painting concrete to concours finish

[lexi]

Can it be done? I aim to pour in Concrete.........possibly Polymer Concrete. Hoping to make a GRP mould to get a very fine finish.

Would like to then paint this in high quality gloss . Which paint system would give best results for a high lustre finish for indoors?

 

[jaykay]

well it's a new one on me.talk to international paints. they do paint for just about everything.
bear in mind it will be slippery when wet.

 

[lexi]

I wont be standing on it Jay............it will be a plinth for a Hi fi turntable.

Would none of the usual epoxy primers do?. Polyurethane is compatible with concrete but no great finish. Polyester Flowcoat may be compatible and it may polish up?

 

[gavuk]

In a former life i was a fitter at a building products factory ,we used to make a slab with a cheap concrete backing but a marble type face,which were ground and polished ,looked very expensive ,but would need to obscure the edges,may be worth looking for ,or something similar?,products were made by Camas building products

 

[lexi]

Thanks Gav. There are polymer concrete window sill (external) on the go. They are cast and finished as smooth as glass........with no paint. Lots of the recipes are a secret

When I was on site many years ago screeding granite, Toffolo Jackson the Terazzo specialists came behind us. They kept their mixes and processes all hush. We used to call them The Masonic Marble men

Much more info is available now on web but not all. Any more thoughts on painting?

 

[dave_sussex]

You been watching James May's Man Lab Lexi? he made a concrete sink unit!

 

[Norm]

Have you considered JAPLAC i used it a few years ago on a slate plinth that had been damaged and the finish was very good and hardwearing once cured. If you are going for a painted finish you could apply filler then sand the surface prior to painting so you could save money and not have to be too particular with the concrete mix.

Hope this helps

Norm.

 

[Ratty]

Is there a reason you're using concrete? If it's being painted it's obviously not for aesthetic reasons. If it's for it's accoustic properties (or just for weight) maybe you could cast a skin of resin (with some glass fibres like choppies so it bonds) and back-fill with concrete, that way you could use a conventional car type paint. Just a thought.
Otherwise, there is a moisture cure PU concrete sealer called G4 which is used for sealing ponds. Available in clear, black and maybe a few other colours. I have used it in the past to seal MDF which had to be spray finished to a very high quality gloss lacquer. I seem to remember it rubbed down fine with Wet & Dry (when fully cured) and formed an excellent base for 2 pack. Read the instructions carefully.... You have to second coat after something like 4 hours or leave it for a week!

 

[Will1983]

if your mixing your own concrete use a fine gravel as aggregate and mix it fairly wet with a high cement to sand ratio. a god mix ratio would be 4 aggregate, 1.5 sand and 1.5 cement

once you've filled your mould give it a good vibrating, if youve not got anything to vibrate it with do lots of tamping and a few taps all the way around the outside of the mould to get the air bubbles out of it. then let it hydrate (go off) for a few days in a warm place before removing it from the mould, a week would be better or you might damage the corners.

if your mould is nice and smooth to start with the fiished concrete surface should replicate it minimising the amount of filling you'll need to do if any.

 

[lexi]

Thanks everyone. Didn't see James May thing no. Having worked with sand cement, concrete, plaster for over 35 yrs that aspect is no probs and I know what can be done

Ratty: Yes it is for accoustic propertys ie. mass but it has to look the part for vanity .

Will: thank you! your thoughts are same as mine regarding method.

I have used Japlac. Never considered what it was made from though.

International will know what paint is suitable for concrete. Ferro cement hulls will need the very same paint as will be suitable for mine. It may even be the suitable primer and then their Toplac. Thanks Simon.

Norman: I had considered leaving a slight honeycomb finish then Bondo. It may happen as you can get a great finish with filler. Testing will show what's what.

The larger deck in walnut is what it's about. That is layered birch ply with walnut veneer and weighs 42lb. Concrete version will be heavier and shaped with contour.

 

[MarkMG]

you wanna save yourself the trouble and get a nice shiny cd player, I'll take the old stuff off your hands for you.

Otherwise, i'd use perspex or similar as mold, get good a finish as possible, polish off concrete with wet 'n' dry and use a high glos concrete paint and cut back to shine.

 

[gavuk]

This is the polished slabs we made ,worth looking at in the flesh ..I used to think they looked expensive ....now i know they are !
bradstone polished

 

[lexi]

you wanna save yourself the trouble and get a nice shiny cd player

,

Yeah . bit like selling a Portamig and buying a Sip 130

There are two cd players in that system.......one has a Valve stage too

Thanks to all for ideas.