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Are you planning a DIY garage floor epoxy installation? If so, consider this a “must read” if you want to avoid the most common errors that people make when applying a garage floor coating. From peeling epoxy floors to bad finishes, these 5 mistakes will cover 95% of all problems associated with either epoxy floor failure or appearance issues.
Day after day people install their own garage floor coatings and with great success. After the anticipation of creating a nicely coated garage floor however, nobody wants to go through the headaches and heartaches created when your floor doesn’t turn out like you expected.
So take a few moments to look over our list of common epoxy installation mistakes in order to insure a successful floor coating for your garage.
1. Poor floor preparation
This is the most common reason by far for epoxy floor failures and/or bad finishes. Many times when doing an epoxy garage floor coating for the first time, people underestimate how important it is to prep the concrete properly. It involves much more than making sure it is clean. Epoxy will not adhere to a smooth surface.
Not only does the surface have to be free of all oils, waxes, and other contaminants, the pores at the surface of the concrete need to be opened up properly. This usually involves acid etching at a minimum. Grinding the concrete in preparation for epoxy is even better, but it isn’t always feasible for the average homeowner. You can learn more about which method is best for you here.
The most common problem associated with poor floor prep is peeling or delamination of the epoxy.
Fisheyes is another problem. This is created by contaminants in the floor, such as grease or oil that causes the epoxy to pull away from the concrete while curing. It forms a circle in the finish resembling a fisheye.
2. Moisture in the concrete
This common mistake usually happens from not allowing the concrete to dry sufficiently after acid etching. Depending on temperature and humidity, you need to allow for a minimum of 24 hours, sometimes longer, for the concrete to dry. If not, moisture that is still trapped in the pores of the slab will rise to the surface and create bubbles in the finish.
Some water based epoxies and primers allow for application to concrete that may still be damp however. Contact the manufacturer for further information if you are unsure.
Not performing a moisture test is another mistake. Moisture under the slab can create hydrostatic pressure that will actually cause the epoxy to separate from the surface, sometimes taking pieces of concrete with it. You can avoid this problem by doing a simple moisture test first to determine if your floor is suitable or not for an epoxy coating.
3. Stretching out the epoxy
Stretching the epoxy out in order to cover the entire floor when you are running low will result in areas with a much less glossy surface and a distinct difference in color appearance. It also creates a weaker coating. This is a common mistake that is made with the single coat epoxy paint kits such as those from Rust-Oleum and Quikrete, but can also happen with premium epoxy products as well.
If you have a 400sf² garage floor for example and purchase a kit that has a coverage rate of 300-400sf², you will not have enough epoxy. A properly prepared floor is porous and will absorb some of the coating. You will run short.
Many manufacturers state in the fine print that you can expect up to a 15% material loss due to product left in the container and first coat applications. Most DIY installers are not aware of this. You can avoid this problem by making sure not to underestimate the amount of epoxy that you need.
Also, when pouring the freshly mixed batch of epoxy onto the floor or paint tray, do not scrape or try to get every last drop from the mixing container in an attempt to get the best coverage rate. The very bottom and sides of the container are never fully mixed properly. Doing so may result in spotty areas of the coating that will remain soft and not harden.
4. Faulty mixing of the epoxy
There are many problems associated with improper mixing. The most common of these issues is mixing too fast with a paddle mixer and trapping air in the epoxy. If this happens, you will get air bubbles in the surface during application. You can easily avoid this by not pumping the paddle mixer up and down or running the mixer too fast near the surface creating a vortex and sucking in air.
Other issues are not mixing the Part A resin and Part B hardener correctly or getting the ratios incorrect. Pay close attention to the mixing instructions. Some epoxies require the newly mixed batch to sit for a specific time before application. This is called induction time. If you don’t allow for this then the epoxy may not cure and harden properly.
5. Not following temperature and/or humidity restrictions
Be sure to follow the manufacturer’s recommended instructions for temperature and humidity. Epoxy applied at low temperatures or below those recommended may not cure and harden correctly.
