Professional Painting Contractors Forum banner
1 - 3 of 15 Posts

· Registered
228 Posts
A couple of things to think about.

We have used Macropoxy on floors and even had it specified in areas for concrete floor that get foot or light vehicle traffic. They may have used it before and had good luck, but you need to questions if SW is going to be willing to warranty it due to the "Intended Service Environment."

To CocoMonkeyNuts Credit, the PDS for Macropoxy doesn't specifically state "Floor Coating" but it does have a "Slip Coefficient" listed which is intended for surfaces that get walked on. So yes it can be used, but the issue is the warranty.

We recently did a Hangar for Delta Airlines and the Specification was terrible. They had listed Rustoleum (Seal Krete) Clear Seal [PDS]

At first glance it does say: Garages, but it's appears to mean a residential garages. We (eventually) had a conversation with the Architect and had to go through a bunch of hoops to figure out what needed to be used.

Problem #1 - We realized this is a Maintenance hangar for their automotive vehicles (Not airplanes) so there exists the possibility for Motor Oil, Transmission Fluid, Gasoline, etc. being spilled on the floor. All at a much higher volume than a residential garage. So the supplier needs to be able to warrant the material for it "intended environment." The other problem was finding a material that wouldn't be slippery when it got wet. (Also it being at an Airport and us being in California, we wanted to make sure that our butt is covered for any leaks that would turn a portion of the runway into a Toxic Superfund site.)

Ultimately we settled on PPG Amerlock 2. PPG was willing to warrant it - But we had to:
  • Moisture test the concrete for an acceptable moisture transmission.
  • Do Sufficient Concrete Prep (ICRI CSP-3) We also had to get a letter from PPG stating that they would accept Grinding with a Diamabrush as an acceptable CSP-3
  • Cut Keyways into the Concrete at the edges of the coating to limit weak point for the coating lifting.
  • Both of the above required a Silica Dust Plan and us to both Wet Grind and Wet Cut to limit Silica dust from the concrete. (California again)
To get past the Non-Slip issue, we had to embed Aluminum Oxide into the First Coat and Apply a second coat over top.

Problem #2 - There was a designated Battery Room that needed an even greater level of containment. PPG suggested Novaguard 840 which required all the same prep as above and a Cove Base around the room and filling of the Expansion Joints in the Concrete. It also needed a Non Slip surface and got the same aluminum oxide treatment.

Any purpose of the long story above is to REALLY think about the project and what it is going to entail.
  • Do they want a warranty?
  • What kind of warranty? (1 year? 5 Year? etc.)
  • What kind of surface prep is required? (Clean? Shot Blast? Etc.)
  • Going over the Macropoxy with more Macropoxy makes sense, (Warranty issues aside) but if you don't know what the other coatings are, will the Macropoxy stick to those coatings? Will the Coating fail once the Epoxy dries and shrinks?
  • Is any of it exposed to sunlight? (Epoxy's are not UV stable.)
  • If you are doing the Floor Prep, are there Silica Dust regulations you need to follow?
Macropoxy is an equal to Amerlock 2. It is likely up to the job, but you need to make sure you know all the variables and THINK through it before signing off on it.

If you want to be REALLY sure, Sandblasting the surface to remove the existing coatings is a sure bet, but you need to worry about the level of CSP required, and be aware that the Profile will show through the coating if it's too aggressive. (You can see the lines that the grinder traveled on through the epoxy.)

Best advice is ask a lot of questions and make sure you get them answered. MOST SPECIFICALLY about what Warranty is required, and the competency of the Installer.

P.S. Sherwin Williams bought General Polymers for this specific reason. So hopefully your Industrial Rep is good!

· Registered
228 Posts
I'm surprised PPG would have written a spec that didn't include a urethane topcoat.
There was no UV exposure so it was a non issue. Also the technical rep for our area (Nye Miller) is awesome.

Having a basic knowledge of coatings properties / chemistry helps a lot when dealing with Manufacturer's. Otherwise they will try and sell you something you may not actually need.

· Registered
228 Posts
More specifically urethanes are commonly spec'd where there is expected exposure to hydraulic fluids and fuel as they are far more resistant than polyamide epoxy
My understanding (which I will admit is limited) is that Amerlock 2 VOC is listed as a "High Solids" Epoxy and the Curing agent uses Amines (Not Amides) which give it a greater Chemical Resistance than an Amide Cured Epoxy.

Given, an Aliphatic Urethane (Like Amershield) is going to have a higher and broader range of Chemical resistance, but Amerlock was deemed suitable for the service environment. (Mostly due to wear.)

Now if Polyester Poly was compliant per SCQAMD, then it would have been a different story! :ROFLMAO:
1 - 3 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.