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JRSutton 04-09-2012 14:16:13 75.130.109.233 Report to Moderator	I'm new to "real" painting - so bear with me- but how would you use sandable primer. I'm using ppg epoxy primer - and it looks fine on most parts. But I'm starting to think about doing the sheet metal, and I want to smooth out some of the tiny scratches and rust pits. I'm assuming I would go with the epoxy first, then cover that with the sandable primer? is the primer supposed to go on and stay on as one solid coat of primer that you sort of smooth out with sanding? - or is the idea to sand most of that layer away leaving the sandable primer only in the little pits and scratches? Or somewhere in between? Obviously I'd use filler on anything deep. Just looking for a general idea of how it's supposed to be use. And curious as to which grit you'd do your final sanding with. Thanks. [Reply]   [No Email]
GordoSD 04-15-2012 15:30:18 208.53.247.197 Report to Moderator	Re: Sandable primer in reply to JRSutton, 04-09-2012 14:16:13   First app of sandable primer you need a rubber sanding block, a pail of water, a big sponge. and 220 wet or dry paper. You tear a sheet of paper in half crosswise, then fold it lengthwise and if fits the block perfect. Flip it over when worn. Dip the block in the pail and also the sponge. Start sanding and keep the sponge above the block. Squeeze it so new water is going under your block frequently. Wipe the whole area and with the shine from the water you can see defects. Reprime and resand as necessary. Fill tiny pinholes and scratches with spot primer from tube,and rubber pad. or use a one inch foam roller, and primer right from the can. Rolling a small spot is the equivalent of about 6 sprayed coats. When the fender or whatever is PERFECT, prime it one more time and then sand it with 360. Wipe with prepsol, blow it clean. Wet your floor down, tack the fender and paint. [Reply]  [No Email]
JRSutton 04-09-2012 17:54:37 75.130.109.233 Report to Moderator	Re: Sandable primer in reply to JRSutton, 04-09-2012 14:16:13   Thank you guys - I'll give it a try. [Reply]  [No Email]
Chief 83 05-02-2012 20:58:03 24.21.76.219 Report to Moderator	Re: Sandable primer in reply to JRSutton, 04-09-2012 17:54:37   All the comments on sanding are correct. To add to them though, you can use warm water (doesn't help the sanding but it feels better on your hands. Also I add a little liquid dishwashing soap to the bucket of water. I use enough that there are suds. It really helps keep the sand paper cleaner and that makes it last longer. With the price of good paper it makes a difference. Use quality paper. The stuff from Harbor Freight is not good. [Reply]  [No Email]
showcrop 05-03-2012 04:53:55 75.67.231.80 Report to Moderator	Re: Sandable primer in reply to Chief 83, 05-02-2012 20:58:03   Do your sanding in a well lighted area [Reply]  [No Email]
showcrop 05-03-2012 04:50:44 75.67.231.80 Report to Moderator	Re: Sandable primer in reply to Chief 83, 05-02-2012 20:58:03   Do your sanding in a well lighted area [Reply]  [No Email]
CNKS 04-09-2012 17:14:13 216.144.104.128 Report to Moderator	Re: Sandable primer in reply to JRSutton, 04-09-2012 14:16:13   Epoxy primer followed by urethane surfacer, assuming you have supplied air. 2 coats of epoxy followed by 3 coats of surfacer (allowing the surfacer to flash between coats) sand smooth with 400 grit and repeat with another 2 or 3 coats if necessary. If the surface is rough you can add a little topcoat (according to the manufacturers instructions) to the 2nd application so that the color is changed. The color will remain in the low places indicating where you need further surfacer. But, I seldom do it that way. You do not necessarily have to use the surfacer on the whole thing each time. A little hard to put into writing, but you will get the message once you have done it a couple of times. As to sanding, you don't have to sand it all off, just remember not to leave an excess on, considering that you still have to topcoat it. [Reply]  [No Email]
Rod (NH) 04-09-2012 17:06:50 69.131.62.24 Report to Moderator	Re: Sandable primer in reply to JRSutton, 04-09-2012 14:16:13   Yes, epoxy on bare metal, then sandable primer (better known as "surfacer" in my opinion) on top of it. The surfacer should be applied within the epoxy time window for the specific epoxy you are using. Depending on the depth of your imperfections, you may have to apply more coats of surfacer after sanding. You likely will sand most of the surfacer off. That's why surfacers are easy sanding. I don't like to leave any epoxy showing because I like to have a uniform color throughout before applying the topcoat. Sand first with 220 grit and finish with 320 or 400 grit prior to topcoat. It is best to leave a uniform color shade that is as smooth as possible before topcoating. Any blemishes that you can see at this point will only be exaggerated after the topcoat is applied. [Reply]  [No Email]
CNKS 04-09-2012 17:16:32 216.144.104.128 Report to Moderator	Re: Sandable primer in reply to Rod (NH), 04-09-2012 17:06:50   Rod, you were typing as I was -- 5 minutes later and I would not have posted. [Reply]  [No Email]
Rod (NH) 04-09-2012 17:39:47 69.131.62.24 Report to Moderator	Re: Sandable primer in reply to CNKS, 04-09-2012 17:16:32   Nothing wrong with having both of us post, even if we do agree on most things. I haven't done any significant painting at all in the last couple of years. Too many other interests that I get involved with I guess. [Reply]  [No Email]