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tmickley 03-12-2005 01:30 PM

This shows how the initial 'tap' tests are going to be done. 3 sizes of hammers, 3 taps on the edge of the wood block to give a sudden shearing force. Pictured is the smallest hammer. They all made it past this one. The middle hammer failed the contact cement. It popped right off on the first whack. All of them made it past the big hammer.

If you look at the edges of the wood, you can see where the wood has been crushed some from the tapping. They all took quite a thumping. I was surprise none failed at this point. Then I stuck the whole mess in the freezer for a couple hours and retrieved it. While still cold, I went straight to the big hammer and all passed except the Devcon 2 ton popped off easily. The epoxy stuck to the wood - as I suspect they all will - but was fairly glazed on the metal side. Inadequite surface prep? Could be but all the others held on.

I've already started the glue up for round two. Chuck Bybee of Alpha Knife Supply kicked in several pieces of metal and blocks of wood along with a couple of adhesives. Blatent plug -Buy stuff from Chuck, here's here and active on the forums.
I ran out of clamps!
I'm going to spend the next several days glueing up several more adhesives and then allow them to cure for a few days. Some of this stuff likes to have 3 to 4 days to fully set up.

Failures so far:
my wifes hot glue gun didn't even make it out of the gate
tanner bond contact cement - this stuff is awesome for leather though
Devcon 2 Ton - probably one of the most popular epoxies out there. I'm anxious to retest this one.

surprises so far:
those darn super glues held up past the big tap tests. I figured they'd pop right off.

several more cycles of heat and freeze. heat to 150 to 175 in my heat treat oven, then to the freezer for a few cycles. I'll tap those in a day or two. Then to the dishwasher for a few cycles. Tap again. Then I'm going to get serious if any are left. :evil

Helpful suggestions:
If you helpfully suggest to 'try this stuff xxxx, it really works well, it's what I use, all that other stuff sucks', send me some right away and I'll test it. I've sunk enough money into this thing so far. :eek:

Here's another helpful suggestion I expect to get, 'Hey, your methodology really sucks, you don't know what you are doing dumb ass!' all I can say is you are right. :p

Round 2 will be different, just not sure how yet.

One last thing, I'll be documenting this on my web site also with a few more pictures and maybe some different text than what ends up here. You can follow along there if you like by having a look Mickley Knives In Progress Area

Shakudo 03-12-2005 01:31 PM

Tracy, you seem to be missing the best epoxy made. and it's a local one from wayzata,mn. huges associates epoxy 330. i have things that have been glued together with it for over 20 years and show no signs of falling apart and it seem to have a shelf life of years. :)

tmickley 03-12-2005 01:40 PM

(this post should have been first in this series but it isn't... :rolleyes: )

This is going to seem like slow motion compared to Steves. I've just started and it will take a few days to get them all glued up and then some curing time. I'll keep posting as this plays out.

Here is some of the candidates. The tube of Weldwood contact already bit the dust as it was basically dried up when I went to apply it so I dug out some Tanners Bond contact cement to replace it. 5 kinds of dual tube expoxy, acra glass, jb weld, 3 kinds of poly glue - one of them is name the Ultimate Glue which I find a bit ballsy, some T-88, golfsmith shafting epoxy and what ever else I stumble onto in the next couple days.

Here is some of the poly's and contact in place. I used some wood burl stabilized by WSSI and some soft metal sheet I had laying around. I put a 40 grit finish on both the wood and the metal for tooth.

This blue stuff is marine epoxy. I didn't know it was actually blue until I cut the tube open. I thought it was just blue packaging for water. Who wants blue glue? Some of these guys need a little marketing lessons. Anyway, this pretty much rules this one out automatically but I'm going to test it anyway. It claims to cure under water. I didn't do that but it sure smells to high hell. It mixed up with a very different texture than the others also. The one thing I did see after mixing up all the dual tube epoxies was they all had a problem pumping out evenly. The idea behind the dual tubes is to meter out the stuff in the correct proportions. The only one that actually worked well that way was my fresh tube of Devcon 2 ton. The rest all sputtered or belched or leaked all over so I had to throw some away and start with a new mixing cup to get it to pump out evenly. One of the dual tube is called a metal industrial and is actually colored like metal. It will never match but it will help blend a little.

The epoxies I have left will have to be measured by hand so I left them for later to do.

SteveS 03-12-2005 04:15 PM

My first round of testing started off with bolting the sample bar to a 5' bar. I pivoted off the end and let it rotate to the concrete (with the end extending off the porch.) In 2 strike everything popped off. I think the problem was I had smooth stainless steel.

Well guess what. This time I used an 80 grit finish on the steel. 2 failures without any tapping or heat or anything. 3 days aging and these just popped off:

JB Weld
West Systems.

