Saturday, July 2, 2011
I Can't Weld Part 3
This is a short look at the second patch I welded in on the dash panel. This was a much longer, thinner strip of rust. I began by wire-brushing the entire dash panel along the leading edge, to identify any spots that were weak or rusted through. I found a couple smaller spots in addition to this larger one.
In a perfect world, I'd probably be better off just replacing the dash panel. But as I said before, this is a learning experience as much as anything. And I can always replace this panel without having to completely gut the car.
As before, I cut a cardboard pattern for my patch. This patch matches up much better than my last one. I left no significant gaps, and the only "extra" filling I had to do was where I overran with the cutoff wheel. I think next time I may use a smaller cutting wheel for these smaller spots. I'll have a much finer level of control, and the smaller, thinner disks will make for less collateral damage.
I held the patch in place with a pair of magnets (good old cheap Harbor Freight), and tacked one end. I then had to make a few adjustments in the patch, and tacked it as well. Then just for fun, I cleaned and tack welded the tabs that hold the dash panel at the front. If you've ever had one of these apart, you'll see that this panel is basically glued in. A quick wire-brushing removes the adhesive, and a quick hit with the welder tacks it down solid.
One other thing I want to add here: I did get the 0.023 wire to feed in this welder. And yes, I am an idiot. I don't know that it was a huge improvement over the 0.025, but what the heck. Also, I'm using next to no gas. I may turn it up to 30 or so CFH and see if it has any impact at all.
After tacking and fitting, I simply bounced around making small tack welds until they all blended together. I did burn through some thin spots at one end--due to some rust I missed. But those areas filled in very nicely once I knew they were there.
Grinding and more spot welding, and a touch more grinding finished it off. I let the metal cool, and then de-greased it with some alcohol real fast. Then I applied some "Bondo Hair" fiberglas filler over the patched areas. This was a mistake. I got the long-hair stuff, when I should've been using the Eversmooth short fiber stuff. I will sand this down smooth, and take a look. If it looks OK, I'll leave it. But I may have to hit it with a dash of the Eversmooth.
Important Note: The only filler I'll use on this project is for minor smoothing and reinforcing seams/patches on the bodywork. There's nothing worse than slathering bondo on with a trowel and watching it crack and flake off. Yuck. But the use of some filler simply cannot (and should not) be avoided.