Problems with Brush Marks

[Jack Manfred]

Hi,

I am painting some bare wood eg a new loft hatch door which is made from MDF which have been removed and worked on a bench.

I applied two coats Dulux Quick-Drying Wood Primer & Undercoat and one coat of Dulux Trade Quick Drying Eggshell so far. I have problems with brush marks on all surfaces I've painted both with the primer and eggshell. I have done some painting before but still relatively inexperienced but I haven't had this problem before. I used Harris Gold paint brushes. I sanded with 120 grit before starting and with

240 grit using a palm sander between coats.

Can anyone please give me some advice?

Many thanks!

[Peter]

Use a gloss roller.

peter

[Bruce]

I think the problem is encapsulated in two words: "quick drying".

The paint is setting before the brush marks have had a chance to settle out. The remedy is to add some thinners which will slow down the setting process until the brush marks have disappeared.

If the paint is water-based, you need to add a little water. It doesn't need much ... no more than 5% and perhaps less.

If the paint is oil-based, you need to add a little white spirit.

You seem to be doing everything else right, so I expect this will solve the problem.

The best finish of all comes from using solvent based liquid gloss. It is no coincidence that this paint takes the longest time to set.

[stephen.hull]

Primers are heavily pigmented and coarse, plus they do not flow-out very well, Primers are initially a build-up coat, although you could dry flat and recoat the opposite way when you lay off. Also a roller can be used to good effect as previously mentioned.

Thinners can help but using the wrong thinner can actually speed up the drying process and not slow it down.

Turpentine or white spirit can in some cases actually accelerate drying, adding raw not boiled linseed oil used to be one way to slow down the drying process.

The older linseed oil paint was much better at flowing out because it took longer to dry and therefore gave the paint a chance to flow out, however most modern oil paints are now Alkyd resin based which gives a longer lasting tougher finish but the Alkyd resin itself is also a drying agent which doesn't help with flowing out.

Stephen.

[Jack Manfred]

Thanks to everyone who replied.

I tried using a gloss roller made by Anza and diluted the paint by 5%. However, the finish is not perfectly smooth but is kind of like an orange peel.

Any suggestions anyone please?

Thanks.

[The Natural Philosopher]

car body spray.

[stephen.hull]

The orange peel is typical of a roller finish, the paint has set before flowing out, so you still have the same problem as if you had used a brush.

Thinned oil paint as I mentioned previously does not slow the drying process down it only eases application. IMO you still need to slow down the drying stage to eliminate brush-marks or orange peel and by adding raw linseed oil which will counteract against the quick drying alkyd resin, assuming it is an alkyd resin based paint.

Or you could purchase a paint better suited for the job other than a trade paint.

Stephen.