I have used a Delmhorst 2 pin moisture meter for the past 25-30 years. It was one of the better meters at the time I bought it for use with musical instrument wood. So today out of curiosity I measured the moisture in cedar ribs, old and new. The old ribs were removed from a 1952 OT Yankee. The moisture content was 10% uncorrected for species ( different woods have different correction factors). A rib steamed and bent yesterday measured 10%. The real kicker was a rib bent and clamped to dry today about 1 pm. At 8 pm it measured 10%. I poked it in a number of unobtrusive places and all readings were 10% uncorrected. I will still wait overnight before tacking but I do feel comfortable in knowing that thin cedar apparently gives up moisture rapidly and evenly. Does anyone else have any similar experiences to share?
Moisture in White Cedar
- Thread starter Jan Bloom
- Start date
Roger Kugler
Enthusiastic about Wooden Canoes
Hi Jan,
I would assume the cedar rib you steam bent was dry to 10% before it went into the steam box. I'm not surprised it was still at 10% after it dried in place since the steam(moisture) was only the conductor of the heat which aided the actual bending. It did not "soak into the wood to make it more pliable." The heat loosened the liguem(sp?) bond between the cell walls to which allowed the cell walls to move independently of each other, allowing the rib to be bent. At least that's how I understand it......
I really should buy a moisture meter. I weight the exotics I work with and wait until the wt stabilizes.
Thanks,
Roger
I would assume the cedar rib you steam bent was dry to 10% before it went into the steam box. I'm not surprised it was still at 10% after it dried in place since the steam(moisture) was only the conductor of the heat which aided the actual bending. It did not "soak into the wood to make it more pliable." The heat loosened the liguem(sp?) bond between the cell walls to which allowed the cell walls to move independently of each other, allowing the rib to be bent. At least that's how I understand it......
I really should buy a moisture meter. I weight the exotics I work with and wait until the wt stabilizes.
Thanks,
Roger
Roger,
Basically that is how it works, you are softening the "lignin". However, with woods like cedar that are almost "sponge" like it is expected that there would be some residual moisture from steaming. I must also add that it was such a nice sunny day that I was working outside and left the canoe out in the sun after bending the ribs. That may have had some effect. So 2 more to bend and I will check one immediately after bending for a reading. Need to go make steam. Bye
Basically that is how it works, you are softening the "lignin". However, with woods like cedar that are almost "sponge" like it is expected that there would be some residual moisture from steaming. I must also add that it was such a nice sunny day that I was working outside and left the canoe out in the sun after bending the ribs. That may have had some effect. So 2 more to bend and I will check one immediately after bending for a reading. Need to go make steam. Bye
Cedar out of the steam box and allowed to cool to an ambient temperature of 80deg F in about 30 minutes gains enough moisture in the box to pin the meter needle. Cedar apparentley "dries" or releases moisture readily. None of this was a controlled expereiment just casual observation I thought intersting and possibly of interest to others.
Roger Kugler
Enthusiastic about Wooden Canoes
The next time you bend a rib, would it be possible to take measurements, say every 15 minutes or so and post the results? Probably make an interesting graph.....
Thanks,
Roger
Thanks,
Roger
Gees, Roger that is a lot to ask for. Might as well throw in loss of moisture in steam bent quarter sawn ribs vs flat sawn ribs.
I am all done with the ribs for the Yankee but have the 18' HW coming up next. That is a massive undertaking with 21 broken ribs. Most are toward the stern right along the center line. How those broke is beyond my imagination. The keel is intact with no visible dents. I probably will not do anything with it until Sept of Oct.
I am all done with the ribs for the Yankee but have the 18' HW coming up next. That is a massive undertaking with 21 broken ribs. Most are toward the stern right along the center line. How those broke is beyond my imagination. The keel is intact with no visible dents. I probably will not do anything with it until Sept of Oct.
Roger Kugler
Enthusiastic about Wooden Canoes
OK, sounds good to me!