Two part epoxy as topside paint

[jonahmcg]

Hello! I've a 36 ft. Tahitiana - steel gaff ketch. I'm doing my yearly rust removal and topside repaint. The boat has been painted with international topside paints previously. I happen to have 10ltrs of a two part epoxy paint called TM-40. It's for industrial use and can be submersed. It's designed as a primer and topcoat in one. The boat isn't pretty up close so finish doesn't matter to me.

I've heard epoxy's can fade and become chalky. What do people think. Does it make sense to use what I have or shell out for the international paint?

[four winds]

Below is a link to some information that may help the paint gurus here provide advice. Assuming I have identified the correct product.


https://www.ulprospector.com/en/asia...OMER-2252-TM40



Edit,...??......or maybe this one.


https://www.ulprospector.com/en/na/C...CRYL-3720-TM40

[Terra Nova]

Originally Posted by jonahmcg

...epoxy's can fade and become chalky...

This is why virtually all use LP.

[pcmm]

Originally Posted by Terra Nova

This is why virtually all use LP.

LP is very hard to use and most DIY'ers do not use LP paint! just to finicky and really needs to be sprayed to look good. I know many Professionals that have switched back to single part paints just because of the chemicals in the 2-part paints.

[Terra Nova]

Originally Posted by pcmm

LP is very hard to use and most DIY'ers do not use LP paint!...

And most DIY jobs are not up to yacht quality.

[jonahmcg]

Hey folks, thanks for the replies. I've decided to go ahead with the RM-40 (by temacoat (not TM-40)) - two coats of epoxy primer and then two coats of Temadur 90 (two pack polyurethane). Thanks for the info, will send pics when it's done.

[pcmm]

Originally Posted by Terra Nova

And most DIY jobs are not up to yacht quality.

Even a lot of professionals are starting to go back to one part paints. for environmental, health and regulatory reasons. spraying LP in a yard is becoming cost prohibitive between the paint, cost of the required tenting, permits for waste removal, etc.

[westcoast]

Epoxies: excellent adhesion to most substrates.
Chemical and moisture resistant
UV resistance, Poor! Not advisable for topside topcoat.

Polyurethanes:
Excellent gloss retention
Good UV protection
Good durability

Most systems use an Epoxy primer for adhesion and corrosion protection and a 2-part Polyurethane topcoat.

The Epoxy will chalk out very quickly if used ASA topcoat.

[reed1v]

Originally Posted by jonahmcg

Hello! I've a 36 ft. Tahitiana - steel gaff ketch. I'm doing my yearly rust removal and topside repaint. The boat has been painted with international topside paints previously. I happen to have 10ltrs of a two part epoxy paint called TM-40. It's for industrial use and can be submersed. It's designed as a primer and topcoat in one. The boat isn't pretty up close so finish doesn't matter to me.

I've heard epoxy's can fade and become chalky. What do people think. Does it make sense to use what I have or shell out for the international paint?

Epoxy breaks down under sunlight, so you will need to cover it with a non epoxy paint to protect it. Its not a fading issue, its a cracking and peeling issue. Once you get water underneath the epoxy, you got problems.

[southpaw]

When we were fitting out Southpaw (Brewer 43 steel gaff schooner) in Oregon 20 years ago, a local military Vehicle Club was fundraising by selling cases of military surplus paint. Aliphatic, chemical resistant, gawky camo green...$30 for 4 gallons. Couldn't abide the colour so experimented with black pigments (one caused the paint to rise up in a solid dome - weird), and wound up with a really nice dark matt green. Very tough paint. Repainted years later in NZ with LPU, but never liked it as well - most steel boat hulls aren't entirely fair, and gloss paint just accentuates the flaws.