will Gorilla glue. The difference is the Gorilla glue will get hard so you know it's bad.
Gorilla Glue will "out hold" most epoxies but there more to it than just that.

The best thing you can do for the best bond is to spend your time on surface preparation...The best glue will fail with poor surface prep.
 
So how do I do surface preparation? Do I rough it up or smooth it out?
Also I still am not completely sure which is better in my case? And the epoxy is brand new, only used the stuff once a day ago, the gorilla glue i haven't had for more than a month or two.
 
I look at the links these fellows posted and say, "Why not read them?" All your questions will be answered there 2thumbs.
 
I use a Devcon Epoxy. The one I use does not get rock hard. When it is cured, it still has a little elasticity. With heat and cold, moisture and dry it has a little give ( thermal/moisture groth and cold/dry shrinkage). Stuff (in my opinion) that cures rock hard will over time crack and give up its hold.

This stuff works for me. It may not work for others. You need to find an epoxy that you are comfortable working with and get that warm fuzzy feeling about. Go to a knife supply site and look at the sellection of epoxies they have. These work or they would not sell them.

Again this is my opinion!!! Gorilla glue has it's great place in life......just not on any of my knives!!!!!!
 
So how do I do surface preparation? Do I rough it up or smooth it out?

If you can't seem to find it, you want it rough. It gives the epoxy something to grip on to, instead of a flat surface. Scratches even from 80 grit paper help hold much better than 1000 grit glassy smooth finishes.
 
Have you ever seen a road surface that they prep for re-surfacing?
Before they lay down the new surface,they 'scarify' the old surface,and one reason for that is to create a surface that the new material will be able to bond to securely...
same principal applies to knife tangs and handles.
 
So how do I do surface preparation? Do I rough it up or smooth it out?
Also I still am not completely sure which is better in my case? And the epoxy is brand new, only used the stuff once a day ago, the gorilla glue i haven't had for more than a month or two.

the best surface prep is to clean any oils and then sand blast both surfaces. The glue industry uses sandblasted parts to test the adhesive performance. If the glue people use it to measure the best performance, that would be the way to go.
 
I've used some of the speedbonder stuff, and may switch to it full time eventually. maybe.

I avoid 5 minute epoxy like the plague. In general, it isn't as strong as the slower setting "60 minute" epoxies.

I use, on a regular basis, both gorilla glue and the 60 minute epoxy Tracy sells. (I think I'm the reason he stocks it at this point. I need a case discount!!!!!)

notes and observations over time:

Gorilla glue expands but is NOT GAP FILLING. The expanded foam isn't without strength, but it's not designed as a gap filling adhesive. and it's not fun to look at. With gorilla glue you want as close to perfect a fit as you can get. I generally have surfaces for gluing at about 120-220 grit.

Gorilla glue is fantastic stuff for natural woods, cloth based micartas seem to like it, and the spacer material Tracy sells as well. I've had NO problems with hold on oily woods such as ipe and cocobolo.

Gorilla glue is water curing. The trick here, with natural woods and the fiber spacer material, is to mist the surfaces and glue up, clamp TIGHT TIGHT TIGH all over, I'll often puzzle 7 or 8 clamps onto a handle. Stick it in a dehydrator or heater vent outlet or something for 24-48 hours. the glue doesn't need that long, but it keeps the wood from wanting to warp and gets it completely dry for an oil soak (or whatever you do).

My surface prep for gorilla glue and epoxy is pretty much the same- soap and water on the blade and any non absorbant synthetics. lots of it. and then more hot water on rinsing. and a bit more.

for woods and such a final wipe on a clean piece of 120 grit clamped on a flat plate. Some oily woods I'll wipe with an alcohol rag after that.


The epoxy is funny stuff. above about 85 degrees "60 minute" epoxy gives me 5-7 minutes of work time.

I always let it cure for 6 hours in a dehydrator set to 105 or so, and sometimes I do that for 24-48 hours if I'm dealing with wood and want to make sure my shrinkage and warpage tendencies are taken care of. generally I set myself up so I won't be touching the knife until the following day, so there's at least 16-24 hours of curing time. But I've worked it after as little as 6 hours with no problems.


With gorilla glue, the tighter the clamping the better. With epoxy you don't want to do that. loosest clamping that will hold your even assembly lines.
 
5 min epoxy in hot weather does not give you much working time. I found I just could not mix completely and get the knife together before it cures too much.

As an experiment I tried gorilla glue on a kitchen knife with buffalo horn. I drilled the full tang for pins but never installed them so I could evaluate the glue. A year of daily use in the kitchen and the handle is still fine. I have no problem using gorilla glue.
ernie
 
Wow I never would have thought Gorilla Glue was any good for anything other than shoes.
Learned something else today...

When I first started making I did some tests with Devcon 5 min , Devcon 60 min and the Ace Hardware brand 60 min. 3 full tangs , all with Dymondwood slabs. All were prepped the same. All cured for 24 hrs. The Devcon 5 min held the best. I beat them on the steel workbench , then hit them with a ball peen hammer to get em to break off. The 5 min was all still stuck to the blade , just the wood broke off. The others were almost as good , but I've been using the 5 min ever since , with NO problems. I clamp TIGHT TIGHT TIGHT too.

I think blade and scale prepp are a huge factor in this as well.
 
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