epoxy & ebony

[Jerry Crawford]

I recently had a pretty exciting few moments trying to epoxy a threaded steel insert into some Bloodwood I was turning for a tool handle. I forgot the natural oil in the bloodwood might prevent a good bond and failed to swab it with acetone befor I applied the epoxy. Later the joint failed, the insert pulled right out under stress. Luckly I was able to salvage the work. I'm now going to use the same two part epoxy on Ebony and I'm wondering if the same rules apply. Anyone used epoxy on ebony and did you need to swab off the wood befor you tried any adhesive?

[Lynn Sonier]

If you epoxied in a threaded insert, and it was drilled to the correct diameter, it should not have come out. I would suggest cleaning the hole with acetone and using a small amount of thickener (baby powder works good) mixed with the epoxy. To make it even more strong, drill a few holes into the sides and bottom of the hold with a 1/16 drill. This will enable the epoxy to kind of get a fist into the wood.
Good luck

[Jerry Crawford]

good suggestion re: baby powder. I'm working with 90 second epoxy though. Next time I'm going to use one with a longer working life.

The insert was a 3/8-16 nut I had put into the end of the handle. When I twised the handle down on a threaded rod and bottomed out the shoulder the nut just twisted out of the hole. The epoxy held to the nut but not the wood. In the ebony I worked to closer tolerance this time. I drilled a .386" hole through the wood for a .375 (3/8") rod. Then roughed up both the rod and inside the hole. Then I spun in the gooped up rod.

Thanks

[Tom Mullane]

Quick set epoxies do not have the same strength as long set epoxies... you give up some strength for the quick setting feature...
For all my lathe tool handles I use slow set epoxy or JB Weld... have never had a tool fail from joint failure...

[Jerry Crawford]

Thanks Tom - lesson learned ... the hard way.