Author Topic: Trying to minimize brush marks on a painted surface  (Read 6724 times)

HSteier

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Trying to minimize brush marks on a painted surface
« on: July 11, 2007, 11:11:10 AM »
Help
I'm trying to paint a poplar chest and I am having a devil of a time getting a surface relatively free of brush marks.
I am using an oil based paint (Benjamin Moore low lustre) and what I believe is a high quality nylon fiber brush which has fine fibers.
The paint can said not to thin. When applied without thinning, the brush marks were horrible. I then did thin the paint about 15% and obtained somewhat better results, but I have seen brushed paint jobs by professionals which are much better.
Any suggestions? Spraying is not an option.
All help appreciated.

Howard Steier

Antiquity Period Designs, Ltd.

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Re: Trying to minimize brush marks on a painted surface
« Reply #1 on: July 12, 2007, 07:41:59 AM »
Howard,

It may not be you or the brush but rather the paint you are using.  Just because it is a major brand does not mean it is easy to use.  In our store we sell Olde Century Colors, www.oldecenturycolors.  Log onto the site to find a dealer nearest you.  I've used the paint (latex) for all the trim, raised panels and doors in our house and it is great to use/spread.  Better yet our customers say the same thing.  You might want to try a quart first.

Dennis Bork
Antiquity Period Designs, Ltd.
Professional period furniture maker since 1985.  Received a B.S. degree in physics then apprenticed and worked as a wood patternmaker for 12 years. Retired Dec. 2018.

kroeger

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Re: Trying to minimize brush marks on a painted surface
« Reply #2 on: July 12, 2007, 10:02:11 AM »
Howard,

I can recommend a product called "Floetrol"--but have one concern. 

The product (which is easily found at places like Lowes, Home Depot etc) can be used with latex paints, and works well in minimizing brush strokes, but I'm not sure if it can be used with oil-based paints (or if they make a separate formulation for each kind of paint).

cbentzley

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Re: Trying to minimize brush marks on a painted surface
« Reply #3 on: July 12, 2007, 12:59:26 PM »
I believe that "Flotrol" is for water based products and "Penetrol" is for oil or alkyd based products. I haven't used either one. I usually add a little turpentine to oil based paints which slows down the drying time and allows the paint to level out better. Foam brushes actually work pretty well also. Period linseed oil based paints actually had a ropey quality to them and brush marks are readily evident. Guess it depends on the look that you're after. Good luck.

Craig

cbentzley

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Re: Trying to minimize brush marks on a painted surface
« Reply #4 on: July 12, 2007, 01:08:37 PM »
Another thing I forgot to mention is that oil or alkyd based paints are basically just varnish with pigment added. To eliminate existing brush marks before applying additional coats, just let it dry completely (may take a couple of days) and you can use 320 or 400 paper and wet sand with a block to level out the brush marks. Then you can try doctoring up your paint and apply additional coats. A decent paint job usually requires 3 coats anyway.

Craig

dkeller_nc

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Re: Trying to minimize brush marks on a painted surface
« Reply #5 on: July 13, 2007, 09:57:18 AM »
Howard - Just a comment, but it doesn't make any sense that you've got bad brush marks with an oil-based paint.  That is, after all, one of the major advantages to an oil-based paint over latex.  How fast is it drying?  An oil-based paint should take at least an hour to dry to a tacky finish, and at least 24 hours to dry to a reasonably hard surface.

If this is not the case, you may have a "fast dry" oil paint formulation, which just won't do.  The other possibility is that you're applying it in a very thin coat, so the brush marks do not have enough surrounding paint to level into.  Oil-base paint should not be applied in multiple, very thin coats - it should be applied in a coat that is just on the verge of running (in fact, you should have to brush out a few runs while applying it).

This is the opposite of the way to apply latex and/or acrylic fast-dry paints, where multiple thin coats are an advantage.  These paints dry so fast that self-leveling isn't really a factor, so multiple overlapping coats tend to mask brush marks.
Period Furniture & Carving as a hobby - about 20 years woodworking

HSteier

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Re: Trying to minimize brush marks on a painted surface
« Reply #6 on: July 13, 2007, 12:11:55 PM »
I am not trying to apply very thin coats. I am aiming for good coverage short of runs.
Your comment about "fast dry" is intriquing however. The paint did seem to "tack" faster than I would have expected so maybe it is a "fast dry" formulation. I'll check with the store though they have not been helpful so far.
Thinning with mineral spirits did help some. I'll try turpenetine which evaporates even more slowly.
Penetrol was mentioned. Does anyone have any experience with this and is penetrol better than turpentine for leveling/delaying drying?

Thanks again for all help.

Howard Steier

cbentzley

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Re: Trying to minimize brush marks on a painted surface
« Reply #7 on: July 13, 2007, 12:55:59 PM »
Howard,

I used to use a fair amount of Benjamin Moore paint but I haven't recently. A while back, a friend of mine in New Jersey told me they were taking their oil based paint off of the market because of problems meeting clean air standards. He recently told me that due to customer demand that they reintroduced the product albeit reformulated. I did a little research on their website. I assume you're using the Satin Impervo C235. According to their TDS (technical data sheet), the solvents used are Stoddard solvent and xylene, both of which have a fairly fast evaporation rate. They also state that it is dry to handle in 4 hours. They don't tout it as a "quick dry" paint but to my way of thinking, 4 hours to handle is quick drying. So, it appears that this is probably why you're having trouble.

Craig

HSteier

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Re: Trying to minimize brush marks on a painted surface
« Reply #8 on: July 13, 2007, 01:19:50 PM »
Yup, I think that's it. I have no technical knowledge about paints and it never dawned on me that there might be differnet solvents in different brands. I'm ready to try another brand. Unfortunately I'm not ready to do all the sanding necessary to get out the existing brush marks; but a man's gotta do what a man's gotta do. Maybe I'll get my wife to do it.

Howard Steier

dkeller_nc

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Re: Trying to minimize brush marks on a painted surface
« Reply #9 on: July 14, 2007, 02:07:45 PM »
One other thought, Howard - while a synthetic fiber brush can be used for either water-based or solvent-based finishes, I always choose a high-quality natural-fiber brush for oil-based paints and solvent-based finishes.  In general, the natural fiber brushes in the $20-$30 range are much finer than synthetic fiber brushes, with the exception of Takalon.

You can't use a natural hair brush for water-based paints and finishes because the hair will absorb the water and the brush will lose its shape. 
Period Furniture & Carving as a hobby - about 20 years woodworking