expoying floor after acid wash

[87GN]

How long after cleaning the floor with acid do I have to wait before applying an expoxy floor coating? It's supposed to go to the lower 70's next week and if I get it cleaned this weekend, hopefully I'll have a colored floor next week. Thanks.

Mark

[RonBou]

You need to make sure the moisture is gone first. Tape down a large plastic bag overnight and remove it in the morning. If it is dry, it is ready for the epoxy.

[GearHead_1]

87 GN is right. The acid content should not be the issue here. Once you've etched the floor with acid you must neutralize it by washing it down with water. Then it's just a matter of making sure that you follow the directions of the product you are using if you happen to be using a water based product then you may be able to paint much sooner than when using a solvent based product.

Taping plastic to the floor will tell you if your floor is dry but if you are trying to dry a floor overnight this will slow down the process.

[Hammerdown]

You really should clean and degrease the floor with a good detergent first. Cleaning with the acid is a double edged sword. Firstly the acid wash is to neutralize the alkalinity of the concrete and lower the PH levels, helping to ensure a proper bond. Secondly it etches the floor creating a mechanical profile for the product to adhere to. Etching the floor basically deteriorates the surface, so you want to make sure that you don't over do it with the acid. Too much acid can create a "soft" surface which is counter-productive to the adhesion of a coating. An over etched floor will leave a powdery residue when it dries out that must be removed prior to a coating application. Rinse the floor well after each acid wash. Choose your floor coating by doing some research and compare products benifits, not just the price. :shocking:

[87GN]

Thanks for the replies. FWIW, it is anew floor-just poured on Sept 30. I haven't driven any cars or anything that could leak oil on it.
I've settled pretty much on Benjamin Moore M79/M80 100% solids expoxy floor coating. It's supposedly used in aircraft hangers so it should be good for my floor. I wanted colored concrete but they couldn't gaurantee uniform color unless it all came from the same truck at the same time. It took almost 3 truck loads of concrete to do my floor.

Mark

[GearHead_1]

Just my 2 cents but I probably wouldn't acid etch that concrete for another couple of months. 30 days out and it probably hasn't fully cured.

[87GN]

Just my 2 cents but I probably wouldn't acid etch that concrete for another couple of months. 30 days out and it probably hasn't fully cured.


Here's my concern: my lease on the garage where my car is expires the end of November. I really don't want to put my cars in the new garage before the floor gets coated I don't want to have to clean up whatever 4 cars would leak onto the floor. I don't know how much longer the warm weather is going to hold out. Should I try the plastic bag/duct tape test and if it shows the floor dry, should I not have the floor etched and go right to the floor coating? Of course, the floor should have been done 2 months ago, but............
Thanks again.

Mark

[GearHead_1]

Tough call. Having been through a new build and considering your circumstance I think that I would put down some protection and park the cars until I could go through all the necessary steps to insure a successful epoxy coat. Most products require the acid etch in order to neutralize the the ph factor in the concrete. This insures a good chemical bond. I don't think I would want to do this before the concrete had fully cured for fear that I would end up with a soft surface. Taking these factors into consideration and knowing that you need to park your cars I think I would suck it up and do all that I can to protect the cement until it cures and then count on the little extra cleaning required to get it ready to coat. As long as you aren't having serious fluid leaks or dragging a great deal of salt on the new concrete I think this would be your best solution.With a little thought I don't think you will create yourself too many extra hours of work.

I've been told one of the worst case circumstances you could face in this situation is putting down and epoxy floor, having it fail and then having to remove it in order to fix the situation. Makes me sick to think about going through that process.