View Full Version : The Shrinking Boat
Texas Boater
07-26-2006, 01:30 PM
Here is a generic question:
How long can a boat sit on the hard before major damage is done?
I realize for a boat left to the elements (sun/rain/snow/hail) the answer is impossible to determine and is dependent upon its location.
But consider covered storage (inside garage/barn) but stripped unsealed wood? Is there a point at which the boat stops shrinking and no more damage is done?
Or will the wood continue to shrink and try to return to its original shape until the fasteners stop it or fail?
JR-Shine
07-31-2006, 11:04 AM
http://www1.istockphoto.com/file_thumbview_approve/1147691/2/istockphoto_1147691_boat_in_the_bottle.jpg
Sorry, i could not help it:)
There will be a slower marginal rate of shrinkage with the reduction of moisture content. I guess the question is at what point does that rate become negligible. I know I have seen data for this books, by I cannot remember where, sorry.
Texas Boater
07-31-2006, 12:09 PM
So I assume that the answer is, if a boat is stripped bare of all coatings, but protected from the sun and rain, it will shrink up to a point and then no further damage or shrinkage will occur.
So my boat that has been bare for 4+ years is not being damaged by remaining bare for another few years while I restore it!
dem45133
08-01-2006, 10:28 AM
Since your approaching close to five years, but covered, I suspect its basically as dry as its going to get (hopefully you not in too dry of a region for humidity).
Any damage is likely done if it was going to. Personnaly, I belive I look at mummying it in a poly tent and use a humidifyer to maintain a certain minimum. I'd have to research where that point is though.
CaptScot
08-03-2006, 12:04 AM
The worst thing I have seen with boats that have been drydocked for too long is that the blocks under the keel and supports elsewhere around the sides will start to push up and bend the hull planks and keel. Wood boats are not meant to be out a very long time. The alternative is to have as many blocks closely spaced under the keel as possible and several supports around the sides. Also occassionally move a side support up fwd or aft a few feet so that one support doesn't remain in one spot too long. Try to also have a side support over a place on the hull were there is a bulkhead or something solid on the inside or at least a rib. When drydocking large ships blocks under the hull MUST be under an inner structural member or the weight of the ship will damage the hull if placed only over hull plating. I have seen wooden cruisers wrongfully support with a few blocks under the keel that eventually push up and crack the keel. Yard staff today think they can block up a wood boat like a fiberglass one. Its wrong. Lastly, don't worry about shrinking. Just make sure the boat has a waterproof cover. A wood baost is like a piece of fine furniture. It will be destoryed if left out to the weather to leak then rot. I have worked with wood plank cruisers for 40 years. Scott J.
CaptScot
08-03-2006, 12:16 AM
One more thing, seems on the hull above and below the water line can be filled with seam compound and painted or varnished. The same with the trunk cabin, and everything above the deck. As the boat takes on moisture from being back in the water, from humidity and everything swells back into shape the somewhat soft oil-base seam compound will bulge out of the seams. It normal. I am presently restoring a large cruiser thay has been out for 4 years and with the heat of this summer and settiing in a blacktop parking lot of the marina with other boats shrinking has been a problem too. Jamestown Distributors.com sells the compound. One type is for about the water line and the other meant for below only. Plank seams below will need cotton caulking first then covered over by the brown compound. Fair winds, Scott J.
Hunter25
08-04-2006, 02:24 AM
Eventually all wood that is not completely encapsulated with a water proof coating, like epoxy will establish a happy place with the environment it lives in. This is the normal reaction of wood to balance its moisture content to the relative humidity in the storage area. All wood does this. If the wood goes from a high moisture content state, like being afloat, to a much drier place, like on the hard inside a shed, then it will dry out, shrink and then stabilize at a new moisture content. If it was very wet or soaked, this can take a long time, but you are past this stage now. Your boat will be fine, if she is supported well and does not get weird shape alterations from being blocked up uneven. When you put her back in the water, she will swell up and stabilize with a higher moisture content, reflecting her new life style. When she was origionally built she was a very dry boat and managed to get through it.
dem45133
08-04-2006, 08:33 AM
Good point. They were all dry when built.
Texas Boater
08-04-2006, 09:50 AM
Thanks guys all great advice and points.
:D
View Full Version : The Shrinking Boat