Composite (not FRP) Trawlers - Pros and Cons

[SeaLion]

I think the steel and aluminum threads are extremely interesting. So what about composite hulls? Stitch and glue and other cored laminates that DON’T come out of a mold. I have read that these are strong, durable and quiet, and I like the traditional wood boat look in some interiors. Wondering what owners think of them...

 

[MurrayM]

I'd be curious as well.

Devlin boats https://devlinboat.com are beautiful and seem to command a good price (asking price anyways) when sold later.

 

[Simi 60]

Stitch and glue is generally a plywood thing

I see nothing wrong with a composite build, for multihulls its pretty much essential, but for a full displacement trawler that actually needs weight down low I cant really see much sense in weight saving in the construction. I am talking foam core, nidaplast, vac bagged and resin infused epoxy, glass, kevlar builds here

"Heavy" composite as in say a western red cedar epoxy build would be great but you'd still end up adding lead and losing space because of it.

 

[Bkay]

I had a cold molded lobsterboat built. So I've looked at the issue pretty closely.

I'm a fan of cold molding as long as the boat you choose doesn't already exist in another material. If you can get it out of a mold, it's much more cost effective to do so. But I feel a cold molded boat is superior than fiberglass in many respects. But it is much less cost effective (and this includes resale value).

I like the idea of stitch and glue but have never owned one. As long as the hull design you choose lends itself to working with sheet material I think this is also a great choice. With either of these methods, the boat will be lighter and stiffer than glass. But the stiff hull produces vibrations more similar to a glass boat than a true wooden (plank on frame) boat.

Pro's and con's to each method - but if money was no object for me, I'd go with composite construction on a one off hull vs. a fiberglass boat any day. That's primarily because you can produce a truly unique hull design and you have fewer design limitations. But quality wood, epoxy, and the labor to do it aren't cheap! Also, places that can do repair on these types of boats aren't in every port.

 

[jungpeter]

Hi Bkay,

I had a cold molded lobsterboat built. So I've looked at the issue pretty closely.

Me too, although mine was a Doug Peterson-designed, Charles Didham-built half-tonner, back in the heyday of my International Offshore Rule sailing days. And, as you say, I looked at the issue pretty closely as well!

I'm a fan of cold molding as long as the boat you choose doesn't already exist in another material. If you can get it out of a mold, it's much more cost effective to do so. But I feel a cold molded boat is superior than fiberglass in many respects. But it is much less cost effective (and this includes resale value).

Right on. And, to my knowledge, other than perhaps Vicem, there simply aren't any production, or even semi-production boatbuilders building large "trawler-like" cold-molded boats ANYWHERE. The market has spoken-cold moulding as a boat building process for these boats is simply not viable. In my opinion, this is due to the extraordinary labor costs involved in cold moulding, and the extraordinary attention to detail in the process required to produce a satisfactory product.

I like the idea of stitch and glue but have never owned one. As long as the hull design you choose lends itself to working with sheet material I think this is also a great choice. With either of these methods, the boat will be lighter and stiffer than glass.

I've built several stitch and glue boats, ranging from kayaks to sailing skiffs. But (with the rare exception of Sam Devlin), I also believe that stitch and glue for "trawler-like" boats (after all, this is a trawler forum!) is also simply not viable. In part due to the inherent limitations sheet products add to the design, but mostly in the (again) extraordinary labor costs inherent in building a yacht-quality stitch and glue product. In particular, finish sanding of a composite (fiberglass over plywood) stitch and glue boat of any size is enough to bring almost anyone to their knees and beg for another job (ANY job, but please, please, oh please don't make me run a RO sander again....".

...but if money was no object for me, I'd go with composite construction on a one off hull vs. a fiberglass boat any day. That's primarily because you can produce a truly unique hull design and you have fewer design limitations.

Minor difference of opinion here. One-off fiberglass (or kevlar, or carbon fiber) are commonplace in the custom boat marketplace today. Multiple builders exist that can generate some "truly unique hull designs" in advanced composites well beyond that achievable in cold moulding. But, as you point out, JUST BRING MONEY!!!!

But quality wood, epoxy, and the labor to do it aren't cheap! Also, places that can do repair on these types of boats aren't in every port.

Again, right on.

Regards,

Pete

 

[HopCar]

I’ve build a few stitch and glue boats the largest of which was 16”. I can see it being an option for boats up to about thirty feet. Beyond that there are probably better options.

 

[Mako]

cold moulding as a boat building process for these boats is simply not viable. In my opinion, this is due to the extraordinary labor costs involved in cold moulding

I think this is spot-on. I had gotten quotes from a shipyard to build me a vessel and they quoted the hulls for a heavy 40ft molded boat at the same cost as a 60ft which came out of a standard mold they used with vacuum resin injection. Although materials are higher for the larger, the incredible amount of labor for the smaller one equalized it all.