Tips for fixing a screwed up epoxy job

[lyonkster]

I posted a while back about my super slippery epoxy coating that was applied by a contractor last May. http://www.garagejournal.com/forum/showthread.php?t=101972

The bad news is that the epoxy is still slippery. In the meantime, if I drop anything on the epoxy (socket, bolt, wrench), it takes out a small chunk of the epoxy. Also, the epoxy started peeling and lifting in large chunks. I can't say that I am surprised, since the concrete was sealed and the installer did not grind it (as we agreed in the contract) but only ran a sander over it, so the epoxy to concrete adhesion is very poor.

I consider this good news because after tos of phone calls and emails, the installer has agreed to remove the existing epoxy, prepare the concrete properly, and reapply the epoxy. But this brings up a bunch of questions that I would like to resolve, so that we do not get a repeat performance. So can someone help me with these:

1. What is the best way to remove previously applied epoxy?
2. Should I insist that this time he use a diamond grinder to prepare the floor, as was stated in contract? And not back down for anything less?
3. What preparation needs to be done after grinding? Washing, powerwashing, or just blowing off the dust?
4. What is the best test to ensure the concrete is ready for epoxy? Is it to see that water does not bead on the floor?
5. If he cannot remove the epoxy from some of the edges and corners, what should he do to prepare those areas, just sand the old epoxy?
6. Last time he got a lot of dirt and roller nap into the final coat, should I insist that he use an "epoxy rated" roller to avoid roller nap? Is that what it's called?

Any other tips?

I am glad that they agreed to redo it, but am very apprehenive because I realize that they are losing money on this and are motivated to do the least they can get away with, so I really need to watch them and be ready to step in if they deviate from they should be doing.

Thanks in advance folks!

 

[Edger]

What a situation! I believe they must diamond grind back to the original concrete which means that no epoxy should be visible unless it is in a hole. They can also shot blast, but that is very likely to leave coarse track marks across your floor which they will not fill with another couple of coats.

The edges need to be hand ground with an angle grinder fitted with a suitable dust shroud see: http://www.situp.com.au/Hoverhood Dust Shroud.html

After diamond grinding the dust needs to be removed thoroughly. There are a few methods, but it depends on the diligence and expertise of the operator to do a good job and also on the quality of the equipment which I will explain in a moment. Then you will very likely have millions of small holes exposed which might produce bubbles in the second coat. The traditional way to stop them is to put down two separate coats of epoxy primer before the main epoxy topcoat and/or to apply the final coat when the slab is cooling down rather than warming up. That probably means starting after dark on a hot day. If it is done in cool weather bubbles may not be a problem.

To remove dust I found that an excellent floor tool with rubbers in good condition connected to a good vacuum dust collector was required, and then the operator needed to be taught to keep it flat as he walked backwards to hold a strong suction. If the wand is moved up or down by an operator's arm the head will lose its high suction as the front or back seal comes off the floor and all the dust will not be removed. The other method was to wet areas, quickly agitate with a broom and **** it up with a wet vac before the dust settled and the water dried. Once again you need good equipment and expertise. You may want to do this work yourself after he finishes diamond grinding.

Those are my tips, I am sure others will have some too.

 

[OBP]

I agree with Edgar, They definitely need to grind off that coating, and yes the edges will come off with a edger grinder fitted with a diamond blade, not a sander.

They may need to use a separate head on the floor grinder to strip the old (or should I say failed) epoxy off first then diamond grind the floor. It will depend on how well the coating strips. Either way it needs to be stripped if its coming off or bubbling and then diamond ground to ensure the next epoxy sticks. Along with that a primer coat is always recommended, depending on what the product is they use, it should be thinned down to ensure penetration into the concrete. If its thick its just going to sit on top of the concrete.

I wouldn't recommend washing and especially not power washing because your forcing water deep into the surface and it will take longer to dry before you can coat it.

We always vacuum twice and blow off the floor twice.
Then you can check with a couple of drops of water to see how the concrete absorbs the water, it should soak into the concrete immediately and dry fairly quick.

As for the roller problem, he should use a new roller cover for the top coat and make sure his bucket is spotless before he mixes the product, when he blows out the garage get him to blow down the drive way far enough that it won't just blow back in with the wind.
Most roller covers will work fine with epoxy, just make sure it doesn't say for acrylic or water based paints only otherwise it will shed like a hairy dog in summer. I usually wrap my rollers in masking tape and pull it off before rolling epoxy that will make sure all the loose fibers come out.

Hopefully all that makes sense, all the best with the job. The good thing is the guy is doing what he should, and thats fixing the problem, gotta give him points for that.

 

[lyonkster]

Thanks Edgar and OBP, these are very useful tips.

