I got some oil based paint for my weekender and started putting a coat on the bottom. I am using a foam roller and tipping with a natural bristle brush. I'm not totally happy with the results and would like to refine the process before I start on the topsides. It seems like the first half of the painted area looks OK the second half has allot of brush marks and seemed to dry quicker, not allowing enough time to tip properly. I think thinning the paint might help and was wondering if anybody ever tried Penetrol
http://www.flood.com/flood/Products/Inte...d+Page.htm
It seems like it might help.
Thanks,
joel
Penetrol shouldn't be used as a thinner, it's a "wetting agent" and can improve the viscosity and flow Properties of alkyd paints (oil based). This will help the paint "lay down" so your can hide the brush marks.
You may have better luck tipping with a foam brush, which will make as smooth a finish as you can get. Mix Penetrol no more then 20% by volume, which may affect the gloss (they recommend 30% max, which will surely effect shine). In other words, too much Penetrol can dull the gloss slightly, but noticeably, depending on how much you use. Controlling conditions the best you can will produce the best results. I rarely need more then 10% Penetrol which doesn't seem to affect the shine of gloss too much, but 20% sure will. The hotter it is, the smaller the area you can work.
If the brush is "dragging" while you try to tip, you've done too big an area, it's too hot or you're "over working" the paint. For some reason, some paints will tolerate lots of brushing, other only so much, before they start to drag. Varnish is similar, but usually worse at this then paint. Tipping is all technique and requires very little brushing to be effective.
Hold the tipping brush nearly straight up and down, rather then leaning it over, as you do while painting. Lightly kiss the surface of the paint, knocking down the high spots created by the brush strokes. One or two passes is all that is necessary, don't over work the paint, which can cause you to experience dragging (where it feels like the paint is grabbing the brush as you sweep the surface). Wipe the brush often, it needs to be relatively dry. If the paint is the right consistency for the temperature and you've got some Penetrol mixed in, it should "flow" nicely and lay down smooth. Long, easy strokes (as long as you can comfortably make) will provide the best results.
Working in the early morning (after the dew but before the heat of the day) or in the evening so you can have kinder temperatures to apply your finish, often helps. Many of my posts here, are a result of using evening temperatures to advantage and literally waiting for epoxy or paint to kick off, as I post replies.
You may want to practice on scraps, so you can figure out the percentage of Penetrol to use for that particular painting session. Just add Penetrol until she's acting like you want and laying down sweetly, then use that ratio, for the amount of paint you expect to use for that painting session. Don't be tempted to pre-mix, each day's temperature and humidity will determine the amount of Penetrol you'll need to get good flow.w
Quote:If the brush is "dragging" while you try to tip, you've done too big an area, it's too hot or you're "over working" the paint.
Paul, I guess I did a little of all of these things. I plan on sanding the painted area lightly and trying again. I will add a small amount of Penetrol and will try painting early in the day before it warms up. It never really gets that hot here but I think the cooler morning temp might help.
Thanks for the input,
joel
Again, mix up a small batch, using some Penetrol and try it on a scrap board. If it drags add a small amount more. Keep doing this until you get the percentage you need for that particular day's painting session. What paint are you using?
Paul, The paint I am using is a semi gloss oil based enamel. Here is a link to a PDF data sheet.
http://www.parkerpaint.com/PageMill_Reso...50atds.pdf
The best part is the price. After asking if I could get a small pint can as a sample. They gave me a gallon of mistint for free. I liked the color so I thought I would give it a try. :wink:
joel
Joel, that paint is a real alkyd, which will work well with thinners and Penetrol. Often times folks get paint, not realizing it's a "modified alkyd" usually labeled as a "modified enamel", which can contain things that may screw with the cure process or require special prep. In other words, using the wrong thinner, on incompatible wetting agent, drying agents, etc. can produce less then desirable results.
I stick with products I've had good success from, regardless of the price, preferring to do it once, then re-do it because I got good deal and the paint didn't act the way I like. It's much like finding a woman to put up with you. You can try different "brands" may be getting a pretty good deal, but you have to sleep next to the results.