Steel builders East of the Mississippi

brian eiland · Oct 12, 2013

Eric Sponberg said: ↑

..... A steel boat is going to rust primarily from the inside out, so in the hull bottoms on the Moloka'i Strait yachts, for example, we use a paint called POR 15 (P-O-R stands for "paint over rust"). This is a very thin, rubbery black paint that covers the steel and adheres like the dickens. That prevents any water in the hull from getting at the steel. The steel of course is primed beforehand. Above the waterline, the inside of the hull is coated with about 1-2" of polyrethane foam. This, as you may know, also sticks like the dickens--try to take it off!!--and this keeps the moisture in the air on the inside of the hull from getting at the steel.

On the outside, of course, all the surfaces are primed before painting. And if you want to take it one step further before finish coats, have the steel cleaned with Chlor-Rid.

http://www.chlor-rid.com/

This is an amazing product. It is a watery clear liquid that cleans the salts off the steel--I mean it really gets into the microscopic profile of the metal and chemically removes the salts. It is the salts on the metal that combine with oxygen that creates the oxides that form rust. If you get rid of the salts, oxygen cannot play a part in the creation of oxides and rust is prevented. If the steel, or aluminum, is not cleaned at the mill, it can be washed at the boatyard just prior to painting. It doesn't matter if the steel is primed--use it anyway. It is pretty amazing technology.

After priming and washing, a yacht hull is faired with a fairing compound like Awl-Fair, which is then sanded, primed, and painted. That's if you want a yacht-like gloss finish. If that is not important to you for an expedition vessel, then go directly with the top coat primer directly onto the primed steel, and then finish with the finish top coat in the color of your choice. Lighter colors will not show the irregularities in the finish nearly as much as the darker colors.

Finally, in any areas where you know there is going to be chafe, such as hawse holes and rubrails, fabricate these out of 316L stainless steel and weld them right to the hull. Bring any finish paint down over the weld and onto the stainless. This works well. Eric
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Hi Eric,
Do you still stand by this POR coating?

It seems to me lots of folks are recommending a good primer coat, then epoxies ?

Eric Sponberg · Oct 13, 2013

brian eiland said: ↑

Hi Eric,
Do you still stand by this POR coating?

It seems to me lots of folks are recommending a good primer coat, then epoxies ?
Click to expand...

I haven't had any steel boat design projects since the Moloka'i Strait projects, so I don't have any first hand updated experience. Barring any changes I don't know about, yes, I would still recommend it.

Eric

Oceanna · Oct 14, 2013

New Castle Yachts Palaka FLorida. Bay Ship & yachts Alameda California. Nichols Bros. Boat Builder. Freeland Washington. swift ship morgan city Louisiana. please check this company. i had been paint many project for Washburn Dorthty close to Hodgdon Yachts. Booth Bay Harbor Maine.

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Steel builders East of the Mississippi

brian eiland Senior Member

Eric Sponberg Senior Member

Oceanna Junior Member

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