If applying epoxy in high temperatures the pot life (time available to apply the epoxy) can be reduced by half or more. This can make the epoxy unworkable before you get it all applied as well as create bubbles from outgassing due to the warm temperatures.
High humidity levels can create a microscopic layer of moisture at the surface of the concrete that you cannot see. This will cause adhesion issues resulting in delamination or peeling of the epoxy. High humidity can cause some epoxies to blush at the surface as well.
Final thoughts
Achieving a successful floor coating isn’t that difficult. Many of these epoxy application errors can easily be avoided by thoroughly reading the manufacturer’s instructions. If ever you are in doubt, contact the manufacturer for clarification. Most problems could have been avoided this way. Also keep in mind that a bad batch of epoxy is extremely rare. The majority of problems associated with epoxy coated garage floors are due to these 5 common mistakes.
If you take the time to research your project, prepare your surface correctly, and make yourself familiar with the manufacturer’s instructions, you should be able to avoid these common mistakes and enjoy a successful garage floor coating that you can be proud of.
Dane says
I am using the rustoleum epoxy shield basement floor kits to epoxy a section of my basement for a workshop. I have 3 kits to cover the area I need. Each covers 250 sq ft. It mentions that I should mix each kit separately is there any reason why I couldn’t just mix all the paint together and then add all the activator in one large bucket? Since I will be applying it all at one time.
Shea says
Hello Dane. In short, the answer is no. The reason is that epoxy is a thermosetting resin that chemically cures to become hard and does not dry like paint does. This curing process creates heat and is the reason why there are pot life limits for epoxy. The larger the volume, the shorter the pot becomes and the hotter the mix will get if it sits. For example, epoxy with a high solids content needs to be poured out of the bucket and onto the floor immediately after mixing or it will begin smoking from heat build up after 5 or 6 minutes of sitting in the bucket. This is why most epoxy kits are not much larger than 2 gallons. The Rust-Oleum epoxy you have is a low solids epoxy that requires sitting for a short while after mixing. This is called the induction time and is dependent on the current temperatures when mixed. Mixing more than one kit together changes the induction time and lowers the pot life by more than half with each increase. Rust-Oleum does not supply this information since most people would not be able to handle the mix and apply the coating in the very short time span it would allow.
Dave says
“Also, when pouring the freshly mixed batch of epoxy onto the floor or paint tray, do not scrape or try to get every last drop from the mixing container in an attempt to get the best coverage rate. The very bottom and sides of the container are never fully mixed properly. Doing so may result in spotty areas of the coating that will remain soft and not harden”.
— I did the above. It is soft and sticky in the last area applied even after three days. Can you please help me out what needs to be done. I called Rustoleum customer support and they simply suggested to apply another coat on top of it. Will that help.
Shea says
Hello Dave. Yes, sometimes applying another coat does the trick. What happens is that the hardener in the freshly mixed batch helps to activate the resin heavy soft areas on the floor in order to get them to cure.
Alvaro Lacayo says
I had the same issue with Rustoleum- after two weeks it is still sticky and has not dried out. I called them and they offer me a refund for the purchase and also offers to cover the rental of a sander to remove it. I went to Home Depot and the attendants told me that the product was being liquidated because it does not deliver what it promises and have had many complaints from customers. They should face up to these complaints and cover for all the expenses. I am never buying any product from this company again!
Shea says
Thanks for the feedback Alvaro.
Angie says
Can u lay the epoxy over spauled concrete
Shea says
Not really Angie. Areas that are spalled should have all loose debris removed first and then patched before applying epoxy.
Brian says
I have several areas of my garage floor that are deteriorating leaving chucks missing. This is caused by the high amount of road salt used where I live (the deterioration is happening where I pull into the garage). I am having a contractor come in to patch the floor. Will doing the recommended cleaning/etching cause the patches to break up and will an epoxy sealer work if I’m putting it over the patched areas? Thanks for the info!!
