Concrete porch approx 10x10. Old paint scraped off. Sanded and ready to paint.
Went on-line. Disagreement among pros whether to prime. It's been such a bitch to prepare, that I don't mind spending another few bux if it will help.
Climate is mild, with (not enough) rain in "winter".
Your always valuable help appreciated.
HB
Who told you that CA don't allow oil base paint I leave in CA and all fences around hear are oil base stain or just weather proof treated. Perhaps for inside house may have different rule but if is out side I don't see any restrictions I just purchase 6G. of oil base stain.
Yes, that's for fence stain, but CA doesn't allow oil-based paint. I just called down to Home Depot & they said they have NO oil-based paint.
I paint that porch every year, & for the past ?? years, CANNOT get the oil-based paint I used to use.
Disgusted, but I can't afford to have paint shipped from out of state.
It's the same for inside & outside paint I use BM Navajo White, and for quite a few years, all you can get is acrylic & stuff like that.
HB
Use an epoxy concrete paint, and follow the manufacturer's instruction in regard to installation - including whether primer is required, and if so what kind of primer - and what kind of preparation is required (acid etch, neutralizing, etc)
Lots of people use an epoxy paint on their concrete garage floors, so it should stick well to concrete and stand up well, too.
Higgs:
The general rule is: You prime over bare materials (bare metal, bare wood, bare drywall, etc.) and you paint over paint.
A "primer" improves adhesion of the top coat by increasing the surface area it has to stick to. Primers do that by having huge rocks in them called "extender pigments". Extender pigments are almost large enough to see with the naked eye. As the paint film dries and the thinners evaporate out of it, the film shrinks in thickness, and these huge rocks leave "bumps" in the surface of the shrinking paint film, making the surface of the primer "rough", and thereby creating creating more surface area for the top coat to stick to. In that way, primers improve adhesion of the top coat to the substrate.
However, with old bare concrete, the surface is already rough. So if this was old concrete that had never been painted, there would be no question that you can paint directly over it without a primer. However, in your case, the surface porosity of your concrete may be largely filled in with old paint, and not as rough as never-painted concrete. How rough it is is really the question.
Probably the best way to test to see if you need to prime is to do a tape test. Apply a few square inches of your paint directly onto what you have now and give it time to fully dry or cure. Now, take a razor blade and cut a checkerboard pattern into the paint. That is, 9 parallel lines this way, and 9 perpendicular parallel lines that way. Now, take some ordinary yellow 2 inch wide masking tape and press it tightly down over your cut checkerboard pattern, and then quickly pull off the tape. The more paint squares that come off the checkerboard with the tape, the more you need to prime. This is how they actually test paint adhesion in paint labs, and anything over 80% adhesion is considered "good adhesion".
Higgs,
Dave M.
It is getting worse. Not only CA, other areas are not selling oil based paints, automotive is getting away from solvent based paints too. VOC emissions have been greatly restricted the past couple of years.
For which los angelenos thank their specific deity every year. Anyone who lived through the 50s to the late 80's in the LA basin would agree that the restrictions on VOCs, stack and tailpipe emissions and outdoor burning were the best thing since sliced bread.
Being unable to run to first after a hitting a single because the air quality was so bad is not something anyone should have to experience. BTDT.
I HAVE checked out epoxy on-line in my search for appropriate paint, but was somewhat deterred by (a) expense and (b) the suggestion that it leaves too slick a surface -- a no-no for a porch. Would adding "sand" cancel out that no-no?
Pretty rough, as the old paint has been removed with Jason stripper and angled blade. I lied -- it's not yet sanded -- but I was going to rent a sander. Maybe in light of what you're advising, do not sand?
Will get the paint; follow the instructions, and report back.
Muchas gracias!
HB
Thanks, Dave. They won't ship to CA. Dammit!!! HB
Not a primer, but I used H & C concrete stain for my front stoop & steps. Bought at the local SW outlet. Paint won't hold up here in the Midwest.
Not a primer, but I used H & C concrete stain for my front stoop & steps. Bought at the local SW outlet. Paint won't hold up here in the Midwest.
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