P38 filler help

[matt_fsr]

Anyone know of a substance that you can add to P38 bodyfiller to make it runnier, i.e. more solvent, and thus make it easier to apply over the really fine holes?

The stuff I have has dried out a bit and getting it even close to a smooth top finish is getting pretty tough, even using liberal applications of water.

 

[matt_fsr]

Thanks Neil, I might have a look into that Upol stuff, wasnt wanting to spend much more on the repair but I dont mind a few £ more.

Yes I have wet and dry paper, 400, 600 and 1200 grit. I'm just using a foam sanding block at the moment to get the rough shape right, but the filler is about 4 years old I think

 

[matt_fsr]

Don't ever wet sand body filler, or get it wet at all for that matter, it absorbs water. For initial filler shaping you want to be using a stiff block and coarse paper like 120grit. Finish the filler with 180 or 240 then go on to hi build filler/primer, then you can let rip with the wet sanding but 600 is enough for paint.

Good point, thanks, but its a tad moot. The filler is going on Fibreglass, so as long as its' dry when I get to paint it it should be fine.

Would love to be able to keep it dry while I'm working on it, but as I dont have a garage then its' not happening. Doesnt need to be a 100% perfect repair, but I do want to get it pretty close to being like the original bumper shape.