The Stovebolt Site Forums The Shop Area Paint and Body Shop "Unconventional Fixes" - Will they work?

As I'm sure many of you remember from being 15, getting your hands on a welder and sheet metal can be a pain. So, my question is as follows: Can I JB Weld small pinholes and expect them to last long enough to not rust further until I get extra sheet metal? I am very well versed in fiberglassing, but I have heard if I try to make fiberglass parts of panels, they will expand to fast, and drop out of place from the original part. Is this true, and is there anyway I can stop this behavior?

The only way to stop the rust is to eliminate it completely. JB over rust will not be a very good fix, as it most likely will not stick very well, and the rust will continue to spread. best bet is to wait until it can be done properly.

problem with fiberglas is differential temperature response causing the bond to fail enough to allow corrosion to continue and eventually causing complete release - fairly soon unless you use the special resin designed to bond with [clean] metal

JB Weld could work, but better for pinhole patches is solder, using a good hot iron and plumbing solder/paste flux .... next best would be 'all-metal' body filler .... whatever you do, mechanically cleaning the area well to completely rid it of rust is mandatory, use a rust converter if you can afford some

Bill

If you are looking for a not-too-temporary fix (non-replacement of metal) to filling small pinholes, try POR-15.

First off, you are asking about a temporary repair until you can replace the rusted area so let's address the your question.

Rust, unless protected from air and moisture will continue to spread. If you can gain complete access to both sides you can treat the rust and stop it's spread. Chances of this are slim so no matter what you do it will eventually fail. If you can access the back of the rusted area, even if not completely, you have nothing to lose by treating it with POR 15 or Eastwood Rust Converter.

The quickest, simplest way to make the outside look right would be to grind the metal, tap it in to form a depression and patch it with a fiberglass impregnated filler such as THIS. Don't let that price scare you, it's also available in smaller cans.

This will last for a while - how long depends on how well you treat the rust on the inside.

I remember what it's like to be 15 with a limited budget and skills, so that's my best suggestion considering the circumstances and your original question.

Thank you guys for all the answers so far, and I notice the common theme of "clean the rust out." I went a little overboard with the grinder last evening, cut out a bit much, that's the reasoning behind the fiberglass. Czechman, thanks or the link!

A very good solution and something that is almost essential to old truck repair is a flux wirefeed welder. Harbour Freight and others sell these for about $100 operates on 115 ac. A angle grinder is available for about $20. Any one can weld light work with one of these.Works well to add metal to small holes . Grind the excess and you have a good repair. A little practice and your repairs will be long lasting. A trick that a guy told me about is "nozzle dip" available from NAPA. Dip the nozzle into the dip and it helps make good contact and helps the sputter. The fiberglass and other fillers will work better if the metal is replaced rather than filling a hole with resin.
Rember that a bad welder is a good grinder.

Good advice if you're replacing metal but you can't weld pin holes in rust as he stated in his original post asking about a temporary repair.

59 rolling iron,

Are you able the get to both sides of the sheet metal pieces that you are referring to?