Two-part marine paints are finicky. Here’s how to handle ‘em.

Pass the Argon, Please

Having already done some touch-up painting on board the Betty Jane II, I was planning on doing a bit more using the same paint I’d started with, Interlux Perfection, a nifty, two-part polyurethane product that produces an especially hard, glossy, gelcoat-like finish. But as I prepared to mix my second mini-batch, I discovered that although Part A was healthy, Part B had turned into resinous glop in well under a week’s time.


Accusatory questions obtruded. Had I failed to put the lid on the can tightly enough the first time around? Had I inadvertently contaminated Part B while mixing the first batch? And hey, was it possible to buy a new can of Part B only? Or would I have to buy a whole new two-part kit.

The answers came via some Internet research and a few phone calls. Generally speaking, it seems, the components of most polyurethane paints are allergic to oxygen and/or moisture. So, once you go through whatever mixing/using regime is appropriate for any given small project and re-seal the cans, chemical reactions are probably going to occur due to the oxygen and moisture that remain trapped inside. And sadly enough, most companies, Interlux included, don’t sell Part B or activator separately.

So another question logically arises. How the heck does your average, small-project boat guy economically deal with a two-part paint like Perfection, where the curing agent (if stored for an appreciable amount of time) can go belly up and require the purchase of a whole new, two-part kit?

Ever hear of argon? It’s an inert, odorless, colorless, tasteless gas that Ironwood Designs of San Luis Obispo, California conveniently packages in a spray can labelled Bloxygen and sells for about $12 per can.

Argon is wholly benign, by the way, and actually constitutes a small part of our atmosphere. But it has a special characteristic that makes it a boon to anyone who regularly deals with two-part marine paints—it’s heavier than air and therefore displaces both moisture and oxygen.

You simply spray the gas into a given container (whether there’s a base material or a curing agent inside) while holding the container’s lid slightly open just prior to closing. Once you re-seal the lid, the gas is trapped inside, settles down upon the component underneath and protects it.

I can personally attest to Bloxygen’s effectiveness—it’s currently keeping my latest and greatest Perfection kit (both Part A and Part B) ready and rarin’ to go.

Bloxygen is available from hardware and full-service paint stores, from marine suppliers like Jamestown Distributors and from Amazon. It works just as nicely for varnishes, one-part paints and epoxy resins as it does for two-part polys. As you’d expect, it eliminates thickening and skinning-over during long storage periods.

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