Sealer Paint Steps Question

[bry2403]

Hello,

Just a couple quick questions.

I am starting to paint my bike using a Dupont bc/cc. The question I have is, is a sealer necessary between steps? And if so what one should I use? I have searched the site but cannot seem to find sufficient information.

Also I am going to be painting fiberglass, steel and plastic parts. Do the steps below look OK?
A. Plastic and Fiberglass
1. Adhesion promoter
2. Primer surfacer
3. bc
4. cc

B. Bare Steel
1. Self etching primer
2. Primer surfacer
3. bc
4. cc

Also would the adhesion promoter be sufficient to coat the backside of the saddlebags and fairing where they were not originally painted before applying primer/surfacer?

I realize that I will have to sand in between applications but just trying to make sure I have the main steps lined up.

I have already sanded all the parts with 600 grit paper, which I believe will allow enough bite for the primers

Thanks for the help,
bry2403

 

[MPAVLAS]

IN MY OPINION 600 GRIT IS TO SMALL
MAYBE 400-500 SIKKENS CAR REFINISHES DEMANDS THAT WE DO IT THAT WAY OR THEY WONT WARRANTY IT AS THE REST OF YOUR PROCESSES THEY SOUND PERFECT BUT YOU DONT HAVE TO SAND INBETWEEN COATS IF YOU SPRAY THE NEXT COAT WITH IN TIME

 

[rex]

600 is pretty fine from the start but if you don't need to prime the stuff you can go right to sealer-it's the original paint you 600'd right?I don't trust adhesion promoters myself.On the fiberglass just sand it and prime it,same for the plastic but if there's bare spots of raw plastic put a little plastic primer on them and then some primer-sealer or surfacer.On the steel parts you only need etch primer on the bare steel,it's not good on paint.I sand my steel with 180 or courser before etch priming and then I epoxy it.You can probably use your primer over it but check the P bulletin of the etch primer for compatable topcoats.

On the sealer,I prefer them for a few reasons.They give better color coverage and holdout,they help minimize sandscratch swelling,some primers don't like to be based over,and they provide some cushion to avoid chipping if you don't have primer down.For an example my plastic primer is like water and you put 1 thin coat on-there's basically nothing there.You can base directly over it but if you don't put at least a sealer over it the paint will chip easier since there's nothing to 'give' between the paint and the plastic.

 

[bry2403]

Thanks for all the info guys.

I guess before I prime I am going to wet sand the fiberglass and plastic parts with 500 grit and the steel with 180 and then continue with my primer steps. All the parts I sanded with 600 were the original finish, which did not look too bad.

Also I have decided to use a sealer. I figure if I am going to spend the time I might as well do it because I will probably regret it if I don't.

I will post back when I get the priming process done. I am fairly new to this so I am trying to take some time and learn along the way.

Thanks,
bry2403

 

[rex]

You can actually go a little courser on the glass and paint if you're going to prime it with a sanding primer.I like 240-320 on a DA (which is quicker and not as messy) or 400 wet.It'll cut down a little time for you.When you sand the primer before sealing is the time to get fine like 600 wet.