Re: The Typhoon is going in for a complete paint job. Any tips?
ShuggsRR said:
Whats the point of sand, primer, sand primer? big thick base makes it harder to chip? or keeps the shine in later down the road?
Each time you prime then sand until the final coat of primer you end up removing most of it so you really dont have a "thick base" under the paint just a smooth surface. Each coat of primer fills in minor imperfections and when you block sand it you remove the primer, for the most part, everywhere but the low spots/imperfections. This gives the paint a nice flat surface to be applied which makes for a nice smooth finish (assuming the paint is applied correctly).
The final coat of primer that you wet sand is what the paint adheres to so thats why you use a finer grit paper (600 grit) and water as a lubricant while youre sanding. It smooths the surface to a point but still gives the surface a microscopic "tooth" for the paint to grab on to. If you use too fine of a grit then the paint cant adhere to the primer (think how good paint peels off of glass) and the first time you washed the area with high pressure water like a car wash the paint would blow right off (you'd be mad). If you used a more course grit paper then you would leave scratches that while not easily visible to the naked eye would stand out like a sore thumb once paint was applied and the light was reflected off of them unevenly.
All this blocking/priming seems like a lot of work (it is actually) but youll hear time and time again that paint work is 99% preparation and 1% paint application and there was never a more true statement. Put cheap paint on a first class prep job and it will like like a show car until the cheap paint is dead from UV but put the most expensive paint you can buy on a crappy prep job and it will look crappy but last a long time.
ShuggsRR said:
Whats do you guys mean when you say block it?
The sandpaper is wrapped around something to keep it flat. Eons ago it was a "block" of wood before foam blocks became the norm...hence the term "block sanding" or just "blocking" for short. If you use your bare hand to try to sand something flat youll end up with a wavey surface since your fingers concentrate the pressure on the paper and there is less pressure on the paper between your fingers.
The first time you sand the cladding you can use your bare hand since all youre doing is lightly sanding to scuff the surface to give the primer something to stick to and subsequent coats of primer and block sanding will smooth the surface. Up to a point the more you prime and block sand the the more level/smooth the surface that the paint is applied to will be.
And is a DA an air sander?
Yes.
BTW, are you doing the body work/sanding? Reason I ask is that by the above questions Im guessing you have never done body work before and if thats the case dont touch the cladding with a DA. Do it all by hand or youll just make a ton more work for yourself or whoever has to do the finish work on the cladding before painting. Hand sanding takes a LOT of effort to goof something up but a DA will ruin plastic parts in a matter of minutes (or less) if handled by inexperienced hands. If you have a body man/painter standing there coaching you over your shoulder thats different othewise leave the DA on the work bench. :2cents:
.