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Painting Old Concrete Floors

Posted: Sun Jun 15, 2014 8:12 pm
by blockislandguy
Like a lot of people we look at the spotless, epoxied NASCAR garage floors with envy. But we live in a different world. We have 65 year old concrete floors that are beyond hope. They've never been sealed, have a few cracks, and certain areas are oil soaked. On the other hand, we don't have to have spotless floors that look like you can eat off them to impress a potential sponsor or retail customer. Our engines all leave by common carrier and parts shipments go out by UPS or DHL. At the same time also, we love the fact that the concrete is 8" thick , reinforced with rebar. In January it holds a lot of heat in very well.

This summer we have two areas we'd like to paint. Paint? You know, you go out to Home Depot, grab a carriage full of $20 gallon cans of grey Rustoleum and and go to work. After all we're too busy to shut down and have a crew come in and shot blast the concrete then apply epoxy or whatever.

Here is what we had in mind. We need and would appreciate your thoughts and suggestions.

1) Small Package Shipping Area. This area gets a lot of foot traffic and the occasional head or crank dragged across it. This area has had numerous coats of different color paint applied over the years and they hold up OK. This summer, once we're done scraping what we can and washing it, would it do any good to apply a coat of primer paint before we roll out he battle ship grey?

2) Engine Assembly Area. We assemble our engines on mobile engine stands and the assembly oil drips down to the floor. This area also gets some forklift traffic. The paint on the floor now is oil saturated and peels off just by looking it at. We can get the floor down to bare concrete but concrete is permeable and it has soaked up a lot of oil over the years. Any ideas regarding preparation? Primer? Is this area a lost cause?

3) Engine Pallet Rack and Shipping Areas. We've never been successful at painting anything a forklift is going to run over with cores dripping oil so we aren't going to bother with these areas.

Re: Painting Old Concrete Floors

Posted: Sun Jun 15, 2014 9:37 pm
by Keith Morganstein
I'm no paint expert, but a good concrete primer is Sherwin Williams Loxon.

Re: Painting Old Concrete Floors

Posted: Mon Jun 16, 2014 7:13 am
by W. Tripp
I have used Sherwin Williams Tile Clad on 3 different shop floors over the years, as well as my home garage. It works very well over time and is tintable.
Scrub the floor with detergent, acid etch, let dry, and apply Tile Clad. I usually thin it a bit with MEK and apply two coats with large rollers.

Re: Painting Old Concrete Floors

Posted: Mon Jun 16, 2014 8:44 pm
by blockislandguy
Thanks guys. While the floor is never going to be in a magazine, I appreciate it.

What though is etching going to do for the floor?

Re: Painting Old Concrete Floors

Posted: Mon Jun 16, 2014 9:17 pm
by nickmckinney
Depending on all the labor costs another option are soft tiles, thats the route I will probably take around my machine area and paint the rest. The tiles have a few advantages - they go right over the nastiest of concrete, they are softer to help the back, and you don't have to waste a ton of time prepping the floor perfectly. They cost a chunk more though at $2-5 a square foot.

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Re: Painting Old Concrete Floors

Posted: Mon Jun 16, 2014 11:20 pm
by Hotz
Great information here ... http://www.garagejournal.com/forum/foru ... y.php?f=20
showing new product repairs many tips ..
hope that helps .. good luck with the project ... :wink:

Re: Painting Old Concrete Floors

Posted: Tue Jun 17, 2014 1:24 pm
by W. Tripp
blockislandguy wrote:What though is etching going to do for the floor?
It helps to clean the concrete nooks/crannies/cracks and ensures a good mechanical bite for the epoxy. Cheap to do with acid from a pool supply, a couple of push brooms and a hose.

For rubber mat material use rubber conveyor belts. Locally, concrete manufacturers and quarries replace their belts every few years, and there is a good supply that normally is yours if you haul it off. Easy to clean and cut for flooring.

Re: Painting Old Concrete Floors

Posted: Thu Jul 24, 2014 5:18 am
by exhaustgases

Re: Painting Old Concrete Floors

Posted: Sun Jul 27, 2014 5:06 am
by BCjohnny
blockislandguy wrote:We have 65 year old concrete floors that are beyond hope. They've never been sealed, have a few cracks, and certain areas are oil soaked.
Fifteen years went through pretty much the exact same scenario.

Spent a week prepping the floor before we moved in, chemicals, mechanical scrubbing, everything that we were told to do, expensive two pack paint........ Complete waste of time, virtually all came up in a matter of months. As anyone who knows 'painting' will tell you, if the prep isn't what the finish wants, don't bother.

