I am replacing the keel of my boat. I have had a challenge in finding a nice long 12'6" x 2" thick piece of white oak. Well a friend has just found such a piece, but it is a little green. This is to say that the tree was cut in to boards last year, and just recently cut further down to the finished sizes. My question is: what is the guideline as to when a piece can be used, and is there a significant difference as to air dried vs Kiln? Keep in mind that this question pertains to the wood used for the keel, which is not being bent. Can I install this timber now? Should I hit it with CEPS now or let it dry further?
Thanks
Eric
How Green is too Green?
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Rodney Syverson
- Posts: 43
- Joined: Tue Dec 27, 2005 4:52 pm
- Location: Ada, Minnesota
Eric;
In the search for 1/4 sawn white oak for my keel I ended up visiting with a professional boat builder in northern Wisconsin that give me the following advice. First of all he said never, ever, use kiln dried lumber in boat building. Seasoned or air dried lumber should always be used. Typically white oak properly spaced will dry down 1" per year. So obviously a 2" board drying from both sides would be seasoned in 1 year.
He also said if you must use green lumber you can, but he suggested you first paint the board with lindseed oil and turpentine then steam for a couple hours and allow to dry for a couple of weeks in a hot box. With this procedure you should produce a stable board and most of the moisture would be removed.
I ended up using Kiln dried lumber out of some planks I got out of Port Angeles WA. As they sat around for quite a while I assume they picked up moisture and gradually became the same moisture content as air dried or ambient moisture content for our area.
You could round up a moisture meter and check your planks to see if they are below 22 per cent moisture content which I believe is the best number for bending frames. So at that point I would believe it would be OK to use for a keel.
You could also build a hot box which is simply a mini green house and let your plank cure in the sun for a few weeks.
I wouldn't apply any CPES to anything but the face that mates up to the hull. You might as well give that plank all the opportunity to gas off moisture.
Primarily what you want is a plank that has shrunk as much as possible to match ambient moisture content so it will not pull any fasteners. and dried enough so that any locked in moisture will not host microspores that will promote rotting of your board.
Good Luck: Rod
In the search for 1/4 sawn white oak for my keel I ended up visiting with a professional boat builder in northern Wisconsin that give me the following advice. First of all he said never, ever, use kiln dried lumber in boat building. Seasoned or air dried lumber should always be used. Typically white oak properly spaced will dry down 1" per year. So obviously a 2" board drying from both sides would be seasoned in 1 year.
He also said if you must use green lumber you can, but he suggested you first paint the board with lindseed oil and turpentine then steam for a couple hours and allow to dry for a couple of weeks in a hot box. With this procedure you should produce a stable board and most of the moisture would be removed.
I ended up using Kiln dried lumber out of some planks I got out of Port Angeles WA. As they sat around for quite a while I assume they picked up moisture and gradually became the same moisture content as air dried or ambient moisture content for our area.
You could round up a moisture meter and check your planks to see if they are below 22 per cent moisture content which I believe is the best number for bending frames. So at that point I would believe it would be OK to use for a keel.
You could also build a hot box which is simply a mini green house and let your plank cure in the sun for a few weeks.
I wouldn't apply any CPES to anything but the face that mates up to the hull. You might as well give that plank all the opportunity to gas off moisture.
Primarily what you want is a plank that has shrunk as much as possible to match ambient moisture content so it will not pull any fasteners. and dried enough so that any locked in moisture will not host microspores that will promote rotting of your board.
Good Luck: Rod
I would laminate the keel with several layers of white oak. Mine ended up being 3 1/2 inches wide. Laminating should creat a straigther keel member than one cut from a single piece. Look at how straigth glue lam beams and plywood are.
The keel is almost the most important part of your boat. The straighter the better. Should be straight within 1/8 or better in 2 or 3 feet.
http://www.aerialimaging.net/johnpics21
http://www.aerialimaging.net/johnpics22
The keel is almost the most important part of your boat. The straighter the better. Should be straight within 1/8 or better in 2 or 3 feet.
http://www.aerialimaging.net/johnpics21
http://www.aerialimaging.net/johnpics22
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TreelineIII
- Posts: 52
- Joined: Thu Mar 30, 2006 6:45 am
I appreciate your insights. As for laminating. My keel is made up of the main beam and then a sister beem on either side. The side beems are what is bolted to the keel and also sit on top of the ribs. Is this what you mean totaled to the 31/2"? In the hopes of moving ahead in the project I thought I could use this Board, ceps the very bottom only which attaches to the hull, then screw in my hull plywood. It sounds like I should wait on the sister beems for a little more drying?
