Body Filler Preferences
Please clarify. Are you doing poly high build, then 2K high build?
Thanks.
I'm using polyester primer surfacer (high build), guide coated and sanded on a 2' board with linear P320 adhesive backed paper, until I'm happy with how flat it is. This is followed by remasking out to cover all areas that I didn't include with polyester, for a urethane primer surfacer (high build).
I don't use polyester primer in the jambs, window areas, gutters or any other place that doesn't require a lot of straightening attention. Any areas that I do not use polyester primer on get coated with a light coat of self etching primer over the bare metal, before urethane primer. Epoxy primers don't need this and can also work.
I sand all of the bare metal with 80 grit paper on a DA for primer adhesion. I've found that 180 is fine on sound prior coatings that are left in place (depending on what is done), but it isn't strong enough to cut steel for good adhesion.
I use panel bonding epoxy on all of the seams, sanded with 180 and followed by a seam sealer that I smooth out with laquer thinner and my finger in a non-latex glove, then sand again with 320 before any primer on those areas to prevent cracking or separating.
I cut the urethane primer with 600 grit (p600 is too coarse) for good metallic layout and I nib each coat inbetween base color coats, going around by hand to get rid of any dust or uneven layout, followed by a final light coat of base. I usually back metallics down and do slightly lighter coats only, to prevent striping/ banding and end up with about 10-13 coats of base. some solid colors get away with about 2-3 medium coats.
Clear goes on light on the first coat left sort of dry in orange peel, let it sit for 30-40 min, come back in with 2nd full medium coat and immediately follow up with 3rd coat on horizontal stuff that takes more UV abuse and lays out nice n flat for color sand.
Color sand lays out with soft backing pad w/ Kovax 1200 dry, followed by Kovax 1500 dry on the same DA, wool pad and egg crate black foam with Meguiars 105 with wool and 205 with foam. FWIW Meguiars is owned by 3M and is cheaper. Kovax blows 3M Trizact away, for color sanding, because it's dry sand and you can actually watch what needs more sanding, as you do it, instead of drying with a squeedgie block and making a huge mess, to check in between sanding.
