Bead or seam across the back of the cab question ? ? ?


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Post Sat Jun 19, 2021 11:42 am

Bead or seam across the back of the cab question ? ? ?

Howdy all. I'm slowly getting my ducks in a row to start sandblasting my cab on my '47 KB7.

So far the truck is pretty rust free except on the bottom of the bead that runs around the back side of the cab. Is this a bead rolled in one piece of sheet metal? Or is it a seam where two pieces join?

If it's two pieces I'm assuming the top and bottom half have the same bead and they are interlocked and welded together? I'm just wondering so I have some idea before I get elbow deep into this. I'm not working twards a concourse restoration but I would like to avoid gratuitous bondoing. I feel good about my ability to repair every other spot where there is a bit of rust, but this spot makes me give pause.

Thanks everyone

Golden Jubilee
Golden Jubilee

Posts: 8630

Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Sat Jun 19, 2021 1:39 pm

Re: Bead or seam across the back of the cab question ? ? ?

Sandblasting and sheetmetal do not go together. I have seen perfectly good vehicles destroyed from sandblasting. My friend had his 1948 Ford sand blasted and within a year rust started bubbling through the paint. The paint and body guys tried to stop the rust through by stripping the paint and starting over. Ten years later the car is scrap.
If the blaster is recycling the sand the contaminates will be blasted into the sheetmetal. Any dissimilar metals and corrosion will become imbedded and cause problems. If the recycled media has any oil in it, forget about getting paint to stick to the sheetmetal, ever.
If you insist on having the body blasted insist on the blaster using ground walnut shell media. Air Strip in Richmond, BC did my 1940 Ford. Ten years on, the '40 has no problems. http://www.osairstrip.ca/ The car was returned to me looking like fresh steel.
https://www.sandblasterinfo.com/prevent ... dblasting/
It is vital to the survival of the sheetmetal to have it coated with an epoxy etching primer asap after the metal cleaning. You will want to have an epoxy primer on the sheetmetal before using any body filler.
In about 1988, I had Redi Strip https://redi-strip.com/ metal clean my 1953 R120. This was very expensive, then, at nearly $3000. Nearly 35 years later the "R" does not show any rusting. Redi Strip followed the cleaning with a phosphate spray and I added an epoxy etching primer called PPG DP40
Attachments
40 FORD RIGHT REAR.jpg
R120 in 1991 (2).jpg
I would rather have tools I do not need than to need tools I do not have
Opportunity is missed by most people because it is dressed in overalls and looks like work.
Thomas A. Edison

Golden Jubilee
Golden Jubilee

Posts: 8630

Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Sat Jun 19, 2021 4:39 pm

Re: Bead or seam across the back of the cab question ? ? ?

There are risks in opening up a seam. If the seam has been factory spot-welded separating the seam without distortion is nearly impossible.
If this were my truck, I would wire brush the seam out as much as is possible then treat the seam with something like rust mort.
https://www.amazon.ca/SEM-69504-Rust-Mo ... 8209&psc=1
My go-to body and paint guy recommends this product for small areas, like hard to get to seams.
https://youtu.be/a-8H1XI-uXA
I would rather have tools I do not need than to need tools I do not have
Opportunity is missed by most people because it is dressed in overalls and looks like work.
Thomas A. Edison

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