Hi..Any advice greatly received.
I painted our bedroom with Dulux Matt at the weekend, one coat. There was a slight cracking effect going on when it dried, but I thought that a second coat would fix it. I have never used Matt before. Did the second coat yeaterday, and it has all well and truly cracked. Looks awful. Now I find that other people have had the same experience and it is probably due to Matt being painted on top of Vinyll Silk. Dulux have told me to get their Trade Primer. The Trade shop that Dulux recommended said that that was not the way forward. I repainted a small secion last night over the cracked area with a Silk, but the cracks have come through. I am thinking maybe a second coat of Silk on top might help, but I dont know if its going to make things even worse.
Any suggestions, (other than steaming all the emulsion off and starting again)???

I`d say its definately from putting the matt over silk.

What you need to do is give it a good hard rub down with silicone carbide paper 240 grit to key the surface (dont use aluminium oxide as the grittiness will scratch the walls), then apply 1 probably 2 coats of zinsser 123

http://www.decoratingdirect.co.uk/viewprod/z/ZINBE/

This gives you a blank canvas to start again, it will probably need at least 2 probably 3 coats of your emulsion of choice (because white is quite difficult to cover).
Also the fact that you used a one coat paint made the problem worse as its thicker. Its a good idea to stay clear of these ' wonder paints', use a good quality trade emulsion such as dulux, just make sure you thin it with water by about 10% to give it a bit of flow.

Generally when painting matt over silk you need to be thorough with your prep work, it needs rubbing down hard to take the shine off and give a good key, i have heard some people say that you need to put a binder coat of mid sheen on before the matt, but i`ve never done this and not had any problems

il second what darren has suggested, could try using oil based undercoat, instead of zinsser

hi,
Thanks for your replies. It was one coat of paint, then a second coat, not "One Coat". Anyway, I have bought the Dulux Trade primer, and a Dulux Trade emulsion . Cant face doing it all again though at the moment, as it all needs rubbing down and it is a bit demoralising when so much effort has been put in already., but I will let you know how I get on. fingers crossed.

me again
just incase anyone else has the same problem, the Dulux Trade primer worked, and the two new coats are now as they should be!! Just a shame that Dulux dont put the warning on the tin rather than telling you to check out their web site for "Preparation instructions!"

thansk for the warning

was about to apply a CROWN bathroom matt tomorrow as hate the dulux bathroom soft sheen. will rub doiwn walls and apply primer

Just want to say thank you so much for this thread and the outcome you have provided. Especially as it has worked for you. I have had the horror of the appearance of many 'alligator' cracks, hairline cracks and blistering in the new emulsion all because I redecorated over some soft sheen paint (Crown Indulgence) with my usual choice of matt emulsion.

Despair led me to try other 'matt' paints (Crown pbw, Wilko, B&Q ), tins of Polyfilla 'Hairline Crack' filler, sanding by hand 2 large walls all because I painted matt over sheen. Had never used a soft sheen paint before so I didn't know the sheen had to be abraded. Never trying out soft sheen again! Sticking with matt.

Thanks so much for this information!! :-) I will get this Dulux Trade Primer asap! :D

Oh No, I have moved house, decorated two rooms no problem and then the same thing has happened again in third room. I couldnt find this post first off, and phoned Dulux trade centres and Dulux themselves. All telling me to sand down, some telling me to use watered down emulsion, some to use soft sheen then try Matt again. I realised that they are still not educated in their own products. Off to find the Trade primer again!

Hi I have bought some Alkali Resitsant Primer (solvent based) as another decorator on another site suggested this. Before I make a mistake is this ok?? thanks.

I have had to put re decorating on hold, and cant face doing it all again. Just hate looking at the cracks and I cant remember which Primer I used. (I know it was Dulux but dont remember which one!). Its so demoralising.

Hi, I have applied one 750ml tin of Alkali Resistant Primer made by International to all walls. This was after I polyfilla'd all the cracks individually and sanded the walls down. I am now leaving the primer to dry for a full two weeks before I apply paint a watered down 'mist' coat of matt emulsion. at the moment it is so far so good.

thanks sunkat, let us know how you get on.

Hi, second coat of the Alkaline Resistant Oil Based Primer went on yesterday and it has dried. However as with the first coat I am allowing six weeks to dry hard before putting on a mist coat of matt emulsion. So far so good. Definitely worth the advised second coat as after the first 3 weeks of the first coat application a few of the larger cracks came through.

Suffice to say I would rather ensure this is done right however long it takes as I never want to go through this again!

You have to add some water to matt paint before painting first coat.

how about them now. i want to do some painting on my upstairs.

hello,

given that the weather conditions went very cold from my last post September last year I have deliberately left this til the Spring. However, I can comfortably say that the Alkaline Based Oil Primer has done very well. (I am still looking at shiny walls but thankfully no cracks have reappeared!) so I am pleased thus far....
I shall do the mist coat of emulsion (thank you v much London Painter!) probably next week as the forecast thiis weekend is for another cold blast. Brr!
I do recommend the stinky Alkali Oil Based Primer as, despite it's head rush whiff, it has done what it says on the tim and I am pleased that I didn't just use the gloss paint option which another decorator warned could pose possible problems further down the line. It's worth getting the right stuff.