My floor cleaning and epoxy. Devoe 224HS. Many pics, notes & questions

I just bought a new house a couple months ago. I'm finally settled and taking on the job of cleaning and epoxying the floor.
I've done a lot of research and decided to commit the time to get this done. I documented everything I've done so far to help others. Also, I still have a lot of questions, so please read and help out if you can.

Background:
I'm the second owner of the house. The garage floor is 55 years old. The previous owner was pretty handy and did a lot of things in this garage over the years, so there’s a lot of stuff on the floor. Apparently, about the only thing they didn't do was clean it, there’s all kinds of contaminants on it.
The house is in southern cal. so as is typical for the area the workmanship is not that great. The garage floor is no exception. It’s very coarse and porous. Also there’s a lot of tool marks from the trowel or whatever they used to spread the cement. It’s not all nice and smooth like I’m used to seeing. I haven't seen too many people taking on really old floors (maybe there's a reason) so I thought this might be helpful to others with crappy old floors.

The two pictures below are what the floor looked like when I started. There's a lot if **** going on.
- generally very dirty
- nasty dark oil stains
- many, many different kinds of paint droppings all over
- rust spots
- plaster & stucco blotches in many places
- roofing tar (?) along some of the edges
- tile adhesive along 3” edge of right wall from a remodel
- bad crack & hole repair jobs
- large holes
- large pitted areas
- hairline cracks





Cleaning Supplies:
The first I did to clean the floor was to scrape off all the surface contamination I could. There was a lot of plaster chunks, tile adhesive, tar-like stuff, and some other residue from what I found after the fact to be extra material from a previous patching job. I used a large chisel and a pry bar to scrape. It’s all I had and it worked pretty well. I couldn’t get everything but I got a great deal of the stuff. This pic is what some of this stuff looked like:



I got the following cleaning items at Home Depot:
- stiff bristle scrubber
- foam squeegee
- ZEP Driveway, Concrete & Masonry cleaner (3g)
- Behr No.990 Concrete & Masonry Cleaner/Degreaser (2g)
- rubber boots
- tsp
- 5g buckets (3)
- pressure washer 2200psi (rented $130 for two days… I could have bought one for not much more!)



- Surprisingly the hardest thing to find was a large plastic watering jug with a large diffuse spicket, every store I went to had these small metal cans. I found one at a local plant store but had to pay $8!



- The gloves I’ve had for many years. I bought them from marinedepot.com for my reef aquariums but you can probably get similar ones elsewhere.



- I got the respirator at Lowes by the paint isle. It’s the one that comes with the pink/purple filters. It worked great. When I had it on I could not smell any of the cleaner, muriatic acid, ammonia etc… When I would take it off I would just about faint.



I picked up 4g of 30% muriatic acid at a local pool supply store. They do still sell muriatic acid at Home Depot outside in the garden area but it’s only 15% HCL and much more expensive.

Cleaning:

First I removed everything from the garage and swept the major stuff off the floor. Next I hosed it out with my regular hose a few times over the course of a few days leading up to the weekend. Saturday morning I covered the walls with 3’ high 4mil plastic. I used regular masking tape to hold it up. I wasn’t too concerned about a little water getting on the walls I just wanted to avoid fludding them too much.



I got the pressure washer fired up and spent about 30 minutes just hosing out all the dirt and debris. The floor was very dirty. Since the garage was in such bad shape a decided I was going to clean it many times. I planned to degrease it twice, then TSP, then the muriatic acid.
I split the garage into three pieces starting at the back 1/3rd. For the first go ‘round I mixed the Behr Degreaser with about 3g water and used the watering jug to spread it evenly. I ended up using both gallons of cleaner for just the back 1/3rd. I let it sit for 10-15 minutes and then I scrubbed for about 30 minutes with the scrubber brush. After scrubbing I rinsed/cleaned with the pressure washer and then used the squeegee to get all the water out of the garage. The pressure washer was very effective at getting off all the paint spots and some of the other surface stuff. The oil stains also came out a pretty decent amount. This picture will show what it looked like after the first cleaning:



