Coating 2160 sq ft shop floor

[JBaggett]

I've got a 36 x 60 shop that I am dying to coat the floor. Here's the stats.
- 7 yrs old
- some stains from oil and fluids, etc
- no paint, but has concrete sealer applied

I dont want to spend thousands of dollars, but want a durable finish.
I've only heard "etching" until I joined here, and now hear "diamond grinding"?
Is it best to do the entire surface at once, or in sections? Whether its based on cost or product effectiveness?
I'm looking at doing at light to medium gray color, with no chips/flakes.

Anything you can teach or tell me, is GREATLY appreciated!

 

[TheBanker]

Talk to the pro's on here. You have a problem with that previous sealer. Take care of that and your good to go.

 

[JBaggett]

I'm all ears Banker!
The sealer was applied immediately after the concrete cured when we built the shop to give it a "slick" look and it didn't even come close!!!!!!!

 

[TheBanker]

I am no where near the pro here but from what I have read on this thing is that you will need to diamond grind. Even that may not work. I think it depends on how deep the sealer has penetrated into the concrete. I think there are some threads on here about it. I'll let you know if and when I come across them. The pro's will chime in here soon enough, they are pretty good with monitoring the threads.

Just think of it like this. The epoxy needs a very rough service to attach to. It needs to be able to seep into the pores of the concrete.

 

[TheBanker]

I just wish I had a 2100 sq ft garage. You can put pics up of it too. that always helps.

 

[JBaggett]

Thanks for the info!
Here's the link to the Garage Gallery thread I posted after I joined.
http://www.garagejournal.com/forum/showthread.php?t=58298

 

[TheBanker]

Ahhhhh I have read your thread and seen your pics. If I had space like that then I could buy toys!

 

[AlphaGarage]

If it has a sealer, before you recoat that will need to be removed, grinding would be the best method. When you're done you want the concrete to have a texture similar to 80 - 100 grit sand paper.

 

[JBaggett]

Alpha, Is it possible for you to go into greater detail?
I'd appreciate the advice.

 

[nate379]

My Dad painted the floor in his ~3200 sq ft pole barn about 8 years ago, still looks decent today. I think he just used whatever left over paint he had and mixed it all together even

 

[gabeancounter]

Nate,
You are correct. You need to grind the floor like Alpha mentioned. Check with Sunbelt rentals for a grinder. I posted a pic below. Seems like it will be around $250-350 with all the items you need to do the job. I would think you could do the job in a day. The rental place will be able to help show you how to operate the machine and the best methods.

 

[rugerlady]

You will have to diamond grind the concrete. You can rent these machines from your local rental company or Home Depot.

 

[JBaggett]

So I'm understanding so far, the first step would be to diamond grind the entire surface. Anything special to understand about the first step?
- certain machine, RPMs,?
- How will I know the surface is ready?
- anything else?

 

[AlphaGarage]

Different machines are designed to run at different speeds, some as low as 175 rpm. And then there are some models that have a Metabo grind head that run at a far higher rpm.

You want that 80 - 100 grit feel. Plus check for water absorption, sprinkle a few drops of water, they should all soak in evenly, if they bead up and just sit there, there's still some sealer to be removed.

 

[JBaggett]

Fred, first of all THANK YOU!
Secondly, should I do the entire area first, or do it in sections?
Since I have (3) 20' wide sections, all 36' long, should I do them individually?

 

[AlphaGarage]

If you mean do all coats on one section at a time - not unless you have no other choice. If you mean do all the sections with one coat, then do the 2nd coat one section at a time - yes.

Let's say you do it right and have a prime, top, and clear coat... I would break each 720 ft2 area into 2 even sections of 360 ft2 apiece. That means that for the prime coat you would be mixing and applying 6 separate batches for the prime, then 6 for the top, capped by 6 for the clear.

If after the prime coat you feel that things are going well, and if you have a helper, you might try tackle a 720 ft2 section with one batch, but that's a lot of area to coat, especially if you're broadcasting flakes.

And on the clear you don't want to be too rushed because that's a sure way to miss a spot, or two, or a dozen. That clear is real clear when it's being applied, and since it's going down over a very glossy top coat it can be very difficult to discern spots that haven't received that last coat of clear.

A pro could do 720 ft2 at one whack - but I'd feel more comfortable with 360.

Hope that makes sense.

 

[JBaggett]

Males perfect sense! Thank you!
So the first step, grind the surface
Second step, apply coating product
Third step, clear.

I've yet to figure out which product to use, but it will be a basic light grey, with no flakes, regardless.

I'm leaning towards doing one 20x36 section at a time due to the shear size of the shop, and moving everything in and out.

 

[sky1]

That's what Sunbelt told me about renting their grinders:

The 20" Edco Grinder rents for $75 a day. It uses 6 stones ($7 each). Each stone is good for about 1 000 sf. The stones come in coarse, medium, fine. For an epoxy floor they suggest the medium.

Depending on the location they may or may not have vacuums to go with the grinder.

Stones are not diamonds. They are meant to grind uncoated concrete. Stones will get plugged up very fast if you have any paint on the concrete. Diamonds will not.

The grinder needs a heavy duty extension cord. If the cord is not fat enough you can burn the grinder's motor and then Sunbelt makes you buy it. They also suggested a 50' long extension cord, not longer.

Bottom line - you either deal with a DIY learning curve or you hire a professional to either prep the floor for you only or do the entire job - prep and coating.

 

[JBaggett]

Good info Sky! Thanks!!!!
Ok so that leads to another question.....if a "pro" does it, what kinda costs am I looking at? I've done some minor searches here locally, and can't find one.

 

[tncatadjuster]

Good info Sky! Thanks!!!!
Ok so that leads to another question.....if a "pro" does it, what kinda costs am I looking at? I've done some minor searches here locally, and can't find one.

PM sent.