Top coat of paint not taking to wardrobes

[ramsus]

Hi all,

We have been painting some new MDF wardrobes, and have run into some problems any advice would be massively appreciated. We are very new to this so don't really know what we are doing. We primed the mdf then did an undercoat layer. Now we have started with the top coat but it doesn't seem to be taking very well, despite using a new brush the paint is sort of seperating - see picture:

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The paint is Crown wood/metal non drip. The underlayers were homebase's own brand. I didn't realise until after stirring it that on the paint tin it said not to stir it, do you think this could be the cause of the problem? Or is it likely to due to some other cause?

Thanks

 

[joe-90]

What type of undercoat was it? Did you use a primer?

There's nothing wrong with Crown paint, I've used it many times.

Stirring it won't give that problem.

 

[ramsus]

Thanks your the reply Joe.

Yes, first we used homebase pure white primer, then we used homebase pure white undercoat (both the ones for wood & metal) .Does this mean we need to use a homebase top coat instead if crown?

 

[joe-90]

No. What I'm trying to get at is whether the primer and undercoat were oil or water based.

It looks to me like you may have used a hard surface type cleaner at some point which has silicone in it - that will give you that sort of problem.

Were all the paints oil paints?

 

[ramsus]

I think the primer and undercoat maybe both oil based. I'm not sure how to tell below is what it says on the tins:

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Also we needed to use white spirit not water to clean the brushes - does that mean its oil based?

I think the Crown paint for the top coat is water based, as water cleans the brushes ok. Do we need to get another paint to use for the top coat?

Thanks

 

[JohnD]

water paint tends not to stick to new oil paint as it is slightly oily.

 

[joe-90]

Yes. Stick to all oil based. The problem is one that is common painting water paints over oil undercoat. It's usually referred to as 'fisheye'.

If the colour is anything other than white then Crown one coat satin (oil based) does a fine job.l

Either that or wait a few days and try again when the undercoat has fully dried.

 

[opps]

As Joe said, painting waterbased finishes over oilbased paints can result in fisheyes.

In this case they would look like little craters, where the top coat paint has pushed itself away from the surface as a result of the solvent being released from the oil based paints.

Sometimes these craters can join together to form something that looks like a streak. It is difficult to tell from your photo.

Again, as Joe suggested just wait a few days for the oil based paints to dry.

 

[ramsus]

Got some oil based paint as suggested, and it seems to take fine now.

Thanks a lot for the help all. And at least we have some water based top coat already to use on the next project.