Testing for the ultimate adhesive

[tmickley]

The Boiling tests have just come in and the results are interesting.
I glued up 10 test pieces. One end was sandblasted, the other end was scratched with a fresh 36grit belt. I glued up a piece of wood to each end. This is the third test series. I haven't finished the second test series yet.

This test proves that knives should never be boiled for an extended period in time with
water and old turkey frying oil.

P=pass F=fail

Glue...............Sandblast.......Scratch
Super E.............. F................F
U-05f................... F..............F
Devcon2...............P..............F Devcon2 actually passed a test!
K&G Epoxy........... P............. F
E-120HP................P..............F
324 Speedbonder...F..............F
Acraglass..............F..............F
West System..........P.............F
Golf Shafting..........P...........F* Scratch passed until I pulled on it hard
T-88......................P.............F


ALL adhesives failed on the 'scratched' surface.
10 of 10 on the scratched surface failed.
Only 4 of 10 failed on the sandblasted surface. The sandblasted
surfaces were done with 70grit Aluminum Ox##e.

More important than the pass or failure of the various glues is the fact that
clearly surface preparation is critical to a sucessful glue up.

This isn't an end all test but combined with the other results to date, I'd suggest
that all things cons##ered, surface preparation is more important than
using the best epoxy.

Knife makers use a limited number of adhesives. I'd say less than
2 dozen different types of adhesives account for the vast majority of custom knives.
I am totally making these numbers up based on my knife making experience,
feel free to step with your guesses. All of these adhesives basically work.
Absolutely some are better than others but they all basically work. All of these
adhesives failed at significantly different rates with different surface
preparations.

My conclusion on this series of tests is:
Surface preparation is more important than the adhesive you use.


I invite any other opinions.
Sand blasting is the best surface I have found so far. If you aren't
setup sandblasting, I'd suggest you might add it to your 'tools to get' list.

[tmickley]

Additional failures on the 2nd series from the boiling test include:
Elmers Craft Ultra
U-05FL
Loctite Extreme repair (pulled off)
PC Super Epoxy

There are 4 adhesives left out of 17 on the 2nd test still hanging on, they are:
Gorilla Glue
Loctite E-120hp
K&G epoxy
Metal Epoxy (superglue brand?)

[justice]

dam i think i need to get me a sand blaster!!
surface prep does seem to be the key!

i think the glue companys would have a heart attack if thay knew what you guys where up to.

great update keep it up!



....justin

[TexasJack]

You know, I was having a pretty crappy evening up until I opened this thread. Not only d## I get more great adhesive info, I also laughed until I had tears in my eyes! Thanks, T.!

[DaveL]

Like everyone, I am interested in the final page but now I have sent some interesting stuff to Steve and curious about how it will turn out too. I hope it shows the best for the maker and why that is the opinion.

It continues though. I just saw a post on another forum asking what epoxy should one use and the answer, from the moderator was Devcon Two Ton, which is the "best" in his opinon.

Wadda ya gonna do........

[SteveS]

DaveL

Devon 2 ton - best compared to what?

I haven't started the next (last ?) test with acra-weld. Life, wife, and strife has gotten in the way again.

I was thinking of gluing samples to the lawnmover blade. Might be fun.

Steve

[justice]

I was thinking of gluing samples to the lawnmover blade. Might be fun

lmao oh that got me!!

i say we get a petition going and send it to all the knife supplyers that sell devcon so thay stop selling that crap!

...justin

[SKIVIE]

A lot of work has gone into this and its well appreciated.

Just to add to Tracy's Theory. I use devcon 2 for everything except full tang and I use jb weld for that. I too believe that Surface prep is the most important. Ive had devcon 2 fail misserably on a stacked full tang handle only because the surface wasnt prepared right. I dont make that mistake any more.

Oh and BTW. Something worse than a Golf ball to the gonnies.......the golf head to the gonnies. Yes ive seen that. The golf epoxy failed and on the backswing came off and nailed another guy in our foursome square. He too went home early and missed 3 days work due to swelling and tenderness.

DO NOT STAND BEHING A GOLFER WHEN HE IS HITTING ! Serious consequences.

Shane

[DaveL]

Since this thread keeps slipping lower, I wanted to post if to say nothing more than I remain curious about what the final analysis will say. I sent AcraWeld to Steve to use and hope it does okay but am now not sure of any adhesive I have used.

This was so good and to check it each day was really nice for me. Things I had never thought of were checked and either confirmed or discarded. Yeah, I love this thread.

So, for those, like me, who are now checking this, add a few lines to let our guys know we are really still here. Dave

[justice]

we are most definetly still looking! just d## not want to rush you guys


...justin

[SteveS]

DaveL

Just got back from Yosemite (life's tough). Other than that I've been busting butt landscaping. Daughter #3 is graduating from High School. She and her friend are having the celebration at our house. After 11 years there I'm finally putting in a lawn..... blah blah blah

Still planning on the JBWeld test. Right now I'm thinking of using 4 glues, with stabilized wood on one s##e and G-10 on the other. Not only will I get info on the glues, but will see how they perform on wood and resin materials.

We'll see!

That will be my last test. Tracy and I can print the final.

Shane, you really have to re-cons##er using DEVCON. Shafting Epoxy & K&G is cheaper and better.

Me? I'm still leaning towards E120HP. Even with the price.

Steve

[jjvenier]

I'm certainly still very interested and still reading this thread every chance I get. Thanks you guys for all your hard work and intrep## epoxy abuse! This is IMO right on for testing knife epoxies. Standardized testing like the ASTM does is good but it is very valuable to test them also in "real life" situations like you guys are doing, since the controlled testing results may not translate well to the application. Plus you have saved us all a lot of testing if we were to do it on our own. I was thinking the other day that if someone has a favorite epoxy that wasn't tested, maybe all he'd need to do to see if it stacks up is to test it against the top one or two epoxies -- which is still a heck of a lot less work and expense than testing it against all of those you guys tested.

Thanks again!

[DaveL]

JP Weld? Uh, probably good stuff but do you rememeber the AcraWEld I sent you?

Just checking....

[SteveS]

You're welcome John! And if someone does to the comparison I hope they share the info will all of us. You're right, shear strength isn't the whole story. Also, technology has changed a lot. When you find out they are gluing airplanes together, you know the adhesive companies are putting a lot of R&D $$ into it. Plain old resin epoxies just don't compare.

DaveL - typo on my part. I meant Acraweld - for sure.

Steve

[tmickley]

Steve, I'm ready to finalize most anytime you are ready to finalize. I'll start my write up and get it off to you along with any changes to the spread sheet. Look for them no later than a week from today. Have you any time to build any knives with all this world travel you've been doing????? I've been trying to learn to golf, what's your excuse?

To those that have been following this, thanks for all the encouragement. When this has concluded, and that won't be soon enough for me, Steve has announced he will be testing Mammoth Ivory and is looking for sponsors. Since I've started to dabble with folders and I seem to have an ample supply of little screws and such, I've dec##ed to test Black Lip Mother of Pearl and I am also looking for a sponsor. (The good stuff too, not that composite stuff made like particle board.) I am hoping that MOP stinks less than ivory when it is ground to thickness as mammoth stinks to all high hell.