Testing for the ultimate adhesive

[robwil]

I had hoped when I started reading your post that in your collection would have been a product called CONAP epoxy available from Angus-Cambell in California, but alas, it was not. I suppose you will get a hundred or so emails just like this, but don't be undaunted, it will be interesting to see what you find.

[DaveL]

Robwil, I think you hit it for many of us. I sent AcraWeld for a look see and am somewhere between worried at its performance and thinking it should have been looked at, recognized for its supreme capabilities and then wondering how these guys did what they have done. I am sure many of us could and have talked about adhesives we have used with good results, but are not included. Alas, this test could go on forever I fear. And by the way, we will be here if it does!

[fitzo]

I would say the commendable work done by Tracy and Steve should be used as a guide for us to be subsequently testing our own favorite adhesives. Once they "publish" their conclusions, we will be able to select one or two adhesives from that list to use as benchmarks and test them ourselves versus our favorite(s).

Possibly the most valuable lesson to come out of their labors is that *surface preparation* is as critical as the adhesive itself. That further necessitates that we all test ourselves to verify our own methods.

Thanks guys for all the effort you've freely given!!

[TexasJack]

This is scary, but once again I agree with Mike!

If nothing else, they've demonstrated the importance of surface prep, including using the right degreasers. They've also demonstrated that it is important to get past the hype and to watch how the products behave under stress.

In the coming years, new adhesives will hit the market. Some will be genuinely new, some will just be repackaged. Some will work great in one set of circumstances and fall apart in another. But the basics of good surface prep, proper degreasing, careful mixing (if required), and close attention to shelf life will always be valuable.

This round of testing identified some commonly used epoxies that are not as applicable to knifemaking as many of us thought. And we had a couple of adhesives that were surprisingly good. It isn't necessarily the quality of the adhesive, per se, but rather the applicablity of that particular material to the range of stresses common with a knife handle. Adhesives don't just stick things together; They also have properties of flexiblity, the ability to fill gaps, water or chemical tolerance, heat resistance, etc.

Hopefully the final report will show a range - with high performers on one end and low performers on the other. Like with steels, there is no single "best" - just a range of those that will do a particular job well.

[tmickley]

Mike, I sure do hope some one steps up with an adhesive they test against what was tested here and comes out on top. That'd be great for all of us.

Jack, you make some of the very points I have in my first 'conclusions' draft. Steve has it now and will be reviewing it as soon as he and his wife get back from their vacation
Saturday -- again. (It's good to be Steve. )
Steve has some Acraglass Weld one of the forumites here sent him to test so he is going to test that and then we will make our conclusions public.

I have decided to test Gold inlays next so if anyone has any gold wire, chain, bars or gold filled teeth laying around, please forward it to my address immediately so I can cash it in and buy more tools.

[TexasJack]

I personally think that's a great plan (the gold thing) and am only upset that I didn't think of it first.

I hope that you and Steve don't think folks are being critical with their comments. This thread has a very appreciative audience - both for the technical findings and the entertainment value. (I particularly like the "whacks".) You've stimulated a following second only to the infamous Toastcutter Contest. And, like a contest, we're anxious to see the results (whenever Steve can fit it in his busy leisure schedule)

[tmickley]

Sorry for the slow reply, I was on a business trip.

I've not any problem at all with any of the comments. Honestly I am amazed that the whole thing hasn't raised a lot 'anxiety' with some when their glue fails or ultimately if it's not 'one of the chosen'.

As for the whacking, well, what can I say. It's healthy.

[SteveS]

Results are in from my final test. Here's the parameters:

4 'glues'

Acraweld
K&G
Acraglas
E-120HP

The test bar is ATS-34, fresh ground with 60 grit, freshly sand blasted, no solvents.

Each glue used Dymond wood and G-10.

The bar was assembled, given 36 hours to cure. Placed in the dishwasher for a week.

Removed from the 'environment' chamber and subjected to my impact test (Bolted to a 5 foot bar of channel steel, pivoted and allowed to fall to the ground - wack! without the test bar hitting anything.)

Several wacks and nothing came off. Great news!

Tapped on each piece with a large screw driver.

Acra-weld/dymond wood failed

Continued imact testing.

Both K&G samples came off.

Clamped bar in vice and proceeded to coax them with a 12 oz hammer - light blows.


100 blows each

100 blows each -

Some where in there E120-HP gave up.
at 90 the second Acra Weld sample gave up.

---------------------------------------
Now there are just 2 left: Acraglas (wood and G-10) and E-120 (G-10).

Boiled in water.

Acraglas Gel/wood failed.

The Acraglas Gel/G10 and E120/G10 samples will not come off. Hundreds of blows with a 16 oz hammer.

-------------------------------------------------

Lessons:

* With sandblasting this is the best Acraglas Gel has ever performed. It usually gave up on impact testing.

* I've tested a lot of E-120 and it never gave up on dymond wood before. So, I guess sometimes it's gonna fail.

* Acraweld - performed very well and K&G performed very well. The K&G was perfectly measured using a reloading scale. But both proved to be less than acraglas gel and E120.

* Acraweld was mixed by sight. Might have performed better if measured. Still it held G-10 just fine for a long time, so I don't think it was mis-measured. It just doesn't hold dymond wood as well as the others.

* G-10 stays MUCH better than dymond wood. Even after boiling in water. If you are building knives for extreme conditions avoid even dymond wood.

-------------------------------------------------------------
All the of the samples did better than my initial testing. Freash sandblasting is the way to go!

Steve

[DaveL]

Thank you Steve for a great report, at least so far. One thing that should be obvious is that the adhesive used now is in most instances, going to be fine. These tests are the extreme of all and certainly tell the story but is a long way from some guys handles falling off in normal or even a little more than normal use.

You guys are doing such a service. This is the most awesome site on the web and I will forever be grateful for your work. Dave

[SteveS]

Dave,

I wouldn't worry about using Acraweld. That's for sure.

Still for ease of use and strength - E120-HP is the ticket.

Steve,

PS - I'll ship your acraweld back this week - thanks!

[tmickley]

I've been gone for a bit.

Steve and I have both been busy with non-knife life but we are now back to conversing via direct email to finalize and release our findings. It's all going to be a bit anti-climatic since if you dig through this thread and ponder awhile, you can pretty much come up with the conclusions we have. In any case, it's still coming. Drum roll.....

[justice]

dam this is a long drum roll! lol
i cant wait to see thre results!

..justin

[canyonman]

Originally Posted by justice

dam this is a long drum roll! lol
i cant wait to see thre results!

..justin

Drum is still rolling?

Larry

[justice]

hey guys what happened?


...justin

[tmickley]

I think Steve has been very busy and it may not change for a bit so I will post the results I have so far this Sunday. My results will include a small blurb and a spreadsheet. I have no idea how to host this spreadsheet on my web site for downloading. If someone can give me a pointer or two on doing this, I'd appreciate it. I am using a wysiwig editor Netobjects Fusion to put up my site.