looking for information on hulls

dutch2004 · #1 09-24-2012

Okay folks, here's a tough question. In the early days of fiberglass hulls were thick and solid. Then they adapted to cores which reduced weight and cost and still made a good product. Is there any source of information that would list the makers of sailboats in the early years of fiberlass hulls and what years they moved to the cored hulls. I'm thinking the move started about 1970 but I'm sure it will be different for different companies.
Can you shead any light on this for me?
Thanks

SloopJonB · #2 09-24-2012

Quote:

Originally Posted by dutch2004

Okay folks, here's a tough question. In the early days of fiberglass hulls were thick and solid. Then they adapted to cores which reduced weight and cost and still made a good product. Is there any source of information that would list the makers of sailboats in the early years of fiberlass hulls and what years they moved to the cored hulls. I'm thinking the move started about 1970 but I'm sure it will be different for different companies.
Can you shead any light on this for me?
Thanks

Coring started well before 1970. Cored hulls were never the majority of boats produced but almost all boats have cored decks going way back. I have actually never seen a "big" boat without a cored deck although I know they exist. I once investigated buying a Discovery 47 in Vancouver. It was scratch built in the late 60's in Richmond, Canada and was reputed to be the first large boat with an Airex cored hull.

To the best of my knowledge, cored construction started with wood aircraft in WW II. The Mosquito was cold and hot moulded birch plys over balsa core. If they had had epoxy back then, history would have passed the Gougeons by.

Read "Heart of Glass" by Daniel Spurr. It's the history of fiberglass boats from the beginning and it's a very good read.

dutch2004 · #3 10-22-2012

I did give "Heart of Glass" a read. It was a little dry, but it didn't contain the answer I was looking for. Unless the answer is it doesn't exist, which may be the case. I was trying to find some kind of date as to when different builders switched to cored hulls from solid fiberglass. What I did find was a history of builders that came and went like tumbleweeds on a desert. Most of which seemed to keep no records or at least none that survived to this day. The point was made many times that thse folks were builders and designers not businessmen. I fully understand that. But if I wanted to find a data source that would let me look at say a 30 foot Seafarer made in 1965. What I was hoping for was to be able to check for hull constuction. The company ran from 1959 through 1985 with many changes over the years. But I don't think there is a collection of data like to refer to??
I know after a fashion designers and builders decided to run the balsa in the other direction to stop water traveling along the grain of the wood. This would be a handy reference for hull constuction as well. it can follow the grain for several feet which is very bad!!! But cross grained it is very water resistant!
Anyway thanks for trying folks!

Tim R. · #4 10-22-2012

Not all builders went to cored hulls and some only used cored hulls for only a few models.

If you need to know whether or not a hull is cored, you have to do some research. Check with owner's groups or the manufacturer if they are still around.

msmith10 · #5 10-22-2012

Tim is right. I don't think you'll find an answer to your question. Even among a single manufacturer, some models were cored, others weren't. Some were cored only above the waterline, others the entire hull was cored.

Faster · #6 10-22-2012

The guys are right... coring takes many forms, covers different areas of hulls, and manufacturers took different tacks at different times.

Among the majors I think Catalina and Beneteau still do solid glass hulls. Others core to the waterline, others right to just about the keel root. You will have to investigate each instance to try to get exact information about each boat.

Probably most boats marketed as 'racer/cruisers' rather than 'cruiser/racer' or 'cruiser' will make use of cored hulls for structural stiffness and light weight, but that's not a guarantee either (eg I think the First series Benes are solid glass hulls)

Good luck!! It's nice to know what you're looking at...

dutch2004 · #7 10-22-2012

Thanks for the help folks! I'm still looking for the right boat. I'm sure eventually I'll find it. I was on the trail of a 30 foot Newport but the seller wasn't serious so back to the drawing board! I expect to find it before next fall. Anyway, Thanks again

paulk · #8 10-25-2012

One source that has at least some of what you're asking for are the Practical Sailors Used Boat Buyers Guides. They have separate articles on different designs and IIRC frequently describe how, for example in this or that design, hull numbers 1-40 were built this way, hulls 40-60 another way, and subsequent hulls a third way. You may be able to find them at the local Library if you can't get them from Practical Sailor.

PCP · #9 10-25-2012

One of the reasons that the less expensive mass market boats have not cored hulls is because they are more expensive to build. The current First 40 had initially a cored hull then they called it CR in a more basic version, lowered the price and made it with a monolithic hull. They don't advertise but they make more expensive cored versions if someone wants a more fast and rigid boat, mostly for racing.

Dehler, for instance on the new 41 offers only cored boat: with a balsa core in the cheaper version and on the more expensive an epoxy boat with airex core.

All Salonas (as many other brands) are cored boats but on the areas of the hull that will slam they use monolithic. To my knowledge all cored boats have monolithic fiberglass in all zones of the hull that have through the hull passages.

A hull of an old cored boat should be checked with a lot of care. Any water infiltration in one point will spread to a large area and with time it will give origin to delamination.

Cored hulls are not only lighter but more rigid and resistant than monolithic hulls, except probably in what concerns impacts with rocks or containers were a monolithic hull, if strong, will have an advantage.

Regards

Paulo