Clear on top of painted surface

[reidy]

Hi all,

I am about to refinish an old timber dresser of my mothers. It currently has an old painted finish and has been sanded back with 240 grit sand paper.

I plan on spraying it white so that she can do some folk art painting on it before i give it a final clear coat to finish it off.

I am unsure of what is good and bad in terms of polyurethane over the top of painted surfaces.
I have some wattyl estapol(satin) which i was intending to use for the clear coat ( turps based). Can anyone recommend a paint(water based, turps based etc) i should use as the base coat.

I plan on spraying it with a Star S-106 1.7mm nozzle.

Thanks again.

Reidy

[ubeaut]

Probably an acrylic water based paint for base and maybe white shellac for top coat over painting. I'm presuming she's using acrylics.

White shellac won't change the colour of the painting where most other finishes will tend yellow it. I'm surprised there isn't a clear finish made specifically for this purpose. Maybe there is. Try asking at the art supply shop.

What ever you choose to use it would be a really good idea to try oit out on a scrap piece of timber before doing the final thing to make sure everything is compatible and there will be no crazing, wrinkling or bleeding through of the base and painting into the top surface.

You would also be wise to make sure the surface to be painted is stripped prior to painting as it may well have been contaminated with silicone or oil or wax etc which the sanding may not remove. This being the case it probably won't accept the base coat. Good test is to water down the base paint and wipe it ofer the surface to see what happens. If it goes on evenly there shouldn't be a problem. If it shows spots that appear to be dry os streeks that don't cover the old surface or anything other than a complets coverage then the surface will probably need to be stripped properly.

Hope this is of some help.

Cheers - Neil

[reidy]

Thanks for the reply Neil.

I think she has used a clear over previous things she has painted but they have mainly been ornamental items, therefore dont not need a terribly durable finish.

Is the white shellac a satin or gloss finish? and also which application method gives the best finish? What sort of coverage do you get from the 500ml bottle.

Thanks again for your help.

Cheers
Reidy