technically you can use a primer as you suggest but I believe that a mechanical grind gives better adhesion because it's removing all contaminants and profiling the substrate before the epoxy is applied. Our products have a 20 yr warranty so it's important to us to get our preparation as close to perfect as possible.
Good video. I call that 1:4 acid ratio. And both will adhere with epoxy. Mechanical is just overkill or peace of mind. I might of rinsed the mechanical or vacuumed the dust out. You are correct it cuts on dry time, but the epoxy will need to be dust free.
Thanks for this video. My epoxy kit didn’t specify if i had to use the etch after grinding the previous coating back to bare concrete but this video answered my question. Cheers mate!
Thanks for pointing out this (obvious) step that I am surprised he did not mention. We used baking soda & water. Then rinse afterwords. I've done some stone work and you always use acid then neutralizer (too much neutralizer is fine).
Absolutely true but to be fair I've also seen baking soda residue left behind when not rinsed thoroughly as well. The fine layer of dust prevents the epoxy from sticking, not just the acid or soda itself
You're comparing a mechanical grind to a chemical reaction. Grinding will always remove most of the surface contaminates at the expense of surface area. I've seen certain epoxy's completely reject adhesion on too smooth of a surface such as freshly grinded garages or basements as sometimes it does not stick regardless of what you do. I would have left your acid etch much longer until bubbling to give some sort of a fair comparison as well as a stronger mixture; excellent results can be had with hydrochloric for the DIY'er if you know what you're doing with it. - Commercial Basement Builder of 30 Years
you can technically etch after grinding but you shouldn't need to because the grinding will remove contaminants and profile the concrete ready to apply your coating
This is not quite related…but we want to use the acid wash before painting our garage floor. When we power wash it off, will it damage the painted driveway that it would run onto to get to the drain at the bottom of the driveway?
Sure grinding might be better but how do you then address the corners of the room or the edges of the wall. Being a round grinder, it does not get to the corners and the edge.
There are shrouds you can buy that allow you to use an angle grinder that almost touches the wall so you get most of the edges done. We use a diamond carbide rasp on an oscillating multi tool to get the corners. Cheers
Howdy, you definitely don't need to acid wash if you grind. If you only want to acid wash then just make sure to neutralise the acid afterwards and rinse it really really well. But grinding is the gold standard and it's the secret all installers use to ensure the epoxy has good adhesion to the floor.
Howdy. I like the Schwamborn DSM250 cub grinders. We have a few of them and find they are very versatile and sometimes even quicker than our bigger machines. I also like the look of the Husqvarna 250 but I haven't personally used one yet. We are looking for contractors to help us out later this year so if you are in Australia let me know. All the best.
Remember that grinding is extremely dangerous especially if doing it inside your home due to Silica dust. I'm debating whether to do it as it's not very vented and it's next to my heater downstairs. Just feels risky to my family even though I'm using a shroud and dust deputy, respirator and all that jazz
We've always found that good powerful vacuums create almost no dust, regardless of the room being ventilated or not. If you are hiring equipment just check with them to ensure they are confident in their vacuum's ability. FYI we did a test one day to see what happens when we turn off the vacuum on a job and it shows what a mess it can be. th-cam.com/video/EwXMYvRTO6s/w-d-xo.html
Acid wash is fine if you: wash acid off after it stops bubbling , ie before it leaves residue. Work in small sections. Then wash with with 10:1 bicarbonate. Then rinse throughly. This actually gives better adhesion than grinding which smooths the surface and reduces surface area. though with acid the first coat will absorb substantially more.
Will acid wash remove acrylic solvent-based concrete sealer? I may need to redo my kitchen counters and am trying to find the best way to remove the current sealer. I don't live in an area that has access to many chemicals, but muriatic acid is available.
also 1 part acid to 2 parts water will do a much better job!!! not better than grinding just better than your example.........If the “acid etch mixture” is not properly mixed at a 10% solution, the solution will be too weak to properly remove concrete latencies or it may be too strong and etch the surface deeper than necessary, and soak into the concrete surface and contaminate it with a destructive, lingering, acidity after floor materials are applied. Never use "straight acid" mixtures for this reason. Muratic Acid is typically packaged at a 30% dilution (be sure); you want to dilute it down to a 10% dilution (1 part acid to 2 parts water).
