how strong is epoxy?

[Plain_Ol_Ed]

A testament to the strength of epoxy ... That's what holds golf clubs together.

[brianh]

I have glued in a few blades and have never had a failure.
I use epoxy for a lot of the furniture I make with good results, and as a final testiment to its strength I make carbon fiber bike frames with it.

[Scott]

I use the slowest setting epoxy I can find. It's 5 to 1 and sets in 24 hours. It penetrates the wood surface 1/16th of an inch with hardwoods and 1/8th of an inch with softwoods. I clean the surfaces of my handle material with acetone because acetone cuts epoxy. A pin or two or even a couple of small holes in the tang where the epoxy can go in creates an extremely secure handle.

I've even put a clamped, glued knife in my fridge to slow down the setting time to assure penetration. On the other side I've set the hardening process off by sitting my work onto a hot wood stove to speed it up.
I've had to take a handle off one carving knife and it was with a chisel and mallet.

You know if you rub your hands with a bit of olive oil or some vaseline before you start handling epoxy it'll wash off with dish soap and wax paper will peel off set epoxy leaving behind a glass finish.

http://www.caribooblades.com

[Thomp]

i agree Scott,
i found anytime a catalyst has to be used, and time allows reducing the amount of catalyst will make the epoxy - bondo stronger While on the other hand
accelerating the activation time by adding too much catalyst bakes the epoxy brittle over time...

epoxy is strongest when it has bonded to all surfaces in a socket.
if you can make a cavity to insert your blade into fill the cavity then work all the air out of the cavity when filling it with epoxy then set the blade into the epoxy pool you will break the blade or the handle before the properly mixed epoxy breaks...

i didn't know about wax paper, but it stands to logic the wax wouldn't allow epoxy to stick, i been using the same plastic that they wrap single slices of cheese with to wrap glue joints with to keep epoxy or polyurethane glue from protruding or foaming, it makes a glass smooth finish wherever the adhesive comes in contact with the film and can be pulled tight enough to stretch around bumps and bulges
some epoxies stick to polypropylene like bread wrappers or baggies but not to cheese wrappers..
yes i clean them first...

wow were all learning stuff here..

[R-OLDS]

Yep long cure Epoxy is the strongest to use. I use to build golf clubs and had quite a bit of the two part epoxy left which I have been using the last few years in my knife making. I use lots of different materials in making them. Drill rod, spade bits, cement nails, many different saw blades, I have recently had great luck using some circular saw blades as the newer ones are made of thinner material so there is less work to get the blades ready for use. I normaly do complete heat treating with the saw blades after getting them to the shape I want.

Randal