That was about it for Saturday since it was getting dark and I didn’t want to piss off the neighbors with the pressure washer running at dinner time etc…
Sunday morning I picked back up with the back 3rd and decided to try TSP. I mixed about 1 ½ cups with 5g of hot water in two buckets (10g total). I used the watering jug to spread it evenly. I used a lot. After about 15 minutes I scrubbed it for about 20 minutes (this is hard work!) and then pressure washed it, rinsed and squegee’d out the garage again. I decided the results weren’t nearly as good as the cleaner/degreaser so I decided to can the TSP for the other 2/3rd’s of the floor.
Don’t laugh, but I did the back 1/3rd of the garage again, but this time with the ZEP cleaner mixed 5:1 with hot water. Same thing… waited 15 minutes, scrubbed, pressure washed, rinsed, squeegee’d. It looked pretty good, like a 15 year old garage instead of a 50 year old one, but I still wasn’t totally happy. I wanted the surface to be smooth and clean so the paint will adhere. I was hoping the muriatic would help (it did).
For the rest of the floor I used the ZEP cleaner just as described above. I went through the whole process twice… degreaser/scrub/wash/rinse/squeegee.
Next I spit the garage up into 6 sections and used the 30% muriatic acid mixed with water 3:1. I used the watering jug to spread it evenly. This was when things really cleaned up. It was very affective. I waited 10-15 minutes until it stopped bubbling and scrubbed again with the scrubber brush. The floor etched just as it was supposed to and it also came even more clean. If you have a newer garage you can probably get away with just some quick spot degreasing and then the muriatic acid.
After the etching I mixed 4 liters of ammonia with about 15g of water and used the watering jug to evenly cover the whole floor. After 15 minutes I used my garden hose to rinse out, followed by the squegee to get the rest of the water out.
This is what it looks like currently just after completing the cleaning/etching:







I wasn’t sure if I made a mistake by not doing something mechanical like sanding or something abrasive. The reason I though some sort of abrasive cleaning might help is because there was a lot of stuff on the floor and it’s not totally smooth (it never was smooth, it just wasn’t layed well). At this point it looks very good. I really don’t think I would gain much although I would love to hear any thoughts. What little is left of the oil stains I’m not worried about at all, they are set very deep. There is still some stuff I need to deal with during the repairs…

Repair

This is the step I’m currently at, and I have a lot of questions.

1. I plan to use Rustoleum Epoxy Shield Concrete Patch to fix the basic small holes and cracks. The first problem I have is that I can’t find it anywhere. Do I have to order it online. Is there some other epoxy concrete patch available to the DIYer that’s easy to get?

2. I have one big hole that is about 3” around and 1” deep. It looks like there was something installed there at some point and there is a steel piece still left in there. The cut off steel piece is below the surface so I’m hoping to just fill in the hole with something. Can I use the epoxy concrete patch for something this big? Do I do it in three or four takes? Should I mix some sort of concrete and patch it? It looks like this:



3. There’s some pretty good gouging or pitting in a couple area like in the pic. Do I bother filling this is with something like the epoxy concrete patching stuff? Won’t I have to sand it or something to smooth it out after I patch? Should I just leave it alone?



4. There are some hairline cracks in a few spots. The cracks are very small, I’m not even sure I could get any material in these cracks unless I just use a shallow patch over the entire area. Is it important to patch these areas? Is it possible the cracks go all the way through and create a moisture problem?



5. The right side wall area towards the front of the garage used to be some sort of entrance way / mudroom. The border on that side of the floor has a distinct gap in it the there is visible another 3” wide length of cement that joins up. This strip of cement had a bunch of tile adhesive on it. There was even some pieces of tile still on it. I was able to get most of it off and I plan to get pretty much all of it off, but the cement is very rocky in this area. Aside from filling the crack with the epoxy cement patch should I do anything with this area?


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[edited November 16]

The floor was pretty much completely dry today. Everything looks great, you can actually see what looks like the swirls from the tool marks from when the floor was laid. The cement looks very whitish after the etching. This garage floor is more coarse than the usual and it's possible I overdid it with the HCL. It seems really good though and ready for the epoxy to adhere once I finish patching etc...there doesn't seem to be any powdery residue or anything it's just very white-ish. I'm going to hose it out one more time on Wed night and test the PH in preparation for the weekend. This is what it looks like tonight. I also put a pic there of the biggest hole, you can also see in this pic how coarse the cement is.





