Filler material for thin sheet metal prior to painting?

[trader4]

I'm looking for suggestions on what kind of filler material to use to repair dents/dings in thin sheet metal before painting. I'm painting the door to a ice maker from my boat. It has some dings that need to be filled in. Last time I did this I used fiberglass. That was a bitch, because the fiberglass is very tough and hard to sand, while the door material is thin and flexible. So, if you try to sand it, the sheet metal flexes from pressure making it hard to sand and get smooth. I finally got it done ok, but it was a lot harder than it had to be.

So, what I'm looking for is a softer filler that can be used on metal. I thought of auto body compound, but I think this is similar to the fiberglass I used last time. Good for a tough fender where you can use a sander and apply pressure, not so good for this. There must be something between joint compound which won't work and fiberglass, which is just too damn hard. Any ideas?

 

[scott_z500]

I would also use bondo.

 

[Duane Bozarth]

This is an opinion based on no experience for your exact circumstances.

I think fiberglass and auto body filler are two really different but related critters. Bondo (auto body) filler is pretty easy to sand provided you don't glob it on. Hand sanding with a fine grit paper (wet or dry) is an option. For example I can shave or scrape it with a sharp blade. For the $6 it will cost try it on a ding before you do them all. I do know that most painters use it for repairs on metal entrance doors.

Colbyt

There are different types of body filler--some w/ and some w/o fiberglass. As noted, the non-fiberglass types are much easier to sand smooth in such an application.

 

[Goedjn]

I'm looking for suggestions on what kind of filler material to use to repair dents/dings in thin sheet metal before painting. I'm painting

So, what I'm looking for is a softer filler that can be used on metal. I thought of auto body compound, but I think this is similar to the fiberglass I used last time. Good for a tough fender where you can use a sander and apply pressure, not so good for this. There must be something between joint compound which won't work and fiberglass, which is just too damn hard. Any ideas?

A planishing block and a mallet. Take the door apart and hammer the dents out.