Tell me why this won't work - patching holes in a door

[KLF]

I have a few holes in my doors that I need to fill in and remove, before painting them. The holes are about 3/8" in diameter, maybe a little more. They are from an old set of mirrors, not rusty.

Can't I just take a piece of scrap 22ga sheet metal and epoxy it to the back side of the door skin under the holes? Then fill in the "divot" on the front side with body filler? Or do I have to weld metal behind them and fill the divot with weld?

I hate bodywork.

 

[hedgehog23]

sounds like it would work but welding is my preferred patch method. complications that may occur with the epoxy fix , patch pops off and body filler cracks.

 

[KLF]

Well, I tried/attempted the welding method, took me over 2 hours to do one hole and it looked like I sneezed on it when I was done. Lots of grinding.

I found some "steel weld epoxy" at NAPA, supposed to be good up to 2600 psi of tensile strength, it's "specially formulated to work on all metals". I know it's all about the prep, but even if I was able to get half that strength, I can't see how it could ever pop off.

 

[PAToyota]

The obvious problem with welding is that you end up with bare steel (internally) which can just start rusting again. More work is being done with autobody panel bonding adhesives for this reason. And personally, trying to do sheetmetal work with a cheap 110V welder is just an exercise in frustration.

 

[KLF]

The obvious problem with welding is that you end up with bare steel (internally) which can just start rusting again. More work is being done with autobody panel bonding adhesives for this reason. And personally, trying to do sheetmetal work with a cheap 110V welder is just an exercise in frustration.

The bare metal is a concern as well, now I have to find some sort of sealant to cover the patch on the back side.

I tried to get some of that nifty 3M panel adhesive, but a tube is ~$60 and you need a special gun. So I was thinking of using the epoxy.

I don't have a cheap 110V welder, I'm using a Miller 211 Autoset, turned all the way down, with 0.023 wire. First time I've done any sort of welding like this, it's frustrating, I guess I need to practice.

Thanks.

 

[PAToyota]

I agree that the true panel adhesive is expensive. But it is also semi-structural. For what you are doing you really don't need the "official" stuff. For a 3/8" hole, I really doubt you're going to have any problems with the epoxy popping loose or the filler cracking.

 

[Spook50]

Well, I tried/attempted the welding method, took me over 2 hours to do one hole and it looked like I sneezed on it when I was done. Lots of grinding.

Flapper wheels are your friend. My welds blended in so well using a 4" flapper on my seat brackets that I'd be comfortable attempting sheet metal repairs as long as I'm able to avoid warping the metal.

 

[merbesfield]

Weld it and use flap wheels. Easy to do with MIG and some practice.

 

[KLF]

Job is complete. Welded it. I need practice.

 

[Living in the Past]

The obvious problem with welding is that you end up with bare steel (internally) which can just start rusting again.

Even if he had used 22ga metal instead of welding he would of had bare metal. I would think to get the best bond with the metal epoxy you would have wanted bare metal. To be able to get excess to put a patch you would have excess to apply paint to the inside either way. Doesn't need to be pretty on the inside of the door but I would be sure to coat the bare metal in any case.

 

[KLF]

Yes, we will be coating the inside of the doors/patches to keep them from rusting, current thought is to use fiberglass resin. I'm also planning to install sound deadening/Dynamat over that.

 

[Gumby]

Lots of repair facilities and even factories bond instead of weld.

 

[Hugh Heifer]

I have just been through this. I just spot weld a piece of metal behind the hole and then fill it with bondo.