I also did some patching of the hairline cracks and the holes. I ended up using Bondo Concrete Brick Stucco Repair Compound:





I also put down a couple patches of plastic to test for moisture:



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[edited November 17]
OK good news from the moisture test. No condensation or water under the plastic. I'm going to do more tests this time by the very edges and corners of the garage because these areas seem much more prone.

I used the angle grinder to starter sanding down the that rough area along the right wall. There's a lot to do. Also it leaves tons of dust as you would imagine so I'll have to wash rinse the floor several more times again.

I also did dome more patching with the cement bondo stuff and sanded some of the stuff I did last night. This stuff leaves an absolute dust cloud as well so I'm really going to have to clean up again before I'm anywhere near ready to lay the epoxy. I used the 4 1/2" grinder for sanding this as well. The bondo worked well - I was able to sand it down nicely in most spots. Is there anything I have to do to prepare the bondo surface for epoxy besides clean it with acetone? I figure it's pretty much similar to the epoxy I'll be using and will bond well?
Here's a pix of that big hole filled up and another spot that had a hole and hairline cracks

I know it's a little late, since you've already cleaned the floor, but did you do a moisture test (2'x2' square of plastic duct taped to floor for 24 hrs)? I had a big crack in my floor. I setup one test over that crack, then one test over the "normal" part of my slab. Neither showed moisture after 24 hrs, so I knew I was good.

As to the Rustoleum Patch. It's great stuff. I found it a little hard to work with, but I'm not handy at all. I'll bet someone who's good with a trowel will have no problem working it. I found my at a local True Value "Nuts and Bolts" mega store.

Yes you can fill the hole with it. 3 or 4 layers w/ 12 hrs between should do it.

The one mistake I did with the epoxy patch was I didn't realize it had to be nearly perfect. I didn't get it all scraped level with my putty knife and, sure enough, now I've got ridges where there used to be cracks! What're ya gonna do?

Good luck.

I haven't done a moisture test yet. I was going to do it after I repaired the floor and after it completely dried. I was going to use a 2' square of plastic in two or three places and tape in down for a day or two. Is it something I should have done first and something that cannot be repaired?

Disclaimer: I'm absolutely not a professional and have only done 1 floor, my own.

My understanding is that you can't easily fix moisture coming through the slab. My understanding is that the slab needs to have a vapor barrier installed underneath it and the only practical time to do that is when the slab is poured.

I would have tested before the work/effort/expense of cleaning the floor. I believe you definately need to test before epoxy as your floor coating will fail if there's moisture coming through. There's a thread on here I remember from the past couple days from a guy who has moisture coming through his slab. There's a discussion of options.

Give it a 3-4 days to become bone dry. You don't want all the added moisture from washing to skew your test. Good luck!

Edit - This thread, starting with post #18: http://www.garagejournal.com/forum/showthread.php?t=14368&highlight=moisture

Epoxy can be ground smooth with an angle grinder with ease. As well as concrete steel or aluminum. You can get a wire cup brush that mounts on the angle grinder also. Cutting wheels are also available for them for cutting almost anything. If you don't have an angle grinder buy one, they are a fantastic tool for cutting, grinding, or sharpening etc.

I have access to a 4 1/2" angle grinder so I'll look into using that for cleaning up the mess along that strip on the right hand side wall and for smoothing out the areas that will be patched.

New to the forum and noticed that you have a bit of concrete along the perimeter of the garage. Are you planning on coating it with the same epoxy or keep it the way it is? I will be attempting to do mine in the near future and still debating what to do.

I edited the 2nd post to update what I did today

noticed that you have a bit of concrete along the perimeter of the garage. Are you planning on coating it with the same epoxy or keep it the way it is?

Click to expand...

I'm going to coat it. I spent a good deal of time cleaning those areas too. Most of it is not too bad at all except that area along the right side that need some attention. I'll have to fix a crack along the whole length and also smooth it out a bit. I'll see how it works out, I'm planning on painting it this weekend or next so it won't be too long.

Good luck with it. I am glad to see some "well used" garage floors. It would be nice to epoxy it. Then you can hose everything down once in a while to clean up the whole floor and don't have to worry about water getting on the edges.

