Area behind weld

[laguna80]

Hey peeps, I'm doing a bunch of rust repairs on my pig and am about to fill some areas that are going to be covered up. The picture is part of the B-pillar that forms into the door jam on the passenger side. Once I weld in new metal that area will be inaccessible to paint. Do you all paint areas that are going to be inaccessible later on, then weld in new metal? The weld will ruin any nearby paint correct? I know there are weldable primers but is a primer enough for that area? I'm going to use phosphoric acid first to neutralize any rust around the area, but should I paint too?

 

[brownbear]

I am very hesitant to weld where you cannot get at the backside to clean and paint. At a very minimum you will want to be able to after pour/spray some corrosion proofing oil in that spot to seal it with a waxy oil

I had some rocker repair to do, I was so against welding into a closed area that I cut slots in the top to be able to clean and paint in there.

Another option to welding is using structural epxoy for attaching body panels.

 

[laguna80]

Thanks for the tips Brownbear. Can I get that stuff at a local automotive parts store? Anyone used the weld through primer before. Other sites have said that it has adhesion problems which is why it is mostly used on lap joints. The oil stuff sounds good because I do have semi access to the panel afterward. I just don't want to set the truck on fire when I'm closing up the holes.

 

[brownbear]

The glue was available at my napa on special order.

If you go to an autobody shop they may be able to sell a tube. I believe most shops it's all they use now. Very few weld anything.

 

[62FJ40]

I am replacing my rear sill, bed floor and fender wells and have been struggling with the same dilema,
epoxy runs about $45 a tube plus about that for the application gun, makes over lap very water resistant.
In my case the fender wells will eventually be supporting a full roll cage so I am a little hesitant on using
epoxy. I am using weld through primer and then applying a coat of high temp BBQ paint ( says withstands
1000 deg) over that, I am just scratching it off where I am making my plug welds, and then I will use a good seam sealer for added protection.

 

[skyclark]

Is this epoxy similar to the stuff used to bond carbon and fiberglass panels in supercars, boats, and the like?

Does anybody have pictures of a fix with it?