Cracked stringer on project boat
- Thread starter $2pearson37-2
- Start date
Any suggestions for securing this stringer? Optimally without taking the mast out if it can be done. I can jack the mast off of the stringers for repair. The prior owner let water leak onto this spot at the base of the mast and it seems to be a stress crack. I’d appreciate any feedback
Looks like lots of rotten internal wood there.
Why are you adverse to removing the mast?
On a rebuild, it is something that you will have to do eventually.
gary
Why are you adverse to removing the mast?
On a rebuild, it is something that you will have to do eventually.
gary
Mast needs to come out.
Hard to tell condition of the stringer on either side of the mast step…but I suspect this will require removing the damaged wood and stringer, fitting in new wood and then glassing it all in place. Remove the old until you are at solid wood.m
Greg
Hard to tell condition of the stringer on either side of the mast step…but I suspect this will require removing the damaged wood and stringer, fitting in new wood and then glassing it all in place. Remove the old until you are at solid wood.m
Greg
It irks me that builders uses so much wood in fiberglass boats. They clearly weren't thinking these boats would last for 20, 30, 40, or more years.
If I was restoring a boat I'd be tempted to pull out any structural wood like that and fabricate fiberglass I-beams or box-beams to replace them. (I would look to see if I could purchase them before fabricating.)
Found:
Fiberglass I-Beams - Multiple Sizes Available
If I was restoring a boat I'd be tempted to pull out any structural wood like that and fabricate fiberglass I-beams or box-beams to replace them. (I would look to see if I could purchase them before fabricating.)
Found:
Fiberglass I-Beams - Multiple Sizes Available
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,566
I agree with Gary and Greg about how I would approach the problem.
Removing the mast removes the stress on the hull. The stringer is placed to maintain the hull shape and transfer the forces of the mast broadly to the hull. With the damaged wood, the mast forces are transferred to a limited hull area, overstressing the hull and eventually leading to hull failure.
The repair requires easing the stress on the hull to permit the shape to return and shaping the stringers to maintain the hull shape. It appears that once the stringers are back doing their job, you will need to rebuild the mast step.
This is not a job that supports taking shortcuts. You may find cracks in the hull, which contribute to the water in the bilge.
Removing the mast removes the stress on the hull. The stringer is placed to maintain the hull shape and transfer the forces of the mast broadly to the hull. With the damaged wood, the mast forces are transferred to a limited hull area, overstressing the hull and eventually leading to hull failure.
The repair requires easing the stress on the hull to permit the shape to return and shaping the stringers to maintain the hull shape. It appears that once the stringers are back doing their job, you will need to rebuild the mast step.
This is not a job that supports taking shortcuts. You may find cracks in the hull, which contribute to the water in the bilge.
I would say that "Whatever you replace down there, it must be a plastic such as FRP to avoid what you've got right now." Never use wood in an area which is likely to have water.
Wood has some benefits. It's cheap, it's strong, it's easy to get and easy to work and it is much lighter than sold glass. In the interior of the boat, consideration has to be given to its environment. Many wooden boats last for decades. Letting a wooden boat dry out is not usually good for the planking. I would guess that water damage was from fresh water, not saltwater. But a mast stepped through the cabin top is difficult to seal when every time you tack, it stresses the mast against the cabin and loosens the seal.
Easing the stress on that frame can be accomplished best by removing the mast. If you jack the mast up, that could work too, but get your job done quickly because you don't want an unsupported mast swinging around, assuming you're on the water and that's why you don't want to drop the mast.
By the way, that's a frame, not a stringer. Stringers run longitudinal from bow to stern. They support the frames during construction and lend stiffness to the hull.
Good luck with your repairs.
-Will
Easing the stress on that frame can be accomplished best by removing the mast. If you jack the mast up, that could work too, but get your job done quickly because you don't want an unsupported mast swinging around, assuming you're on the water and that's why you don't want to drop the mast.
By the way, that's a frame, not a stringer. Stringers run longitudinal from bow to stern. They support the frames during construction and lend stiffness to the hull.
Good luck with your repairs.
-Will
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,566
Of course Ralph is right in today's world of modern material.
Of note is that we have been making boats out of wood for centuries. While molded fiberglass stringers and pans are used on new boats, the use of wood stringers in repairs of older boats still has merit. The ability to fit and shape a piece of water resistant wood can facilitate the repair of a mature boat. Then care would be given in assuring minimal water exposure and proper drainage of bilges to minimize water inundation helps to lengthen the use of wood in boats.
Of note is that we have been making boats out of wood for centuries. While molded fiberglass stringers and pans are used on new boats, the use of wood stringers in repairs of older boats still has merit. The ability to fit and shape a piece of water resistant wood can facilitate the repair of a mature boat. Then care would be given in assuring minimal water exposure and proper drainage of bilges to minimize water inundation helps to lengthen the use of wood in boats.
Not so, from a strength to weight ratio. For the same strength FRP I-beams are much, much stronger than wood. And - they don't rot.
Ha, ha, ha.
Yea, and you know what? How long do you think the builders expected them to last? For the Royal Navy in the 19th century it was only five or so years.
I used to fret over wood that's prone to rot. Then I realized, this wood has lasted 45 years. I think my repair will outlast the boat
If it was FRP, may have cost more than I'd be willing to pay for the boat. So either way, you're rightIf it was FRP you would never have to have done that repair.
PS - This is why boats and water dont mix
I'm not following. Do you mean the boat would have been worth more than you could afford if it didn't have the damage due to the wood?
Solid fiberglass would cost more. There's a limit to how much more most of us would be willing to pay for a smaller boat
I'd rewrite that - enclosing wood with glass ....
Encapsulating wood in epoxy designed to penetrate the cellular structure of the wood works extremely well. But the wood needs to be fully encapsulated, otherwise as you say - it will get water infiltration and rot.
dj
The replica of Henry Hudson's boat, Half Moon, was built that way, and they had rot problems soon after building. I recall they used a lot of pine, which rots quickly. I think a wooden boat not encapsulated will probably last longer than one encapsulated!
I friend had a Beetle Cat with a beautifully varnished tiller, probably at lest seven coats, and recoated annually. Once, sailing, the tiller just broke in half! Turns out the only thing left was a thin, outermost layer of wood and the varnish. It had rotted out and was hollow, with no outward signs.