Marine Plywood Core

[KnottyBuoyz]

Would you shy away from an extremely well made custom boat that used marine grade plywood as a core?

The jist of what I'm getting at is we're starting the construction of a Stitch & Glue trawler next spring. (30.5' x 10', 11000 lbs, 40 hp diesel) The boat comes as a CnC cut kit. I've been practicing with Resin Infusion to glass the hull inside and out. We're putting a lot of effort into selecting the best materials and methods to build the boat and at some point down the road we'll eventually want to sell it to move up. Even though I've used the best materials, put a reasonable amount of craftmanship into its construction (we're shooting for an above average fit & finish) I doubt we'd be able to expect a reasonable sale price just because of the core material. Don't get me wrong, we're not getting into this as an investment, but then again you don't want to just throw away tens of thousands of dollars.

I could build the boat and save about $10K to $15K by choosing cheaper materials but the quality (which is important to me) would suffer. I don't like building/fixing and selling things that I wouldn't have confidence in buying/using myself. On the other hand I could spend another $10K and use a foam (Corecell, Divinycell etc.) core material. Would knowing the core of the boat was foam as opposed to plywood make you feel better about spending another $20K to $25K more on a used custom boat?

I expect we'd probably use this boat for 5 yrs before moving up to the next larger model (34' x 12').

 

[tashasdaddy]

Re: Marine Plywood Core

there are a lot of old wood core cruisers still around. proper maintenance, no problem.

 

[fishingdan]

Re: Marine Plywood Core

I have built, enjoyed and then sold two S&G boats. Quality materials are important. A fully documented build process with receipts is also important. When it is time to sell, be very upfront and honest of the facts (composite boat with marine plywood core, all wood 100% encapsulated in epoxy, etc). In the end, you shouldn't have a problem recovering your material costs. The selling story is themed with I built it from professional plans, with proven methods and here is the proof that I have done well. The larger the boat, the greater the opportunity to recover some labor as well since larger boats are typically surveyed and many continue to be built using wood cores.

The fact remains that quality marine LLoyds approved plywood is still one of the best core materials available. It is incredibly strong for its weight. Combined with properly oriented structural glass, it makes a great hull.

 

[BillP]

Re: Marine Plywood Core

Rick,
We aren't talking fishing skiffs or small trailer boats...so I would go with "foam" if expecting highest resale. Right or wrong, most buyers (not me however) think foam is better, so do insurance companies. If you haven't checked insurance rates yet it may be a good idea. Be sure to tell them it's a homebuilt. Here in Florida it's not only tough to get wood boat insurance, it also difficult to find yards that will haul a 30' "wood" boat for bottom jobs. In the past couple decades, glass covered wood boats were advertised as a "composite"...now it's getting harder to fly them under the wire as anything more than a "wood" boat. It's even more difficult to find buyers who will buy anything but fiberglass.

Also, homebuilt boats traditionally have WAY less resale than professionally built boats...regardless of shape, size or material. You will be lucky to recover material costs on this boat no matter what material is used. There are always exceptions ($4.5 mil 70' custom sportfishers are laminated wood) but the odds are highly stacked against favorable resale on most homebuilts. There's a lot of historical sales data out there to reflect actual values. You might want to talk with a few experienced brokers about resale to grasp the whole picture.

bp

 

[erikgreen]

Re: Marine Plywood Core

I'm only an amateur, but I'll chime in.

I'd have no problems personally with a wood core hull, but I do agree that a lot of buyers would prefer foam core. Wood has gotten such a bad rep due to what happens if it's not properly encapsulated that it's harder to sell a boat with a wood core hull.

I'm considering building a fishing boat for sale next winter, and it'll be foam core rather than wood, since it'd be very hard to sell a wood core hull.

But it's just harder, not impossible, and if you combine a surveyor's report with your build documentation it should still sell for a good price.

Personally I intend to someday build a pocket trawler (maybe the bateau TW34 or a Bruce Roberts design) but I'll be doing it with a steel hull.

Erik

 

[KnottyBuoyz]

Re: Marine Plywood Core

Lots of good thoughts here fellas. I appreciate that. The insurance thing we've considered and I've spoken to a few mates who are surveyors. We'll carry insurance from the time we start including the building shelter. There'll be a lot of expensive materials and tools in there for 2 yrs or more it takes us to build.

Erik, we're building the TW28 stretched to 30 1/2'. If this first one goes well I'd like to build the TW34 if Jacques ever gets it off the drawing board. I participated in the design specs for that model.

My buddy, a 30 yr Coast Guard marine engineer is also a surveyor. I had a lil' chat with him the other day and we discussed amateur built boats and core materials. He's seen some good and a lot of badly built boats over the years and those that were bad weren't necessarily plywood core and if they were they were cheap construction grade ply. His job as a surveyor is to look at the boat objectively and not predjudice his report with his own personal views on materials. He showed me some pics of a 30 yr old 22' Sharpie (I think that's what he said) sailboat built in ply (meranti) and close attention was paid to encapsulating the entire structure in glass/resin. All openings were properly sealed and there was no sign of water intrusion. His report was extremely positive on this boat. He also showed me a good number of small boats, power and sail, with delaminated foam cores. The devil is in the details, core failures are almost always related to water intrusion or collision damage. Of course modern materials are better at resisting water intrusion than those used yrs ago.

We discussed my project and he couldn't see a good reason to use foam in the hull when performance isn't really an issue with a displacement hull. I'd have to add more ballast to bring her down on her lines if I did that. Add in the overall cost increase it really doesn't seem to make a lot of sense other than the other issues we discussed. We'll have it surveyed a number of times during construction for Transport Canada registration purposes. I know the registrar of shipping personally! ;-)

I think someone who knows boats and can spot quality workmanship and materials would see the benefits of using ply over foam in this type of boat.