Shea says
Just make sure your contractor is using a polymer-modified repair patch Brian. It will cure harder than your concrete and it adheres real well. If you grind the repair afterwards to blend nicely with the rest of the concrete, it won’t telegraph through the coating. Acid etching will not affect the patched areas.
Mike Dennison says
Hey Shea,
If I am mixing four packets of Rocksolid Silver Bullet to apply to my garage floor, do I need to put each packet in a separate container so that there is no mingling of each batch or can I just use one large bucket four times?
Also, I am going to do one two car bay first and then prep and install the the second bay three days later. This fits within the 7 day time frame for the product doesn’t it?
I don’t have room to store all our stuff at the same time.
Shea says
Hello Mike. RockSolid is mixed within the burst pouches and then poured out in ribbons onto the floor. If you are applying a metallic additive or anti-skid additive, you would pour what was mixed in the pouches into a bucket in order to mix in the additives. You do not want to mix more than one pouch kit at a time. If you do, the thermosetting properties of the polycuramine will greatly shorten the pot life and you will not get it applied fast enough.
One of the issues that Rust-Oleum has been having with RockSolid is consistent color matching from kit to kit. If you require more than one kit for 1 coat of the floor (which it sounds like you do), then we suggest mixing the RockSolid differently. You should cut open the one side of the pouch from each kit that contains the Part-A colored resin and mix it together in one container. When you are ready to apply it to the garage floor, pour into a separate mixing bucket the Part-B hardener of one kit and the appropriate amount of Part-A colored resin that you mixed together from all the kits. That way, each time you mix it up and apply it, the floor will be the same color throughout. Rust-Oleum should be able to tell you how much Part-A resin is in each kit.
Doing two sections at different times is no problem if you have a contraction joint to act as a natural border between sections. People do that all the time. What I don’t understand is why you think it needs to be completed within the 7 day recoat window?
Tim says
Hello,
I used the Rustoleum dark gray epoxy. Upon drying there were darker and lighter areas as well as some areas with a thinner coat despite applying a little extra in these spots (our garage is a year old but has a few minor scratches/imperfections in the concrete). Is it possible to apply another coat to even it out after the chips have been applied or would the entire coat have to be removed and a do over.
Thanks!
Shea says
If you put down the Rust-Oleum EpoxyShield Tim, you have 48 or 72 hours to recoat without any prep depending on which EpoxyShield product you purchased. We recommend contacting Rust-Oleum to get the recoat times. If you are past the recoat window, it will require deglossing the surface by roughing it up with 100 grit sandpaper before applying a second coat. Either way, it’s not a problem coating over again.
Mike Schroeder says
After the acid etching and neutralization with baking powder, then final water rinse with the pressure washer, how long should the water dry before starting the painting of the epoxy?
Shea says
Pressure washers drive the water deeper into the concrete Mike, so it can take longer for the concrete to dry completely depending on the weather. Though the surface dries fairly quick, the water within the concrete releases water vapor as it dries. If the coating is applied to soon, the water vapor can get trapped under the coating and form bubbles. Two days will usually be enough when pressure washing unless the weather is more humid. If so, you may need to wait an additional day.
Nikki says
Recently applied Rustoluem Rock Solid (believe is polycuramine not epoxy), part of the garage floor has not dried – areas are still wet. We believe this is due to the two parts not being mixed properly. the bag burst when we tried went to mix the two parts together, so we mixed it best we could and started painting it on. Do you have any suggestions on how we remove the unhardened/wet floor coating so we can reapply?
Shea says
Hello Nikki. Generally it requires cleaning up the uncured coating using a large scraper and cleaning the surface with acetone, MEK, or denatured alcohol before reapplication. However, we recommend giving Rust-Oleum customer service a call first. They’ve been good working with customers and may be able to help you out. Sometimes applying a second coat over a coat that did not cure properly will work. The hardener in the second coat can sometimes activate the cure, but it depends on the situation. They can advise you on that.