A year of air drying is probably sufficient for this 2 inch board. Borrow a moister meter and figure out what she actually is reading for moisture content. If too wet it will shirink over time and loosen fasteners, possibly cup and twist, etc...
Make certain this is ALL HEARTWOOD WHITE OAK. The sapwood has NO decay resistance.
Just a primer on terms used for these boat parts. The KEEL is on the outside of the boat. The KEELSON is on the inside and made up of three individual boards that are screwed together to creat a single piece. The center portion extends down to the GARBOARD planking and the two outer pieces only go down as far as the RIBS. This inner piece is also called the INNER KEEL. The two boards that are parallel to the keelson on either side about 18 inches from the boat's centerline are called SISTER KEELSON or STRINGERS.
Andreas
Make certain this is ALL HEARTWOOD WHITE OAK. The sapwood has NO decay resistance.
Just a primer on terms used for these boat parts. The KEEL is on the outside of the boat. The KEELSON is on the inside and made up of three individual boards that are screwed together to creat a single piece. The center portion extends down to the GARBOARD planking and the two outer pieces only go down as far as the RIBS. This inner piece is also called the INNER KEEL. The two boards that are parallel to the keelson on either side about 18 inches from the boat's centerline are called SISTER KEELSON or STRINGERS.
Andreas
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TreelineIII
- Posts: 52
- Joined: Thu Mar 30, 2006 6:45 am
Thank you for clarification of the terminology. I realize I was a bit loose in my description, but your lucky I didn't use the words I was calling them last night. But on to further understanding. How do I know it is Heartwood? Sorry big learning curve hear. And is the 22% or less an accurate target?
Thanks
Thanks
My keel and both sisters total 5 1/4" wide and about 3 1/2" deep. Keel alone is 3 1/2" wide. I started with 4/4 white oak and ran it thur the thickness planner, to just clear it up. That turned out to be about 7/8".
I did this for two reasons. My rib ends were soft at the ends, and it took removing about an inch to get to good wood. So what I took off the ribs, I added width to keel. While I was at it I made the keel taller. Wider and taller makes a very strong keel. I used epoxy to laminate the 6 pieces together. Since I was able to cut my boards from a 8" wide board, I flipped each pair of boards to minimize any future wrapping.
I coated each piece with cpes 3 times before glueing. I then ran the complete keel thru thichnest planner to clean up.
Two years, 100 plus hours of engine time, and over 5000 miles of trailering with no problems. The bottom is still very flat.
My 16' 202 Cruisers will run 28 gps with my 1960 40hp Evinrude and better than 38gps with my 1960 Evinrude 75. Has run over 40 with windshield removed.Without a flat running surface, speed would not be as good.
I did this for two reasons. My rib ends were soft at the ends, and it took removing about an inch to get to good wood. So what I took off the ribs, I added width to keel. While I was at it I made the keel taller. Wider and taller makes a very strong keel. I used epoxy to laminate the 6 pieces together. Since I was able to cut my boards from a 8" wide board, I flipped each pair of boards to minimize any future wrapping.
I coated each piece with cpes 3 times before glueing. I then ran the complete keel thru thichnest planner to clean up.
Two years, 100 plus hours of engine time, and over 5000 miles of trailering with no problems. The bottom is still very flat.
My 16' 202 Cruisers will run 28 gps with my 1960 40hp Evinrude and better than 38gps with my 1960 Evinrude 75. Has run over 40 with windshield removed.Without a flat running surface, speed would not be as good.
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Rodney Syverson
- Posts: 43
- Joined: Tue Dec 27, 2005 4:52 pm
- Location: Ada, Minnesota
I purchased a book on drying wood and in other publications they echoed the same thing. Wood had to dry down to a Fiber Saturation Point of approximately 22-25% moisture content. Beyond that it can be kiln dried but that probably is not advisable for something that is going to ultimately reach ambient moisture levels. Ambient moisture levels vary for different regions of the country.FSP is the point I believe where there is no free water between the molecular cells of the wood. I am kind of winging it here as it has been awhile since I have reviewed this information but it would be good to check some sources to give you a better handle on what is proper. There is a lot of information out there and I found in exploring it that some things contradict others. Its best to evaluate and determine for your self what is right. Good reading on this subject is Danenberg's Book. The great part about this whole process is the learning curve. But it requires some reading and exploring.
Good Luck:) Rod
Good Luck:) Rod