Many manufacturers are touting "no wood/no rot" construction, and some are
using a composite grid system (fiberglass over some type of foam) to replace
traditional hull stringers and forms. Several bay boats I am interested in use
this type of construction. Of course, from a marketing perspective, it sounds
great. But I'd be interested in some real world opinions. Is such a boat less
prone to flex? Does it result in a more solid boat? Are there other problems
to be aware of? Any pre-purchase inspections that can be accomplished,
assuming it's even possible to see the below-deck structure?

Comments appreciated.


-- Rich Stern
www.nitroowners.com - The Nitro and Tracker Owners Web Site
www.mypontoon.com - The Pontoon Boat Web Site
www.fishingreportdatabase.com - The Fishing Report Database
www.mysporttrac.com - The Sport Trac Web Site

Rich Stern wrote:

Many manufacturers are touting "no wood/no rot" construction, and some are
using a composite grid system (fiberglass over some type of foam) to replace
traditional hull stringers and forms. Several bay boats I am interested in use
this type of construction. Of course, from a marketing perspective, it sounds
great. But I'd be interested in some real world opinions.

OK

Is such a boat less prone to flex?

Than what? It is certainly less prone ot flex than the same hull with the same
layup and no grid of any type. Is it less prone to flex than the same hull & grid
with wood as the grid core? No, because wood is stiffer than foam.

In order for the grid to be stiffer due to the foam, then either the hull or the
grid (or both) have to be of stiffer construction such as triaxial weave, vacuum
bagged, etc etc.


Does it result in a more solid boat?

Not necessarily. If the grid is not laminated properly then it may not even last
longer. Foam doesn't rot but some types can become saturated and all types can
delaminate.

Some people hate foam core construction, probably because there are so many bad
examples that have long term problems. But it can be a great type of construction
*if* the details are properly done.

Are there other problems
to be aware of? Any pre-purchase inspections that can be accomplished,
assuming it's even possible to see the below-deck structure?

There are a number of things to inspect that indicate good quality work. Without a
lot of details plus pictures, it's difficult to compress 'how to do a structural
survey' into one usenet post. I'm not the greatest expert anyway.

http://boatdesign.net/articles/foam-core-properties/

Some resources on the web, another good place to look would be in your nearest
library in books on surveying boats.

Some people will say 'foam core = crap' and they probably have some bad experiences
with poorly done foam core. Like anything else, there is good and bad. When it's
good, foam core construction can be very very good.

Fair Skies-
Doug King

Rich,

I have a 1978 Winner 24 I/O which has fiberglass over foam in the
stringers. Since we hadn't used it in a few years, I had it surveyed
last winter before putting any money into a trailer, etc. The
surveyor found absolutely no issues with the hull, stringers or
transom which he said is very unusual for a 25 year old runabout.
Your mileage may vary of course but it is a fact of life that water
almost always finds its way into wood, or wood core stringers if you
keep the boat long enough. Good engineering and construction, using
the best materials for the job, is still the secret to longevity
however regardless of any one factor over another. My Bertram 33 for
example has a lot of structural wood but it is top quality marine ply
and heavily encapsulated with resin and fiberglass.

================================================== =

On 18 Nov 2003 21:18:00 GMT, (Rich Stern) wrote:
Many manufacturers are touting "no wood/no rot" construction, and some are
using a composite grid system (fiberglass over some type of foam) to replace
traditional hull stringers and forms. Several bay boats I am interested in use
this type of construction. Of course, from a marketing perspective, it sounds
great. But I'd be interested in some real world opinions. Is such a boat less
prone to flex? Does it result in a more solid boat? Are there other problems
to be aware of? Any pre-purchase inspections that can be accomplished,
assuming it's even possible to see the below-deck structure?

Comments appreciated.


-- Rich Stern
www.nitroowners.com - The Nitro and Tracker Owners Web Site
www.mypontoon.com - The Pontoon Boat Web Site
www.fishingreportdatabase.com - The Fishing Report Database
www.mysporttrac.com - The Sport Trac Web Site