Bad epoxy experience.

[alexkuzn]

Just wanted to share... I've got 30 Epoxy made by "Super glue" company from Home Depot.
I used it to glue ebony-liner-O1 steel. It was about 60F in my garage so I put knife into a toaster oven for 30 min. set on "Warm" - it's below 200F. Blade was quite hot after that.
Then I finished handle. It was getting relatively hot during that.
Because of crack in Ebony I had to take off the scales and found to my surprise that epoxy almost didn't have any holding power between liner and steel. Ebony with liner came off steel very easy with a mirror image of steel surface imperfection and grind lines. Bond between ebony and liner is very strong though.
Before gluing I wiped all surfaces with alcohol and roughen them on 120 grit disc.

I wonder if this is a bad epoxy or overheating that made bond that weak?
Any suggestion is appreciated.

[Lane Ritter]

I have had the same exact thing happen with the 2 ton epoxy. It sticks to the handle material, but not the metal. Cleaning, sanding, didn't seem to help. The glue is there and solid, but it came apart as if it had no glue at all. Slid apart with no pressure at all.

It's probably just surface preperation. But maybe they just nerfed my glue.

Lane

[Ray Rogers]

Could be the extra heat but, according to some testing done by a couple of our forumites a few months back, the most effective way to get a good bond with steel is to sandblast it. They tested many epoxies and very few held well to metal that wasn't sandblasted.

However, the strength of that bond should be of very little significance. No epoxy is strong enough to reliably hold scales on a handle if the knife is actually going to be used. The only reason epoxy is used is to fill the air spaces between the scales and the steel in order to keep moisture out. Making sure the epoxy you use will not soften if the knife gets wet is much more important than how strong the bond is. The rivets, pins, or screws will take care of holding the scale on the handle. If the handle doesn't have rivets, pins, or screws then it belongs in a collector's display case ....

[M&J]

I've used this same epoxy and have had similar incidents when straving the joint of sufficient epoxy. The heat also isn't good because during cure, it generates it's own heat. Compounding it with more may not be the ideal setting. I've found that 80-100 degrees works well for me.

To insure a better join, I drill holes and hollow grind the tang area using the 2" wheel. This leaves a good epoxy well to join the porus handles. Mine are also sandblasted under the handle.

[alexkuzn]

Guys,

can you recommend me a minimal knifemakers sandblasting setup?

Thanks,
Alex

[EdStreet]

epoxy, there's a HUGE and I mean HUGE thread on this forum about epoxy testing. over 17 pages worth if I recall. they composed an excel spreadsheet ranking epoxy's, bottom line, loctite E-120HP, loctite 324 speed bonder, golf shafting glue, gorilla glue. that's about all you need.

Also stuff like the devcon, super glues and other mystery glues belong in file 13.

Ed

[DaveL]

Stay away from that crap. I have used Loctite Depend 330 for a long time and Loctite was the winner in that long test on this forum. Stay with the right adhesive.

[M&J]

Here's the thread.

http://www.knifenetwork.com/forum/sh...ad.php?t=27463

[alexkuzn]

Just found this:
DAMASCUS-U.S.A. of Tyner, North Carolina custom knife company using Loctite 330 for bonding bolsters WITH NO PINS! How good this glue must be to do such a thing?

http://www.loctite.com/int_henkel/lo...pdf/ACH172.pdf

[Ray Rogers]

It's a very good glue, but not that good. Don't take my word for it - or anyone else's - do some tests yourself. Glue some bolster material to some blade steel and then test how much abuse it will take to get it to break off. In some cases you'll find it can be very, very difficult. Other times, when the metal surfaces aren't prepared just perfectly, or you strike the bolster at exactly the right angle, it will pop off easily.

Their results will not necessarily be YOUR results. Do your own tests so you can see how the glue performs under the conditions and with the methods that you can provide. You already know my opinion if you read my last response which is that using glue alone is a very bad idea. If you do your own testing you may decide that it works well enough for you and I'm full of bull puckey, or you may decide that the risk of getting a knife back for repair from a customer is just too great to take the chance ....

[orvet]

The material used and the prep work seem to be key in my experience, but I am with Ray, I don't trust ANY glue alone without pins or rivets.

I botched a pair of rosewood handles and had to take them off. I had used Gorilla Glue, one came off pretty easy the other split and I had to sand it off....the only way I could get it off. But, I still don't trust it by itself.

My son had problems with Beech wood on a knife he is making. The handle kept popping (with the slightest tap) off no matter how he prepared it, nor which glue he used (he tried 4 or 5 different glues). I told him he would have to rely on the rivets to hold the handle on.

Dale

[NuViking]

For any Canuks reading this thread, I have had very good luck with Canadian Tire brand 5 minute epoxie at room temprature. I rough the blade and the handle material with the belt grinder and 220 grit. The only thing is it drys with a slight pink hue to it but I found coloring with testors model paint to the color of the handle also covers them there little flaws that we claim not to have.