Hull problems.

[Matt]

When doing some work on the boat yesterday, ('83 H27)I noticed the starboard stern pad on the cradle was causing the hull of the boat to flex inward. Is this a sign that the inner core is rotting away, if so is there any way of firming up this section with foam or some other material?We have had the boat three years with no problems, using it as a day sailor on lake michigan. We would like to go on longer ventures, but now I am wondering about structual soundness. Any responses appreciated.

 

[Tim]

Its not a boat problem...

its a jackstand problem. The weight is supposed to be on the keel not the stands; they're just there to keep the boat balanced. Either the boatyard screwed up or the boat settled i.e. the boatyard screwed up a different way. Make sure the boat is level.

 

[Tim]

Oh, and the coring...

There isn't any. This a solid fiberglass layup i.e. fabric of glass fibers saturated with plastic resin and set with hardener. This is a strong but flexible construction, so yes it might flex under load in the wide flat sections well aft of the keel. It should be quite stiff anywhere near the keel since it will be a lot stiffer. The deck is different; its a sandwich of two thin skins of fiberglass with an endgrain balsa wood core in between. This is to provide stiffness, mostly for when you walk on the deck.This is how about 95+% of boats are made. A few exceptions (J Boats, Tartan, C+C, and many trimarans) use cored hulls but this has some real potential disadvantages (difficulty of repair and adding throughulls, problems with delamination and water migration.)

 

[Joe]

mine too

This happened once to me in a very reputable yard. Have the yard readjust the stands to eliminate the flex. I needed to eliminate some blisters, so I had the bottom sand blasted, dried out the hull, filled and faired, then applied 7 gallons Interlux barrier coating. This stuff is epoxy based...no more blisters or flex problems. You can do it yourself if you follow the advice of Interlux.

 

[John D LeClare]

flexing hull

I had the same thing happen. The weight should all be on the keel with the jack stands located where there are stiffeners or bulkheads inside the hull.John in North East MD

 

[Matt]

Thanks for info.

Thanks for the information. I will have the yard readjust the cradle. This site is a great resource for information. It will ensure that if I ever decide to upgrade it will be a Hunter. Thanks again.