I wonder if you can help me with a couple of follow-ups:

What if he decides to do something other than diamond grinding to prepare the concrete? This is what happened the first time, when the installer showed up with a very coarse sander and said that it is better than grinding, which is what was stated in the contract. I let him do that, thinking that he was the expert, but we see how that turned out. So, since the same installer is showing up, should I insist on diamond grinding or can some other method be acceptable?

I'm just trying to anticipate what could go wrong, and when to stop him, since my experience with these guys so far has not been very good.

Thanks again.

 

[nmanitou]

You might consider taking another approach.

Rather than telling him what methods to use, tell him what finished product you both agree on. Make it a performance based project rather than a methods based project. For example, before he starts, you both agree that you want a finished product the adheres to the concrete surface, resists dings from dropped objects, has a non-slip surface, and is free from roller lint and air bubbles. Specify and agree on the results - not the methods.

This might seem unusual at first, because you want to make sure he "does it right". But in this case, if he is warrantying a service it is up to him to choose a method that works. If you tell him to do something a certain way, and there are problems later, he can use the excuse that "I did it the way you told me too".

All of this advice assumes you have a qualified professional who cares about quality work. If not then you probably do have to do a lot of babysitting during the project. On second thought, the fact that you had an agreement to diamond grind and he didn't is a red flag. Maybe you need to babysit!

 

[Edger]

Your questions are very relevant because sneaky operators will tell all sorts of believable tales.

As I said it should be diamond ground or shot blasted. No other method should be accepted and shot blasting will leave track marks so that leaves diamond grinding.

I also said that no epoxy should be left except perhaps in holes. I reckon that is what should be done. Complete removal and opening of the concrete surface.

Sanders are cheap and next to useless because they only scratch the surface and their abrasive is not good enough to get into the concrete.

Poor adhesion is what you have because the epoxy was not applied to porous concrete, do not allow him to make the same mistake again. No amount of extra epoxy on top will make the base coat OK. It has to be removed completely and the concrete surface has to be diamond ground to remove any shine or other sealer.

 

[OBP]

Again I agree with Edger.
The concrete will just smooth out the grit on the sand paper instead of etching the concrete surface, diamond grinding is the best, and if the guy is a bit amateur he could leave track marks with a shot blaster.
If he doesn't have a diamond grinder, he could rent one easy enough, just make sure he gets all the dust up.
I liked what nmanitou said about agreeing on a finish, but you don't want him to come back every 5 months stripping and redo'ing the floor, I bet he doesn't want that either.
Get him to diamond grind it.
Maybe find out the product he is using and ask the manufacturer for the preparation specifications.
I hope it goes well for ya Lyonkster.

 

[lyonkster]

Make it a performance based project rather than a methods based project. ... ...On second thought, the fact that you had an agreement to diamond grind and he didn't is a red flag. Maybe you need to babysit!

nmanitou, thank you for your thoughts. I actually really like your approach, and it is the approach I used the first time around - I tried to let the pros do their stuff instead of being the dreaded "homeowner in the loop". But like you said, look where it got me! OTOH, I really don't know how much "control" I have at this point - they are coming in to do the repair (which I give them credit for doing), but since they are not getting any more money for this, I don't think I can dictate very much of whet they should or should not do.

They do warranty the floor for 3 years against lifting and peeling, so it would seem that it would be in THEIR best interest to do it right this time, instead of keep coming back every six months.

 

[lyonkster]

Also, I wanted to ask about one other item. There is a tiny hairline crack that goes through the middle of the slab. When the salesman was out, he said no problem, they'll fill it with something and it will be gone. But now there is chipping around the crack, and when the installer came to look at the lifting problem and saw this, he said "well, you have to expect this with cracks".

I was under the impression that it is possible to properly prepare cracks prior to epoxy, was I wrong? Again, this is not heaving or shifting of concrete, it is simply a shrinkage type hairline crack. I am thinking of repairing it myself prior to the guy returning, but I'd like to know how to do it right. So, what is the proper way to prepare a crack prior to epoxy?

 

[OBP]

Hey Leon,

Hows the floor going? Have the guys started yet?

 

[lyonkster]

OBP, thanks for asking. They asked to postpone the job by two weeks, so they'll start after Thanksgiving. In the meantime, I got some Shark Grip for them to use in the clear coat (since before it was too slippery before) and I also looked at the crack and realized that the crack filler they used is still intact, so I'll leave it alone.

So I am optimistic, but you can be sure I'll watch them like a hawk when they show up. And you guys will be the first to know if something starts going awry .

 

[jimmie jam]

subscribed....good luck!

 

[lyonkster]

Here is an update and a question. The guy is here today, grinding the floor (yay!). It is down to bare concrete in most areas, but in some there are patches of apparently well adhered epoxy (see pictures). The installer is saying that these are very well adhered and will be fine.

