Filling small holes without welding

My K20 square box was Swiss cheese. I cut a 1” copper tube about 2” length which I hammered flat. Used that to cover the hole on the backside held with magnets. I converted my 30 amp electric stove circuit to 220 to electrify the MIG welder with 0.023 wire. Holes welded up in 15 seconds or less. I never once opened up a hole with too much heat and I am a total rookie welder. The welder was stored in a box for 5 years before opening. I don’t know how I lived without this welder for so long, definitely a very useful tool which I have used for many projects other than the square. Recently, it worked awesome when I replaced my boat trailer axle to weld on the perches and leaf springs mounts.

1977banana said:

What I measured was some un-rusted sheet metal on my 1977 at 24 ga. When I cut away the rusty cab corner areas and got to unrusted metal where the join would be welded. The replacement cab corners (aftermarket) measured 19 ga. and the original was 22-24 ga. which I thought was odd. I expected the original to be as thick or thicker. The cowl sides and upper rockers were also very thin and actually rusted through from the inside out on the upper side not the bottom which was also odd. Maybe quality control on the steel chosen was lacking the week my truck was built, and they ran through some wrong gauge steel through the presses lol. Stamping Honda parts Monday then Chevy truck parts Tuesday without changing steel thickness? lol.

Click to expand...

I've never actually measured any of mine for thickness, but they have all definitely had thicker sheetmetal than the average newer vehicle. And I worked a body shop for a good while too.

Now, they definitely don't have sheetmetal as thick as most 60's and early 70's GM stuff though.

bucket said:

I've never actually measured any of mine for thickness, but they have all definitely had thicker sheetmetal than the average newer vehicle. And I worked a body shop for a good while too.

Now, they definitely don't have sheetmetal as thick as most 60's and early 70's GM stuff though.

Click to expand...

Not as thick, but definitely thicker than some cars out there. I have been pleased with the stoutness of the sheet metal on my 81 c20

Has anyone tried an aluminum pop rivet or brass counter-sink head screw?
Cave the hole inward a bit with a big center punch. Install rivet/screw of right size and use loctite. Hand file and sand level, then bondo.
Maybe small copper riviets that require peening?

I would think gas welding would be fine with right size tip. Just slap wet rag on to quickly cool and retain hardness.

hey mister said:

Has anyone tried an aluminum pop rivet or brass counter-sink head screw?
Cave the hole inward a bit with a big center punch. Install rivet/screw of right size and use loctite. Hand file and sand level, then bondo.
Maybe small copper riviets that require peening?

Click to expand...

I'd be afraid of electrolysis with dissimilar metals.

WFO said:

I'd be afraid of electrolysis with dissimilar metals.

Click to expand...

Once you trap two dissimilar metals under Bondo and they get the slightest amount of moisture on them, the holes will grow and you've got bigger spaces to repair.

Aluminum rivets belong in aluminum --- but they have to be in the correct alloy 'cause there's a lot of very different alloys called "aluminum" out there.

I guess I can see using steel rivets --- and there are blind-hole versions that they make for boats and aircraft that are not open on the anvil side.

I use flux core 0.030" M/S on a H-F 220 wire machine -- I hate that stoooopid machine 'cause it loves to flame out inside the sleeve and then I get a rat's nest after the feed wheels.

I've use Pam, bacon grease, WD-40, Creepy, Seafoam, and 2-cycle premix and it fails after a while. I guess I should go out and buy a decent wire machine --- but I'm stubborn.

Imma gonna teach this machine to obey me! I will!

I have the typical rust through on the hood and I opted to use bondo extreme. The extreme doesn't absorb moisture like the standard bondo.
Welding holes is tricky and may warp the surrounding metal.