I don't think this was meant to be a how to acid wash video but that being said it should've been mixed stronger to be a fair comparison. Lots of misinformation out there concerning the correct ratios and it causes poor etching almost as often as people using the crap etching powder that comes with the kit epoxy
Howdy, If the Moh's hardness test is 8-9 we use a 16grit shoe and then do a second lap with 40grit. If the Moh's test is between 3-7 we will use a 40grit shoe. Hope this helps ya.
I use 2 seg 16grit diamond trap if I’m doing epoxy over it. And where I am located, it’s usually hard concrete so I use soft bond metal but that can vary.
@@dodyh657 I have the xps Geneie grinder with the dust control tromb 400 vac that attaches right to the grinder. It’s virtually dustless. It’s OSHA requirements. But after that I vac with my dustless hepa shop vac multiple times and a quick chemical mop with denatured alcohol. I can grind 700+sf in less than hour and be ready for product. Stay safe.!!!
Victor the grinders kick out a lot of dust if they are on softer concrete floors but on very hard floors they aren't so bad. Having said that I think you'd find that a shop vac probably just won't be powerful enough. By "shop vac" I assume you mean one that its used for vacuuming in a residential home. If you want to see want to see how much dust a concrete grinder can create and what happens when we turn off our vacuums, check out this short video: th-cam.com/video/EwXMYvRTO6s/w-d-xo.html
@@epoxyflooringco3130 it would be a 12 gallon Ridgid vacuum. I'm doing research to rent the concrete grinder and industrial vacuum together. Thanks for your reply.
This is another example of a failure to acid etch correctly. Didn't wash off the oils etc before attempting to etch, so the etch wasn't even. Here-in lies the issue with etching; there are more steps and far more things that can go wrong.
I put down an acrylic solvent-based sealer on my concrete kitchen counters, but for some reason olive oil penetrates the sealer, stains the counter and does not wash off with soap. I am considering removing the sealer and putting an epoxy sealer in its place. Do you recommend grinding the acrylic sealer off in this case?
You probably don't need to completely remove the acrylic but at least ensure it is completely cleaned and profiled with a sander or grinder to ensure the new coating will obtain sufficient adhesion to it.
@@epoxyflooringco3130 Thanks for your reply. We are now wondering if we can apply polyurethane as a clear coat to prevent staining. Any experience with this? Will polyurethane stick to sealer? to epoxy?
@@chdao Polyurethane will work as a coat to prevent staining. You are best to contact the supplier of the acrylic sealer and the polyurethane to check compatibility but if the acrylic was prepared properly I'd think it'll be fine. The polyurethane will definitely stick to epoxy. Just ensure you prepare the substrate really well.
@@epoxyflooringco3130 Does this include polyurethane designed for wood or wood floors? I live in Guatemala and we do not have the luxury of selection here. Pretty much, all we have are Sherwinn Williams' products.
Porous surfaces have that issue no matter what. For example, my marble countertops take all kinds of stains that won't wash off with soap, but cone off effortlessly with a foaming bleach spray...
The correct way to acid wash is to apply evenly, let dwell, broom it in more evenly, surface clean it with a disc cleaner pressure cleaner, than neutralize and rinse!
Hi, I’m planning to do my garage and debating grinding vs acid etching, my garage floor is 15 years and no previous paint. Can you suggest proper way to prepare the floor. Thanks in advance for your help.
for a DIY project of approx 500 sq. ft., i'll go with the grinder! but then again, at this point i've almost decided to support my local professional for prep work. got a fair quote, not cheap, but fair. if this is decided, then 95% of the project is done. 5% is just me laying down the epoxy paint on the garage floor. the more i think about it, i can't beat that logic.
