I plan to start doing some rust repair this week on my car. The first spot will be patching 2 holes in my fenderwell. I am wanting to remove the undercoating so it wont catch on fire while I weld. As well, see if there is more rust spots I'm not seeing yet.

Any good tips, advice, chemicals to use?

A small butane torch, a plastic scraper, lacquer thinner, elbow grease.

JamesC

wire brush on a drill

This just smears it around.

mine was thick and dry enough that i was able to bust/pick/scrape it all out with a 1.25 putty knife, no heat or brushes, didnt take long either. It just scratches the metal up a bit, but if you repaint it there is no problem.

HAHAHA! Ummmmm ... keep the torch away from the lacquer thinner. Although that would take it off. lol

I'll be re-undercoating, yea.

you have to get the proper wire brush....one that is bent towards the ends of the wire so it bites into it....i use this a lot at my body shop....works like a charm...contours to the shape of whatever your doin and cleans it to the metal...

ovencleaner, scotchbrite pad, and a putty knife.

did my floor pans yesterday ovencleaner does work spray on let sit 30 sec sand or scothbite it then use putty knife might have to do this 2-3 times

charged? you got a pic of what your talking about?

redbird, what brand are you using and I'll go pick some up and give it a try.

if your takin about the rubberized undercoating, dont bother, its junk.

I used the heavy duty ovencleaner I think any brand will work

give it a try you'll be suprised

RUBBER GLOVES if using the oven cleaner

oven cleaner didnt work for me.

So far I have just been letting it burn while welding.

they actually sell a spray on remover that you can get from eastwood. works really well. never tried the oven cleaner method so i cant compare to that though. if oven cleaner doesnt work, you might want to look into that