Just curious if anybody has used a tig welder over a mig seam to fill tiny pin holes etc? I really don’t want to use lead or no lead solder , and I’m not completely sold on all metal or fiberglass filler over the seam, I was thinking to tig over the bead anywhere I see a pin hole sort of a fusion weld

 

I've used a TIG to remelt a weld bead, and fill pinholes.

 

thanks for the reply , I think I’ll give it a try

 

X2 ,but if all you have is pinholes, body filler will hold well. I would fill as little as possible and sand smooth till all that is showing is the filler in the fill holes, prime and paint.

 

Thanks Ted, the weld is nearly there , I really tend to over think things lol it’s why I’ve been working on this project so damn long lol , I feel it should be leaded but I’m hesitant to adding heat, the flux residue, etc, there are minor imperfections in the welds I really want to make them as perfect as I can and was thinking a little fusion weld would really dress it best with minimal heat, I put the quarters on and have ground both sides smooth ( where accessible) I’ll post some progress in my thread , I ordered a tig welder from Santa lol and hopefully it works out as planned

 

The TIG will put more heat in the weld seam, so you may get a bit more warpage, But the good news is, TIG welds are softer, and respond very well to after welding hammer and dolly work. If you're going to do quality welds on sheet metal, you really need to have good H & D skills.

 

Eddie:
I made quick tack welds with my MIG to fill pin holes. With lots of light (so you can see what you're doing) you can precisely do a quick tack in the center of the pin hole. Make sure you have clean metal and snip off the end of the MIG wire to remove any slag from previous passes. On some of the larger pin holes, I used a copper backer to help the weld material spread outward into the hole. Don't try to do too many holes at one time if they are close together; if you put too much heat into a small area you risk warping the sheetmetal.
Rodney

 

Sometimes the start of a mig weld leaves a pin hole in the center under close examination. One trick to fill a pin hole with mig is to start the weld slightly to the side of the hole to be filled and move towards the pin hole. Sounds like you’re close to finishing and would fill them with weld versus filler.
Dustin

 

Thanks Rodney , these are very very small holes I could certainly go back and quick tack , I’m not a welding pro when I attached the quarters I used the cut both pieces , align them and tack then move on , once piece was fully trimmed and attached went back and welded between tacks, then between them so on and so forth till it was a complete seam then cleaned the welds etc and addressed the seam with hammer and dolly etc , there was very very minor metal bumping required , I cooled each tack with air gun , etc, I will try the tig just to see, the pin hole is smaller than the .023 wire I used so I’m hoping that a fusion weld will just seal it. I’ll keep you posted

 

thanks Dustin indeed the center of the tack has a tiny hole here and there , great tip on the side start , I’ll try the tig I’m comfortable with hammer and dolly but there should be less heat then a tack

 

thank you chop, it’s a super small pin hole(s) not necessarily planning on a big bead , I’ll cool it similar to when I tacked the quarter zap and cool lol I’m comfortable with hammer and dolly, but your exactly right

 

To add clarity , here’s a couple pics of the pinholes

 

I did go over the weld seam with a tig , I used only about 20 amps, and used .023 mig wire as the filler rod , there’s a learning curve with tig, and well I began learning I was happy with results , but I ended up using non lead body solder over the seam just in case :-)

 

Hey Eddie:
Post up a pic of the final results after going over your Mig welds with the TIG. I'd like to see how it turned out. Thanks!
Rodney

 

rod sorry bud I didn’t take pics after and I have now filled with body solder , I do have some more welding to do around the wheel well I’ll take pics , basically I used the finger feature on the torch I put the .023 along the seam not in the conventional way and went along sort of spotting

 

No worries man. I had similar issues with my MIG welds on some of my fender patches. I don't have a TIG so I just placed quick tacks with the MIG over the pin holes and ground them down. In the end, the quick tacks worked for me, but I had to do this multiple times on some spots before I was satisfied but in the back of my mind I wondered if the heat from all the extra grinding would warp the metal.

I read your recent posts on your build page. You're making significant progress!

Rodney

 

Rick I’ll grab some shots of the reverse side?

 

Yes I did the same I did not run any beads , the most was three quick spots together then air cooled ( with the mig) after grinding there were still minute pin holes , I’m not a fabricator or pro but I then went over with tig similarly put the filler rod in and tacked the tig also liquified the previous tack some , I will say it looks like it put more heat I didn’t cool it this time and it was a softer weld

 

for future applications, be sure to overlap each tack, that will help with the pin holes. i didn't learn that trick right away, but it definitely helped once i did. good luck eddie, this is your last decade of working on this car buddy. i know you can get'r done. i should be putting the frame back on this week. i just finished my final coat on the underside, and inside the wheel wells. few things to do to the chassis before i put the body back in the way. i will have some pics up this week.