I guess the alternative is to paint it, but it won't be waterproof.

Keep us updated.

Is that a two part epoxy patch filler? If so where did you buy it? I have one small hole to fill and want to buy a product at a hardware store like Home Depot,Lowes, or Ace.

Is that a two part epoxy patch filler? If so where did you buy it? I have one small hole to fill and want to buy a product at a hardware store like Home Depot,Lowes, or Ace.

Click to expand...

It's a 2-part with a base and a hardener like other bondo. It has a base and a hardener. The hardener is mixed in small amount with base like other bondo products. The MSDS states all kinds of stuff in there... oxirane, polymer with methyloxirane, monobutyl ether, limestone, styrene monomer
magnesium carbonate, sodium silicate... I checked it this morning and it bonded very well to the concrete. I decided to use it after reading the notes on www.epoxyyourgaragefloor.com

azone said:

...It looked pretty good, like a 15 year old garage instead of a 50 year old one, but I still wasn’t totally happy. I wanted the surface to be smooth and clean so the paint will adhere. I was hoping the muriatic would help (it did)...

Click to expand...

Actually, smooth is worse than rough. You want the surface to feel like 80 - 120 grit sandpaper.

I used the Devoe 224HS on a new slab, and I don't think you will have any issue with the hairline cracks. I did multiple degreasing/etching/powerwashing as you have ... and from your pics, I think there is one issue.

It looks to me like you do not have all the residue left from the etching powerwashed off. As I look at it, it appears there are areas where you were more aggressive with the powerwasher than others, so in some spots it looks really clean and others by comparison look like they still need to be powerwashed.

If it were me, I would aggressively powerwash/brush another time. Keep the tip of the powerwasher about 4 inches from the concrete. Have someone brush the snot out of the floor at the same time.

You are already doing the moisture test - but if it fails, don't give up. You may just need to let the slab dry more and test again. Are you in a humid section of SoCal or are you out in the dryer areas? If you can, let it dry for a solid week (maybe two) before doing the moisture test again.

Finally, let's say it fails the moisture test after a solid drying out, and you're convinced it does not have a vapor barrier underneath the slab. At that point, call ICI Devoe & ask them what to do. They may tell you "don't use our product."

If they DO tell you not to use their product due to the moisture test, don't give up. There are other vendors that might have an epoxy product that will work for you.

I think you are on the right track!

azone: Where did you buy the Bondo product? Online or in a store?

I updated my second post again with details on the patching

Where did you buy the Bondo product?

Click to expand...

I got it at the local true value hardware store. I called the closest one from my work and luckily they had it. I would search the truevalue.com website and search by zip code ...you can search specifically for ones that have a paint department - then call them and ask if they have it.

Jaguar Fan thanks for chiming in, I've seen your post on your floor many times and it helps a lot. It's the same exact color and same chip colors as I plan to use so it helps a lot. About the smoothness I wasn't really referring to the grit or coarseness of the cement as a hole I was referring to the fact that my floor had many bumps and swirly bumps marks and grooves and other uneven stuff. I was able to make it somewhat level so the floor will be pretty flat. As far as the etching it worked very well and I have a nice heavy grit to bond to. As for the residue from etching I pressure washed it a few times afterwards and even used ammonia twice (more than 1g all together) but I think you may be right that it's not all neutralized yet. It shouldn't be a problem since I still need to hose it out a few times anyway. I don't have the pressure washer (it was rented) but hopefully I can blast it with just my hose.

by the way does the epoxy fill in the small pitted areas and other minor inconsistencies in the cement or is it still visible when you're done? I would guess the typcial application of 224HS is probably not thick enough to sort of self level and harden to hide everything but I wasn't sure. Also I figured from what I read that the flakes (i plan to use a healthy amount) and clear coat helps cover things up and even things out.

I'm still not sure what to do with that area along the right side wall.
I'm going to use a 7" angle grinder tomorrow to continue to grind it all down so that it's smoother and more even with the height of the rest of the floor. Right now there's a bit of a lip in many places where that crack is so there's like a lip/hump going down lengthwise along the crack. I already grinded a bunch of it to make it more level but it needs more work. Also there's still more of those chippy areas that I want to grind down and smooth out. I'm not sure what to patch that area with. Should I just patch the crack and leave the rest of it the best I can? or should I patch that whole 3" width all the way from the wall to the other side of the crack? If I do this should I just use the same bondo cement stuff?

