[igneous]

I recently stained two concrete pads for a customer using H&C solid stain. No problems there. The front porch concrete pad had been painted before they bought the house. I was told by SW rep to used denatured alcohol and rub the surface. If the paint came up, it was latex. I did, and it didn't, so I used solvent based paint. I had to purchase this paint from Lowes since a SW rep said "SW has nothing for outside concrete applications."

First, did I do the correct test to determine the type of existing paint on the surface? Second, how can SW have nothing for exterior concrete? Was there anything in this description I should have done?

 

[wptski]

Hmm, sure looks like it here: http://www.sherwin-williams.com/homeowners/products/catalog/categories/interior-paint-coatings/masonry-concrete-products/

 

[igneous]

I may have not made myself clear. The SW rep said he had no concrete paint for exterior applications. I used H&C solid stain for two of the areas. Any thoughts on my other concern as to testing whether existing paint was latex or solvent-based?

 

[Nestor_Kelebay]

The SW rep said he had no concrete paint for exterior applications.

Either the SW rep didn't understand your question or you didn't understand his answer. ANY interior or exterior latex or alkyd paint that SW sells can be used over old fully cured concrete. Asking him if he had a paint specifically for concrete would have thrown him off because they probably don't. That's because any paint will work over fully cured and old concrete.

Fresh concrete is a different matter. Fresh concrete, which is less than a year old is highly alkaline, and you need to use a special acrylic concrete primer on it which is highly alkaline resistant. You can then use any paint you want over that special acrylic primer. Generally, the alkalinity of concrete subsides after about 2 years. After 3 years you can generally use any paint you want on it without using an acrylic primer first.

Any thoughts on my other concern as to testing whether existing paint was latex or solvent-based?

Your test sounds about right. Alkyd and oil based paints have much better resistance to alcohols than latex paints.

 

[AlphaWolf]

Ask SW about a product called Tread-Plex. I have used it myself on decks for exterior work. In my opinion best floor coating they have. Its better than normal deck coats and better than normal paints used on concrete. Pretty much self-priming to ever surface. Says right in the data sheets apply 2 coats to exterior concrete. Here is the link to help you out.

http://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&doctype=PDS&lang=E&prodno=B90W100