As you can see in the photo the epoxy held just fine on the dymond wood. Came clean off the steel!? Feel free to assume I did something wrong. The West systems is pre-measured. So that isn't it. The JB Weld is plenty hard and really on the wood. Came clean off the steel. You tell me why?

I know every epoxy I could find spec sheets on show much less adhesion to stainless, than carbon steel. Could this be it? I don't know.

The rest of the block was subjected to drops down a 20" pipe onto a block of wood - mild jaring effect. THen I did 'thumb' pressure and they are all still on there, fine.

I really don't know why those 2 failed.

Tracy, are you testing any hardened stainless?


Chris Daigle 03-12-2005 04:30 PM

Finally a good use for Dymondwood! :eek: :lol

Just kidding guys. I'm enjoying the results so far...


tmickley 03-12-2005 04:41 PM

Steve, I'm not testing using stainless. First batch I used mild steel, 2nd batch I'm using high carbon. I just can't see where it would make that much difference between hi or low carbon, or stainless or not. We need one of those metal heads to come and tell us if adhesive properties are different between the steels. Now if it was Ti, copper, or other totally different metal, I'd have to wonder about the test.

Are those pieces that failed at the very end of the piece of metal? Could the vibrations be a lot more violent at end of the rod than just a few inches in?

The more I think about this, the more I think the metal surface preparation is causing the bulk of the failures. The majority of failures leaves the metal slick and clean and the residue stuck to the wood. I believe this is all going to come down to how well the metal is prepped for the adhesive. I'm entitled to be wrong. It's probably too early to be guessing like this, at least in my tests.

SteveS 03-12-2005 09:08 PM

You might be right on carbon vs. stainless. The loctite sheets all have 'grit blasted steel' and stainless steel as two separate entres. I thought one meant carbon other stainless.

Shear Strength
'grit blasted Steel' = 4270psi
Stainless = 3350
Aluminum etched = 4800
Aluminum anodized = 2120

OK do you think maybe there's a difference between hardened and annealed? I'll bet there is. But it might not be enough to make a tangilble difference. Oh Dang I feel another test coming on.

RE: the vibration idea

That's a great theory but they came off before I did anything!?

They just didn't stick. The other adhesives are just fine. The same bar prepared in the same way.

Chris: hahahhahahahha Actually I had a block laying around - I've finally found a use for it!

Well I'm off to try the drop tests on concrete. If anymore come off, .....?


SteveS 03-12-2005 11:10 PM

The remaining samples didn't care how many times I dropped them down a tube, 12" to the concrete. It created a nice little jolt.

So the survivers right now are:

Loctite Xtreme

Just for fun I cleaned off the bar where the failures where with a 50 grit belt. Then I re-abraded the samples with a 36 grit. Then re-glued Devcon, JB Weld, and Gorilla Glue.

But I didn't do ANY washing. No simple green, no brake cleaner. I just want to see if the cleaners where part of the problem.


PS For anyone else that has had failures. Did the epoxy stick mostly to the handle material or the steel?

All of mine leave the steel clean.

SteveS 03-12-2005 11:39 PM

FWIW, I made a sample with E-120HP and JBWeld on mild steel. I used the same cleaning procedure as with the hardened stainless. We'll have something to compare now.


justice 03-13-2005 05:20 AM


The only one that survived was Gorilla Glue. That stuff, I believe, would make a great adhesive for knife handles. However, as it expands it makes an icky, stick foam. If it expands onto the ricasso, I don't I'd ever get it cleaned up. And you'd have to watch for a long time as it hardens. Once that foam hardens you have to grind it off to remove it.
i have used gorilla glue on handels(mabey 2) and once its dry you can cut it with a razor/utility knife. it cleans up fairly easy. if you are using this stuff make sure to wet one side of the piece to be glued together removing the excess water so that its just damp. i wet the handel slabs becaus thay are more porus then the metal. if you check on it a few times and clean up the bubbling excess its even easyer to clean after its dry.
another thing dont get it on your skin or clothes becaus its very hard to get off you once its dry.
i have made a cast like sheath with this glue(ugly as sin) using it and fabric to make a sudo micarta. it
seems very tough and hard as a rock(almost). its not nearly as strong as micarta from what i can tell but it is a very thin layer. it wont scratch usng my finger nail.
i was thinking about trying to make some flat slabs of fabric micarta with it. it should saturate the fabric very well since its foams up. what do you guys think?


