Steel hulls in the PNW?

[Mako]

Apparently to many coats of epoxy doesn't allow the spray foam to stick to the metal, rather it adheres to the paint instead.

I’ve read that also. My 40 year old steely was spray foamed and it held up great.

However these days, I’ve never spoken to a commercial shipyard which uses anything other than rock wool.

You may consider a thin layer of spray foam to eliminate condensation and then a thick 3” layer of rock wool for additional insulation.

 

[mikehar]

Have you followed the Bering steel boats? I don't know if they are a real company or a couple guys that send a design to Turkey to be built (?) The photos of their interiors look pretty high-end but I'm curious about build quality, particularly what would they would be like long-term, corrosion etc

I've been watching them with a lot of interest. I'm not in the market for that kind of boat, but if I were, I would definitely be visiting Turkey.

My concerns about Bering are that they have come on very fast and their track record is mixed. Their older boats, not that old really, are heavily discounted. Part of that is because they have a sub-optimal layout and some weird design choices. However, they have been making some good progress in those areas. While the designs are very Euro heavy, that is a reflection of their customers. I saw this at Northern Marine too -- being a custom yard is tricky because your customers are defining your product with their choices. I'm assuming that I could get a less Euro (but modern) design from Bering.

Also, I don't know much about how the boats perform. Lots to learn there.

I do think Bering is bringing a much-needed update to the trawler world. I know they aren't the only ones, but they are leading the way. The industry is way overdue for a refresh. Having great outdoor spaces, fresh interiors and some nice ideas.

It will be interesting to see how this plays out over the next few years. The Nauti Styles folks are building a 75, so we will get a varnished view of the buildout.

 

[Ken E.]

Mike, not an issue in this thread but since you have a Northern Marine, did you ever hear what happened in Anacortes when one fell over on its side during launching a couple years ago? I'm thinking there might be a 'back story' to that incident (?)

 

[Portage_Bay]

Mike, not an issue in this thread but since you have a Northern Marine, did you ever hear what happened in Anacortes when one fell over on its side during launching a couple years ago? I'm thinking there might be a 'back story' to that incident (?)

I found this article. Author says NTSB determined lack of stability was the cause. The link to the NTSB report in the article does not work.

https://www.tradeonlytoday.com/industry-news/capsize-revealed-northern-marine-yacht

 

[Portage_Bay]

Digging around in the NTSB web site searching for Baden I found the attached. Glosten, a well respected naval architect firm in Seattle determined it was a stability problem.View attachment Glosten, Yatch Salvage Stability Evaluation 5-22-2014-Master.PDF

 

[Judy at JWY]

I would venture to say that the first stability problem was ownership/management. Much after that was the consequence of that. The second stability problem was finances. The rollover of Baden was shocking, but on the other hand, for those who knew the circumstances of NM at the time, it wasn't surprising.

NM had a period when they produced what I considered the best-build fiberglass long-range cruisers..but then ownership and management changed, and numerous times at that.

 

[dannc]

This website would be on interest to the OP, https://buildingkoloa.blogspot.com/2009/07/welcome.html.

The owners built a Buehler designed Swan 55. There is a great deal of good information on the website.

For insulation they used Armaflex glued to the Epoxy painted hull to form an air barrier as well as sound proofing and insulation. They then used rock wool to provide more insulation. This seems like a good combination. Later, they had to move the insulation to add a modification to the hull. The rock wool was easy to remove, the Armaflex took more work.

Last time I looked, Armaflex is more expensive than rock wool, but both are good insulation and fireproof. Using the combination seems like a good idea. Hopefully this link works to some of their insulation installation. https://buildingkoloa.blogspot.com/search?q=insulation

I have been following a different boat built and they used spray foam on the hull and buried plumbing hoses. There were no ends or junctions buried in the foam but it still makes me a bit nervous. I wonder if using Armaflex against the hull, then putting in rock wool, including around the plumbing would be a better choice. Likely more expensive labor wise though.

Later,
Dan

 

[Mako]

The idea is to completely encapsulate the steel to prevent condensation. Rock wool laying against the steel does not accomplish that. However, Armaflex and spray foam are expensive and difficult to manipulate later for the inevitable modifications. So spraying even a 1" layer or thinner will cover the steel, as would very-well applied sheet foam material. Even the stringers/frames could be covered if desired.

The balance of your insulation can be rock wool, so you have the best of all worlds. If OP wants to go 3" or 4" thick, then that's fantastic. Hope he's putting in double glazed windows as well.

 

[mikehar]

Mike, not an issue in this thread but since you have a Northern Marine, did you ever hear what happened in Anacortes when one fell over on its side during launching a couple years ago? I'm thinking there might be a 'back story' to that incident (?)

From what I heard, it was poor communication between the yard's marine architect and the owners marine architect/rep. Also, Northern always launched their boats with minimal balance because of the poor condition of the ramp they use to launch. When they launched my boat on 2002, it also looked like ti was going to roll over for a second, but it didn't. They finish the ballast work in the water after launch.