Glue Wars 2

T

tmickley

Joined
Apr 4, 2001
Messages
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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.

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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.

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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.

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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.
 
Here is the list of adhesives I am going to beat until they fail.
2 part epoxies
T-88 2 part epoxy
Clubmaker Shafting Epoxy from Golfsmith
Acraglas
JB Weld
Devcon 2 ton
Devcon 5 minute
Super Glue brand Metal Epoxy
Anchor Tite brand Marine

Super Glues
Loctite 416 superbonder 41650
Handibond Rubber Toughened Super Glue

polyurethanes
Elmers Probond
Gorilla Glue
Elmers Ultimate glue (looks identical to Elmers Probond)

others
Tanners Bond contact cement
3M Hi-strength 90 spray adhesive
my wifes hot glue gun

Some others I just found in some local stores that I will be trying out
loctite contact cement
Super Epoxy by PC Products
PC-7 epoxy paste by pc products
All Purpose Welder
Liquid Nails 2 part epoxy Perfect Glue 3
Elmers Craft Bond Ultra Stix All
 
smalltap.jpg


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.
bigtap.jpg


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.

test2glueup.jpg

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.

coming:
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
 
Looks 'good to go' to me. Only one suggestion ....when I glue up a knife, I wipe the edges as clean as I can get them, cleaning off any excess that squeezes out. On some of your test subjects, I see globs of glue that have squeezed out around the edges, the Gorilla Glue is a prime example. I'm thinking that a big bead of hardened glue around the edges of a sample could give a product an 'edge up' over it's competitors, particularly on the hammer test. Maybe it would be more uniform if any excess glue that squeezed out the edges upon clamping was wiped off before it hardened.
 
Jiminy, good point. The poly glue really foamed up but not right away and by the time I noticed it, it was too late.
 
After 1 cycle of heat at one hours at 150F, then freezing, then heat for 1 hour at 175, then freezing, we have two more failures tonight.
The 3M spray adhesive (held out way longer than I ever thought it could) and the rubberized super glue. I think the rubberized super glue holds better at room temp, at freezer temp it seemed to be quite a bit harder at freezer temp and it just seemed to 'shatter off' when tapped. The tap is 3 solid whacks with the big hammer on the edge of the wood trying to shear it off the metal. The remaining adhesives are holding much better than I thought they would with the whacks they are getting. I'm going to do one more heat, freeze and whack cycle and then move on to some other kind of destructive test.
 
I glued up a couple more things today. One I used was called PC-7, a 2 part paste epoxy. It comes in a little cans like 1/2 pints of paint or that wood putty used to come in. The colors look like and mix up to the color of JB Weld but with the thickness of plumbers putty except it is a lot tackier. This stuff is very thick and looks like it would go on like laying a welding bead. I knew right away it was not appropriate for handles or even sealing bolsters since it is too thick and would not squeeze out. It is very interesting stuff and I was immediately looking around for *something* to use it on. I settled for glueing up a few test pieces of metal, 1 set sand blasted, 1 set roughed up with fresh 36 grit, 1 set just as it came. I hope to test which surface prep will provide more tooth, the sand blasted or the 36 grit, the plain will give me some idea to compare to. When you need to epoxy something together with a mechanical lock that is the consistancy of thick toothpaste, this is the stuff. If epoxy can be cool, this is cool beans. Won't work worth a damn for knives, but it looks fun to use on something.
 
Tracy, I really enjoy your tests! Your pictures are great, too. I'm looking forward to seeing your final tests and conclusions.
 
onebroken.jpg

One broken to failure piece, one not yet tested. Three of these were constructed using PC-7 epoxy (which is amazing stuff) to test what affect (or is that effect? I can never keep those two straight) surface preparation has on a joint quality. One set had no surface prep, one was sand blasted and another was roughed up using a fresh, sharp 36 grit belt.

loadtesting.jpg

Here you see the load test. I added 25lb bags of lead shot. Here is a picture at 50lbs where the metal is actually bending under the load and the joint is still holding strong. The size of this joint is maybe 1&1/2" square. I was really impressed with this PC-7 stuff. Maybe all the others would have held just as well. I may do a couple more tests to see but I was still impressed. All three held 75lbs, all three failed as I added another 25lb bag so I never was able to accurately measure, by weight, how much each surface held but we can still draw some valid conclusions I think.

