filler material

I need to fill and smooth a hole in an aluminum valve cover before painting.
The hole is blind and is 3/16 diameter and 5/8 deep. I thought about using
JB Weld. Anybody have good idea?

 

That's probably what I would do. Fill it, sand it smooth, paint away!!!

 

JB Weld - Best idea since toilet paper.

 

Why not take it to a local welding shop and let them repair it
properly. HRP

 

J-B would probably work but I would weld it up and finish off the bead.

 

I saw an article in an English antique motorcycle magazine where the guy was restoring a 30s motorcycle. The cast aluminum clutch cover had 2 deep pits corroded into it.

He drilled right through the pits and took pieces of aluminum rod the same diameter as the drill. Peened them into the hole like a rivet. Filed, sanded and polished the cover smooth. When he was done it looked brand new. I expect he countersunk the holes just a hair to help the repair hold on.

 

Well, I'd say you are half right - weld is good, but there shouldn't be any JB in it.

 

Welding is always the preferred method, but a couple times I've done "quick and dirty" repairs on aluminum that wasn't practical to remove, weld or repair correctly. I used an epoxy similar to JB, but had aluminum flakes in it, so the color match was better, and a bit stronger.

 

Thread the hole and use a threaded aluminum rod, no JB, smooth and paint