Epoxy-Coat without Primer???

[i make it rain]

I've read many posts where everyone says to use a primer with Epoxy-coat even though the manufacturer says its not needed. I'm thinking of about doing Epoxy-coat without primer (I will grind, acid). Can anyone share their experience with using Epoxy-Coat without primer? Thanks

 

[jimshep]

I applied Epoxy-Coat with and with-out a primer (sort-of) and would recommend using a primer or two base coats.

My garage floor had a few rough areas due to degradation of the concrete surface. Per the recommendation of Christine at Epoxy-Coat, I made a small batch to put a pre-coat over the rough areas. The floor was prepped through a light hand grinding followed by muriatic acid etching and the floor was dried for a couple of days assisted by a dehumidifier. I applied the pre-coat over the rough areas late in the morning. Around 20 bubbles formed over the ~50sqft area covered by the pre-coat. I was able to pop half of them before the epoxy began to set and sanded down the remainder prior to the primary coat. The primary coat was applied in the evening and only a few bubbles formed over the entire 550sqft (none on the pre-coated surface). It seems that the time of day (rising temperatures vs falling temperatures) has an impact as discussed on this board previously.

If the same density of bubbles formed during the primary coat had formed as during the pre-coat, I would have been very disappointed in the quality of the resulting floor (especially after the amount of effort put into prep work). As a result, I would definitely recommend at least two coats of the base epoxy as an insurance policy against bubbling, unevenness, or other cosmetic blemishes.

 

[ariscus]

I just did my floors and really wish I would've known to prime beforehand. I didn't even realize it was a thing, and regret not doing it. I used rustoleum epoxy coat.

 

[beerdog]

I had a friend tell me a crucial step is to riugh up the surface with a drum sander.

 

[Big-Foot]

I used epoxy-coat with no primer, but I did have 5 year old concrete and had it shot-blasted to remove the sealer that the previous owner had done. No issues here..

 

[csp]

No issues without a primer on mine. I didn't grind the surface either. Just prepped it with a good cleaning and etch with muriatic acid.

 

[i make it rain]

i think there was a seal on the concrete but i already diamond-ground the floor and will acid wash a couple of times. I called Epoxy-coat and they assured me that no primer is needed. I think im gonna go cheap and not put the primer unless someone talks me out of it!

 

[munkey]

It seems to me that, when you do the math carefully, it is an absolute no brainer to do the primer coat. The vast majority of the cost and time of installing an epoxy floor is preparing: doing the research, choosing and buying supplies (not just the epoxy but the roller covers, squeegees, rags, flakes, spiked shoes, buckets, drill mixers,...), getting everything out of the garage, getting the floor properly cleaned, ground/etched/shotblasted, making sure the surface is dry, taping off any boundaries, and acquiring helper(s).

Once you have done all of this stuff, the "real work" is basically done. I don't really understand how you would get to that point, having already done all of the difficult stuff, and decide to not prime in order to save a relatively small amount of time and a relatively small amount of money. These floors can be amazing, durable, and long lasting when everything goes right -- so if I'm installing one, I'm going to do everything reasonable to make sure that everything goes right!

That doesn't mean that your floor is going to fail if you don't prime, but I think the cost/benefit analysis leans strongly in favor of spending slightly more to substantially increase your chances of a perfect outcome.

 

[i make it rain]

It seems to me that, when you do the math carefully, it is an absolute no brainer to do the primer coat. The vast majority of the cost and time of installing an epoxy floor is preparing: doing the research, choosing and buying supplies (not just the epoxy but the roller covers, squeegees, rags, flakes, spiked shoes, buckets, drill mixers,...), getting everything out of the garage, getting the floor properly cleaned, ground/etched/shotblasted, making sure the surface is dry, taping off any boundaries, and acquiring helper(s).

Once you have done all of this stuff, the "real work" is basically done. I don't really understand how you would get to that point, having already done all of the difficult stuff, and decide to not prime in order to save a relatively small amount of time and a relatively small amount of money. These floors can be amazing, durable, and long lasting when everything goes right -- so if I'm installing one, I'm going to do everything reasonable to make sure that everything goes right!

That doesn't mean that your floor is going to fail if you don't prime, but I think the cost/benefit analysis leans strongly in favor of spending slightly more to substantially increase your chances of a perfect outcome.

thats a good point. I've thought of this, but i was hoping that someone would say something like they used Epoxy-coat without primer and it went bad, which I havent heard yet. I did read somewhere else that since Epoxy-coat is epoxy and primer in one, if you put an extra layer of primer under it, it may not stick as well.

 

[jimshep]

thats a good point. I've thought of this, but i was hoping that someone would say something like they used Epoxy-coat without primer and it went bad, which I havent heard yet. I did read somewhere else that since Epoxy-coat is epoxy and primer in one, if you put an extra layer of primer under it, it may not stick as well.

The concern of putting down a non-Epoxy-Coat primer and voiding any warranty plus a time constraint in getting a primer led me to skip the primer. As I and several others have observed with our Epoxy-Coat projects, it is possible for a large number of bubbles to form even after significant prep work. Do you really want to take that chance after all of the effort already put into the project?

I would suggest getting enough Epoxy-Coat to put down a thin first coat and then follow it with a full coat. Christine at Epoxy-Coat has mentioned once on this board that Epoxy-Coat can be diluted with 6-8% MEK. Perhaps diluting a 1/4 to 1/3 of a normal coat would be enough to get a good bond and complete coverage?

 

[hardhat]

I have 2 gallons of preprime 167 that is supposed to be a good primer, I'll sell you one or both as I won't be able to lay down my floor this year. Weather window is almost gone for me. 500sq ft/ gal.

 

[i make it rain]

I have 2 gallons of preprime 167 that is supposed to be a good primer, I'll sell you one or both as I won't be able to lay down my floor this year. Weather window is almost gone for me. 500sq ft/ gal.

Can anybody recommend a primer? I will be using Epoxy-coat, and I heard that some primers are made for single part epoxies and would not be compatible. I dont want to use that Preprime 167 because i will be filling a lot of cracks and Preprime 167 cant go over crack filler (I called them and thats what they told me)

 

[hardhat]

You use it before you fill the cracks.