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SteveS 03-11-2005 03:17 PM

Glue Wars
tmickley and I love everyone here. But, there are different factions among us. "What?" you say. "How can that be?"

The difference is adhesives. We put our faith them. We trust them when the chips are down (or the pins are loose). And we follow our favorite blindly, never having the time and money to try the vast array that?s available.

So, Tracy and I have set out to dispel the myths. To end the dispute or maybe we just want to stir up the pot :).

Tracy and I are testing a variety of adhesives (not all epoxies) to see, as best we can, which ones will hold up the best for standard knife construction.

Please note we?re not about to compare HOW to construct a knife. That?s a religion of a different color. We?re only setting out to see how certain adhesives perform under a variety of conditions. For example, one adhesive might have better shear strength or peel strength than another. But it?s thick and ugly and no one would use it on a knife. One might hold well at room temp, but fall apart in the snow.

Because we?re testing epoxies and not methods, we?re using blocks of whatever simply attached to steel ? no bolts, no peening, no hidden pins, just epoxy testing.

Tracy and I are also using different methods and tests and conditions. I believe this will help evaluate the results.

Given that, let the games begin! So, belly up to the bar and place your bets!

And may we all learn a new thing or two.


SteveS 03-11-2005 03:26 PM

So here are my contenders:

1. Loctite Xtreme
2. Loctite U-05FL Flexible Commercial Adhesive
3. DEVCON 2 Ton Epoxy
4. Loctite E-120HP
6. Acraglas Gel
7. West Systems Epoxy (10 min Pot life)


I 'glued' the samples to a single bar of ATS-34 hardened to 60HRC. The bar was roughed up with a new 80 grit belt. The bar was then scrubbed with Simple Green, then sprayed down with Brake Cleaner.

The samples are dymond wood abraded with a 36 grit disk.

The clamping was done with hand clamps - loose enough that the block could be slid underpressure fairly easily.

This was done on Tuesday, March 8th at 9PM. Curing started with a light bulb over the sample to keep it warm over night. It's been at room temps since then (68 to 80).


chrisinbeav 03-11-2005 03:30 PM

There is one adhesive I would like to try. It's made by a company called Fusor. Typically they make autobody adhesives not knife adhesives. There is a particular one that is for panel bonding. (panel bonding...the adhesion of outter non-structural or semi-structural parts body parts)
I figure if this adhesive is crash tested, which it is.... shouldn't it work on a knife? The only problem... it's kind of a pale green color when dried and it has micro beads in it. The beads ensure a layer of adhesive between two panels. It might be a bit too thick though for custom knife tollerances.

Chris Nilluka

SteveS 03-11-2005 03:31 PM

Thursday, March 10th 10pm.

I ground the samples flush with the steel. By evaluating the glue lines I've found:

1. Loctite Xtreme:

It's a thick gel like stuff. Hard to get smooth coverage. It needs a good squeeze. But the glue line looks fine.

2. Loctite U-05FL Flexible Commercial Adhesive

This stuff is a urathane (sp?) adhesive and bubbles/expands while it cures. I've used it before and learned it requires heavy clamping to keep the glueline looking good. With light clamping the glue line doesn't look so hot.

3. DEVCON 2 Ton Epoxy

Glue line is fine, but under microscope there some tiny gaps on one side - and I mean tiny. Maybe I didn't apply it perfectly right there at the edge.

4. Loctite E-120HP

Looks fine.


Leaves a thicker glue line and is visible on one side. It's thinner than I thought it would be, but will probably always show something if used for handle slabs. It's visibly not the color of stainless steel.

6. Acraglas Gel

Looks fine.

7. West Systems Epoxy (10 min Pot life)

Looks fine.


SteveS 03-11-2005 03:46 PM

Oh Yeah, I forgot to note. In a previous round I tried silicon, a commercial super glue, and Gorilla glue. 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.

So, it's off my personal list of usable products. If you can deal with the mess, I'll bet it'll make a great glue.


Chris Daigle 03-11-2005 03:53 PM

Steve, in your photo you show a bottle of Gorilla Glue. Are you going to include it in your testing? I had always wondered about that stuff and their claims.