1L acid in 4L of water is not a 25 to 1 ratio. That is a 4 to 1 ratio (more commonly 1:4), or a 20% concentration (1L acid in 5L of total liquid). If it was 1L acid in 3L of water then it would be a 25% concentration.
I washed my brand new driveway after landscaping with a cleaner and etcher and it discolored my entire driveway I would suggest to never use chemicals you don't know about when washing , just leave it to the professionals
Correction… grinding is still mechanical bond only. Not chemical. Chemical is when you put epoxy over a still uncured layer of epoxy. You cannot get a chemical bond on concrete to epoxy.
He's comparing the surface breakdown between the 2. The point is to bust past the cream layer on top to get to the much more porous aggregate layer underneath. Gives the epoxy much more to grab onto
This video is the equivalent to comparing a 400 grit palm sand to an 80 grit orbital when the goal is to remove multiple layers of poly off of a piece of baseboard.
You're the man. Exactly what we were looking for.
Cheers Sammy
But can't you use a multi-surface bonding primer? Wouldn't that make it where it doesn't matter?
technically you can use a primer as you suggest but I believe that a mechanical grind gives better adhesion because it's removing all contaminants and profiling the substrate before the epoxy is applied. Our products have a 20 yr warranty so it's important to us to get our preparation as close to perfect as possible.
Good video.
I call that 1:4 acid ratio. And both will adhere with epoxy. Mechanical is just overkill or peace of mind.
I might of rinsed the mechanical or vacuumed the dust out. You are correct it cuts on dry time, but the epoxy will need to be dust free.
Thanks for this video. My epoxy kit didn’t specify if i had to use the etch after grinding the previous coating back to bare concrete but this video answered my question. Cheers mate!
glad to help. good luck with it
Yep, you gotta neutralize with a basic wash (high pH) after the acid. Do that, and you don't need days of water washing.
Thanks for pointing out this (obvious) step that I am surprised he did not mention. We used baking soda & water. Then rinse afterwords. I've done some stone work and you always use acid then neutralizer (too much neutralizer is fine).
@@ScottB-k7v Exactly! It's the acid that damages.
Absolutely true but to be fair I've also seen baking soda residue left behind when not rinsed thoroughly as well. The fine layer of dust prevents the epoxy from sticking, not just the acid or soda itself
But will it not add moisture to concrete if we wash it.
Great video ! It makes me think about my basement floor .
You're comparing a mechanical grind to a chemical reaction. Grinding will always remove most of the surface contaminates at the expense of surface area. I've seen certain epoxy's completely reject adhesion on too smooth of a surface such as freshly grinded garages or basements as sometimes it does not stick regardless of what you do. I would have left your acid etch much longer until bubbling to give some sort of a fair comparison as well as a stronger mixture; excellent results can be had with hydrochloric for the DIY'er if you know what you're doing with it. - Commercial Basement Builder of 30 Years
Thanks for your comment. I'm trying to learn more about paint, stain, epoxy, etc. for my job. It's hard to sell stuff you don't know much about!
If your surface is ending up smoother than when you started, you're grinding wrong.
Excellent video - thanks !
Hello.mate, that was very helpful. Is it okay if I etch my garage floor after grinding it?
you can technically etch after grinding but you shouldn't need to because the grinding will remove contaminants and profile the concrete ready to apply your coating
This is not quite related…but we want to use the acid wash before painting our garage floor. When we power wash it off, will it damage the painted driveway that it would run onto to get to the drain at the bottom of the driveway?
Should be fine as long as you ensure you wash it all off with fresh water
Sure grinding might be better but how do you then address the corners of the room or the edges of the wall. Being a round grinder, it does not get to the corners and the edge.
There are shrouds you can buy that allow you to use an angle grinder that almost touches the wall so you get most of the edges done. We use a diamond carbide rasp on an oscillating multi tool to get the corners. Cheers
Serious question. I am about to apply an epoxy. But I was told to acid wash/etch AND grind. Are you saying that I only need to do one or the other?
