Body seams

[daverclasper]

Hi. Even with a good restoration, are these just left alone with (often) rust inside?, as difficult to sort out, and will still last for ages anyway, without rot issues?.

Dave

 

Edited July 13, 2021 by daverclasper

[PeteH]

The Theory?. Is that if seam sealed the oxygen and moisture needed for the corrosion to continue is no longer available.

On My current (13/60) where there was sign of corrosion starting it was dosed with "converter", cleaned up and dried and re-sealed. To be fair there isn`t much else one can do practically.

Pete

[daverclasper]

Yes, the theory never seems to quite work?

[PeteH]

Yes, I expect that even Acid dip/pasivating/drying the shell might not produce any better results. Probably the best one can hope for is that the rate of deterioration is vastly reduced by the reduced Oxidisation due to the exclusion of Oxygen/moisture as far as possible?.

Pete

[chrishawley]

Dealing with seams. Hmmm. It's a very broad question. If one takes the very top end of restoration (e.g. having one's E-type done by Jaguar Heritage) then every seam will be picked apart and remedied to better than OE standard. Fine, if one's got the odd £150k to spend (!). Alternatively, say, one might have Daihatsu Copen worth 2 or 3 grand and only a limited budget to get it good enough to have a bit of fun for a while; In which case compromises must be made.

One can expect all seams put together 3 , 4, 5 decades to have some degree or corrosion in them and perhaps a  useful guide is whether the seam is 'blown'; e.g. has got fatter due to internal pressure from rust  with the spot welds becoming deeper and more pronounced as the metal tries to expand apart. Once 'blown' there is little option but to make a welded repair either sooner or later.

And, of course, not all seams are of equal significance. Take a GT6 for example. Any rust in the front roof seam (to the screen surround) requires a full repair since any spread onto the roof will look terrible. Conversely, rust in the seams on the tailgate can be todged over with seam sealant or filler and can be out of sight/out of mind for reasonable number of years.

I'd be interested to know how others approach this but for myself I have two tactics for dealing with 'marginal' situations where a welded repair is not cost-effective  but the aim is to protect the seam for longer:

1) Take Bondaprimer, dilute with standard thinners to get a watery consistency, then work into the seam repeatedly with a fine brush

and/or

2) Saturate the seam with WD40 or similar. Then after a few minutes flashing off follow up with a very thin wax (e.g. Supertrol, Dinitrol ML) that has good creeping properties. NOT, as I've found to my cost, using a heavy wax  (e.g. Waxoyl) which won't creep and by sitting on top of the seam does more to seal water in, rather than sealing it out.

I suppose my only other thought is not to do things which make the situation worse. I have my hands on a VW camper where the PO put carpet underlay all over the interior of the vehicle and it became a damp sponge, blocked all the drain holes and prevented any air circulation. Result sadly predictable!

 

[DVD3500]

On my car we scraped the paint off and found rust in the seam ever few inches and finally decided to ditch the whole body.

My body specialist said you would have strip each and ever panel out to make sure there is nothing in there. The problem he explained is the rust had formed a "bubble" that you might not get to even with acid dipping. Hence,.... we are binning the body...

See:

 

[daverclasper]

I have on occasion prised apart seams that haven't blown at all, though showing signs of inner rust. Used a thin wire brush with a drill to clean up. Treated with Kurust, then primer and paint. Sqeezed  back flat with Mole Grips, or G clamp with small blocks of wood to not dig in and also spread load (surprisingly neat result). Treated the back/internal area with mix of Waxoil and maybe 10 % engine oil (oil seems to stop it drying out?).

Is not showing problems yet, after quite a few years and car is kept outside (under a cover).

 

Edited July 15, 2021 by daverclasper