Matt over silk paint

pineapple

Can I paint over a silk emulsioned wall with matt? I've googled it and am getting mixed results. Some say its ok, some say to paint the wall with undercoat or some sort of sealer first, or simply sand first. Thanks.

erdd2

Yes however the matt may slide and need more than one coat. The first coat could be an undercoat, sealer, primer, whatever and is less messy than sanding, albeit may not be as cost effective.

betsie

I have done it loads of times without any probs. You will need 2 coats min if not a dark colour and use a decent quality pait and a roller.

BigBananaFeet

I've never had any problems painting matt over silk.

keystone

No most likely it will craze/crack. Abrade it with 240 grade first (although this doesn't always work) or better still undercoat it or apply a coat of softsheen.

Matt paints are relatively inflexible irrespective of formulation. Silks are more flexible. So, put something inflexible over something that moves can cause cracking. When it happens it looks kind of like a crackle glaze. The cracking happens as the paint is drying and is caused by the silk absorbing a moisture from the matt you're applying on top. This causes the paints to shift around at a microscopic level and although this causes the matt to crack, adhesion remains good & it doesn't flake.

You may be lucky and it won't crack but if it does then you then have no choice but to go down the undercoat/soft sheen route. It ain't worth the risk.

Cheers

pineapple

Thanks. Would traditional undercoat (that you use for wood) do? And if I use this should I thin it first? I have some turpentine substitute - can I use that to thin it?

keystone

pineapple wrote: »

Thanks. Would traditional undercoat (that you use for wood) do? And if I use this should I thin it first? I have some turpentine substitute - can I use that to thin it?

Yes standard spirit based undercoat and do not thin - it will go everywhere!

Cheers

pineapple

Just to lay I eventually chose the option of simply sanding. It was not as messy as I thought it would be. The new matt coat adhered well and seems to have dried out with no problems. Touch wood! Thanks keystone and others for your advice.