You're painting a very broad, unscientific brush against acrylic.
You’re correct – I’ve painted, or back rolled, a response with an 18” roller when I should have maybe first used a 1” cut-in to get started. But here’s why I used the broad roller cover…
First, the OP mentioned being “…torn between paying for acrylic (what the local contractor presented to me)…” I broadly assumed he was speaking of an acrylic polymer sealer. That assumption was because epoxy and MMA are often close in price but there seemed to be 2 disparate price points in what he was offered.
Second, on this forum at least MMA has not been mentioned much and when people mention acrylics, here they are usually speaking about acrylic polymer sealers. I’m not aware of any DIY here who has opted to purchase MMA monomer and work with industrial peroxides, but then there are a lot of projects and I’m not familiar with all of them. Likewise, MMA isn't nearly as popular with the Pros either.
Third, it's impossible to speak specifically to every variation of every chemistry on the market. Of course I am speaking "in general" and the subject of this thread - which I believe is commercial acrylic sealers. Methacrylate (MMA) typically referred to as Methyl Methacrylate and not 'acrylic'. It's a Monomer and I don't think that too many companies would be willing to sell it to a homeowner. Even on the specialized coating forums MMAs are seldom referred to as “acrylics.” One of the reasons may be that MMA is technically not an acrylic until it is polymerized into PMMA (Polymethyl Methacrylate) by adding initiator and heat.
Finally “Acrylic” is a VERY big word. Is it thermoset? Is it Thermoplastic? The list of questions to classify the acrylic could go on for days. Garage Journal is where a lot of DIYers, home owners, and small business operators hang out, not chemists.
So I did backroll with that broad brush because I assumed the OP was offered an acrylic, on this forum acrylic generally means “acrylic sealer” not “MMA,” and also because the subject matter pointed to a lower cost, one component, DIY oriented, easy to apply, safe, generally consumer accessible, acrylic sealers – all qualities that indicate we’re not discussing Methyl Methacrylate.
Now, a bit more about that broad brush... Just like I can't know every acrylic chemistry or product on the market, no one can know all of the epoxies either. So although one can safely state “Most epoxies do not sublimate into concrete,” claiming that “Epoxy does not sublimate into concrete…” is using that same broad brush. I am aware of products from Wolverine Coatings that are very much penetrating EPOXIES. BondTite 1501 for one - while I was at their facility I saw concrete blocks that had been cut and could clearly see BondTite primer penetration about 1" deep.
Part of the reason why our system penetrates concrete is because the 100% solids BondTite 1101 is modified with a Fluoropolymer, which lowers the surface tension. Eric has pointed out that you can make epoxies penetrate by lowering the viscosity with solvents, or by modification of the surface tension. Modification by solvent is the least desirable way. And along with Fluoropolymer Resins Wolverine Coatings Corporation also modifies with other high tech resins. I know they have some epoxies that are modified with Polysiloxane resins. So while most epoxies do not sublimate into concrete – some do.
Anyway, if I confused anyone, subliminally or otherwise, my apologies, that certainly wasn’t my objective- and that's a fact.
