Norklad 200 prep? Primer?

[bdk1976]

I'm 99% set on using Norklad 200 on my 3600 square foot shop and am looking for any input on actual experience with application/prep of this product. My concrete just hit 30 days old (6" slab/15mil vapor barrier/4k crete/hard trowel finish) and I want to get started on this step ASAP so I can eventually start moving stuff in.

My main question has to do with primer. I see suggestions to use primer with this 100% solids product - a lot seem to use the devoe product - however, with such a large area, primer is not exactly a small expense - especially when I don't see any in bulk amounts - so I am looking for other potential options, or wondering if I can get away without primer over a freshly ground surface (I'm okay with using some excess Norklad 200 due to lack of primer, as I have 45 gallons at my disposal).

I know enough to be dangerous when it comes to surfaces/coatings on automobiles. What we call epoxy in that realm sticks like glue to a properly mechanically prepared surface. Why should it be different in this case? To me it seems like primer would negate some of the mechanical adhesion and present more of a chemical adhesion situation(?). If primer is indeed necessary, can I simply acid etch before primer as if all it does is soak into the concrete and provide a substrate for the topcoat via chemical adhesion?

TLDR: Can I achieve success by applying Norklad 200 without a primer over a properly ground concrete surface? Looking for real world experience if anyone has any.

 

[Shea]

Can you apply a 100% solids epoxy to concrete properly prepared via grinding? Yes, it's actually done quite a bit by DIY installations. Is it the recommended method to ensure the best bond and finish of a 100% solids epoxy coating? No, it's not and the pros don't apply it without an epoxy primer either. The primer coat is considered the ugly coat since it can look blotchy due to the varying densities of the concrete surface that control how much of the coating is absorbed. The resulting primered surface will not absorb the 100% solids epoxy and will allow for consistent coverage rates, gloss, and color. The article in the link below explains why you should use one.

https://allgaragefloors.com/epoxy-primer-for-your-garage-floor/

More than one person who has applied 100% solids epoxy to bare concrete has complained about bubbles, color inconsistency, or some form of cosmetic defect. Others have had no issues. You just need to ask yourself if it's a risk you are willing to take for 3600 square feet of concrete.

 

[bigjon]

@Shea, could bdk1976 thin the epoxy and make that a suitable primer?

 

[Shea]

@Shea, could bdk1976 thin the epoxy and make that a suitable primer?

Yes, that could be a viable option considering the amount of epoxy he has available. However, you generally don't want to thin much more than 10% or it can effect the performance of the epoxy.

 

[woodee]

Did you contact Devoe/Norklad/Colorchips and ask them for bulk pricing on their primer? They probably have it, just not advertised. I used their primer and was very happy with it.

https://www.originalcolorchips.com/...220-sq-ft-96?zenid=4u8jt511sk38dgic5k86hdrha5

 

[bdk1976]

I will most likely go with primer, but I still want to understand this step - much of what i read about it seems contradictory or vague, and I have yet to read a specific 'scientific' reason as to why I would put a seemingly inferior product between my 100% epoxy coat and freshly ground concrete. Not saying it's "wrong" - just want to understand it from a technical perspective.

To me, this seems like the equivalent of using a spray bomb primer on a prepped bare metal car and then topping with a 2 part epoxy, which would be a horrible idea.

 

[Shea]

You can't compare dissimilar materials (epoxy and metal) with epoxy adhesion. It's apples and oranges. I will try to break it down so it makes more sense.

Concrete coatings require specific profiles for adhesion. These are typically referred to as CSP (concrete surface profiles), with 1 being the least aggressive. As an example, a CSP-1 profile is usually achieved via acid etching. A CSP-2 is achieved via grinding with either a 16 grit or 25 grit segmented diamond disc. A CSP-3 is achieved via light shot blasting, AKA brush blasting.

If you look at the data sheet information for Norclad 200, it clearly states under Surface Preparation that the most suitable prep is to brush blast. This is a CSP-3 profile.

When you look at data sheets for coatings, one of the many bits of information that is provided is adhesion which is measured in PSI. Norklad has an adhesion rating of 450 PSI. This is typical for a 100% solids epoxy. For reference, it is generally accepted that anything rated over 300 PSI will pull concrete up with the coating first before it can peel. However, this rating is only accurate if the coating was applied to concrete with the proper CSP recommended by the manufacturer.

Many quality epoxy primers typically have adhesion ratings of approximately 425 PSI. However, many of these primers require a surface profile as low as CSP-1 (proper acid etch) to a CSP-2 (grinding). Why? They are a lower solids epoxy that is much less viscous than 100% solids epoxy. They penetrate deeper in less aggressive surface profiles and gain a good mechanical bond as a result.

You can get away with applying a 100% solids epoxy to concrete that has been prepped via grinding, but you are not going to get the same adhesion results specified by the manufacture. In addition, you may even get less than 300 PSI if applied to a surface that was only acid etched.

Now, if you grind the surface of the concrete, apply a quality epoxy primer, and then apply a 100% solids epoxy, the lowest adhesion rating possible is going to be approximately 425 PSI. In addition, this doesn't take into consideration the greater chemical bonding that is achieved within recommended recoat windows.

Of course, this does not address all of the cosmetic and coverage advantages when using a primer. You can learn more about data sheets in the link below. I hope this helps

https://allgaragefloors.com/how-to-review-tds-for-floor-coatings/

 

[aventino68]

I'm 99% set on using Norklad 200 on my 3600 square foot shop and am looking for any input on actual experience with application/prep of this product. My concrete just hit 30 days old (6" slab/15mil vapor barrier/4k crete/hard trowel finish) and I want to get started on this step ASAP so I can eventually start moving stuff in.

My main question has to do with primer. I see suggestions to use primer with this 100% solids product - a lot seem to use the devoe product - however, with such a large area, primer is not exactly a small expense - especially when I don't see any in bulk amounts - so I am looking for other potential options, or wondering if I can get away without primer over a freshly ground surface (I'm okay with using some excess Norklad 200 due to lack of primer, as I have 45 gallons at my disposal).

I know enough to be dangerous when it comes to surfaces/coatings on automobiles. What we call epoxy in that realm sticks like glue to a properly mechanically prepared surface. Why should it be different in this case? To me it seems like primer would negate some of the mechanical adhesion and present more of a chemical adhesion situation(?). If primer is indeed necessary, can I simply acid etch before primer as if all it does is soak into the concrete and provide a substrate for the topcoat via chemical adhesion?

TLDR: Can I achieve success by applying Norklad 200 without a primer over a properly ground concrete surface? Looking for real world experience if anyone has any.

Also keen to do Norklad. My garage is smaller, what did you use and how did it go?