Howdy, you definitely don't need to acid wash if you grind. If you only want to acid wash then just make sure to neutralise the acid afterwards and rinse it really really well. But grinding is the gold standard and it's the secret all installers use to ensure the epoxy has good adhesion to the floor.
Awesome demonstration, may I ask which concrete grinder would you suggest for someone whose starting up an epoxy install company? Thanks in advance.
Howdy. I like the Schwamborn DSM250 cub grinders. We have a few of them and find they are very versatile and sometimes even quicker than our bigger machines. I also like the look of the Husqvarna 250 but I haven't personally used one yet. We are looking for contractors to help us out later this year so if you are in Australia let me know. All the best.
@@epoxyflooringco3130 awesome thanks for the suggestions, unfortunately I’m not located in the area. Thanks again.
@@epoxyflooringco3130where in Australia are you? I’m on the central coast
Remember that grinding is extremely dangerous especially if doing it inside your home due to Silica dust. I'm debating whether to do it as it's not very vented and it's next to my heater downstairs. Just feels risky to my family even though I'm using a shroud and dust deputy, respirator and all that jazz
We've always found that good powerful vacuums create almost no dust, regardless of the room being ventilated or not. If you are hiring equipment just check with them to ensure they are confident in their vacuum's ability. FYI we did a test one day to see what happens when we turn off the vacuum on a job and it shows what a mess it can be.
th-cam.com/video/EwXMYvRTO6s/w-d-xo.html
Acid wash is fine if you: wash acid off after it stops bubbling , ie before it leaves residue. Work in small sections. Then wash with with 10:1 bicarbonate. Then rinse throughly. This actually gives better adhesion than grinding which smooths the surface and reduces surface area. though with acid the first coat will absorb substantially more.
True, smooth is the enemy of adhesion. Not a lot of people put two and two together on that one...
Will acid wash remove acrylic solvent-based concrete sealer? I may need to redo my kitchen counters and am trying to find the best way to remove the current sealer. I don't live in an area that has access to many chemicals, but muriatic acid is available.
you should ALWAYS neutralize the concrete after you rinse the acid off ?? Why did you not do or mention this (1 cup baking soda to 1 gal warm water)
also 1 part acid to 2 parts water will do a much better job!!! not better than grinding just better than your example.........If the “acid etch mixture” is not properly mixed at a 10% solution, the solution will be too weak to properly remove concrete latencies or it may be too strong and etch the surface deeper than necessary, and soak into the concrete surface and contaminate it with a destructive, lingering, acidity after floor materials are applied. Never use "straight acid" mixtures for this reason. Muratic Acid is typically packaged at a 30% dilution (be sure); you want to dilute it down to a 10% dilution (1 part acid to 2 parts water).
I don't think this was meant to be a how to acid wash video but that being said it should've been mixed stronger to be a fair comparison. Lots of misinformation out there concerning the correct ratios and it causes poor etching almost as often as people using the crap etching powder that comes with the kit epoxy
What grit of metal bond you would advise to epoxy prep?
Howdy, If the Moh's hardness test is 8-9 we use a 16grit shoe and then do a second lap with 40grit. If the Moh's test is between 3-7 we will use a 40grit shoe. Hope this helps ya.
@@epoxyflooringco3130 Thank you for your reply, man 👍
I use 2 seg 16grit diamond trap if I’m doing epoxy over it. And where I am located, it’s usually hard concrete so I use soft bond metal but that can vary.
@@miked6097 Great! Thank to share with me. How do you clean up the dust after grinding? Just vacuum it or other method you usually done?
@@dodyh657 I have the xps Geneie grinder with the dust control tromb 400 vac that attaches right to the grinder. It’s virtually dustless. It’s OSHA requirements. But after that I vac with my dustless hepa shop vac multiple times and a quick chemical mop with denatured alcohol. I can grind 700+sf in less than hour and be ready for product. Stay safe.!!!
Would you be able to connect the grinder to a shop vac with a fine dust collection bag? Or does it need an industrial vacuum?
