Screw Holes

[Danjo]

I’m getting ready for paint. I’ve been doing all the modifications to the outside before the paint. This includes changing rub rail placement. Now I have holes to fill. I figure I had better ask now so I won’t have to fix later.

I’m filling screw holes in the aluminum skin with JB Weld. Anyone think this is a bad idea?

Question: I’m removing the lights from the fiberglass ends. I’m going to reinstall these and I’m worried about the fiberglass holding the screw again. I suppose I could go to the next screw size, but was thinking about using something in the hole to hold the existing screws. Any ideas?

Thanks

[EastCoastCB]

body filler would work and much cheaper and easier to use than jb weld.

[TheHubbardBus]

Yeah, I think it's a bad idea, assuming you want them to stay filled. In my experience cured JB weld has zero flexibility, and is very much prone to cracking/chipping over time.

[Danjo]

Originally Posted by EastCoastCB

body filler would work and much cheaper and easier to use than jb weld.

I’m only doing about 25 holes so a small pack of JB weld is enough.. I thought JB weld would hold the hole better.

[o1marc]

Machine screws and nuts if you can access the back side.

[banman]

Originally Posted by Danjo

SNIP...

Question: I’m removing the lights from the fiberglass ends. I’m going to reinstall these and I’m worried about the fiberglass holding the screw again. I suppose I could go to the next screw size, but was thinking about using something in the hole to hold the existing screws. Any ideas?

Thanks

Rivnuts.

And once you own the tool, you'll use it for other stuff!

[somewhereinusa]

JB weld is pretty runny for quite a while. I think you would have trouble getting it to stay until set.

[Danjo]

Originally Posted by somewhereinusa

JB weld is pretty runny for quite a while. I think you would have trouble getting it to stay until set.

Actually it worked great that way. I used a swab stick to put it in and get some on the inside, then I fill up the hole. It runs a little but stays put.

It’s pretty hard, so it sands at a slower rate than the paint. So far it’s working. Maybe I should try to destroy a patch to see how it holds up.

[musigenesis]

Originally Posted by Danjo

I’m filling screw holes in the aluminum skin with JB Weld. Anyone think this is a bad idea?

Are you talking about Steelstick? I used that to fill the holes from when I drilled out the stops on my windows (it's a NY bus thing), but I found that unless I put a bit of a dome on both sides of the hole (making it like a steelstick rivet, sort of) it would pop out of the hole easily - like, it doesn't adhere to the material at all (this was in aluminum windows).

Bondo is pretty easy for little holes, although a random orbital sander is a must for that stuff.

Originally Posted by Danjo

Question: I’m removing the lights from the fiberglass ends. I’m going to reinstall these and I’m worried about the fiberglass holding the screw again. I suppose I could go to the next screw size, but was thinking about using something in the hole to hold the existing screws. Any ideas?

I second the rivnuts suggestion. I used them when I replaced my rear lights with LEDs. My original metal was pretty floppy, so I put a 1/8" steel plate behind the lights and ran the rivnuts through that and the bus skin. I used closed rivnuts so the screws would be watertight without needing to be gooped up with anything.

[Danjo]

I’m worried that a rivnut will crack the fiberglass. Anyone with firsthand knowledge?

Maybe I can jbweld them in

[banman]

Originally Posted by Danjo

I’m worried that a rivnut will crack the fiberglass. Anyone with firsthand knowledge?

Maybe I can jbweld them in

Use a back-up washer to spread the load.

[musigenesis]

Something else you might try is bondo metal, which is metal-reinforced filler that is harder than normal and tappable. When I replaced my headlights and headlight housings, some of the various screws had pulled out chunks of the fiberglass mountings. I cleaned the big chunk holes thoroughly and filled them with bondo metal and then redrilled the holes. I didn't tap them but just ran sheet metal screws in and they're holding well. The filler seems to adhere well to the fiberglass.

[EastCoastCB]

I like the fiberglass bondo type fillers.

[musigenesis]

Originally Posted by EastCoastCB

I like the fiberglass bondo type fillers.

That stuff doesn't hold a screw very well, though, does it?