The properties of oak...

[Georg Moe]

Hello

Does someone know how dry oak reacts when it is soaked in water? I'll be posting more details about the actual problem in a day or two, but, the boat I am restoring at the moment has a dry keel, and some of the scarfs have lost some of their tight fit (there are throught bolts of galvanised iron/steel), so, water will find its way out of the boat quite fast through this scarf. Once the oak has dried out a bit, will it be 'locked' into its new shape, or will it expand again? Given that it will be locked in its new shape, could one just pour epoxy into the void and have a 'new and perfectly sound keel'?

regards

Georg Moe

[Thaddeus J. Van Gilder]

don't use epoxy, That will just act like a wedge and damage the keel when she takes up.

[Bruce Hooke]

Unless things have shifted for some reason the oak should swell back up once it hits the water. Of course it may take a while to do so, during which time water may be coming in through the scarfs in a hurry.

As a general rule wood will expand and contract depending on the moisture level. The only exception I can think of off-hand is that if it is prevented from expanding then the fibers will crush, and in the future, even if it is not contstrained it will only expand to about the place where it was stopped in the past. However, that should not be an issue in the situation you are describing.

[Georg Moe]

The reaon for asking the way I did is that someone told me that oak has a nasty tendency of locking itself into a new shape when it dries out, and become quite unwilling to expand once it gets new contact with water. BTW, the boat has not been in water for about 25 years, the only water it has seen is occasional rain and snow for a period of 2-3 years when the shed collapsed back in about 1995. Some of that water found its way into the bilge.
:) Georg

[Andrew Craig-Bennett]

I would start coaxing it back to size well before launching the boat - wrapping it in damp cloth is quite good. It takes a very long time to come back and maybe it just won't - only way is to try. I had a dayboat where the oak cutwater had warped so you could see daylight through it (clear of the rabbet, luckily!) It never did quite come back but it came back enough to be tight.

[Georg Moe]

Hello again.

Seems that 'a day or two' did become 'a few months...' Anyway, here are some pictures of some of the problem areas. The first picture shows the scarf at the keel, the distance between the two parts is about 1/8" on the sb side, it is tight on the port side.
http://www.cmbweb.no/KJOEL1.JPG

The next picture is the knee between the keel and the stem.

http://www.cmbweb.no/KJOEL2.JPG

The last picture shows the keel where the propeller shaft will meet the engine.
If you see on top of the keel, the forward end is still painted with red lead, whereas the rear part (but still ahead of the floor timber) has been cleaned. There is a scarf starting there, and it meets the crack at the floor timber. The mentioned forward part of this arrangement is part of the 'rest of the keel', i.e. the shaft log is not a separate piece of wood.

http://www.cmbweb.no/Kjoel3.jpg

Is there a possibility that the oak will expand, or should one fill the void with epoxy or 3M 5200, or Sika, or...?

Thanks

Georg

[Concordia..41]

This was one of the questions asked Giffy Full at the Wooden Boat Show last summer. The person was referring to the large seams in the oak dead wood of his boat. Giffy stated that the oak would swell back to its original size and the seams would close.

I would not use epoxy or anything that gets hard. With the new floors we are installing in Sarah, I do not tighten the floor bolts to tight and will not seal the top of the floor where the nut is until the boat has been in the water for a while. Tony Harwell who also has a Concordia said he had to loosen some floor bolts after the boat was in the water.

I would recommend using Dolphinite in the seams. I have used Dolphinite and soft cedar wedges to close seams in areas where I felt there would be excessive leaks before the wood swells. The oak crushed the cedar as it closed up and I had to fair the seam.

Dave Fleming may have other suggestions, as I am sure he has dealt with this before. If he does not respond to this thread, just e-mail him.

Dave

[Mrleft8]

Think of it this way...... Wood is a really really dense sponge. It'll take a while... But it will swell back up to its original dimensions, as long as the cell structure hasn't been destroyed.
WHATEVER you do, DON'T fill the voids w/ epoxy!

[Mrleft8]

(And I thought this was going to be a post about tree's buying up land in Connecticut....) :D

[Georg Moe]

So, basically you say that a week or two with water would do 'wonders'? However, what about possible stresses in the propeller shaft area?
:) Georg

[Georg Moe]

By the way, what is Dolphinite?

:) Georg

[Mrleft8]

If the prop shaft was installed prior to the wood drying out, it may have deflected a bit in the drying process, but will probably "deflect" back during the swelling cycle. If you installed a propshaft in the dried out keel, and made sure it was deadnuts straight, it may be deflected when the wood swells. Most shafts, I would think, have enough stuffing around them to deal with this issue though. You may (probably will) have to restuff your shaft...

[Mr. Know It All]

Dolphinite is a bedding compound I think. The windshield on my Lyman was bedded with dolphinite.
Peace---> Kevin in Ohio

[Georg Moe]

The prop shaft was installed before the wood dried out. BTW, today it is almost impossible to rotate the shaft, so it could be somewhat deflected today...

:) Georg

[Allen Foote]

Georg, do not put anything at all, into those openings. The planking ect should be induced to reswelling by spraying down the inside of the hull 2-3 times daily for at least a week prior to launch. In severe cases, the hull is wrapped with plastic and the ground under is covered with plastic and lawn sprinklers are put under neath while a "soaker" hose is place ontop of the keelson inside. Often, the boat is launched without the dead wood having swelled at all. 2" and 3" gas pumps are used the first days. Haul outs are required after the first week to retighten keel bolts and check on the keel timber swelling. In fact the better way(here on the Potomac) is to relaunch without bottom paint and babysit the boat then after a week haulout and tighten AND THEN paint the bottom. (you may not want to do this in salt water).

