Wooden Boat People

By McKenzieDriftBoat.com

Plascore

I've spoken with several wood boat builders who are starting to experiment with Plascore and had a few questions:

Is it used in conjunction with plywood?

How do you attached it?

How is it seemed?

Just the honeycomb or panels?

What do you coat it with if used on a boats bottom?

Duane

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Replies to This Discussion

Permalink Reply by Bob burda on October 6, 2012 at 8:53am

I would not use any plastic honeycomb in a boat bottom or sides. The nature of how honeycomb reacts to impacts requires bonding to thick skins,(heavy) so what is the point. HC will crush in a localized impact with properly sized glass skins if weight is what your trying to save.In the world of sandwich construction honeycomb has a greatly reduced bonding surface area, little sound and temp insulation value and water ingress from damage and condensation. It is low $. If your going to have sandwich panels in your hull I would use a 6lb density PVC or SAN foam core. There are no plastic cores that are approved for primary structural applications in the world of ABS and DNV classifications. Great for interior panels. Last comment for today is processing. To minimize secondary bonding issues the core should be vacuum bagged or infused to the skins. You inherently use more resin and adhesive to bond HC vs foam core. Goes against the rules of proper sandwich construction.

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Permalink Reply by lhedrick on October 6, 2012 at 10:28am

Bob you voice some good points about cores. I won't ask for more here as this is a wood forum. It would be great for you to check the forum at montana-riverboats.com where many of us are looking for wood alternatives.

Every time I buy plywood it seems worse then the previous year and costs more. I wonder what it will be like 25 years from now?

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Permalink Reply by Bob burda on October 6, 2012 at 11:59am

I agree, that is why I joined. I will check out the Montana forum. Couldn't help but to comment on the plascore. Thanks

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Permalink Reply by Duane Doran on October 6, 2012 at 12:11pm

Bob, your responses was exactly the sort of thing I was looking for when I started this post. I found your technical insight quite interesting and hope you continue to offer your perspective. This forum is about building wooden boats but when new and advanced products start becoming integrated with wood it's important everyone gets insight from those who have experience with them.

Duane

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Permalink Reply by Bob burda on October 6, 2012 at 12:38pm

In part of my past life I worked for a structural core manufacture. People tend to incorporate new materials into traditional structures based solely on price. You have got to look at the life cycle and the intended use/environment of the boat hull in this case and you will always be able to justify buying better materials to keep the best quality and toughness possible. Even maintaining an all wood boat. Cold molding is a very good example of that. Basically layering veneers to produce your own customized plywood for strength and aesthetics.

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Permalink Reply by Sandy Pittendrigh on October 15, 2012 at 8:23am

RE> "I would not use honeycomb core"

This sounds authoritative and confident. But it misses several points. You seem to be talking hypothetically. Larry and I and others (Jason Cajune) have been building with honeycomb core for years now. I hope to experiment with CoreCell and/or DiviniCell foam soon. But I do know I prefer honeycomb core to plywood (for the bottom panel anyway). So. Several points:

Who are we talking about? The boat buying public at large or the do-it-yourself boat builder? Boat builders tend to be careful rowers. I've been making drift boats since 1979. I use my boats hard. But don't hit very hard. Not often. I pay attention. I read the water. I row with skill. When I do smack a rock I fix it.

Yes, delamination is a problem with honeycomb core. But it's a problem with plywood too. Honeycomb core is patchable. I do it all the time.

Honeycomb core does NOT necessarily depend on a thick heavy fiberglass outside bottom. 4 or 5 layers of 6 to 10oz glass makes a stout bottom that is STILL lighter than plywood (if that plywood is glassed, perhaps with a few less layers).

A bottom like that will get dinged. If you are a consumer you're stuck. You have to go back to the boat dealer and beg for mercy. If you are a boat builder you just fix it. Plywood skinned in glass is far more trouble in the long run.