Guide coat for block sanding question

[JC6715]

I am using a high-quality epoxy primer, but a rattle can of Rustoleum auto primer for my guide coat.

Do you all think there will be any adhesion or compatibility problems in the low spots where the Rustoleum doesn't get sanded off?

Should I lightly sand off the Rustoleum in the low spots before using filler or more primer?

Thanks guys

 

[ron67fb]

No experience using Rusto as a guide coat, but I have had it lift over cracks in repair areas. I sprayed the Rustoleum on just to keep the bare metal around the repair from rusting and the cracks, which were previously filled, primed, and blocked, had lifted the paint almost immediately. Maybe it was my prep, but if it was then why did the primer stick and show no flaws during blocking?

I would suggest the 3M dry powder guide coat. Expensive at about $40 a container but it's well worth it. No drying time, no spray bomb blowing in your face because of wind, and I've used it for both wet and dry sanding. You prime and wait for the time-to-sand window, wipe this stuff on, and sand right away. It also spreads easily while you sand so a little goes a long way.
Eastwood Co. - 3M Dry Guide Coat With Applicator

 

[chromedog]

dont use rustoleum for the guide coat... it dries so slowly, you will need to let it sit for days before you can sand it. not that you are putting on enough to build a film, but you will clog more sandpaper than your wallet will allow. go with any cheap, rattle can enamel, or trim black.... look for the works fast drying on the can...

 

[JC6715]

Thanks guys. No more Rustoleum...

 

[mustangmike6996]

rusto. is horrible... it is made with fish oil... (at least the paint is) and if you use an actual base/clear paint it will not stick to rusto... unless the rusto is sanded to bare metal again...

 

[zookeeper]

I used plain old lacquer primer, it dries nearly instantly, sands easily and is cheap. But next time I plan to use one of the dry-guide powders, they look like a good way to go, and you don't need to mask anything off before you use them.

 

[NasaGT]

I've heard that those dry guide powders work really well. I'm definately going to use one of those the next time I'm doing body work.

 

[rusty428cj]

I just use left over paint from another job reduced alot. Gets rid of paint laying around.