I've gotten a lot of good help from this site, so I thought I'd try to contribute something for a change. I recently replaced my fork seals and found considerable corrosion on the fork tubes. I don't think the seals would have worked with how rough the tubes were in the damaged area. I decided to grind out the corrosion and repair with JB Weld.













Damaged areas before grinding:

closeup of damage after just a little grinding:

closeup of damage before grinding:

before grinding:

After grinding, you can see how deep some of the damage was:

Here's what I used to grind out the corrosion. A Rotozip with flexshaft attachment, I'm not sure what type of bit this is but it worked very well. You can see the tube in the background has already been filled and sanded somewhat. There is a visible low spot that I later re-filled and re-sanded.

After the initial application of JB Weld:

I used some cut up pieces from a butter container to smooth the JB Weld right after applying it with a plastic knife. I made sure the bottoms of the butter container pieces were cut with a straight edge and wrapped them partially around the tube and held them at a slight angle as I slid them along the damaged area to smooth it. This probably wasn't totally necessary but it saved me some sanding time and I only had to refill a couple low spots after the initial sanding.

another shot of the smoothed JB Weld prior to any sanding:

Here's a shot after some sanding. I started with 280 grit and went up to 320, 600, & 1000 grits. I probably should have used the 1000 grit more to get a better polish but I was tired of sanding and it is a $600 bike after all. I also used some stiff plastic pieces and parts of a cardboard tube to back the sand paper and try keep the sanded area from getting wavy. I wet-sanded the whole time.

Here's a little closer shot, still quite a bit of sanding to go:

Completed area:

Both tubes done with repair and one installed with new seal:

The jury is still out on whether this will work well or not. I've only been able to test it for about a half mile due to a clutch problem. But, the forks feel better now and don't bottom out as easily. I'll probably peek inside the fork boots after a while and see if it looks like they are sealing or not.
This certainly would have been easier if I owned a metal lathe but I'm surprised how smooth it came out using sandpaper. There are some areas that look like they're not perfect but when I ran my fingers over them they were perfectly smooth. You can't feel any irregularity in the surface at all.
Hopefully this might help someone with a similar issue.
