thirsty oak

[stormsvala 2]

i'm restoring "stormsvala", a very dry ketch (50'). she's been out of the water since 92'-93' for various reasons and is in the process of a serious facelift. her framework(ribs, floors,keel) is very dry. my question is this: is there something i should do to this dry oak before the new framework is put in? can i do the required replacements and laminations as is or would the wood be better off treated now to get some life back in them prior to the new framwork. thanks

[Leon m]

Bump...This is not my department of expertise
,This subject has been talked about before,so
sombody knows about it.

I'll bump you up...some one will come along soon.

[ 01-24-2004, 10:12 PM: Message edited by: Leon m ]

[Allen Foote]

It really is amazing how much white oak will shrink when drying but expand back when soaked. BUT beware, it does have its limits.

The NUMBER 1 thing to watch is DO NOT tighten any keel bolts. Any timbers bolted together must beallowed to expand when soaking and taking up. So, as the boat sits and the gaps arrive between timbers....LEAVE THOSE BOLTS ALONE!!

It is very tempting to assemble timbers that are bolted together and crank down on the nuts. When the timbers expand something has to give...and those timbers will likely split at the bolt head/nut. Think of this.......the timber is weakened where the bolt hole is drilled and then when the timber swells, the pressure is centered where the timber has been weakened.

Anything you soak that oak with now will retard the swelling when launching. You should not be attaching anything to the keel or timbers with epoxy, instead relying on mechanical fastenings.

When launching, place a weeping garden watering hose over the keel/deadwood and soak it as much as possible. There are other ways to "presoak" a severely dried out hull.

[ 01-24-2004, 11:19 PM: Message edited by: Allen Foote ]

[stormsvala 2]

thanks for the info guys. i am seeing some 1/4-1/2" gaps between the floor timbers and the keel which look as though they could be "influenced" to come together with some torque. you think these will swell to an acceptable spot when launched? on the new floor timbers i am installing, you are suggesting solely mechanical fasteners and no epoxy etc. in the installation? i have heard some say that a 5200 bed would be good for the adhesion of the floors to the keel and since it will move and stretch would be a viable option in the floor installation as well as the floor to frame joints. any info would be terrefic, thanks again

[Allen Foote]

Hmmmm...lets see,

The gaps are appearing because the baot is drying out and the oak is shrinking...

Once the boat is luanched, and the planking takes up, the dead wood and other timbers will take longer. Generally after a week, you can start to tighten up some of those bolts. On a big rebuild/dry out, I'll luanch without bottom paint, and after a week or 10 days, hualout and tighten bolts and bottom paint, it takes 1 day and you splash again.

[stormsvala 2]

thanks allen, how about on the floors that are being replaced and refastened? would you advise installing these new oak floors as you would on new construction or leave a bit of room for swell and tighten after the rest swells. my concern is that if the floors that are just getting refastened are left with these small gaps at the floor/keel joint and the adjoining new floors are put tight to the keel i will run into some problems when the old ones swell up after launching. keep in mind that a bunch of new laminate frames are being installed as well as new floors so the swell factor is going to vary on different parts of the spine, hope i'm not being to confusing. i'll download a couple of pics tonight that may help. thanks

[Allen Foote]

What makes the biggest difference is the differences in moisture between the new oak going in and the existing, drying-out oak. If the new oak is too wet, it will continue to dry at a different rate as the vessel is being rebuilt. There is a big difference between seasoned-dimensionally-stable oak and unseasoned lumber. The unseasoned oak will continue to season and change shape (shrink) while the existing pieces will swell and sabalize in roughly the previous dimensions.

How seasoned are the new pieces?

[ 01-26-2004, 02:08 PM: Message edited by: Allen Foote ]

[stormsvala 2]

the new floors/ribs are coming from new england naval timbers and are supposed to be very well air dried and clean, so hopefully any checks etc. will already be in the wood and i can select the stock to my liking.

[Allen Foote]

Do you have the time to let them sit for awhile before they are cut to fit? With the bolts running from the keelson up...leave plenty of threads at the top. snug down to assemble then slack off to luanch, leaving the washer and nut above the top of the floor an inch or more...how deep are these timbers? 8"? 10"?

[ 01-26-2004, 06:24 PM: Message edited by: Allen Foote ]

[stormsvala 2]

actually the smallest floor timber is 11" and then they go up to app. 13 1/4. they are 2 1/2" thick by this depth and no shorter than 30" abeam (up to 75") the ribs are 2 1/2" and the keel sided 14". she has 1 3/8 fir planking as well. she's all iron fastened which is coming out and being replaced with ss.

[Bob Smalser]

Originally posted by stormsvala 2:
actually the smallest floor timber is 11" and then they go up to app. 13 1/4. they are 2 1/2" thick by this depth and no shorter than 30" abeam (up to 75") the ribs are 2 1/2" and the keel sided 14". she has 1 3/8 fir planking as well. she's all iron fastened which is coming out and being replaced with ss.I'd take a chunk of that floor timber oak and test its moisture content in Mama's oven:

http://www.woodweb.com/knowledge_base/Moisture_content_oven_tests.html

http://www.woodweb.com/knowledge_base/Eliminating_Wood_Problems.html

The hull timbers will stabilize at 18-20 pct M/C or so...if you install oak at 25 pct, it will shrink...install it at 15pct, it will swell.

Assuming your oak stock was originally milled at 2.5" thick, it would take three years to dry to 20pct in your supplier's yard. That's a long time...take nobody's word for it...get a postage scale and do the simple test.

[Allen Foote]

Nice post Bob. Those are around the same dimentions on my 43' Egg Harbor. Have you thought of laminating them instead of cutting them from a single piece? That makes them a whole lot more dimensionally stable.

My replacement floors were made up of seasoned white oak that was 1/4 sawn. but made up of stacked pieces to get the proper height. They were through-bolted together and glued together with 5200. each piece was 2&1/2" X 2&1/2".
then a new keel bolt was run through in the original hole.

[ 01-27-2004, 09:39 AM: Message edited by: Allen Foote ]

[stormsvala 2]

laminating the floors is definately an option and i've considered it. what is the cost relationship compared to cutting it out of one timber. the time is really no problem as long as the end result is satisfactory. my keel bolts will be replaced as well, if i can get the #$@%^& things out they spin easily and come up a bit but are being held down by god knows what (i don't know how they were installed) but i'll get em'. seems as though the laminates would be just as easy and a bit stronger perhaps. do these laminates swell as much or are they pretty stable?

[Allen Foote]

The demensional stablity of the smaller laminates is alot greater. In fact, the changes are practically nil per 2 &1/2 " so the total is practically nil. The first reason why I did the laminates...it allowed me to drill for the long keel bolts 2&1/2 inches at a time (per laminate) instead of trying to drill 14" straight through.

As it came together I realized another advantage of doing it this way, I could get tighter fits against the existing frames because I'm custom fitting each 2&1/2 piece instead of trying to fit a 14" cut on angle.

[ 01-27-2004, 12:14 PM: Message edited by: Allen Foote ]

[Tim B]

Great set of posts! I haven't been here for awhile, it is nice to read an informative, concise and interesting post about boats. Allen, thankyou for sharing your time and expertise. I've learned alot from this post even though I'm just a lurker. Ed, Bob and Storm - thanks for your contributions as well.