loadresults.jpg


The joint to the left is 36 grit, the middle sand blasted surfaces and to the right no surface prep at all. Starting from right note one piece ended up with most of the epoxy and the other piece had maybe 50% of the surface with epoxy residue. In all three cases, the epoxy failed, not the material, but in the test pair on the right, the adhesion partially failed by not sticking well to the metal. The left pair shows fairly even epoxy failure with 10% or so adhesion failure. The center test shows very even expoxy failure with no adhesion failure visible. The residue coverage was very even on both pieces. The conclusion we can draw is that sand blasting a surface is clearly the best method of surface preparation followed closely by a good, even ‘scratched up’ surface from a new, sharp 36 grit belt. I’ve been using a 36 grit belt but going forward I will be using the sand blaster to surface prep any where I can for better adhesion performance.
 
"The conclusion we can draw is that sand blasting a surface is clearly the best method of surface preparation"

Great test Tracy! Well done. I agree with the conclusion. I'm thinking of investing a few $$ in a hand held blaster just for this purpose. Quick and easy. Probably faster than all the crap I've been going thru.

BTW did you just wipe off the blasted sample?

Steve

PS Found one: $14 http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45998
 
Devcon 5 minute half fails.
I pulled my test piece from my heat treat oven that is in my cold garage. The last heat cycle was 175F for one hour last weekend and since then it's been around 20f to 40F in my garage. I took it and whacked them all again -- which I'm starting to enjoy -- and we had half of a failure. The Devcon 2 Ton failed early, today the Devcon 5 minute half failed. Just about 1/2 of the test piece of wood broke in half and popped off aftera couple whacks.

The ones people have been rooting for, Acra Glass and shafting epoxy still look very good. The wood is getting pretty chipped up the rest are still holding strong. So far, if you can manage the mess, gorilla glue looks pretty good between both Steves tests and mine.
Personally, I'm rooting for shafting epoxy.

I just put the test piece into the dishwasher. I'll keep you posted.
 
I should have gotten a picture of this because it was amazing. The Loctite 324 speedbonder test piece between two metal strips held 100lbs! This was glued up like the sandblast vs scratched test pieces posted earlier. All of the others failed betwen 75 and 100lbs. This stuff held 100lbs and the metal started bending to nearly 30 degrees. I think this would have held until the metal bent completely over but I started moving it around and the bond broke. I immediately glued up another piece so I can verify it and get a picture this time. It is unfricking-godly expensive at $14.66 for 1.69oz or $200 for 33oz :eek: and then it requires an activator for another $20.


Here is a description from www.McMasters.com

For parts requiring high-strength adhesive and jobs requiring high impact resistance. Begins to harden in 5 minutes. Shear strength is 2175 psi. Fills spaces up to 0.040”. Temp. range is -65° to +275° F. Note: Adhesive must be used with Activator 7075™
For nonporous surfaces like magnets and mirrors to steel housings
 
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Last week I left the test piece in my heat treat oven for 1 hour at 175F and there it sat all week. It’s warming up here in the spring so the garage has been in the 20’s and 30’s. I brought the piece in to whack it. The Devcon 5 minute epoxy half failed. You can see 1/2 of it broke off, the other half is still hanging in there. All the others took the beatings. Then I threw the whole thing in the dishwasher. This is where I had to explain what I was doing to my wife. Even with all the goofy things I tend to do, she knows better but this one still forced her to ask why I was doing this (it's her dishwasher you know). "To see which one holds the best" was my answer. After the dishwasher cycle, I took the piece down and whacked it some more. Keep in mind, this is all with a large framing hammer and I have long since stopped tappjng these things I am giving them 3 or 4 good thumps each time. Two more failures to report, the Permatex and T-88 epoxies both fail. The Permatex came loose in the dishwashwer, the T-88 got tired of getting beatings and gave up.


t88fails.jpg


The T-88 failed by 3/4ths. A quarter of the test piece is still attached and I’ll leave it that way just to see how long it goes. The most usable leaders at this point are Acra Glass, Golfsmith Shafting epoxy and oddly - metal superglue. The polyurethane glues, I believe will with stand all of the tests better than any of the others but it appears to be a horrible product to work with on a knife - it’s fine for wood working. On the other hand, maybe it's time to focus a bit on the polyurethanes a bit more. The drawbacks to the poly glues are, they cure a light brown or dark honey color; it really expands, you'd have to really clamp it down, but then who doesn't have plenty of clampls for one knife handle? Then you need to ask, if you clamp it down very firmly, does it still have the holding power? I bet it does. I'll have to test that... For the money, ease of purchase, general availability, toughness to date in all of the tests, the polyurethanes are looking very competitive. Be warned, if you get any on your fingers you will have stained hands for days.
 
