Front Wing repair problem

[PeterCrowl]

Working on the left front wing.
The edge adjacent the door was rusted through..so I sand blasted it, cleaned it out and welded in a sheet metal strip. The rolled edge was still solid so I left it as an attachment point.
My problem is, the span between the rear edgs and the arch itself now has a bulge. If I run a straight edge along the rear of the wing, it isn't flat as it's rocking on this bulge in the center of the panel.
I've tried heating and quenching to shrink the metal..little or no success.

I suppose I could just beat it into submission and fill it back to level..but that doesn't seem right.

Does anybody have an idea about this?

Must say..I understand now why they rust so much. I've had sandblasted sheet metal in my garage..including Italian sheet metal.. for a year and its only shown the least bit of rusting. Morris Metal..sandblasted..begins rusting almost immediately.

Peter
in Denver

[Alec]

Hello Peter,

heating and quenching will not shrink steel. Shrinking can be acceived by heating a spot of metal to cherry red then quickly, with a dolly and hammer hit around the heated area to produce a little pimple then beat that flat.
However the problem is getting a dolly behind that section of the wing as the inner skin may be in the way of the dolly.

I don't know what grade of steel you have that hasn't rusted, but that is a normal reaction to sandblasting, (particularly if the water trap doesn't too well) it needs painting imediately after blasting.

Alec

[PeterCrowl]

The heating/quenching idea comes from here
http://allshops.org/cgi-bin/community/c ... 0121727059

by way of here

http://groups.google.com/group/rec.craf ... 31d5203a60

The structure behing the panel is indeed in the way of a dolly.

The sheet metal in question was . among other things . the leg shield of a Lambretta TV175. Blasted..then left to sit for a very long time without rusting. It's very dry here..humidity is usually in the 15 to 20% range. Even at that and with the parts inside the house the rusting was virtually immediate on the Morris Metal.

[Alec]

Hello Peter,

I have read about these shrinking discs but have no experience of them. I do know that just heating and cooling will not shrink.
You can either obtain one of these discs and try to see if it will work, knock down the loose metal and fill, or cut out that area, make a new patch starting closer to the arch area to give room to dress, but leave the wrapping of the trailing edge of the wing until last, i.e try and pull the metal back as you make the trailing edge wrap.

Alec

[PeterCrowl]

Perhaps another patch piece would be the answer.

I'll now more tomorrow after working on the piece some more.

The sheet metal that didn't rust <to speak of> was a leg shield from a Lambretta TV175 and a couple other bits of American cars.

I noticed today that my rear wings are probably replacements. They rusted faster than the front I blasted which I believe is original.

Since I have your attention, I'd like to review my bare metal process:
Rust convertor solution - dry 24 hours
Light sanding to remove any residue
Metal Prep wipe
Primer
Filler
Primer
Finish

Thoughts?

Peter

[jonathon]

You need to etch prime between prep wipe and primer. Always fill onto bare metal not primer to avoid sinks. We would etch,fill,prime, guide coat and dry flat ,stop up if required(stopper not filler)re prime and wet flat with 600-800 panel wipe and tack rag, final top coat, cut and polish.

[PeterCrowl]

Right..I'm using a self etching primer.
The supply house I bought my materials from recommends filling on top of epoxy primer as the filler can absorb moisture and cause rust underneath.
All of the finish steps you list are what I'll be doing.
Gosh this is fun