RMS 427 - in your situation where the floor stain/sealer was coming up, the Racedeck overlay was a very good fix.
Still curious as to the Racedeck cost per square foot....
For any of you interested in some more detail on acid etching and the reasons for problems that have been documented earlier in the thread, I am presenting below a copy of the more detailed reply I have sent out via email to various people who contacted me.
Like all things, there is a right way and a wrong way....hope this helps...
"What it comes down to is this - the floor must be a) - roughened up to achieve a mechanical "bite" similar in texture to a fine/medium grit sandpaper (rub your hand along a #100 grit sandpaper), and b) - clean and dry.
The acid etching (dilute hydrochloric acid - commonly called "muriatic acid and available cheap at Lowes or Home Depot - read directions carefully - dilute as directed - - wear gloves and eye protection!) method actually works by "attacking" the Portland cement paste which binds the aggregate (fine sand and coarse stone) together. There should be a slight "fizz" and the acid will turn "whitish" - this means it is working when you pour it on. It is important to "scrub" it in real good - get a coarse 8-12" "scrub brush" on a painting pole and bring lots of "elbow grease"... and don't be afraid to repeat a few times - you really can't over-do it. The top 1/16" of concrete is primarily the "fines" mixed with cement paste, so the surface etching can achieve this sandpaper effect quite well if done with care.
Other methods of concrete prep include mechanically abrading the surface instead of chemically 'attacking' it - essentially blasting away the weakest parts of the top surface layer. This method is touched on in the thread earlier...This method is generally more consistent, and does not have the safety issues (wear rubber gloves and goggles when handling the acid! - rinse any splashes on skin thoroughly with water).
Acid etching is less expensive than shotblasting - especially if your time is not a factor. Mechanical abrading is more consistent , but requires special equipment (called a "shotblaster" - a self contained machine that vacuums up the spent shot (special hard sand) as it goes- kind of a specialized sandblaster for floors) that not even most rental shops carry (except the contractor-only type places).
The problems with acid etching, and the reasons for the "failures" people talk about, are as follows:
a) - disposal of the spent acid - diluting by flushing with lots and lots of water can be a problem...can you rinse it out somewhere? Most common is to flush out onto the driveway and to the drain on the street. By flushing and diliuting the heck out of it, it isn't as hazardous as you may first think...you are dealing with relatively weak acid to begin with, and the flushing dilutes it even more. Check your local regulations.
b) - inconsistency - not all areas of the floor will react universally -some areas require re-doing - high points, low points, more cement paste (ie stronger floor surface needs more attention), etc. Don't hesitate to repeat as necessary. Surface prep is 2/3 of the time investment for this job - the coating work itself is the home stretch.
c) - neutralizing the effects of the acid (lots of flushing water). The residual acid MUST be removed with lots of flushing water. I rented a 5hp Honda high pressure blaster for this part - worked great.
d) - not allowing the floor to dry before commencing the coating work (the easiest test method to check is called the "mat test" - simply tape a piece of 18" x18" plastic on the floor with duct tape and check 16 hours later for presence of condensation under the plastic - if present, the floor isn't dry enough) There is no reason to get on it too soon unless you rush....)
e) - assuming "etching" will "clean" a floor - which it doesn't. These are separate steps - an
oil saturated floor must be treated before etching. Check again at Lowes or Home Depot for TSP (tri sodium phosphate) based solutions, and scrub well -
oil penetration can be 1/2" deep or more on an old floor.
Surface prep can be "outsourced" to a specialty contractor -with a
shotblaster. Rates will vary from as low as +- 20 cents per SF, but usually small jobs like a 400 SF garage floor will likely go for more. Worth looking into however, and weigh it against the "do it yourself acid approach". Try to find a guy who can "fit you in" between jobs. It will depend on local availability of a contractor with the equipment and the desire to do a small job - most guys with this gear do larger industrial jobs. Look under "Concrete Restoration" .or even "Concrete Finishing" in the yellow pages .
The "finishers" don't likely do this kind of work, but might point you in the right direction.
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