Quote Originally Posted by EddyCurrent View Post
I had those thoughts myself but decided to epoxy onto bare metal. I had put metal primer on the box section beam but before putting the moat on I sandpapered it off the top. My intention is to fit the linear rail and paint over everything up to that.
I'll take the paint off where the epoxy will go with a flapper disc on the angle grinder so it's back to bare metal. I guess the epoxy would be OK when the paint was in the oven (180°C) but will get it painted before just in case.

I know this is somewhat less than scientific but I just had a play with the sample epoxy pour I did 3 days ago, a scriber barely scratched the surface and a centre punch made no more of a mark in it than it did in the steel box section. Overall I'd say that stuff was rock hard.
That's good to know that it sets rock hard. Will be interesting to hear how you get on with the filing the meniscus off, I can imagine it clogging the file. I might have a go at how Graham (Wobblycogs) suggested getting the meniscus off with a router. If you have a bit with a guide bearing and ran the bearing on the epoxy surface and the router plate on the side of the box section I can see it being quicker. Might have a play when I get there...