How much of a stink can/should I make over this? My leaning is towards letting it go, but I wanted to get some feedback. I don't want them having to come back yet another time (and I'm sure they don't either).

Oh, it may be obvious, but the epoxied area in the front corner is an area he did not get to yet, so it won't remain like that .

 

[dcs Inc]

Take a razor scraper and see if you can scrape off the white areas. If it does, have them remove it. If it has wicked into the surface and wont scrape off it should be good to go. Remember, what ever goes on top of this will be only as good as what is under it.
gene ec-Indy

 

[lyonkster]

Thanks Gene! The stuff would not scrape off, and it really looks like it's adhered pretty well, so I didn't make a fuss. He put down the primer coat and left for the day. Tomorrow he'll put down the body coat, and the next day the clear coat with the Shark Grip. And then hopefully I'll have the epoxy floor that I wanted and paid for, instead of the slippery and lifting version I ended up with initially .

 

[dcs Inc]

Depending on how much shark grip is used and the mil thickness of your finish coat, it may want to matt out your finish to a semi gloss. gene ec-Indy

 

[Edger]

lyonkster, I don't want to be a wet blanket here, but I still stick to saying it should all be removed. I reckon those epoxy areas are low spots, not where it has adhered properly. The grinder just goes over it flat and misses the low areas. The operator is full of sh*t and obviously comes up with any excuse.

I know it is too late to change and I wish you well, I think you have done a great job just getting the guy to come back and start again. Congrats.

 

[lyonkster]

Edger, good to hear from you and thanks for your input. No worries about being a wet blanket, and unfortunately I can't help but agree with you here - the areas with the remaining epoxy are probably low spots that were not as easy to grind as the high spots. Unfortunately I was not able to "convince" him to grind all the coating off, and now he already put the primer coat on. Then again, he is the same installer who applied the initial coating 6 months ago and refused to grind the sealed concrete, telling me that the sander was "better" - and we saw how that worked out for everyone involved...

I guess I can contact the office this morning and tell them that this is unacceptable and that they would be better off grinding everything down to bare concrete than applying more epoxy and a clear coat, only to come back yet again in 6 months. I am not sure that they will agree, and I am not sure that I have any leverage to insist that the floor be ground down to bare concrete, other than it would appear to be common sense . The downside is that this will definitely cause bad blood between myself and the installer, although I am not exactly trying to make a friend here, I just want to get a good epoxy job done.

Or can I convince myself that with ~75% of the area being ground to bare concrete, I should be OK?

 

[lyonkster]

I shot an email over to the office this morning, to at least go on record with my concern. We'll see if/how they respond .

 

[lyonkster]

Got a quick response, gotta give them credit for that:

I spoke to the installer and the owner regarding your concerns. The way your floor was removed yesterday was the normal and proper way we remove a floor. The only way we would be able to get the small low spots would have been to bead blast the floor which then there would be concrete damage that would need to be repaired. If we did this then these areas would be weaker than the rest of the floor which would not be ideal for your epoxy floor.

Installer explained also that the only area that was not that difficult to remove was the back of the garage where the floor was already peeling. The rest of the floor was very difficult to remove because the epoxy did adhere to the floor well. This is good news because this means that the grinding we did yesterday was more than sufficient. Installer also noticed that there were not any other new areas that were peeling. There should not be a problem with your floor peeling anymore. Hopefully this will put your mind at ease ) Please let me know if you have any other questions or concerns.

I think I'll have to go with their judgement at this point, and I'll have this correspondence to use as ammunition if any future problems arise.

 

[Edger]

That sounds about as good as you can get. Fingers crossed (for good luck), it may end up a great job.

 

[lyonkster]

Thanks Edger, I sure hope so. If I had known this was going to become such a fiasco, I would have done it myself and saved the aggravation .

 

[lyonkster]

I just wanted to get back with a summary. They completed the job, applying a binder coat, a color coat, and then a clear coat with Shark Grip. Of course I won't know right away if this will be any more durable than the original application, but given that the original concrete surface was not suitable for epoxy, and this time it has been properly prepared, I am hopeful.

I can say that I do like the Shark Grip look and feel better than the glossy epoxy. The appearance is indeed a bit less glossy, but that is fine with me, since my floor is far from flat, so no sense showing off all the imperfections. The texture is very fine, and is not at all abrasive or sharp - no road rash from running your elbow over it. Most importantly, it is completely non-slip now, I had a chance to practice after the recent rains, and it was less slippery than the uncoated concrete driveway - so I am extremely happy with this. I would definitely recommend Shark Grip type product for anyone who is concerned about slipping on an epoxy floor (which IMO should be everyone ).