The one thing I did see after mixing up all the dual tube epoxies was they all had a problem pumping out evenly. The idea behind the dual tubes is to meter out the stuff in the correct proportions.
i hate those things thay never work rite unless you are using the entire tube at that moment. but if you are stuck using this type of despencer i find that if you cut the piece of plastic that connects the 2 plungers. then push them one at a time you can messure it out easyer.
the devcon and the jb weld seem to clean up well using a wire brush wheel on the dremmel
jb weld sands to a light gray but it will darken very fast and the devcon seems to get yelloish amber after a few monthes.
super glue says it should be used one drop per inchand seems to help. can you do 2 pieces with one covering the entier area with the super glue and one with just a few drops? the i would like to see if it realy helps the bond.
just a few of my expirenses wiht some of the test subjects

by the way i love this test!! but i think each sample should be glued to there own individual piece of metal for the tests. i think we will find that each glue has its advantages and draw backs. mabey we need a thredd listing all the glues and epoxys used and every one add there expirenses with each one positive or negitive.listing tips to working with each one. make it an on going informational sticky thredd.

great thredd...justin

Coutel 03-13-2005 09:38 AM

Great ideas..

I thought I would tell you about Gorilla Glue that I am using....I use it on hidden tang knives only......It pours in to the hole made in the handle material easily....but the blade really needs to be clamped tight against the handle as this stuff expands a lot.

The good thing is that as it expands it fills all the gaps and pin holes you never even knew about. If you use it with stag, it will find its way through the porous sections to the surface....
Last week I used this glue to secure a piece of acrylic stabilized wood....The Gorilla epoxy managed to find some porous holes which were un noticeable and bubbled thru the handle!!!! when this stuff eventualy seals everything up well with no air gaps....It even found its way thru a solder joint which I though was perfect...there must have been a minute worm hole that I just couldnt see!!.

I needed to remove a handle which I had previosuly glued with Gorilla....I had to smash the wood under a 25 ton press....the glue stayed in contact with the wood and also stuck to the steel......It had to be ground off the tang.

DaveL 03-13-2005 04:07 PM

LocTite 330 is a very good glue for micarta handles but the shelf life is a problem sometime. It is one I would be curious about in the tests though

SteveS 03-13-2005 09:00 PM

Thanks for the updates and detailed information!

It's odd that my personal testing has moved away (temporarily) from the epoxies to the preparation methods. I've had failures that I don't think should have happened. I can't tap anything with a hammer like Tracy!

So what's the difference. The type and condition of the steel is one. Plus how the steel is cleaned prior to use.

I won't be suprised if we end up with something like steel. You know how we tell people, "Heattreating has more to do with performance than steel choice". Well I think we might end up with, "How you prepare the materials is more important than the epoxy choice" (Of course that's not the whole story, but it doesn't matter how good an epoxy you use is, if your steel is oily when you put it on.)

BTW In another test I found most epoxies shrink on curing. IF you have large gaps under your slabs, the epoxy will actually pull away from the steel as it cures! JB Weld, acraglas, we the only epoxies I tried that didn't. Gorilla glue and U-05fl both expand. Something to think about!


markd 03-14-2005 08:11 AM

*markd puts a dollar on jb weld*

TexasJack 03-14-2005 12:04 PM

Years ago, I worked in the research lab for a pipeline company. (Back when those companies actually did research.) One of the groups did a lot of coating testing. How does that relate to adhesives? Well, good coatings are also good adhesives.

Some of the tests they ran:
- small pieces of pipe were coated and put on a carosell with a mercury street light shining on them. That gave them the equivalent of years of sunlight exposure in a few days.
- Pieces of metal were coated, except for a corner or tab, and a very small hole was drilled into the coating. It was placed in a brine solution and connected to a dc power supply to make the pinhole corrode. Then the plate was removed and an "X" cut across the pinhole. The tech would see how far back the coating would peel from the hole.
- A spinning wire brush was used to bombard pieces of coated metal with gravel and concrete
- Coated metal was bent to see how the coating stuck under stress

After years of testing coatings - and every new coating that came out - it was determined that underground piping should be coated with epoxy and aboveground piping with urethane coating. (Epoxy didn't hold up as well in sunlight and was more susceptable to mold damage. Epoxy 'stuck' better under stress.)

Another thing that was a big factor was mixing those '2-part' coatings. A bad mix ruined an otherwise good coating.

From all this I would say that I'm not surprised at some of the conclusions so far in this test. There are many factors in play with adhesives. (Color, for example, could be an important one in some cases.) No adhesive will overcome bad preparation - of either the glue or the surfaces. Some adhesives will not hold as well in a thick layer as in a thin layer. (Epoxy does well thick; acrylics don't.) Water resistance claims are often useless (as has been pointed out.) Shrinkage (epoxy) and expanding (urethane) seriously affect the application.

Just my 2 pesos! I look forward to more results!

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