Club 80-90 Forums

In between coats, is it best to go down through the grades of paper when flatting?

i'e not just flat the previous coat, with the highest grade used in each stage? If that makes sense!

Chris

Ah well Chris, this depends on what you are applying, first lot of primer/undercoat 180-220 wet dry, subsequent 220-400, prior to gloss/top coat of any type then 800 wet,
in the good old days of cellulose then subsequent coats nothing coarser than 1200.
As a rule think about it this way the coarser the paper you use the deeper tha scratches and the more work will be required with subsequent finer grages,
And allways wet flat undercoats/paints.
Mike

I usually use 400 between the first and second coat and then 600/800 and finally 1000 before applying the final coat. Much depends on the type of paint you are using and the 'quality' of the finish of the applied coat and whether you have specific problems such as overspray, runs (knife them!) blooming, orange peel,etc. Use soapy water and sanding blocks for flat panels and roll the wet n dry for curved surfaces, take care at edges as the paint is always thinner.

Thanks bud!!

I've been flatting to 400 grit for both coats of primer, and then upto 1200 grit for top coat. then 1200 grit between the first and second top coat.

Also whats he best way to finish fresh paint,a 1200 grit followed by rubbing compound then polish and wax???

Chris

What paint are you using?

It was just on my bumpers, 1st came up really well, Just doing it with acrylic rattlecans at the mo.

Is it different for 2ks,cellulose etc? I cant say I really understand any of the different paints.

Chris

Acrylic final coat I usually just cut back with rubbing compound and plenty of water, Celly I always flat back with 1600 or higher then compound.

Ok cheers, i tried that last time and it seemed to go white and pastie initially so ended up polishing back with a finer polish, which seemed to bring th shine back.

Any reason you dont take paper to acrylic paint?

If its applied properly it doesnt generally need flatting. There are different grades of compound but thin it down with a bit of T-cut and apply it wet and don't allow it to dry. Leave the paint to naturally harden, a week is good, longer is better. If you are getting good results with your method stick with it.

Leave it to harden for a week before flatting?

Only buy chance,lot ofhardwork for ok results..

Chris

Leave it, your top coat feels dry but the solvents penetrate the under coats and take time to fully evaporate. Patience.....then flat!

SWEEET cheers!

Chris

Have left the bumper to fully harden.

I've had a small what looks like reaction on a few areas of a panel I've painted. Only primer at this stage, is that because of grease etc on the panel, or previous paint reacting? It has had paint in the areas that have reacted, so bare back to bare metal?

Chris

No need, get some primer sealer (halfords or any good paint factors). Flat back to iron out the wrinkles then spray the primer sealer (its also a very good filler/leveller), flat back again. If you go 'through' put another coat of primer sealer and then your normal primer if you want. Spray can is best for you but you can brush it on. Other remedy is use anti rust primer available from any good motor factors but usually have to brush it on.

/cheers, just read up on it and that was also what i found, is it down to dissimilar paints then?

I'll get some and give it annother go!

Chris