Drying thick keel timbers

[Puka]

I am currently drying out a 20mm edge glued, strip planked yacht,and wondered if anyone had
developed a method of selective drying for the thicker timbers?
(Keelson,bow stem etc)
i.e. Localised heat & bagged de-humidication.
or portable RF and partial vacuum.
I realize there is a tendency to over dry the thinner timbers but their mc can be adjusted easily.
I am hoping to speed up the process.
The potential hazard of excessive shrinkage is in the back of my mind. (at present anyway!)

[Bob Smalser]

If I read your post correctly in that this is an intact boat that's been flooded or sunk, those timbers were already seasoned before they were installed.

If so, they are still seasoned timber, regardless of how long they've been soaking. The water within the cells is gone...all soaking does is add water between the cells and they'll dry out just fine without any special help.

My cedar and fir work boats remain sunken for most of the winter here, and the worst the planking ever gets is around 20% M/C, which quickly goes down to 13% when I pump them out...and with no shrinkage.

[Puka]

Most of the planking (kauri) is around 15% but near the keelson it approaches 30%. It is not rot affected and in any case, softer planks will be replaced. (as a cautionary measure).
I noticed when the humidity went up recently, these high mc planks began to sweat.

[Dave Fleming]

WHY do you wish to reduce MC in the wood?

[ 02-14-2005, 01:14 PM: Message edited by: Dave Fleming ]

[Puka]

am currently drying out a 20mm edge glued, strip planked yacht Heheh.....your reputation precedes you Dave.....
I just need it <20% uniformly.

[Dave Fleming]

WHY?

[Puka]

OK...wrong tack.
To provide optimum adhesion for double diagonal sheathing. As near as posible to the mc of the
new timber.

[Dave Fleming]

Understood in the sense I now grasp the question NOT offering an answer.

[ 02-14-2005, 01:03 PM: Message edited by: Dave Fleming ]

[RonW]

NOT UNDERSTOOD..

Why? why are you covering a older strip planked hull with diagonal planking?
Are you trying to strenghten it, stop leaks, make it prettier, or just want to? You would have to have 100% paint removal, seems risky to me.

At any rate I would think plastic tarp and dehumidifiers would be a more gentle approach then blasting it with heat.

[Puka]

Reasons for wanting to strengthen.
*It is edge glued and nailed strip planked, which I understand,was a build to econimise on materials and is weaker in tension across planking.
It is not as strong as tradition carvel with heavy frames and large numbers of fastenings.
*Current framing pattern doesn't inspire me.And I would rather continue the concept of a monococ.
than sister frames and re-engineer.
I have considered sheathing with hi-strength triaxial glass.

All I need is advise on faster drying methods if possible.

[JimD]

Pardon me for changing the subject, but how's the mast step coming along?

[Bob Smalser]

I'd see if RGM or any of the other professional refit folks have a technique to speed things up without damage.

The only method I can think of that makes any sense is to cover the skinny stock with plastic and apply light heat and a gentle fan to the thick stock. How much air and heat would depend on the humidity in the storage area.

Either way, bringing thick, 30% M/C stock down to the 12% it needs to be throughout for reliable gluing is gonna take a while.

I'd also get longer, insulated pins for my moisture meter or borrow a commercial one. I don't think sound, caulked and painted DF or WO would be as high as you report throughout its thickness....but dunno about your local woods.

[ 02-14-2005, 09:53 AM: Message edited by: Bob Smalser ]

[Puka]

It seems warm air circulation and lowered humidity is the method to suit my budget! I guess a little gentle localised heating would be an advantage as well, plus a nip of patience!
I guess, once again preparation is crucial.
The mast step will be laminated up last when the two replacement frames are installed.It will be three times the length of the old one and maybe
a flitch.

http://www.imagestation.com/album/pictures.html?id=2130491226

[ 02-20-2005, 02:45 AM: Message edited by: Puka ]