Best way to fill holes?

[Ingersoll444]

OK, I am working on my N's fenders, and there are a lot of drilled holes I want to patch. These are varous sizes, from 1/4" to 1/2" What is the best way to fill them? They are too small to cut a patch for, but a little big for welding shut. If they can be welded, how would I fill a hole that big? Thanks for any help!

[modre]

maybe back them up with a big chunk of steel that won't heat up and quickly puddle some braze in the hole...then grind the surface smooth? watch the heat distortion tho with a torch.

maybe JB Weld a plug in place then finish the JB Weld as a sandable putty?
may sound silly but I patched 100 sandblast holes in a motorcycle gas tank successfully that way.

maybe try to use some as mounting points for toolboxes, grab straps ect?

maybe using a lead solder similar to pre-plastic filler auto bodywork?
then sand the lead smooth.

[Ken N Tx]

OK, I am working on my N's fenders, and there are a lot of drilled holes I want to patch. These are varous sizes, from 1/4" to 1/2" What is the best way to fill them? They are too small to cut a patch for, but a little big for welding shut. If they can be welded, how would I fill a hole that big? Thanks for any help!

You might try threading a bolt of the same size in the hole..Grind the head off and then braze over that and then grind it smooth..Maybe do the same to the backside..

[RoGT5k]

I've heard of patching small holes by backing them up with a piece of copper or brass and mig welding the hole closed. The backer doesn't get welded to the steel, pull it off and use again. (disclaimer: I have not tried this)

[sixchows]

I've heard of patching small holes by backing them up with a piece of copper or brass and mig welding the hole closed. The backer doesn't get welded to the steel, pull it off and use again. (disclaimer: I have not tried this)

Yes that'll work. You can even get special vise-grip style pliers that have an opening on one jaw for welding and have the bronze face on the other jaw for backing up the hole.

You could also weld a washer of the same diameter into the hole and then just weld the opening in the washer.

Another choice would be to back up the hole with a piece of sheet metal, weld or braze the hole shut and then grind off both sides.

[John Deere Addict]

Here is what I did when I restored my 69 chevelle....

I needed to weld in new floor pans and floor braces, the only way I could get everything lined up correctly was to use 3/8 bolts to hold the braces to the pans. Once i get that part done I tacked in the floor pans, and the braces. Welded everything in solid and then removed all those 3/8 bolts. That left me probably 40-50 holes to fill. I had a wire feed welder w/argon gas. I slowly started to weld the holes shut a little at a time...start at an edge and weld just to get a puddle, let it cool and weld again until hole is filled then grind smooth. I learned this trick from a friend who is the body man at the local Chevy dealerships body shop. Apparently that is what he was taught at the body shop classes he attends on a regular basis.

[pigsitter]

:ditto: start on the outside edge and go inwards and weld in halves bottom and top very slowly with plenty of cooling time between welds!

[mark777]

Use a penny. If you plug weld the holes from the top and back them up with a penny they will either fall off or you can knock them off with a paint stick.

[drbailey]

Use a penny. If you plug weld the holes from the top and back them up with a penny they will either fall off or you can knock them off with a paint stick.

Thats a good one Mark . I have been welding hole for near 50 years of street rodding . I never heard of that . I wire weld now , to stay away from the intence heat and metal warping.
You see ,, I`m almost a hundred years old and I`m still learning :omg:

[Ingersoll444]

Thats a great idea Mark!! I had heard the copper/brass trick, but had no luck finding anything thick enough. thanks for the tip.

[Carl]

Mark, which penny is that? The old mostly copper, or the new copper coated zink pennys? Would expect the zink pennys to melt much easier.

[mark777]

Yeah, we used to do it all the time. When a customer wanted his body side moldings stripped and plug welded, that's what we used. Think the penny with the higher copper content is best, but either will work.

DrB, as my old teacher use to say "You learn some of the neatest tricks from some of the dumbest people", I always knew he was referring to me!