Endeavor Hulls:Solid or Cored ?

[JakeLevi]

I've been reading about the Columbia and other incarnations, and not finding a lot of info on the Endeavor,

were they built with solid hulls or cored ?

[seabreeze_97]

From the Endeavor site. Not all the boats listed have a detailed breakdown of construction. This came from the Endeavor 32 listing.......The hull is molded as a single unit of a combination of polyester resin and fiberglass woven roving and multidirectional chopped strand fiber (MCSF). The keel is molded integrally with the hull and all ballast is contained inside. The deck and cockpit, like the hull, are molded as a single unit of a combination of polyester resin and fiberglass woven roving and MCSF. Plywood coring is incorporated between layers of fiberglass in the cabin top, deck, seat, and cockpit sole areas to give additional stiffness.

[Jeff_H]

The two Endeavours (37 and 40) that we had in our family were crudely laid up non-cored hulls with balsa and plywood cored decks. There was a lot of non-directional fabric used which was either chopped glass or mat, neither of which are a good thing. Over the long haul I would take a properly cored hull any day over a hull built out with such a large percentage of non-directional materials.

Jeff

[JakeLevi]

Thank you, there is a myriad of construction techniques in these older boats,

a definite learning curve working through them all. On some of them techniques varied from year to year.

thanks again.

[mhfowle]

I've been seeing a lot about cored hulls on this site. Why are they so undisirable?

[TXS-ALAMO]

Jake, my endeavour 37 is a solid fiberglass hull with 8000lbs lead encapsulated keel. The walking area of the deck, the coach roof and the cockpit sole has a plywood core. There is no balsawood anywhere in the boat. Jeff H. may consider it crude, and they are, but with the purpose for which they were designed, the boats have stood the test of time. The biggest gripes are slow speed, and a tendency for weather helm due to hull design.

[sailingdog]

Cored hulls, if not properly designed or modified, especially at the points the through-hulls penetrate the hull, can lead to large-scale delamination/core saturation problems that vastly compromise the strength of the hull.

Also, repairs on cored hulls are more complicated than those on solid glass hulls.

[sailingfool]

Originally Posted by mhfowle

I've been seeing a lot about cored hulls on this site. Why are they so undisirable?

there are plenty of Sailnet threads on this subject you should search and read. Also no discussion of hull coring is complete without a reference to David Pascoe's screed http://yachtsurvey.com/structuralissues.htm

[Jeff_H]

I keep seeing references to David Pascoe's articles on cored hull contruction. These article are generally based on his observations of powerboats, which experience very different loadings and are built using different core and laminate materials, as well as different methods of contruction and engineering than sailing craft. The foams that he seems to encounter are all of a low density variety, in many case open cell variety, whereas the sailing industry tends to use moderately high density closed cell foams, a completely different animal in all ways. If you read his articles carefully, you will see such items as:

"The actual failure occurred because the cored bottom panels were not properly terminated at the keel. In this instance, the major ply separations occurred within the solid laminate (containing a LOT of CSM) first."

(In other words a delamination near the keel area, such as frequently occurs on encapsulated keel sailboats, lead to hydralic pumping which then resulted in a breaking down of the non-directional fabrics within the solid laminate.)

"How About Cored Hull Sides?
No problem. Hull sides are not submerged and are far less likely to become water saturated. The potential for hydraulic erosion is far lessened even if it does. And because the sides are vertical, water will collect at the bottom near the chine. Water saturation in sides is fairly easy to detect: All you have to do is drill a small pilot hole on the inside and see if water runs out."

At least in the long term studies that I have seen, properly constructed cored hulls seem to be less of a problem than hulls that have laminates that are resin rich or which contain large amounts of non-directional fiberglass.

One other comment on the Endeavour 37, TXS-Alamo said, " The biggest gripes are slow speed, and a tendency for weather helm due to hull design." I would add to that my biggest gripes, besides poor construction techniques throughout, would be that the Endeavour 37 had one of the most uncomfortable motions (if not the most uncomfortable motion) that I have ever experienced in any boat with the possible exception of some of the older CCA boats going up wind in a chop or in a quartering sea, where you can get an extreme combination of extreme roll, yaw and pitch angles.

Jeff

[seabreeze_97]

"Hull sides are not submerged and are far less likely to become water saturated."

To be fair, cored decks aren't usually submerged either, but get one leak......