Grind it then fill it with the Bondo.

I also would grind it then smooth it over with the bondo. That way it all looks uniform.

I'm a bondo junkie - use it for all sorts of stuff. Got into it when I was in "show biz", a lot of the set guys would use it to fix a lot of problems. But I'm not fond of using it on concrete, at least not in areas that are going to see any heavy use. For those areas you should use a product designed to patch concrete.


Small pitted areas will be either filled with the epoxy (assuming you're using enough) and/or masked with a good broadcast of flakes.

JF is right, that white residue is calcium from the acid etch and should be removed before you coat.

He's also spot-on with the mixing and applying. Measure carefully, mix thoroughly, get it out of the mixing container and onto the floor, don't try drain out the last drops. Apply with quality no lint, no shed, rollers; use a piece of duct tape to pat down the rollers to remove any wild hairs, if a lot comes off you may want to go get better roller covers.

I think the Bondo he's using is made for concrete and stucco repair.

He has a pic of in post #3.

Bullet120 said:

I think the Bondo he's using is made for concrete and stucco repair.

He has a pic of in post #3.

Click to expand...

Got it - thanks for the clarification.

The real Bondo is pretty good for mots of apps. We have a wood threshold for our front door. It was neglected and pretty well toast when we moved in. Didn't have the time or resources to fix it then so I thought I'd just use Bondo to patch and replace the entire piece eventually. Being the front door entrance it receives a lot of traffic, but six years later it's doing fine. I just paint it every couple of years.

I also use Bondo to patch window sills, eaves, and quite a few other exterior wood items. The fact that it's easy to mix, apply, shapes well and cures in 30 minutes or so and takes primer well all adds to its utility.

thanks for all the replies - helps a lot.
One thing I am wondering in preparation for doing the epoxy is what I should use to spread it. Specifically you guys that used the Devoe 224HS what did you use? squeeguee or serated squeegee and then backroll?

Azone first go to devoes website and punch in your product number it will tell you how to prep and apply your product. As for the cracks i would use a self leveling caulk for epoxy coatings and a good quality roller cover. When you get ready to mix your material follow the instructions and let material sit for 15 minutes. It is important that you mix enough material to complete the first coat. When you start painting cut everything in first then roll keeping a wet edge in other words dont stop till you are 100% done with first coat. Repeat second coat as above mixing enough material to complete 2nd coat. It is better to throw away a little material in the end than to run short on the second coat. There is no need to trowel just dip and roll

thanks for the advice jake.
last night night I ground down and leveled out that strip along the right side. It came out very nice. I ended up using a 7" angle grinder and went through three discs. After that I clean and etched that area, then rinsed with ammonia. When it fully dries I'm going to patch it up. I'll post pics. It looks like I will be ready to start painting next wednesday.

Another question,
should I "V" out the groove between the two concrete sections or just patch it as it is?

the right side of the floor was still damp tonight so I couldn't do the patching. I ended up getting a hold of some of that Rustoleum EpoxyShield concrete Patch stuff - I found it at the local Dunn-Edwards. It was the first place I called, they had a lot of the EpoxyShield line of products and they had plenty of these kits. Each kit is about 24oz of material and is about $22 so it's not the most economical solution. I decided I wanted to use it for the cracks and other areas that require a decent amount of patching because I figure it's better to coat epoxy over cement and epoxy patch versus some other patching material.



Here's what that right side area looks like now after grinding. It looks good, uniform, I really just need to patch the crack and a few other areas.



A couple things I see that I'm not sure what to do with...

1. I can see now that it looks like a couple spots may have been patched with cement at some point. Now that I can see the whole floor all cleaned it looks like the whole floor is rather flat except for two areas. Now that I get a better look it looks like these areas may have been patched because they are not as uniform as the rest of the floor and there are sort of scrapes and inconsistencies and it looks like the whole area is a shallow hump (you can see some of the marks and grooves in the pic below). The cement looks pretty much identical to the rest of the floor so that's the only reason I'm not sure. I'm not sure what to do with this. As you figured out by now I'm pretty picky like most of us and want the floor to turn out good as I can. I'm wondering if I should rent a floor sander and smooth out these two areas? or maybe they were patched for a reason?



