caustics?

[desi 14]

what are the caustics in hydroflouric , oxallic, muriatic acids? Secondly, is soduim hydroxide the best agent to use when cleaning concrete & asphalt?

Lastly, anyone care to give me an education on how bricks are made, different types and what causes efforessence? And what is the best way to treat the white spots.

thanks

[Dave O 15]

Try the search function and read and read and learn and learn then read some more while searching. Then when you think you know it search some more and read some more.

[Celeste 341]

Desi,

www.bia.org This is the Brick Industry Association website. That should keep you reading for a bit.

The best concrete cleaner is debatable in many threads. Just read read read.

here is some of an article on efflorescence:

"Efflorescence is a crystalline deposit of water-soluble salts (usually white) on the surface of masonry. All masonry materials are susceptible to efflorescence. Water-soluble salts that appear in chemical analysis in only a few tenths of one percent are sufficient to cause efflorescence on a masonry surface. The amount of salts and character of the deposits can vary widely, according to the nature of the soluble materials present and atmospheric conditions. Temperature, humidity, and wind affect efflorescence. In the summer, even after long rainy periods, moisture evaporates quickly and small amounts of salt or efflorescence are brought to the surface. Usually efflorescence is more common in the winter, when the slow rate of evaporation allows the migration of salts to the surface.

Efflorescence that occurs on new construction after the masonry dries is referred to as "new building bloom". New building bloom is generally an unsightly nuisance and no cause for concern, as it will normally weather off within a few months to a year. Efflorescence that persists in masonry walls and chimneys generally means that excess moisture is entering the system and (if not remedied) is a precursor to more serious damage. "

Again, the cleaning of this is always up for multiple opinions.

Dave O has nailed it.....you will find more answers than you may ever need in these posts. Make a big pot of strong coffee and hit the search button! (If you really want to see chemistry in posts, look for Ryan's.)

Cheers,

Celeste

[RyanH 14]

Caustics are usually used to describe basic substances (most commonly hydroxides, "whatever"-ols, and "whatever"-amines, or most any compound that has a metal as part of its name). You will most likely see potassium and sodium hydroxides used for most cleaning purposes. Their primary use is to act as a degreaser. As for what to use when cleaning concrete, you should always progress from the most safe method to a more extreme method, not the reverse. If cold water will work, use it. If you have more grime, hot water will usually be plenty sufficient (from what others have said and my limited experience in using it). If you have stains (like oil or some tannins from leaves) then a degreaser will generally be needed (like a butyl-based cleaner, hydroxide, etc.). Other situations call for a mild acid....read through the board for these situations....there are MANY references, tips, suggestions, and data the pros here have posted. Search for "hydrofluoric" as a starter and read through all results....PaulB and Allen have some really good information on which acids work well (not that hydrofluoric does, but the threads contain the information in ongoing discussion). Then, like was suggested, read on and you will learn much more than you will by just asking questions. If you absolutely can't find an answer, or want more details or explanations, then ask and someone here will more than likely have one for you.

Oh yeah, and welcome to the group!

Ryan H.