Quick sanding/primer question

[DCRocks]

I have finished removing all the paint/primer from my blaster, and was starting to sand it smooth in prep for applying the primer.

How fine a grade of sandpaper do I need to go to, before I spray the primer?

150? 220? Higher?

Does it really matter that much?

Is the smoother I can get the hull, the better for the primer layer?

Or is there a point where the fiberglass will be to smooth for the primer to go on the best?

 

[Ericfox]

I was told 220 is the standard if you are applying a primer... someone else can confirm or correct

 

[beachedflunkey]

300 or 400 wet, whichever you or sLowe's has handy. All the 220 I've seen is for dry sanding and goes fast...

 

[spazzit]

useually we start with 320-400 after the primer wet sand with 600 to get ready for paint. i wouldnt go less than 220 wet or dry for primer because of scratches

 

[Soul Man]

Xotic Colours recommends to sand bare fiberglass to 180 grit. http://xoticcolours.com/technical_primercoat.htm

I would leave the primer fairlly "rough" with 180 or no more than 220. You want the primer to get a good hold on the ski. You'll be sanding your primer flat, so you aren't going to see any sanding scratches once you start putting basecoats down. Getting the fiberglass smooth (400 grit) isn't really important as the primer will fill in any scratches. Getting your primer smooth (4-600 depending on your basecoats) is important.

Make sure you block your hull down really well. I blocked the crap outta mine and am now getting ready to spray my third round of primer as I keep finding high spots that I sand through :squint: I think I have it flat now :fingersx:. I'm using 220 grit over what is now mostly primer with some patches of exposed hull. Assuming I don't burn through again when I block the primer, I will sand that with 400 grit before basecoating. Some would use 600 under a metallic paint, but Xotic says: "Never final sand with finer than 400 grit or adhesion of Basecoat will be impaired. " so check with your paint manufacturers recommendations.

 

[suva]

220....

 

[Mark44]

I never sand I have Katie do it, the glory is in the spraying.

Mark44

 

[monsterSJ]

i sanded mine with 400 turned out good

 

[Vumad]

I used rustolium. I sanded with 80, sprayed a single coat and let it dry for a week.

Looks pretty good from the shore. I figure the stuff on the water should be the stuff worth taking pictures of.

I derail... I can't stay on topic. It's a disease.