2. The left side and rear border of the cement has a typical groove which is obviously related to how they frame it out and pour the cement. This groove is lower than the floor at some points and transitions to higher than the floor at other points. I know this is pretty typical but I'm wondering if I should just leave it or try to even it out? It would be a pain in the *** to even it out. Again, I'm just being picky and want it to come out the best I can. Should I just leave it alone?

It's kinda hard to tell from the pics. But you can always try the grinder see if you can smooth out some of those spots a little bit. You can't hurt too much if you keep the grinder moving. In a nutshell, the smoother the better. I found out that the rough stuff can be coated over, but it takes material to do it. So you need it thicker in that area which can be difficult when your applying the epoxy. The prep work is the hardest and longest. But gives the best final results. You could grind the rough stuff or skim coat it with the epoxy patch.

About "Chasing" those joints by creating a "V groove..." It all depends primarily on whether or not you expect any movement between the two sections of substrate; if they're static there's no need to chase them.

A V grove help will help reduce the chance cracks developing in the epoxy coating should the cracks expand or contract. See this doc for more info.

Those rough areas were probably patched for a reason, but it looks like the patches are holding well, and if they are there's no reason why you couldn't smooth them down by grinding or sanding. There is a small chance that the patch could pop off, but should that happen you already have some patch material on hand. Grab that 7" grinder and try a few test spots.

A lot of great info here, my floor is in very similar condition. Very thorough, can't wait to see the results...

This is my situation to a "T"- old, dirty, poorly poured concrete with trowel marks and year of oil. I plan on doing mine in a year or two but I have a large crack down most of my slab. I'm looking forward to seeing the end result.

Great writeup. Keep posting all the pics and keep telling us the details. Us guys trying to make due with an old garage need this kind of thing to give us hope!!

so the 10-day forecast said 0 percent chance of rain for the next 10 days. Well it rained last night! not much but any rain is good here in southern california, unless you're trying to epoxy coat your garage! It shouldn't be wet inside the garage but the humidity might keep it damp and not allow me to do patching tonight.

the edges of the floor were still very slightly damp tonight so I'll have to wait until tomorrow to patch and continue with the grinding. One thing of major concern is that I noticed that it seems that the edges and corners are more vulnerable to humidity and such so I started testing more patches of plastic taped down. I've done six places so far and I found that one area I patched at the far right back had an ever so slight discoloration to it... like there was the slightest bit of dampness underneath. Not anywhere near wet and not moist to the touch, but possibly the slightest hint of moisture. It won't show up in pictures so couldn't post it. I put two more patches in two more corners again and I'll check tomorrow. It did rain last night so that could have had something to do with it (or it could have exposed a problem if it rained and moisture did come through). So what's the deal? when you get an appreciable amount of moisture is it actually damp or wet? In this case the cement feels cold, it's about 50 degrees, but not damp.

[edit]
alright, I took this picture a few minutes ago (I know, I know lame Friday night but what are you gonna do...). You see that dark spot, that's moisture. I used a blow dryer to dry that spot about 5 hours ago and it's moist again. Is this a concern? I must note that this is right at the garage opening, and there wind blowing in there and it's abot 53 degrees out and 82% humidity so I guess it could be moisture coming from outide...not from below the concrete.

I am just speaking out loud, but could you fill the hole in the wall and maybe that will prevent the cold draft?

yes I'm going to fill it tomorrow. I think it's safe to say it's coming from the surface and not from underneath.

It's been very humid here compared to usual so it's throwing a wrench into my plans. Ideally I would be doing this in the summer. I think I'll be ok it's still 70 - 75 degrees during daytime and 50's at night.
I've noticed that the cement border of the floor (not sure what you call this) stays pretty wet where as the rest of the floor is pretty much bone dry. I can tell because it's still darker in color because it's still damp, and if I use a blow dryer on it it dries out and lightens in color. I'm wondering if I should not epoxy this area, meaning only epoxy the floor and not these vertical surfaces. This border only exists along the left wall and back wall of the garage.

