Not sure how to fix this. I have 3 areas on my 1938 underbody like this. The biggest hole in this picture is a half inch long and 1/8" tall.
The back side of this is also sandblasted so is clean and healthy just the holes. These are the only areas needing work under there. It's thick enough to weld but would end up chasing holes I suspect. My preference is a welded rectangular patch on top with length suitable to blend in and then some undercoating oil on the inside after paintwork.
A coupe local restorers have seen it and laughed since it is so minor and told me to use seam sealer and not mess with it since it's so solid overall. I'm tempted as a two part seam sealer could outlast me....
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
I am partially inclined to agree with the other restorers but I also see the point of while it is there it will grow therefore needs some treatment. It looks like the outer sill panel is pinch folded over the inner in which case it can be partially unfolded while a replacement piece is welded in, not an impossible task but wont be a 5 minute job. I think I could do it though may not be pretty Tony
TIM..............you could zip cut out the offending area and TIG weld or MIG weld a new piece in. How anal you want to get about the repairs , is up to you
Or you could try TIG or MIG welding the small holes and they will blow up into 1/4--3/8 holes quickly. But, putting , clamping a piece of copper plate behind them will allow you to fill the holes with weld then grind down carefully. That's providing you can get behind the area. ?
Thanks for the ideas. Even considered some of the modern structural epoxies but if there is any hint of rust or moisture gets in, it could rust quickly. I examined both sides of these and the metal is very solid and I can access both sides.
I have the magnetic tool in the attached photo designed to back a hole with copper while welding plus some copper sheet and it should fit in there. My welding is more structural so will use a local guy that does onsite TIG so will try filling them first, then a quality seam sealer coating over prime.
There are some factory panel gaps bigger than these that survived just fine all these years so won't fiddle excessively. I will treat the inside of all these types of areas with an oil based rustproofing after paintwork and these will be fine for decades I think.
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
Today’s mig and tig welders are so good repairs like this are easy. I purchased a tig welder and welded up my running boards to splash aprons on my 32’ Olds. A welder wanted $500 to do the pair and the machine cost $630. After doing two jobs with it, I more than payed for the labor costs and stayed with he machine for further use. I’ve done about another 4-6 jobs with it already so it was a great investment and taught myself another talent to use in this hobby. It’s always worth the effort to do the repair with replacement metal. We already use enough plastic when we skim coat or touch up any low areas so adding more in places that should be metal doesn’t make sense to me. A restoration takes a fair amount of time anyway so skipping an hour or two here or there for what eventually will become an inferior repair will just be time wasted in the long run.
It’s always worth the effort to do the repair with replacement metal. We already use enough plastic when we skim coat or touch up any low areas so adding more in places that should be metal doesn’t make sense to me. A restoration takes a fair amount of time anyway so skipping an hour or two here or there for what eventually will become an inferior repair will just be time wasted in the long run.