Harry G Campbell says
A friend says he rolled on a quickcrete etch that was blue in color. I gather it was an etch/stain. He said he got the product at Home Depor. After it dried he applied the rust oleum epoxy right on top of the etch stain. He claims he did not do any other surface preparation. While his garage floor looks very good; it seems to me he went against all the guidance I have seen. Your comment please. Thanks
Shea says
We are assuming he did an acid stain followed by a coating of clear epoxy Harry. It generally requires applying the stain and letting it set for a required length of time. It is then neutralized and rinsed with fresh water. The amount of acid in the stain generally will etch the concrete enough for the Rust-Oleum low solids epoxy if the surface wasn’t real smooth to begin with. It’s about equivalent to the less aggressive citric acid etches that these epoxy kits come with. If a higher solids epoxy was used, then a more aggressive profile is recommended.
Keep in mind that the Rust-Oleum epoxy is not going to perform well over a long period if it’s used in a garage environment. It will eventually peel or wear away. This article explains why.
Darlene Murawski says
My husband prepped our garage floor, put the epoxy down and we are finding that the new paint scuffs up easily showing the old paint color. We allowed the paint to dry for almost a month without parking vehicles. Each time we pull into the garage you can see the old color paint as it seems that the new paint is pulling up? The 1st bay is newer and smooth floor and the 2nd bay is old and course. Is it because of the smoother surface?
Shea says
Hi Darlene. Did your husband apply paint or was it epoxy? There is a big difference between the two. Also, is the new paint/epoxy pulling up in both bays or only one of them? Finally, did your husband prep the old surface by roughing it up with sandpaper or did he just clean the surface and apply the paint/epoxy?
DJ says
How clean does my garage floor have to be before i mix epoxy and apply to my floor. I scrubed it with a brush and i used the etch .should i wait 24 hrs or just a couple of hours
Shea says
The concrete needs to be very clean DJ. You should wait at least 24 hours to let the floor dry. Longer if the humidity is up. If you don’t wait long enough, water vapor escaping from within the concrete will form bubbles in the coating shortly after it is applied.
Larry says
After applying the Rock Solid marble concrete finish I experience bubbling all throughout the paint question is how long can I repaint and can I sand material before repainting a second coat what would be the best type of sandpaper can I use an electric sander also how long after the this cold was applied can I sand and put the second coat on thank you
Shea says
Hello Larry. It sounds like you didn’t allow the concrete to dry long enough and experienced outgassing from water vapor rising up through the concrete and getting trapped in the coating. You will need to aggressively sand it with 100 grit sandpaper or use an 80 grit sanding screen on a floor buffer. The floor buffer is the easiest and fastest method. If you go the sandpaper route, you can use an electric sander or a pole sander. Once the coating has cured for 24 hours you can start with the sanding. Make sure to wipe the surface down with denatured alcohol on a lint free cloth before you recoat. This will remove the remaining dust and dirt from sanding.
Jami says
I applied rustoleum rocksolid metallic on basement floor noticed after curing time that it is very thin in places and some look thick and great almost like it ran , also am now noticing circular looking scratches what would cause especially the circular scratches? Used rollers that were recommended on box.
Shea says
It’s hard to say what would cause that, Jami, without seeing it in person. It’s possible that some foreign material got caught in the roller and created the circular marks. They could have been created when you swirled the roller in circles to create the cloudy look to the coating.
Holly Hobbs says
Is it okay if we forgot to mix the water in with the primer base floor coat? We are doing a 270ft room. The base epoxy is is black. The floor was etched, acid, then diamond roughed, denatured alcohol applied 2x& dried completely. The base coat was applied& temp 70°. Will the base coat be okay??
Shea says
Hello Holly. You do not add water to epoxy. Are you referring to the clear part-B hardener that is mixed with the colored part-A resin? If so, the coating will not go through its chemical reaction and will never harden. You will have a gooey resin mess your hands that will need to be scraped up and cleaned before applying a new, properly mixed coat.
