Patches repaired...will they bubble/rust

I've made and welded in several patch panels on my car so far, I used body filler to smooth and sprayed a couple primer coatings over them while I work on other parts of the car.

A few peices have sat for months and others weeks with no bubbling or change to the appearance.

Is it safe to say the repair was done correct and should not bubble or crack the paint when it comes time to paint the car?

 

If there is any chance it will get wet, coat the primer with an epoxy primer or paint to keep the moisture from the metal. Most primers are porous and will absorb moisture and allow rust to form under the paint causing said bubbling. If the repair was done properly, it should be fine.

 

Need to be able to seal the backside or it will eventually rot back through

 

Yea I have all the backsides primed and coated then truck bed coating over top of that.

 

As long as water and air can't get underneath the repair it should be fine if you just prime something it will rust through primer if its exposed to the weather

 

Yea, currently all my fenders and the car itself is in the garage. The repairs were made severel weeks and months ago, as long as I get paint to them before they see rain I hope they hold up.
I don't want the flaking/bubbling to happen once I paint the car

 

This is what worries me...

I have a chunk of rocker panel that has been perforated inward. Fan2488 wants me to cut it out and replace it, but I fear the inside of the welded area will eventually rust through.

I am leaning toward either pulling it out, or putting a metal patch OVER it, and shooting rustoleum or something in between the two layers before I close up the welds on each end (even then, the final welds will melt the paint at the ends).

So, how do you prevent rust in an area where you CANNOT get behind it and seal it?

 

If you cut the rust out, it won't come back. For interior panels, Eastwood makes a spray to seal inside of frame rails and stuff like that.
http://www.eastwood.com/internal-frame-coating-w-spray-nozzle.html
If you grind the rust down, and fill over it...it will come back.

 

Easy.....never get the car wet.

Seriously....if it doesn't get wet...it won't rust.

 

Yeah me to ben so proud of my rust free garage kept mav on this site. I found a bubble on the bottom of the rear quarter panel just behind the door obviously from an old C/B antena hole that leaked in the past No hole on the bottom of the car. Looks like the rust was just getting some condensation all this time.

 

Gulf Coast of Texas...it is ALWAYS wet. It is just too humid here.

 

It took 40 years to get as rusty as it is now. I think it is safe to say it will be less rusty in another 40 years if you take care of it.