EDIT: you just answered my question! :lol Thanks.

tmickley 03-11-2005 04:27 PM

I have three kinds of polyurethane glue, including Gorilla glue, curing now. I'll start posting some pics and progress this weekend. Steve has done one round of testing already. He's on round two. I'm on round one. Chuck Bybee sent me some metal and wood to use for round two. Currently I have 15 kinds of adhesive curing now.
Here's a starter pic with part of the first batch:

Ray Rogers 03-11-2005 06:23 PM

I think this is a great test and look forward to the results. Thanks for doing this.

If you get the chance, try some of K&G Finishing's house brand of epoxy. I've heard some say it is similar to acraglass. It's ivory colored, quite thick when mixed, and incredibly strong. The only downside to it is that it must be mixed by weight rather than by volume....

SteveS 03-11-2005 10:18 PM

Ray, You're welcome.

I'm having way to much fun with this and it's nice here in CA. Tracy.... well he doesn't have anything better to do this time of year ;)

I can't wait for the results to start coming in.


ragnik 03-12-2005 07:12 AM

Great test guys...I am anxiously awaiting the results!! On a side note....I have read of some folks using golf club shaft epoxy or glue...anyone ever try that stuff....supposed to be real tough...which makes sense since they are attaching golf club shafts to the club heads. Just a thought.


Ed Caffrey 03-12-2005 08:32 AM

A few things to think about when considering the adhesives are:

1. What is the shelf life of the product? (most of the "epoxies" are only 6 months) If the shelf life has expired the two parts will not mix properly, giving you only a fraction of the advertised "hold."

2. What is the "hold life" (how long before the adhesives starts to chemically break down after it has been mixed and cured)

3. The adhesive's ability to tolerate moisture. (I found that the devcon "waterproof" is not really waterproof)

It's no secret that I prefer the standard Accra-Glass, mostly for the reasons listed above. If the testing lasts that long, I suspect you'll find it doesn't reach it's full hold strength until about 5-7 days after it's applied, but if the testing were to go on for a number of years, the 50/50 mix epoxies would start crumbling and falling apart at about the 4 year mark. Put them in direct sunlight, and that time would be reduced to about 1 year.

Maybe I just look at it differently, but for me it's not the inital "hold" that sells me on a given's whether or not it's going to be holding 5-10 years down the line.

I'm looking forward to seeing how the results of this test come out.

Ray Rogers 03-12-2005 08:56 AM

I agree with Ed's points. That's why I like the K&G epoxy. So far, I've repaired a mirror on my Jeep with it (so it's in the sunlight and weather), used it to seal a cracked cast iron fuel pump on my 50 gallon gasoline storage tank (outside, in the sun), sealed up a massively cracked water pump housing on a 2 hp gas powered water pump (works great now), and sealed the argon gas port on my Paragon oven (inside, but subject to about 150 F continuously when in operation). All of these repairs are at least one year old and some are several years old. Also, I have had the glue on the shelf for two years with no noticeable loss of performance. I've never used Acra-Glass but it seems to be similar from what I've heard....

SteveS 03-12-2005 11:56 AM

Ed and Ray. The time issue is exactly what I'm worried about - not really holding strength - we're on the same wave length. And your real results are more important.

I'm hoping to subject the samples to stuff that will speed up the aging process.


Gary Mulkey 03-12-2005 12:19 PM


Curiousity, for the super glue that you tested was it the typical thin glue or the gap filling gel?


tmickley 03-12-2005 01:07 PM

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
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

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

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

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!

tmickley 03-14-2005 07:57 PM

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.

SteveS 03-14-2005 08:24 PM

OK Just finished the dish washer test - no easy failures. My current samples (sorry if it's getting confusing, but deal with it :) )

ATS-34 60HRC cleaned with Simple Green/brake cleaner
1. Loctite Extrem
2. E-120HP
3. Acra Glas
4. West Systems (failed)
5. U-05fl
6. DEVCON (failed)
7. JB Weld (Failed)
8. 2nd West Systems (failed)

Redo ATS-34 60hrc no cleaning (freshly abraded with 50 grit)
7. JB Weld (failed after dishwasher)
8. Gorilla

Mildsteel test: Simple Green/brake cleaner
9. E-120HP
10. JB Weld

Again after the redo and the dishwasher test everything is still holding but the JB Weld/simple green combination.

This is VERY interesting to me. JBWeld on stainless cleaned with Simple Green/brake cleaner failed right away. JBWeld on stainless that was not cleaned is just fine. JBWeld on mild steel cleaned with simple green/brake cleaner failed.

