Epoxy over sealed garage floor

[Rjjencke]

Hi guys, first post/question.

I decided to epoxy my garage floor which has previously been painted and bought a Rustoleom solvent based kit. I'm not sure what paint was used on the floor.

First issue: the old paint is chipping away pretty easy with a razor, so I assume I need to remove all the old paint.

2nd issue: after scraping some of the old paint, I noticed the concrete is very smooth, shiny and brown in color. (The brown I believe is normal as all the concrete inside the house is brown too) But I'm now assuming the concrete was sealed. I put water on it and it doesn't soak in.

So ... Has anyone painted over sealed concrete? I've been searching the web for days and have read different stories. Some say you have to diamond grind, some say to just rent a sander and rough it up.

My plan is to rent a sander and rough it with 80 grit then possibly acid etch then apply epoxy.

Also wondering if there is a primer that will adhere to sealed concrete.

Thanks for any past experience/advice.

 

[Edger]

Rent a Diamabrush on a swing machine. Others here have done that and said it worked well so search this forum to find out where.

You must get water to soak in so grind it and then check.

 

[Rjjencke]

Thanks for the response. If I decide to rent a diamond brush (if I can find one) do I still need to manually scrape the paint that is coming up or will the diamond take this off for me?

Also how long does this brush take to remove a sealer? 400 sq/ft.

 

[pauloman]

acid etching will not do much if the floor is sealed. Any clue why the old paint come up?

could be a moisture issue and that could mean the epoxy will come up too.

You might replace your epoxy with a 100% solids epoxy where wet thickness equals dry thickness, this means any bits of the old paint remaining will get buried and remain hidden. Also solvents in you new epoxy might soften any paint or sealer under them. I really suggest you go solvent free (say Industrial Floor Epoxy)

see www.epoxyproducts.com/floorlinks.html for more on acid etching.

paul

 

[LegacyIndustrial]

A diamabrush will work if the paint is not too thick. No more than a coat or two.
If it is more, look to a diamond grinder, rented locally.

Your epoxy will only adhere if it gets a good connection to the substrate.

Upon clean-up you need to prime and then apply your coating.

 

[Rjjencke]

Paul, I believe the paint is removing easy because it was put on top of sealed concrete. Does that make sense?

Scott, It seems to be only a coat or 2 of paint, some areas come up very easy and some I can barely get the 4" razor under. Should I at least attempt to scrape the whole floor before the brush?

Also, after diamond brushing, is primer necessary, and if so, can I use a basic cheap primer with my 2 part solvent kit?

Also, will the diamond brush get close to the wall and corners?

Thanks!

 

[LegacyIndustrial]

Diamabrush will take it up pretty good, you can scrape if you care to. It gets pretty close to the sides. For primer, put down a coat of the same material you are using for compatibility.

 

[Rjjencke]

So are you saying I would need a 2 part epoxy primer? Will this cost the same as my epoxy paint?

Also, do I just ask Home Depot if they have a diamabrush or what exactly do I ask for? Sorry if these are dumb questions.

 

[LegacyIndustrial]

Diamabrush heads are not available through Home Depot for purchase.
You would need to contact a reseller like myself.
Link: http://legacyindustrial.net/cart/diamabrush-concrete-prep-tool-c-12.html

However, Home Depot will rent you a swing machine with a diamabrush head.

 

[pauloman]

A correctly sealed floor would have have no impact upon the adhesion of an epoxy floor. Most surfaces epoxy is used on, like equipment or steel hulls, are not porous (just like a sealed floor). The big question is why is the old coating coming up. Check the bottom of the pealed up coating. Are there sand/cement grains on it? That tells you a lot.

Epoxy primers are nothing more than solvent thinned epoxies. The solvents soak into porous surfaces a tiny bit, making the surface more 'stable' for the topcoats.

just removing the surface with some expensive tools might do nothing at all.

I've been in the epoxy floor - marine epoxy business for over 20 years. You need to proceed carefully.

you might pm me and we can talk more in detail.

paul

 

[LegacyIndustrial]

Pauloman, that is a dangerous statement you just made You darn well better be getting a mechanical or chemical lock or risk failure.

I don't care how you do this in marine circles. In the flooring industry you need to get that lock.

Existing sealed concrete needs to be deglossed and solvent wiped if the sealer is compatible with the coating to be applied

If not. You will have to grind it off and get back to concrete.

Flooring epoxy can be used to coat steel. And when you tell me that I will tell you to profile the steel and clean well with a suitable solvent.

 

[Rjjencke]

So, I've contacted the 2 closest Home Depots in my area and they were not familiar with the 'Diamabrush' attachment. One guy said he was new but he had a 'Hexpin Surface Prep' tool with carbide bits that would go on the Floor Maintainer.

Is this common or do these guys not know what they are talking about?

 

[Big-Foot]

I had a sealed floor in my shop and did not want to take any chances.. Looked all over for Diamond Grinders for rent and came up with nothing. I ended up paying to have the floor shot-blasted... When it was all done I could not believe that I paid someone $750 to make a floor that was relatively new and looked great look like sh!t. Yes it looked terrible, but after putting down a bunch of epoxy-coat, it looks just fine,.

 

[dcs Inc]

So, I've contacted the 2 closest Home Depots in my area and they were not familiar with the 'Diamabrush' attachment. One guy said he was new but he had a 'Hexpin Surface Prep' tool with carbide bits that would go on the Floor Maintainer.

Is this common or do these guys not know what they are talking about?

Call corporate and ask them. You can also call diamabrush and ask where the stores are that they supplied. It may be that they haven't gotten to your area yet.

 

[Rjjencke]

Damn, I contacted Diamabrush and they have not moved to the AZ area as of yet. She said it could be headed here in Feb '13.

For anyone else looking, she did say she could look up which stores would have it available for rental.

I also called another tool rental 'A to Z Equipment' and they had not heard of it yet but told me about the Edco.

Any thoughts here? Anyone own a diamabrush in AZ? lol.

 

[Rjjencke]

Will the Edco grinder take off my paint and sealer like the Diamabrush will? Is this my best and cheapest option?

 

[dcs Inc]

If you go edco, rent their 10" single head with the diamond heads on it. The double head machines are fixed heads (non floating) and with that larger foot print you have to take the hills down to get to the valleys when grinding. Concrete is very unlevel even though it looks flat. To understand this, one evening after dark take a flashlight and lay it on the concrete. (Turn it on first) this will show all the unevenness in the concrete.

The 10" single head edco has a smaller foot print and will actually grind quicker. If the rental company has the floating head adapters on their duel head grinder then go with that. (They wont and probably wont even know what it is)

The biggest thing is the tooling, diamacerts I think is what they call their diamond segmented grinding heads. The 10" can have a flat plate diamond segmented attachment on them. this is the best way to go. Now these machines wont have any dust shrouds on them so keep that in mind. If the rental company has updated their grinding equipment then good for you as the newer equipment has addressed these issues.

 

[Rjjencke]

Thanks for the info on the Edco. The rental place did say it was a single head, I believe an 11".

Can I hose down the garage with the Edco to minimize dust? How much dust are we talking here?

Also, can I get away with just using the Edco and not having to rent a hand grinder too for the corners?