Capping rusted frame rails

[Holtzer1]

I've got rust holes in the bottom of the front frame rails, I found a company called safe t cap, but those aren't as long as I would like them to be. I'm good with fabrication and welding, but I'm curious as to what thickness steel I should use. I've got some 18g but I'm thinking of going with 14g just for the extra strength. I planned on doing full length welds along the top where it will beet the pinch weld points as well as numerous plug welds along the sides.

 

[747mopar]

I'd take a good sample out for measuring (sorry can't remember how thick mine were). Not a huge fan of caps though, those rails rust from the inside out and really need opened up. If just patching I'd cut the rust out then continue opening the hole up until I'm into all solid metal then make the appropriate patch. Good luck

 

[flypaper]

if you are good at welding
why dont you just find some good donor rails
and just replace the whole thing?
those caps are just ugly bandaids..

 

[Holtzer1]

I've cut out all the rust and treated the remainder of the inside of the rails. By doing the cap the way I have planned, it will look better than factory, be stronger, and smoothed out. I did some searching on the net some more and found its 14g.

 

['68 Charger]

What year? Model?

 

[71charger_fan]

I had a rust hole in a frame rail on my '71

plated. The problem with that was the rust just comes back. I eventually bit the bullet and had the frame rail redone with an Auto Rust Technicians piece.

 

['68 Charger]

Okay the reason I asked is that I have a pair of rust free front frame rails for 1973-74 B Body, much different. And that's not knowing if you even considering replacing yours. Just saying. Moot point anyways.

 

[Montclaire]

These days, I would honestly replace the rail or cut a patch from another factory one to make the original whole. If this was about a DD 1982 toyota, I'd cap it.

 

[Holtzer1]

So, what I did was cut out the old rust, treat the inside of the rails. Patched the rail with 14g, fabricated a 14g cap and welded it on as well. Got that metal treated for now until i finish everything up front. Then por15,smooth everything out with fiberglass reinforced filler, another coat of por, then por topcoat.