This tells me directly that there is a problem with the cleaning method. I've never had a problem with brake cleaner, but never used Simple Green before. I had a number of failures that shouldn't have been (this test and the one before) all of them I used simple green to de-grease.

Does that tell you something!!!!????


Texasjack, thanks for the information that is extremely useful.

fitzo 03-14-2005 08:34 PM

This is interesting, Steve. Simple Green is touted by the manufacturer as leaving "no residues". That and it's environmentally-friendly attributes are considered its selling points. I used it for years to clean my motorcycle that was loaded with chrome, and I never saw that dullness of soap film. On the other hand, I have unsoftened Lake Michigan water, which has enough minerals dissolved in it to make concrete, and it rinses soaps off wonderfully. Out of curiosity, do you use softened water to rinse the soap off, or is it hard water?

Thanks for the effort, guys! Steve, I feel bad that I recommended the Simple Green, and apologize if I have wasted your time and effort.

tmickley 03-14-2005 09:48 PM

Steve, the only cleaner I use is rubbing alchohol and that is rare. I only use cleaner (alcohol) when I can't give the surface a fresh grind to clean off anything stuck on there. I figure there isn't a much cleaner surface than a freshly ground piece of metal.

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 #### for knives, but it looks fun to use on something.

Omega 03-14-2005 09:56 PM

ive been reading this thread for awhile now and i just cant see jb weld every failing, i used it to fix a carbarator and its still holding. it has to be the cleaning agent


SteveS 03-14-2005 10:45 PM

Bingo - the acraglas popped off. Yup that was washed with Simple Green. The only things that held are U-05FL, e-120hp, and xtreme.

Don't feel bad Fitzo. Who would have known? It might not be the simple green, exactly. But all my results point to it.

Dang, but I did go thru a lot.

I'm sitting here looking at this bar, hammering away on the pieces set without cleaner using the angle iron sans JB Weld. This is very different results.

I think now I'm going to have to grind everything off and start a-fresh.

Still, I hope we all learned something here. Something valuable. And that my friend Fitzo is worth the effort.

Fitzo, I used the RO water from my home filter system. Most of the just is gone. It's still not distilled, but close.

Tracy, I like the idea of straight from the grinder, but that's not always practical for me. Hmmmm, must be an answer.


justice 03-15-2005 12:25 AM

i may be wrong but i would think that acetone is the best thing for degresing and cleaning the surface to be glued.
dish soap and hot water might be good. dish soap gets some realy greasy stuff clean.

but i think grinding the surface or sanding then a fast light wipe down with some alcohol or acetone is the best way.

sometimes i just scratch the surface up with a file in a random patern insted of grinding/sanding it. sanding/grinding seems to leave a uniform patern. and i think that a random one might work better

or how about drilling holes half way though or all the way through(plus normal ruffing upand cleaning) the metal to give the epoxy more surface area to grab. mabey even taping these holes so the epoxy forms perminent screws inbetween the two glued surfaces.

just some thaughts.
keep up the good work guys!! every day im chomping at the bit for more info from this thred

tmickley 03-16-2005 04:34 PM
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.
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.

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.

McAhron 03-16-2005 10:27 PM

A good way to check for residues is to take the simple green or any other cleaners and mix it according to the instructions and spray a piece of cleaned glass,wait for it to dry and look at it from an angle to see if there is residue.I have tried cleaning windows with simple green and i can tell you it leaves a residue that has to be be polished off with a dry cloth afterwards ,or if left on its own streaks your windows.Acetone isnt good for surface preperation either because it is common for the acetone to have some levels of varnish and other impurities such as kerosene.Alcohol if its the 99.99 stuff works very well but many of the ones sold are only around 70%.I would have to say i think your both right that the best preperation is newly abraded metal that hasnt even had time to oxidize.I realy appreciate folks like you two who take time out of their busy schedules to benifit all of us.Thank you and i look forward to the final results.

p.s no pine rosin? :)

peregrine 03-17-2005 08:10 AM

Not to muddy the water but...
This info is great! Just a thought, after the tests are complete, I am now wondering how the holding power of silver solder would fair similarly (in your joint steel on steel tests), since "you are only as strong as your weakest link."
Just a thought.

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