Sheet metal screw help

[wireguy]

You can't successfully use self tappers in sheet metal because the drill head is removing the very limited thickness of material you are trying to hang the threads in. If you absolutely must use sheet metal screws bang a hole in the sheet metal with a very sharp scratch awl, which will add to the amount of material the screw threads have to hang in. The ultimate solution to the problem of screws in sheet metal is nutserts. You can but a nutsert setting tool on ebay quite reasonably, the nutserts are quite inexpensive when bought by the hundred. Something like 10/24 will do almost anything you will want to fasten. I have ended up buying 8/32, 10/32 and 1/4 20. Once you use these you will never want to be without them.


https://www.ebay.com/itm/Rivet-Gun-K...wAAOSwdFdc203n

[Strata]

Originally Posted by CMORGANSKOOL

I bought self tapping screws from home depot that I can remove and reinstall. They're called self tapping zinc coated metal joist screws I think They come in a black box. I'll take a pic thursday when i'm on the bus. I've used them all over the bus. I think these are the screws. https://www.homedepot.com/p/Everbilt...1042/204275119

Another alternative is to use the screw clip or anchor https://www.webstaurantstore.com/jad...xoCQ6cQAvD_BwE

I'm wondering if, for me, the 3/4 inch screws will be too long and penetrate the outer shell of the bus. I'd be using them to attach 1/8" laminate over reflectix, rather than a more substantial ply.

[oleman]

Originally Posted by musigenesis

Yeah, that's the kind I'm using (only with a gasket washer as well) but they don't seem to be coming out. Maybe that gasket is hosing things?

You probably stripped the threads out of the sheet metal when you installed the screw. That type of fastener is basically a single use screw. Sort of a self drilling pop rivet widly used on gutters and such.

[Choo]

Another idea is Drill oversize hole on the inside of door. Drill hole in plywood for a bolt. Maybe a 1/4-20. Counterbore oversize hole so nut fits in allowing the plywood to sit flush. Then JB Weld the nut to the door. I’ve had a lot of success with this product.