Applying Filler???

[rix313]

I'm wanting to apply some filler. I have abig tub of Upol on a yellow tin.

Do I need to rub down the surface first? If so what grade paper do I need?

What do I need to use to then flatten down the filler?

[baptie0]

filler goes onto bare metal. use wet and dry paper with water to remove paint from area to be repaired, apply a thin layer of filler first, once dry then you can apply more to repair the dent, then sand to the correct shape. use wet and dry paper with water in grades from p400 up to p1000. then you are ready to prime.

[rix313]

Tah

[town325i]

you DONT use water on filler at all because filler will lift with water in it when heated

[E30Mark]

Filler is bulked out with talc, which will soak up the water like a sponge and rust the panel beneath. Also for best results you want to let the filler dry for at least a week prior to painting in my experience, as it continues to 'sink' whilst curing / drying out.

You can use a fairly coarse paper (80 / 120 grit) to sand the filler to shape. Your best bet is to knock the panel back to shape and use the least filler as possible. Then use stopper / high build primer and fine paper to finish.

Filler / paint work is a skill which can't be perfected on your first attempt, personally i believe you either have the 'knack' or not.

Also painting in this weather, unless you have a heated garage is a no no! you'll end up with moisture trapped under the filler / paint and eventually the paint will 'micro-blister' as the dampness condensates under the paint.