E30 Trunk Rust- Plexi or Steel Patch?

[pjens]

Cancer towards the front of the car above the frame support behind the spare tire well. Gas filler line is right beneath the cancer. I have a Harbor Freight wire feed and struggle to get a good bead on sheet metal.

Would Plexiglass and a sealant such as epoxy be a bad idea? It is in an unseen spot regardless.

Otherwise, the way I see it I will need to drop the gas tank and the rear diff, weld in my patch and paint inside the trunk and the bottom side (probably with rhino liner).

Any opinion appreciated.

[JGood]

I'm not sure what your plan is with plexiglass. That's a clear sheet of plastic, sort of like glass. You may have meant fiberglass?

The only proper way to fix that would be to remove all of the rust, weld in patches, seam seal it, and paint it. Otherwise the rust will continue to spread and eat up more of your car.

[pjens]

thank you for your thoughts JGood. Fiberglass may be an option as well, but I did mean Plexiglass. I was going to cut plexiglass into a proper sized patch, remove the rust, drill holes around the outside edge of the plexi and around the outside of the hole in my trunk where the rust was removed, and use small bolt/nut through the drilled holes to secure the plexi against the sheet metal. the epoxy or silicone would be laid in a bead before tightening the bolts down, creating a seal.

Too ghetto? Should I just drop the tank and dif and weld?

[LittleBimmer]

thank you for your thoughts JGood. Fiberglass may be an option as well, but I did mean Plexiglass. I was going to cut plexiglass into a proper sized patch, remove the rust, drill holes around the outside edge of the plexi and around the outside of the hole in my trunk where the rust was removed, and use small bolt/nut through the drilled holes to secure the plexi against the sheet metal. the epoxy or silicone would be laid in a bead before tightening the bolts down, creating a seal.

Too ghetto? Should I just drop the tank and dif and weld?

thats awesome you are taking initiative to fix this problem, props to you.
PLEASE do not do this to your car. re read what you typed and sit on it for a minute.

[nomansland92]

I wouldn't even bother with plexi glass. And you don't have to have a steady beed when patching sheet metal. The trick is a lot of spot welds then seam sealer cause no matter what you'll get small pin holes in your welds.

Dropping the tank wouldn't be a bad idea, I never liked welding around something full of fuel :)

Good luck