Originally Posted by aa7483
Hello. I'm going to be painting my basement floor and looking for some prep suggestions. I'm probably going w an epoxy bc that will stand up better from what I understand. The floor has previously been painted. The paint seems to have held up pretty well in most of the basement. Should I scrape any loose spots use a good degreaser and then paint. Should I use muriatic acid?(read that should only be used on unpainted concrete. Any suggestions appreciated.
Epoxy will stand up better than a conventional coating, but what kind of traffic are you gonna be exposing this floor to? If you're just talking about foot traffic, a high quality acrylic satin finish will also "stand up" just fine - at a lesser cost.
If you still choose to use an epoxy, go to an independent paint dealer and ask for his/her recommendation regarding surface prep and ask for his/her recommendation regarding this preparation and application - Epoxies can be tricky if you're not familiar with them.
As far as surface prep goes - it really won't matter what is on the floor right now (few people will agree with me on that, but I'll get to that in a minute). The surface must be clean (free of dust, dirt, grease, etc.)…it must be free of loose and peeling paint…testing should be done on the areas that "appear" to be in good condition by performing a cross-hatch adhesion test - it'd help to determine the cause of those areas that aren't in good condition. If the existing coating is glossy, it should be sanded with a medium grade paper (not to remove coating, but to create a necessary profile for maximum adhesion for new coating). Do not use muriatic acid
…If all these preps are conducted, and assuming the remaining coating passes the adhesion test, you're pretty much good to go with any type of coating you decide on, with only a couple of caveats.
Epoxy is available in many different presentations (solvent borne epoxy, waterborne epoxy, polyamide cure, polyamine cure, epoxy esther, acrylic modified, etc. etc.) - and, of course, each has it's own advantages & disadvantages…If you're looking for a true epoxy that has the ability to withstand just about anything you're gonna throw at it, stay with a 2 component epoxy (must mix parts A & B). Personally, I'd go with a Water-borne 2 component polyamine or polyamide cure product - I would not
go with a 2 component acrylic
As long as you stay with a water-borne, there will be no incompatibility with whatever is on the floor and the epoxy - there are no hot
solvents in water-bornes (WB) as there are in the epoxies that JMays spoke of…I'm not going to go into the differences between poly amines and polyamides on this post, but generally, very generally - poly amines are a 4/1 mixture (short filled gallon of epoxy mixed with 1 quart of activator or catalyst - polyamides are usually a 1/1 mix (1 part epoxy mixed with 1 part catalyst). Both will perform very well for your application.
Epoxy summary - Do not use a solvent borne epoxy - Use WB. Do not use an acrylic epoxy (there is really nothing wrong with acrylic epoxies, the reward generally doesn't justify the cost difference over conventional single component floor paints). Epoxy esthers are single component "epoxies" and are available in both an acrylic and alkyd modified.
There is also mixing and application instructions different than that of conventional coatings. Follow all manufacturers recommendations explicitly. If you then choose to go with a more conventional coating - I'd go with an acrylic floor enamel (some are straight acrylic, some are epoxy esther, some may be modified with urethane). There are many exceptional acrylic floor enamels on the market - they are easy to apply, dry quickly, performs very well in typical, normal household exposure, available in lower sheens (satin, semi as opposed to high gloss finishes in most
epoxies)…and are especially easy to recoat and maintain. Personally, I'd also stay away from oil-based (alkyd) floor coatings - they are fine coatings, but they are more expensive, may require more surface prep, harder to recoat and maintain).
Sorry to be so long-winded, but when choosing the right product for painting any floor, you need to be aware of the advantages and limitations of all coatings being considered. Good luck and let us know what you decide.