Julio says
My co-worker forgot to mix part A with Part B only applied the A to floor and left it too dry thinking he could apply second can B later. My question is since it’s been on floor for 10hrs can I still apply The B can noto floor and still work the same without it being mix from start or do I have to purchase another epoxy shield set and start from scratch even though the other part still is on floor
Shea says
Ugh… We’re sorry, Julio, but you cannot just apply the part-B over the part-A. It won’t work. In order for the epoxy to react properly and cure hard, it needs to be mixed together in a container. If it’s a store bought product from a home improvement center, it generally requires an induction period where it has to sit in the container after it is mixed for a certain length of time as well. Unfortunately, the only thing you can do is scrape up the part A (it will never cure and will remaining gooey on the concrete), wipe the concrete down with denatured alcohol or Xylene, and then apply a new and properly mixed coating.
Christian says
after applying rust oleum epoxy in my garage floor, i notice that the color of the walls changed which is stranged. what can ecplain that?,
Shea says
Hi Christian. The epoxy coating reflects light much better than bare concrete. The reason it seems as though the color of your walls has changed is due to the light reflecting off the coating onto the walls.
Simon says
I have a six month old garage floor that I would like to epoxy coat at some stage in the future (12-18 months – budget allowing) . The dust from the raw concrete is getting everywhere and driving me nuts. I have coated some of the floors in the basement with a plain acrylic sealant which has worked really well. If I apply this type of sealant to the garage floor, how will it react with the preparation process for the epoxy floor in the future?
Shea says
Hello Simon. You will need to grind the concrete in order to remove the acrylic sealer before you epoxy. It is not compatible with epoxy or other resinous coatings. The grinding will prep the concrete at the same time and will not require an acid etch.
Simon says
Thanks for the reply. No acrylic coating then.
Is there an epoxy friendly “dust-prevention” coating that I can use?
Shea says
Here is the issue you need to consider, Simon. Epoxy coatings require that you profile the concrete before application in order for the epoxy to penetrate the substrate and achieve a mechanical bond. This requires either acid etching the concrete or grinding. If you apply any type of coating or sealer to the concrete previous to epoxy, it will effectively prevent you from acid etching and will require that you grind instead. Acid only works when it comes in contact with bare, untreated concrete.
The easiest way to treat concrete for dusting is to apply a densifier. They are relatively inexpensive, easy to apply, an they harden the surface of the concrete as well. This article here explains how they work. Keep in mind, however, that when you decide to apply an epoxy coating it will require that you grind the surface just as it would when you asked about the acrylic coating. The densifier will not allow the acid to react properly with the concrete and it will not be very effective.
Dan Nelson says
I have a garage floor that has been coated with Behr 1-part epoxy paint. Should I remove it or can I clean it and rough up the surface with sandpaper before applying Rust-Oleum RockSolid product.
Shea says
Technically you can rough up the Behr paint with 120 grit sandpaper and apply the coating, Dan, but we don’t recommend it. The reason is that your coating is only as good as what it is applied to. 1-part epoxy paint can peel under vehicle traffic and since the RockSolid will be applied to the paint and not the concrete, it will peel up as the paint peels.
Jackson says
Have prepared my 940 foot garage floor with a dual disc grinder and made all required repairs. I’ll be applying a primer coat and base coat of epoxy and then at least two coats of polyurethane: My question has to do with the @ 300ft of saw cracks (1/4 inch wide x 1 inch deep) that I filled with EXTREME SET 200. When grinded down with the dual disc machine 95% of the “lines” are milky white in color……there are occasional low spots (none longer than 2 inches) where the fill is “clear” due to the grinder not hitting these small low spots. Do I need to be concerned about these small spots?