Alright, moving ahead. I patched some of the area on the right side wall. The epoxy patch is pretty difficult to handle. It's like ...well...epoxy I guess. It's rather thin for a good hour so it's not good for patching vertical surfaces or big holes. Definitely the bondo stuff is better for that. However it's very good for cracks, although it makes a mess. I'll say I'm very handy and I do most everything myself, woodworking, drywall, electrical, etc.. and I've used many many tools and adhesives and stuff and this stuff is gooey and somewhat hard to handle. It also takes 10+ hours to harden. Here's a pic of an area I haven't sanded yet and an area I got started on. It actually looks better than in the pics.When it's all sanded down with help from my 5" orbital sander and the 4 1/2" angle grinder it'll be smooth and I will have taken off a lot of the epoxy material.




I also went to home depot with ideas of renting a 10" floor grinder. After I saw the size of it and the fact they charge extra for use of the diamond disc and vacuum attachment I thought better of it. I figured the 7" angle grinder has a diamond disc so I would just use that along with regular grinding discs. I'm glad I did, renting it would have been overkill. I wish I practiced with that diamond disc beforehand because boy does it cut! I'm really good with hand tools but this took a minute to get used to. I put some pretty good gouges in the cement at first. I got used to it really fast and spent an hour or more trying to level out the area. After the diamond disc I went back over with the regular masonry disc for a good while to try to smooth and level it out. It's pretty hard to do and t will never be that perfect. I did come to the conclusion that those humps are from the original pour. It's as if they had a little extra cement and pooled it and troweled it around the middle area. Here's a picture of that crazy grinding disc and that area of the floor. You can see in this pic how rough the floor really is in this area, those grooves you see are the original floor - not from me.




Next I ground the border on the left side. I figured what the heck might as well. It's a mess and leaves so much dust (wear a respirator or you'll really do some damage). I also quickly went over that 45 degree edge in the sidewall to smooth it out a bit. I used the 4 1/2" grinder.

Any update?

yes, I finished all the patching, grinding & sanding (lots of dirty work) and pressure washed the cement several times. Today I found I still had some residue from etching last weekend! I've pressure washed every square inch several times and I can still see some residue in some areas. I have some pics I just haven't taken the time to upload yet, all the patching came out very well. Tomorrow I will vacuum a couple times and then wednesday I will mask out wherever needs it. The earliest I will do the first coat of epoxy is Thursday or Friday. The latest would be Saturday. I found it really does take about 4 days for the cement to be completely dry.

I was planning on getting started with the epoxy coating tomorrow but the cement is taking a long time to dry. I may even have to wait until Saturday.
I finished up all the patching over the weekend. Here's a pic where you can see I patched that crack with epoxy patch and I also patched the gap at the base of the wall with the cement bondo. The second pic is after it's all sanded and complete.





This pic is after I used the epoxy patch to level off the uneven areas on the left side edge of the floor.



Monday night I carefully vacuumed the whole garage with the wet/dry vac. I also vacuumed every square inch of the floor. I was down there for about 2 1/2 hours. Tuesday night I did a little more vacuuming and did some testing to make sure I had got up all the residue left over from acid washing and grinding. At this point I could eat off this thing So far it's been two full days since the last time I pressure washed so I'm hoping another two days I'll be ok. Tomorrow is going to be in the high 70's and sunny so I'm going to open the garage door during the daytime to help dry it out.

I also picked up the rest of the supplies on Monday. I'm using the Devoe 224HS for primer and color coat and the 379H for the clear coat. I going to thin the primer coat with the T-10 thinner. I have three kits of 224HS total (6g). I plan to use about 2.3g for primer coat and 3.7g for the color coat. I also have 16lbs of black marble blend chips from Original Color Chips. I divided them up into six of those reuseable plastic storage containers. I'm going to use them all. My floor is pretty old and not very flat so I figured the more the better to help blend/hide imperfections. With this in mind I bought three 379H kits. These kits come with 1 gallon part A and 1 quart part B. The spec sheet says one kit will over up to 500 sq ft. Since I'm using a lot of chips I decided to buy three kits just in case and do two or three coats over the chips to get it a bit smoother.