welding question
 

Welding in some cab corners. After grinding I have some pin holes in the seam. I have some POR15 epoxy putty to use in small pinholes elsewhere. Rather than chasing pinholes I was going to fill with the pore 15 grind and finish with duraglass fiberglass filler. Will this work?

Re: welding question
 

Not really a good idea.. really need those holes welded up..
Then you need epoxy primer on it..

Re: welding question
 

Quite a few years ago I restored an old sports car. It had some pin-holes in the sheet metal that I was too lazy to fill. I wire brushed then acid etched the pinholes and they were covered with the skim coat of filler, then on to paint.

I had the car for 4-5 more years then sold it. A couple years later I got a note from the president of the car club I'd belonged to. It seemed my car had been exported to Austria and the new owner used the car club sticker in the windshield to track me down.

The new owner had driven the car in rain and climate conditions it never experienced in its life in Arizona, and she asked my why it had rusted so soon and the paint was bubbling around the area of the pinholes. I was a little embarrassed and told her the car was never exposed to rain or moisture in Arizona - I never anticipated that it would be a problem.

I guess the moral of the story is you can't ever completely clean the pin hole and given the right conditions, rust will always find a way to come out.

Since then I've always put a strong light source in back of a panel I've patched and look for pin holes in the weld and fill them with metal.

YMMV

Re: welding question
 

I'm looking at the Evercoat metal to metal filler for the welds. Check it out.

As Mongo said, I chased pinholes that I found with a LED drop light on the other side until I'm sick of it. I will probably hit the few left with another round of welding and grinding to try and get them all, but that metal to metal sure sounded good.

Re: welding question
 

Several manufacturers of the metal filler, but simply put it is the replacement for exterior panel seam seal instead of lead solder between body parts. It actually has bits of aluminum (or aluminium.. however you pronounce it) in the filler. It says on the label that it is for small pinhole filling, and not structural.
I first found 'All metal' at the local Napa, then they switched to Evercoat, but it will still fill the tiny holes, sand, then prime and paint. I recommend painting or POR'ing both sides of the surface after filling and sanding.

Re: welding question
 

if you have pin holes that means th metal has eroded to the point that it is very thin and has started to make holes. the best solution to stop the process is to cut that panel out and replace it with new metal of the original thickness. you can fill tin foil tilll you're blue in the face but it will show it's face after you have spent all that time and money on the rest of the restoration. if it is a rusty patina triuck then I guess it is character but something that is getting paint should get repaired properly first or you might as well drive it in primer till it shows rust and then cut the panel off and replace it.
sorry, the bandaid is off now though. spend the time qelding in anew part instead of chasing the old part, the old part will eventually win otherwise.
it's your truck and your money, but think about how you spend the time and money on the foundation before you spend money on the finish. if you built a house on a crappy foundation it wouldn't matter how well you build the rest of the house, the foundation is gonna fall apart and the house won't be so good anymore.

Re: welding question
 

I'd assuming popeye has clean metal either side of a new seam with pinholes in the new weld, not rust pinholes
If you rely on the filler in a spot where your seam is flush or proud, once you sand that filler all you will have left is a tiny plug of filler in the pinhole. Will it stay put and stay sealed? I'd get after the pinholes you can. But inevitably there are going to be some you miss or can't see. Unless you do wray schellin quality work.
The important thing is to seal well with primer and paint including sealing the backside and keeping it sealed. And for hard to get to areas do some rust preventative like a grease with oxygen inhibitors, or a waxy non drying rust preventer. or a toilet ring melted into some oil.....anything except one of the 'rubberized rust encouragers' that are so popular with people reselling cars

Re: welding question
 

sorry popeyestruck, I read the part where you said you welded in cab corners but my brain took me to a place where the metal was rusty and had pinholes. thanks LG for the snap back to the actual scenario and question.
do like LG says and weld the pinholes you can get to and recheck with the light. if mig welding ensure the wire in the gun has a chisel tip on it (freshly cut off after each weld) so you get as clean a weld start up as you can. of course the metal also needs to be clean both sides as LG says. sometimes its a good idea to try the gun, without welding, so you can ensure you are getting gas flow right away when the trigger is pulled. also, set the contact tip and gas cup so the contact tip isn't stuck way back up inside the gas cup otherwise it is like having too much stick out and the weld is affected.

Re: welding question
 

Panels are welded in and got out all but a couple pinholes. I'll seal up inside and out.

Re: welding question
 

the only way to get pin holes to seal if you cant weld them is to lead the area, i had a "soft spot: in a rear fender of my 34 Chevy and a freind leaded the pin holes 20 years ago, no rust thru yet.