The one area that could eventually stand paint was where I placed an open base ('wheel in') oven. Over the course of a couple of months the daily application of 240degC slowly sucked all the oil out of the concrete. Surprisingly as the oil came out, it looked as clean as the day it went in, clear and golden. After all the oil had been boiled out the concrete was as clean as a new pin, spotless........ lol.

Hardly practical and definitely not recommended...............

Re: Painting Old Concrete Floors

Posted: Sat Oct 18, 2014 11:06 pm
by wagspe208
But real industrial floor paint. NOT big box store crap.
Tennant Sales and Service (I work for them in the interest of full disclosure) makes everything from paint to concrete restoring products (can build up to 3/8 or 1/2").
It must be thoroughly cleaned. Real industrial degreaser and scrubber, then etch, paint.
It WILL not come up if properly prepped.
I am 28 days from doing my new floor. I did my old floor and the only places it was failing is where I drug heavy objects across it, or repeatedly dropped blocks on it. It was 15 years old when I had a shop fire. It is still in good condition btw. Building is wiped out.
Wags

Re: Painting Old Concrete Floors

Posted: Sun Aug 07, 2016 3:13 am
by Hairyscreech
I have had pretty good success by heavily thinning an oil based paint with an industrial thinner (xylene) and using that as a wash coat over the difficult areas. The garage was unpainted when we moved in and was built in the 60s. The wash coat soaks in a bit and seals the concrete, lots of thinner seems to disolve the oil as well. After that I went straight in with the oil based rubberised top coat.

Re: Painting Old Concrete Floors

Posted: Wed Aug 10, 2016 5:35 am
by crazyman
Muriatic acid cleans concrete exceptionally well, but, it's an acid. Proper protective gear.

Re: Painting Old Concrete Floors

Posted: Sun Aug 14, 2016 4:23 am
by JoePorting
I found the easiest, cheapest, and safest way to remove oil from concrete is to repeatally wash it down with water, nothing else. I noticed the water draws up all the oil to the surface where you can just wash it off. You have to do this for hours to make it work, but it does work. You can see the oil sheen in the water as you wash it off.

Re: Painting Old Concrete Floors

Posted: Thu May 18, 2017 5:44 pm
by bentvalves
crazyman wrote:Muriatic acid cleans concrete exceptionally well, but, it's an acid. Proper protective gear.


muriatic acid indeed does clean extremely oil soaked concrete exceptionally well.

like magic. turns the concrete a yellowish dull grey and you just know shits gonna stick to it.

Re: Painting Old Concrete Floors

Posted: Fri Jul 07, 2017 10:27 am
by j-c-c
JoePorting wrote:I found the easiest, cheapest, and safest way to remove oil from concrete is to repeatally wash it down with water, nothing else. I noticed the water draws up all the oil to the surface where you can just wash it off. You have to do this for hours to make it work, but it does work. You can see the oil sheen in the water as you wash it off.

My experience over the decades is, the bold above is is a misconception. What really seems to happen is, all the methods mentioned so far mainly remove the uppermost layer of any soaked contaminants in the concrete, oil, grease, etc. Then over time, based on the mobility of the contaminants, it slowly wicks back to the surface. There is nothing, including etching, sand blasting, etc that will remove completely contaminants have had a long time presence on raw concrete. The trick is, use whatever method one chooses for the needed removal, and promptly paint the surface after drying or whatever, to prevent the contaminants from returning to the surface you want the paint to adhere to. It the paint has a stronger bond strength then the containment, you should be good to go. Where ever the paint is scratched enough in the future to the bare concrete, the contaminants will eventually reappear. I think the mistake is the incorrect conclusion that the contaminants caused the paint to separate from the concrete rather then from the physical abuse. It would however over time, with multiple cleanings, to able reduce the amount of migrating contaminants with repeated cleanings, but likely will never achieve 100% removal, more removals is of course is better then one, but diminishing returns will likely occur at some point.

I have used drumfull amounts of P&L, (Pratt & Lambert Palguard) commercially, a 2 part solvent based epoxy for decades, current $60?/gal ea part. i abuse the crap out of it, it's tough. In my car work area, I gave it a 2 part urethane over coat for a nice gloss look, which gets slippery when wet, but that is to be expected. Using any sand components for grip for seems to me to be counter-intuitive and just asking for coating break down as the sand(?) crystals fracture microscopically and degrade.