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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> emulsion paint as wood undercoat https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1173637354 Message started by Tessa on Mar 11^th, 2007, 6:22pm

Title: emulsion paint as wood undercoat
Post by Tessa on Mar 11^th, 2007, 6:22pm

Hi,
I have started painting my kitchen cupboards white.. they were a wood base... so I wire wooled them then gave them a emulsion undercoat.... I have just given them a coat of paint with a cupboard paint from crowns range, only thing is it is chipping off :-/ what do I do.. im tempted to paint them with gloss paint but im woried that will chip off too....im assuming its cause i used emulsion as my under coat :'(

Title: Re: emulsion paint as wood undercoat
Post by hamilton on Mar 12^th, 2007, 6:59pm

Hi Tessa. What do you mean by 'chipping off'? Do you mean flaking off or giving it a clump and then it chips?
Using emulsion paint as an undercoat is not good practice. What type of emulsion was it? Was it a silk or matt emulsion?

I know some people use matt emulsion as a wood primer and the annoying thing is, it can often work; although the finish doesn't look as good as a proper oil based primer.
How long ago did you paint them before it started chipping?

Title: Re: emulsion paint as wood undercoat
Post by Tessa on Mar 12^th, 2007, 7:57pm

hi I painted the emulsion on tues last week, think it was a matt emulsion... and painted the cupboard paint on sat.. it was chipping pretty much as soon as it was touch dry.. with in six hours :(

Title: Re: emulsion paint as wood undercoat
Post by Tessa on Mar 12^th, 2007, 7:58pm

what i meant by chipping was i could scratch it off with my finger nail.... not even hard scratching...

Title: Re: emulsion paint as wood undercoat
Post by hamilton on Mar 12^th, 2007, 10:05pm

I assume that you are talking about cupboard makeover paint. I have never used it, so am not familiar with it. Do you wash the brush out in white spirit or water? (That's really a patronising way of asking if it is oil or water based paint.)

It is safe to say the emulsion was dry when you put the cupboard paint on. The cupboard paint (if oil based) although touch dry, was nowhere near dry after six hours, it would need about 24 hours to dry properly.
Check the back of the tin to see how soon you can apply the second coat.

When you scratch it did it go back to the wood or to the emulsion?
I have to ask, why are you scratching it?

Sorry about the questions Tessa but as I can't see it it has to be a sort of process of elimination. :)

Title: Re: emulsion paint as wood undercoat
Post by corablimey on Mar 14^th, 2007, 6:15pm

The problem is painting over wooden cupboards with emulsion :o, never use emulsion as an undercoat, I hate it when people do that, that is a common pratice on new build, 2 coats of emulsion then gloss, terrible......

Are they real wood, or wood effect?

If they were wood effect, then you apply 'ESP' primer, then do your oilbase undercoats, then your top coat, 'Satin'

If they are real wood, you have to sand the doors to get a key, then use oil base primer, then oilbase undercoat, followed by your oilbase satin, eggshell or gloss.

The primer will stop the future coats from chipping or peeling off, failing that, try putting 2 coats of matt clear varnish over the crown paint.

Title: Re: emulsion paint as wood undercoat
Post by Twobarrows on Mar 18^th, 2007, 12:10pm

This may be a bit of a silly question (but I am a bit of a silly boy:-), but what exactly are the differnet functions of primer & undercoat & why are they two seperate products ?
Yours, in blissful ignorance............

Title: Re: emulsion paint as wood undercoat
Post by hamilton on Mar 18^th, 2007, 10:40pm

Like any building has to have a good foundation, so does a paint system.
Usually this consists of a primer, undercoat and finish coat.
The primer will be the foundation for the other coats and is the most important part of the paint system.

Different surfaces require different primers. Some surfaces are absorbent, some are non absorbent and some are chemically active.

Metals, glass, melamine, glazed tiles are all non absorbent and without the correct primer the following coats of paint will chip or flake off. ‘ESP’ (easy surface preparation) being an example of a suitable primer. Zinsser also make several primers for the same purpose.

Plasterboard, paper etc are absorbent but not chemically active. Building blocks, cement rendering, plaster are absorbent but are chemically active. Both need different primers. If you are going to paint a plastered wall with oil based paint, then you must use an alkali resisting primer; if you don’t the paint will go soapy (saponification).

Metals need a different primer to stop them rusting.

The undercoat follows the primer and should form a good base for the finish coat.
Usually one or two coats of gloss paint follow the undercoat. Satin finish, eggshell etc are self undercoating so need no undercoat, just several coats of whatever it is you are using.

As to having seperate products there are some combined primer/undercoats, usually acrylic and for use when in a hurry.

Title: Re: emulsion paint as wood undercoat
Post by corablimey on Mar 19^th, 2007, 5:40pm

WOW Hammy!!!!!, very impressive, :) I knew you had a way with words, couldnt have put it better myself.

Title: Re: emulsion paint as wood undercoat
Post by hamilton on Mar 19^th, 2007, 8:52pm

Cora, I think I got a bit carried away. ::)

Title: Re: emulsion paint as wood undercoat
Post by Tessa on Mar 26^th, 2007, 8:55pm

Thanks every one, i have actually removed all the paint and sanded the surfaces and im starting again. it chipped back down to the wood :-( and came of really easily :(

Title: Re: emulsion paint as wood undercoat
Post by Twobarrows on Apr 17^th, 2007, 5:34pm

Nice one Hammy, lifes an education 'ere innit :-)