Victor the grinders kick out a lot of dust if they are on softer concrete floors but on very hard floors they aren't so bad. Having said that I think you'd find that a shop vac probably just won't be powerful enough. By "shop vac" I assume you mean one that its used for vacuuming in a residential home. If you want to see want to see how much dust a concrete grinder can create and what happens when we turn off our vacuums, check out this short video:
th-cam.com/video/EwXMYvRTO6s/w-d-xo.html
@@epoxyflooringco3130 it would be a 12 gallon Ridgid vacuum. I'm doing research to rent the concrete grinder and industrial vacuum together. Thanks for your reply.
This is another example of a failure to acid etch correctly. Didn't wash off the oils etc before attempting to etch, so the etch wasn't even. Here-in lies the issue with etching; there are more steps and far more things that can go wrong.
I put down an acrylic solvent-based sealer on my concrete kitchen counters, but for some reason olive oil penetrates the sealer, stains the counter and does not wash off with soap. I am considering removing the sealer and putting an epoxy sealer in its place. Do you recommend grinding the acrylic sealer off in this case?
You probably don't need to completely remove the acrylic but at least ensure it is completely cleaned and profiled with a sander or grinder to ensure the new coating will obtain sufficient adhesion to it.
@@epoxyflooringco3130 Thanks for your reply. We are now wondering if we can apply polyurethane as a clear coat to prevent staining. Any experience with this? Will polyurethane stick to sealer? to epoxy?
@@chdao Polyurethane will work as a coat to prevent staining. You are best to contact the supplier of the acrylic sealer and the polyurethane to check compatibility but if the acrylic was prepared properly I'd think it'll be fine. The polyurethane will definitely stick to epoxy. Just ensure you prepare the substrate really well.
@@epoxyflooringco3130 Does this include polyurethane designed for wood or wood floors? I live in Guatemala and we do not have the luxury of selection here. Pretty much, all we have are Sherwinn Williams' products.
Porous surfaces have that issue no matter what. For example, my marble countertops take all kinds of stains that won't wash off with soap, but cone off effortlessly with a foaming bleach spray...
The correct way to acid wash is to apply evenly, let dwell, broom it in more evenly, surface clean it with a disc cleaner pressure cleaner, than neutralize and rinse!
Nice
As a Master Finisher, the grinding is a little overkill.
So you prefer acid cleaning?
Hi, I’m planning to do my garage and debating grinding vs acid etching, my garage floor is 15 years and no previous paint. Can you suggest proper way to prepare the floor. Thanks in advance for your help.
for a DIY project of approx 500 sq. ft., i'll go with the grinder! but then again, at this point i've almost decided to support my local professional for prep work. got a fair quote, not cheap, but fair. if this is decided, then 95% of the project is done. 5% is just me laying down the epoxy paint on the garage floor. the more i think about it, i can't beat that logic.
1L acid in 4L of water is not a 25 to 1 ratio. That is a 4 to 1 ratio (more commonly 1:4), or a 20% concentration (1L acid in 5L of total liquid). If it was 1L acid in 3L of water then it would be a 25% concentration.
Nice demo!
I washed my brand new driveway after landscaping with a cleaner and etcher and it discolored my entire driveway I would suggest to never use chemicals you don't know about when washing , just leave it to the professionals
Correction… grinding is still mechanical bond only. Not chemical. Chemical is when you put epoxy over a still uncured layer of epoxy. You cannot get a chemical bond on concrete to epoxy.
Pretty lame attempt at acid wash....
Easy to say on 16 sq ft.
How are you camparing without actually applying the epoxy? 😂😂😂
He's comparing the surface breakdown between the 2. The point is to bust past the cream layer on top to get to the much more porous aggregate layer underneath. Gives the epoxy much more to grab onto
This video is the equivalent to comparing a 400 grit palm sand to an 80 grit orbital when the goal is to remove multiple layers of poly off of a piece of baseboard.
@bradleyhewitt9999 I've done epoxy both ways and I haven't had an issue with either one, its all in doing it the proper way
He is smoking HOT
Acid etching is a disaster.