I've welded up a few small holes (< 5mm) in some obscure areas but now I'm thinking about closing the "wart holes" where the side turn lamps reside and I'm looking for a little guidance. Is it best to weld in a plug of similar thickness doing a little at a time to avoid warping? Also, I plan to add OEM side mirrors once I have "Little Frankie" running and I expect I shall find some holes that need to be filled when I do. Can I just use a backer plate and MIG these w/o fear of warping this area. TIA, Kent

That's how I did my last one. With the flares, it's a little easier, because you have 1/2 the hole closed up by the flare.

I forget what the size is, but I used a piece just a hair smaller, and then tacked it up until the whole thing was tight, then grind, seam-seal the inside, and you're ready for some bondo and primer.

cut a plug. Butt weld it in. A backer is fine on the mirror if you can get it inside. I usually do it without any backer. .023 wire and a little heat and it is fine. Little to no warpage

Scotty, what is the advantage of .023 over .030 in this instance? Is it related to the ga. of the metal or puddle area or what? To tell the truth I would have welded with the .030 had you not spoke up. BTW, nice work on the flared, blue car you just shot.

More heat necessary with 0.30 wire to achieve penetration (which leads to more chance of warping) and more material than is necessary?

Just less heat and you can make the gap a little tighter. I used to use .030 all the time as none of the local shops carried .023. After I special ordered 2 rolls they have been keeping a few in stock

With .023 you can turn down the welder a little more. Same arch but smaller spot.

Also you can use a piece of copper and some clecos or sheet metal screws to hold the copper behind the weld seam.

Starting at post # 46 I have an example of what I'm talking about.

http://www.914world.com/bbs2/index.php?sho...07923&st=40

Thank you gentlemen, all.

Nothing on these unibody cars require larger than .023... If you need have a spool of .035 sitting if you want to weld some plates together to build stuff.. But in general its much nicer to do thin autobody/restoration stuff with .023.

That being said, I keep .030 in my welder. I find I do a lot of heavier stuff around the house/building things.

If you need to get some .023 anyway, try to get "easy-grind". It really does make it easier to finish welds on exterior panels. If you are not scotty/rick (which I certainly am not) you will have some bead proud of the panel which needs to be ground flush.

Also, if you don't have a lot of experience filling holes, practice on scrap for a few minutes first. Maybe I'm revealing my ignorance but to me it's a different skill from running a bead.

HTH
Brian

^This is true, Its a much different weld. The best way to fill a hole is to build a tach layer around the hole (especially if its a rust hole, as that metal will just keep eating away) very gently then just tack/weld around as the weld pool will let you. You spend most of that time watching the metal cool through the helmet as thats your determining factor for when and where to weld next.