[Georg Moe]

Apart from the lawn sprinklers, the nearby water is salt water. Seems to me that I'll have to wait for better temperatures (right now we have somewhere between -10 to -20 degrees (C) here in Oslo), then spend a lot of water and wait and see...

Thanks to all of you so far!

:) Georg

[Chris Coose]

Wet rags, soaker hoses, whatever, to begin getting things moving again now instead of in the ocean.
Like the other guys rang in. Don't put anything solid into those voids. That would be fatal.
I set one in the harbor that had been in a garage for 5-8 years. The pumps were aboard for 10 days but she took up well.
At the time I'd wished I'd pulled the motor and let her sink and swell.

Any shots of the rest of the boat. I feel like I've gotten a good look at her ankles.

[Georg Moe]

The rest of the boat, Chris: http://www.cmbweb.no/sulamit.htm

:)Georg

[lumberdude]

Interesting boat Georg, what is her story and how long have you had her?

Just curious.

Kory

[Georg Moe]

The boat is a 1937/38 cruiser (31') designed by one of Swedens most famous desingers, Ruben Östlund. I bought the boat in Sweden two years ago, the seller bought the boat in 1998. Before that the boat was in a poor condition (the first time I saw the boat was in 1997, but it was impossible to agree upon a 'fair price'). When I bought the boat the seller had just started to restore it, his heart failed so he wanted to spend his time doing other things. The boat is still in a fairly poor condition, but improving. Right now nothing is done, it is too cold outside. The decks have to be replaced, the engine has to be installed (a Penta EC6, sideventilated straight 6, 74 hp.), instrumentation and steering has to be installed, some areas of rot have to be brought back into shape, new electric installation, well, a lot of work. My plan is to have the boat back into the water in 2004.

[lumberdude]

Wow, sounds like you have your hands full. Keep us in pictures please. I'm anxious to see this boat come back to life.

Kory

[Georg Moe]

me too...

;) Georg

[Georg Moe]

Hello again

The earlier mentioned oak has now been soaked for about 3 weeks, but, there is practically no movement. How slow is oak...?

[Mrleft8]

Not that slow. The cell structure may have been damaged....

[holzbt]

How have you soaked it? Are you wetting it each day or have you launched the boat? If you are wetting it I'm not surprised at the lack of movement. I've seen old really dry timbers take months to swell fully after the boat was relaunched.

[Dave Fleming]

G, that OAK is old, dense and hard. The checks and separations you show in the initial photos are on the ***INSIDE*** of the vessel. With the closed cell structure of OAK, IMOOP, that wood will take some time to swell and perhaps it will never swell back completely to the original.
20+ years is a long time for timbers to be dry!
Another thing, wood does develop a 'memory'.
By this I mean that if the boat has not been shored/braced/blocked properly and the same has not been checked periodically then the actual shape of the boat can change and be almost impossible to coax back to its original form.
And with most boats/vessels be they of steel or Aluminum or wood there is always a bit of deviation from true plans measurment. CAD and NC not withstanding. For example, it has been my experience that doors that swung freely when the vessel was still in build on the ways would sometimes be just a tad bit snugger when the vessel had been launched and in the water.
Materials move, expand and contract with temperature. I have seen Aluminum hulls, not fully plated and sitting out doors in the hot summer sun 'tweak' as much as 2 inches in 100 feet fore to aft. And later in the day towards evening, that very same 'tweak' will have returned to its original lines!
If you have been following Ed Harrow's saga of his restoration, you might recall that RGM and I both advised Ed to string a strong taut music wire centerline above the deck and use that to check for movement from time to time. Brace pads set on earth especially will shift oh so subtely with freeze thaw cycles and if not checked for alignment can throw the hull out of alignment. The fact that the propellor shaft does not move at the moment could be caused by a number of things. If it has not been turned in that over 20 year period, bits of corrosion, dried grease, seized bearings and misalignment caused by the above mentioned poor bracing and or dried timbers could be the cause for no movement.

[Georg Moe]

Hmmm...
Well, I am wetting the boat.
:) Georg

[Georg Moe]

Dave, given that it will not go back to its original shape (say after 2 months), will that be the time for epoxy, 3M 5200, or some other stuff? Or just pour red lead into the void in order to prevent rot, and use the lead as some sort of bedding compound? Or just replace the keel... :-(?
:) Georg

[Dave Fleming]

Dave, given that it will not go back to its original shape (say after 2 months), will that be the time for epoxy, 3M 5200, or some other stuff? Or just pour red lead into the void in order to prevent rot, and use the lead as some sort of bedding compound? Or just replace the keel... :-(? Don't be in such a bloody hurry!
Just like so many folks today, relax, smell the Pine Tar. Figure out how to get the prop shaft out whilst you are waiting or do some other work.

Has the boat been back in the water for 2 months or just you wetting it down with a sprinkler or similar? If the checks do close up no worries. In the mean time soft putty to prevent water staying in those checks might be in order and as the wood swells to close the checks the soft putty will ooze out.
IMOOP, 5200 or epoxy are no-no's. From those photos you originally posted, looks like the oak was painted with something, a secret sauce mixture, perhaps.
and in other spots it looks like red lead was used. You check the alignment, the braces?
You are not letting any sprinkler water build up in the bilge are you?

[ 07-04-2003, 07:42 PM: Message edited by: Dave Fleming ]

[Georg Moe]

Hi
Guess I'm a only bit impatient..., at least anxious to get the boat back into the sea ;)

I'm just using a sprinkler. The oak has just been painted with read lead, and then with bilge paint. The sprinkler water is just flowing through the bilge to the nearest 'exit-point', there is just about 1 inch of water in the bilge.

:) Georg