Well after testing 3 glues with grinding and no cleaned I can confirm simply green/brake cleaner was the problem. The stuff held really, really well!

The three where

DEVCON (gave up after a trip thru the dishwasher and one imact test)
Gorilla glue (needed a hammer to knock it off)
JB Weld (It would not come off. The hammer complete destoyed the dymond wood and the glue bond never broke. Had to be ground off.)

I've started a new test bar. This time sanding with 50 grit and sandblasting was the prep phase. No washing.

Steve
 
Wish I had some to send you, but you ought to try Bob Violet Models Aeropoxy. It's a cream colored thixotropic aerospace grade adhesive. It's a variation of Hysol.
We used this stuff in radio controlled jet aircraft, that travel well over 200mph. It will bond anything. I've had it bond slick parts together, with no prep at all.
In addition, if you add "milled fiber" to it, the glue joint is WAY stronger. Almost unbelieveable.
I wish I had some to send you. It's the strongest epoxy I've ever used, and we've use a TON of them in the R/C world...
It's a VERY high quality glue kit, that comes with a gun, that mixes the glue for you (the gun WORKS perfectly too).
Anybody got some of this stuff to donate?
I'm all out, and don't fly r/c planes like I used to anymore.
 
Razer, I'd like to try some of that stuff if you ever stumble onto any.

In the mean time....
The body count rises...

boiled.jpg


After boiling for a little over an hour (that is a highly scientific term that means about a hour or so) we had some failures. JB Weld that is supposed to be good to 300F plus took a walk. Super Glue Metal epoxy failed. There was 1/3 of a piece held by T-88 that gave up and Devcon, the epoxy we all love to hate now, had 1/4 of a piece left that fell away. The just fell off, no whacking needed. All the others were whacked because at this point they expect it and I think I'm starting to like it.

Whats left: all three poly glues. (I know, I'm sick of them too) but ALL THREE POLY GLUES, Acra Glass! (Huge cheering from this bunch), Golf smith shafting epoxy (my new favorite) and the blue marine epoxy. If you have anything that is in the water a lot and needs to be epoxied, the blue marine stuff is the way to go. If you are making a weird looking knife and need blue liners, the marine stuff is the way to go.

So, what tests can we do now? Any ideas?

So back to the poly glues. Here is that picture of a glue up using Gorilla glue. I clamped it in scientific terms again, real good. It did not expand to make an uneven glue line or even exposed glue line. There is no glue line, if you think you see one in the picture, I assure you, you do not. Does it hold? I beat the heck out of this piece, it is still holding fine.
(I belive I am getting a little punchy from this stuff)
noglueline.jpg
 
If I wasn't tapped out, from buying knifemaking tools right now, I'd send you a bit of the Aeropoxy. You would like it.
I was also wondering if you are "moistening" the mating surfaces before using the poly glues??? I remember that these glues required moisture to obtain their fullest bond strength...

Just curious...
 
razorhunter said:
...
I was also wondering if you are "moistening" the mating surfaces before using the poly glues??? ..
Click to expand...
yep, i am. moistening between metal pieces doesn't work, at least one piece needs to be wood. same thing for micarta, it just doesn't hold moisture to get the poly glue to kick off.
 
Perhaps this has already been addressed and I missed it in my fog:

While reading about Gorilla Glue on their website, I noticed that they recommended "something other than poly adhesives" if one is going to use oily woods. Specifically, they mentioned cocobolo and kingwood. They basically said the wood will not hold the necessary water and also the adhesive won't penetrate enough to grab well because of the oils. This leads me to think that polyurethanes may be great in some cases, not so great in others, considering the oiliness of so many of the woods we use.

Sounds like it would be awesome for stick tang antler handles if it doesn't exert sufficient pressure to split it during the expansion/cure.

Just a couple thoughts....
 
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