Hello! I am also getting ready to epoxy my 3 car garage within the week. It is a 5 year old garage with very minimal fluid spots on it. I have read all the posts I can find, and watched probably 50 videos covering various techniques. Here's my question regarding the floor prep. I read one post where the man used a diamond grinder, and stated that even if the floor didn't need it he was so impressed with how it prepared his floor, he would never do a garage floor in the future with using the grinder. The post also stated that because of the grinder, neither a degreasing product, nor the etching was needed. And that all he had to do was shop vac up the waste the grinding turned out, and he was ready to put on his epoxy...no need to even spray down the floor before he put down the epoxy. Does anyone have any thoughts, or warnings about this procedure. Seems like it makes sense. But should it be sprayed down with water after the grinding, instead of just using a sop-vac? Thanks for any input.
Floor Prep for Epoxy
- Thread starter cohibaiii
- Start date
aqr81
Well-known member
In all the posts you have read it emphasized preparation. Preparation is everything! You wouldn't paint a cabinet or piece of furniture after simply hitting it with a vacuum. That will leave behind a layer of fine dust and residue.
Same goes for your floor. Don't take any short cuts. Reread the posts and if you still have questions, it would be best to call the customer service at the mfg or the dealer where you purchased the product.
Same goes for your floor. Don't take any short cuts. Reread the posts and if you still have questions, it would be best to call the customer service at the mfg or the dealer where you purchased the product.
agqr81: Thanks for the reply. When I read of the application of the epoxy right after vacuuming up the debris, it wasn't sitting with me that an approach like that would be best. But...this poster said he had good results, hence my question. Believe me, I want it done right and am not looking for a short cut, just the most effective, and highest quality job possible. That is the reason I'm going to grind it instead of just etching it, I want a better bond. Forgive my ignorance, I will hose it down a few time after the grinding and vacuuming to be sure. Thanks again..Doug
After you grind the floor, there is not need to acid etch. You can, after vacuuming it go over it with a damp mop or hose it down. I always recommend using a leaf blower before you start to blow out any residual dust. Good luck with your project.
AlphaGarage
Well-known member
A lot will depend on your specific situation. If you have access to a very good vacuum, you can coat right after you grind, very often the rental yard will offer such vacuums. They're not a typical shop vac, they move more air, they'll have better filters, and they frequently have some way to shake the filters to keep them from clogging.
Assuming the equipment is working as designed it will leave the floor clean enough to coat.
Check by using a damp piece of clean cloth and wiping test spots on the floor, if it it comes up clean without any dust residue, you're good to go. If there's a lot of residue you might be facing a situation where any coating will be adhering to a layer of dust instead of the concrete, a recipe for failure.
BTW that's not to say that you must use a commercial, specialized vacuum, just that you need one that will do the job, and the ones at the rental yard are designed for the task.
Grinding can also remove oil and other stains, but again that depends on your situation. Grinding simply removes a portion of the floor, if a stain is heavy and has penetrated the concrete deeper than the grind, you need to do more.
A test for this is to sprinkle a few drops on the floor in an area you know to be clean, and a few drops on the stained area, the water should be absorbed evenly in both areas. If i beads up or is slower to absorb on the stain, the stain needs more attention.
So - do you treat the stain first or grind first? Before grinding you should lift as much stain as possible without going overboard, and if it looks like you're getting a good chunk of it go ahead and grind, no reason to spend a lot of time on the stain if the grinder will do the trick. After grinding do the water test and if it doesn't pass then focus some more energy to its removal.
Assuming the equipment is working as designed it will leave the floor clean enough to coat.
Check by using a damp piece of clean cloth and wiping test spots on the floor, if it it comes up clean without any dust residue, you're good to go. If there's a lot of residue you might be facing a situation where any coating will be adhering to a layer of dust instead of the concrete, a recipe for failure.
BTW that's not to say that you must use a commercial, specialized vacuum, just that you need one that will do the job, and the ones at the rental yard are designed for the task.
Grinding can also remove oil and other stains, but again that depends on your situation. Grinding simply removes a portion of the floor, if a stain is heavy and has penetrated the concrete deeper than the grind, you need to do more.
A test for this is to sprinkle a few drops on the floor in an area you know to be clean, and a few drops on the stained area, the water should be absorbed evenly in both areas. If i beads up or is slower to absorb on the stain, the stain needs more attention.
So - do you treat the stain first or grind first? Before grinding you should lift as much stain as possible without going overboard, and if it looks like you're getting a good chunk of it go ahead and grind, no reason to spend a lot of time on the stain if the grinder will do the trick. After grinding do the water test and if it doesn't pass then focus some more energy to its removal.
Last edited:
nip_tuck123
Member
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- Sep 22, 2010
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- 18
I'm going to grind my floor as well and was also wondering if I need to etch. I thought keeping the concrete completely dry before applying the epoxy would be best. If I hosed out the garage with water, how will I know when all the moisture has evaporated? I heard there can still be moisture in your concrete even after it appears to be completely dry, and that could cause lifting of the epoxy. I will be asking this exact question to epoxymaster when I place my order. Thanks.
AlphaGarage
Well-known member
If you do a good grind there's no need to etch. A good grind should leave a texture close to 120 grit sand paper.
Most, but not all, epoxies will require a bone dry substrate. Some (like BondTite 1101) can be applied on damp, but not moist, concrete.
Most, but not all, epoxies will require a bone dry substrate. Some (like BondTite 1101) can be applied on damp, but not moist, concrete.