What's wrong with my painting technique?

Question

I'm struggling with paint. I've been using a high-gloss Behr enamel for our trim work in our house.

This photo shows a door on the left that was rolled on, and the casing on the right, which was brushed on.

I don't mind brush strokes (not that they are intentional, but I do find they give a bit of interest) but rather it's the light/dark spottiness I get everywhere.

I can't tell what causes it. I don't think it's coverage, as all surfaces were primed (white) and then got two coats. It's as if the paint, as it dries, splotches like this. I'm about to apply a 3rd coat, but it's frustrating to paint trim with 3 coats.

It seem like every coat I give it, the problem persists.

Any ideas as to what the issue is? Can I improve my technique? Lousy paint? Something else?

(Ignore the blue tinge...that's just a side effect of the iPhone's camera).

Answer 1

Latex paints have a known attribute that allows certain things to persistently come through the paint even though you try applying multiple layers.

I once had a problem of a wall that had a poster glued to it by a previous owner. I removed the poster and apparently the glue residue, however small it was, kept changing the paint I applied over that area.

Another time I was trying to paint a door that had been finished with an oil based product. I had worked diligently to strip and sand off the old finish before painting. Unfortunately the old finish had penetrated the wood to varying degrees in different spots. The paint I applied to the door was not uniform even after four or five coats - hard to remember exactly how many as it was 25 years ago.

The fix for both of these problems is to apply a sealer / primer product like Kilz before applying the final paint. One needs to make sure the surface is properly prepared before applying the sealer / primer. Light sanding can help and washing with a strong solution of hot water and TSP can help.

Answer 2

Well, after posting the question I did some googling and apparently I'm not the only one experiencing blotchiness with this particular Behr product.

I went to the local True Value yesterday and picked up a brand of theirs and...it went on MUCH easier and faster. I put two coats of that on areas I hadn't painted and it covers much better.

So, the verdict...I guess I just wasn't using very good paint. Which is a shame because it wasn't cheap paint.

I did notice that the Behr, compared to the other product was extremely thick. I've used the Behr product in the past as well (same experience) and it, too, was also very thick so for whatever reason, they seem to use a rather thick formula, which perhaps contributes to the uneven finish?

Answer 3

My guess is the paint wasn't stirred well enough and this is caused by a separation of the paint in the can.

Answer 4

Behr paints aren't the greatest. I only use their ceiling paint.

With regard to covering stains and the like, a quality primer makes all the difference. Kilz is a good one, but it stinks. Sherwin-Williams Pro Block is my usual primer. It's a good quality, but doesn't work on the tough stains. Pigmented shellac is the nuclear primer option, but it's awful smelling.