Shea says
Hello Jackson. I’m not sure what you mean about the spots where the fill is “clear”? As long as the saw cuts are filled and ground flush (no matter the color) then you are good to go. If what you mean by low spots is that you have some parts of the saw cuts that are not flush, then you will need to fill them and hit them with a grinder to make them flush. If you don’t, these spots will telegraph through the coating unless you are applying a 100% solids epoxy with a gauge rake.
Aaron says
Hi,
A friend has given me some Wattyl Water based epoxy garage floor kits to paint onto our new garage concrete slab floor.
The kit is light/medium grey colour. It says on the kit that it is tintable. How would we change the colour to black. What would we need to add to the mix. A black paint? Or some sort of black paint powder?
Thank you,
Aaron
Shea says
Hello Aaron. It’s a general description of their epoxy. If the product you had was a clear epoxy kit, then you could tint it a color of your choosing with the available tint packs by Wattyl. Because the product you have is a light/medium gray, it has already been colored by the manufacturer.
Kevin Goudreau says
I asked recently how to apply Rock Solid polucuramin grey color over an Epoxy floor that is yellowed and about 12 years old. The article I was referred to explained how to rough up the old epoxy . My old epoxy is in really good shape other than it has yellowed. The article made it sound that this was really going to be easy. I first tried a pole saner with 150 grit, then a orbital sander with the recommended grit of 100. I finally rented a floor buffer tried the 100 grit sandpaper screen. I finally ended up with a 20 grit sandpaper just to get some of the shine out. The floor looks somewhat roughed up, it’s not slick , but it’s still smooch when I rub my hand over it . I spent over 100 dollars trying to rough up a 440 SF area, took me a good 6 hours I’m still not sure if the new Rock Solid is going to adhere, ? My question is how can I tell without wasting a 200 dollar Rock Solid kit , ? Rouhing up this floor is Not as easy as the article suggest. There is no way a pole sander would ever work Thanks
Shea says
Kevin, you way over did it here. Your floor is more than ready. Just make sure to wipe it down with some denatured alcohol to remove the fine dust. The object is to degloss the surface and rough up the finish, not remove it. If you block sand a piece of wood with 150 grit sandpaper and then again with 100 grit, it may still feel smooth, but it’s roughed up enough to apply a finish. It’s the same with the coating, only it’s many times harder than wood. You are mistaking a hard surface for a smooth surface. The coating is not going to feel like bare concrete if that is what you are thinking.
Kevin Goudreau says
Thank you, your comparison to a block of wood makes since
Stephanie Schneider says
I am prepping my basement for a rocksolid epoxy coat. Previously painted x3, with carpet glue on top. I have diamond grinded the surface, used leveller, 3L of Behrs degreaser, 8L of TSP, 10L of behrs etching solution, all at near max strength. It has been scraped, brushed for hours. Some paint still remains. I’m not sure at what point to stop, or if the epoxy tolerates the small paint and glue still remaining between the pebbles, or if at this point the adherence is acceptable? I’ve been working this for more than 5 months.
Shea says
Hello Stephanie. When you say that you have glue and paint between pebbles, is your floor extremely rough concrete and not smooth as is typical?
bob says
I followed the instructions for the rocksolid garage floor kit, or at least I felt I did, but after it dried I see what I believe you are calling fisheyes, small round areas that do not seem to have been covered.
The question now is how do I fix this?
I have a couple days, according to the instructions that I can apply a second coat without sanding the entire area.
Shea says
Fisheyes are generally a sign of contamination on the concrete surface, Bob. For a garage floor it’s usually oil or silicone from tire dressing that causes it. Is the problem only in a few areas or is it all over the floor?
Bob says
It is random – but in many places.
Some of the places are where I filled gaps/cracks with Sakrete Crack Filler Polyurethane Concrete Patch. Once this was dry I sanded it with 80 grit – random orbital.
The majority of the garage looks good except for these areas. The strange thing is the sanding removed most if what I used and left just the filler in the crack. I wonder of sanding these spread the material into the pours. Just a guess.
Shea says
Our guess is that it’s the crack filler you used, Bob. The data sheet for this product is not very helpful and is lacking information. One key, however, is that it states there will be shrinkage for larger cracks. This is an indication that it is latex based. It says that it is paintable with latex paint only which is another indicator. Your coating is not latex. This is not a good product for repairs that need to be made prior to a coating as it is not compatible. More than likely the sanding spread some of it into the pores as you had suggested, thus causing the fisheyes.
Sometimes you can get away with applying another full coat to the floor. If a very thin film of the RockSolid is left in the cavities it should be enough to form a bond. We suggest pouring a small amount of coating on the floor when you get to each of these areas and then use a trowel to float the coating over the fisheyes. Lightly roll the areas so that you don’t pull any of the coating out of the cavities. If that doesn’t work, your only option would be to grind those areas clean and patch with the appropriate product.
LJ says
I apologize if this is explained somewhere and I missed it, but I have read and reread and still am confused. We moved here 5 years ago, and the garage floor was a beautiful, painted gray. But before long, the paint began to flake and peel, and now it is a mess. It peeled first at the entrance, but I’ve noticed that where the tires landed deeper inside also peeled (from the heat of the tires, I assume.). Since it continues to peel, I would think that the entire floor might eventually peel. Will the cleaning and etching be sufficient prep, or will we have to remove every inch of paint! Naturally I have no idea as to the makeup of the paint, whether latex, epoxy, etc.
Also, we are no longer able to do extremely hard labor projects, so is this even doable for us? I do paint, do moderate repairs, built some terraces with landscape timbers, etc. Recently put down kitchen flooring. Just don’t want to tackle something that is beyond me.
Shea says
You have a couple of issues going on here, LJ. The first is that the paint is peeling in multiple areas. This could be due to one or more of a few different reasons. It could be from poor concrete prep, it could be a moisture issue, or it could just be the simple fact that it’s paint. Paint does not last long on a garage floor. Regardless, you don’t want to apply a coating to a surface that is peeling or the new coating will peel with the old surface. The other issue is that a true coating such as epoxy should not be applied to paint. The reason is the simple fact that paint does not adhere to concrete as well as epoxy does. Epoxy needs to be applied to bare concrete or an older epoxy surface in good condition in order for it to perform as intended. Lastly, paint cannot be etched nor will etching remove the paint if that is what you may be thinking. Only bare concrete can be etched.
The only real solution to your problem is to remove all the paint via grinding. The grinding will also prep the concrete for the epoxy so that etching would not be required. Grinding is less work than chemically stripping and scraping the old paint off, but I can’t tell you for sure if it’s going to be too laborious for you or not. A floor maintainer with a Diamabrush removal tool is not that hard to operate, but they can be a bit heavy to lift and transport. I know it’s not the answer you were hoping for, but removal of the paint is the only way you can apply the epoxy correctly.
Michele Dorner says
We are planning to put a two part epoxy coating on the concrete floor in our brand new winery. The concrete floor has a ‘broom finish’. Other than pressure washing the floor and allowing it to dry thoroughly, is it still necessary to prep the floor prior to the primer coat, or does the ‘broom finish’ solve that step?
Shea says
Hello Michelle. No, a broom finish is not a substitute for proper surface prep for epoxy. In fact, it’s not even a good finish for epoxy. We highly suggest grinding to knock down the broom finish and profile the surface correctly. Though the concrete is new, the pores still need to be opened up in order for the epoxy to penetrate and achieve a good mechanical bond. Broom finished concrete also requires quite a bit more epoxy to fill the valleys and smooth out the surface.
mark scofield says
I am using rustoleum garage floor epoxy on a basement floor I see the instructions say do not use the etch on a basement floor but TSP instead why is that?
Shea says
We aren’t sure why that is Mark. It may be for the simple fact that rinsing is required and it can be difficult to do in a basement unless you have drains. You can always contact Rust-Oleum customer service and ask why.