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Mike B

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Hi

I have 3 boards of American White Oak approx 1.7m long by 130mm wide. They started life as rough flat sawn boards, supposedly kiln dried and a friend helpfully thicknessed them to about 32mm thick for me. The finish was bad so I wimped out of the hand planing required and put them in the spare room nicely stickered up and forgot about them for 6mths or so :oops: :oops:

When SWMBO finally lost patience out came the hand tools. Two of the boards had bowed about 6 or 7mm so after a lot of blisters, sweat and tears I managed to get them pretty straight and flat again, now about 28mm thick. So far so good. Unfortunately, had a bit of a family crisis so they were once again in the spare room, this time standing on their long edges 6 - 8 inches apart, for the next 3 weeks. Now I've dug them out again, 2 of the 3 have bowed another 3mm or so!! :x

Any suggestions to what I am doing wrong here?? Is this normal?? Should I have got a finish on them asap?? Were they not properly dry to start with?? Or just awkward boards?!

Cheers
Mike
 

wizer

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comments from a non-expert:

Could your spare room be subject to extreme temperature/humidity changes? Did you seal the ends with preserver or gloss paint?
 

jasonB

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Sealing the ends will not help with this problem, if the ends were splitting then maybe so.

When the boards were thicknessed by your friend he may have taken more wood of one side than the other which may be causinf an imbalance in the moisture content of the wood. ie. if it gets drier as you go towards the center then the side with more planed off will be drier than the other, over time they will equal out so one will gain or loose more moisture than the other.

I assume your friend surface planed one side flat then thicknessed the boards, if he just thicknessed them then they would come out as crooked as they went in!

Without being able to measure the m/c of each side of the board and see where they are being stored it is hard to be definate, I would leave them to totally settle in the room where they will end up before working on them again.

Jason
 

Mike B

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Thank you for the comments, guys.

The boards are (were!) destined for the spare room so I had hoped that leaving them in there this long would have caused them to settle...

Unfortunately, I have no idea how they were originally prepared and only managed to get them as they were surplus to requirements for a renovation job.

When the boards were thicknessed by your friend he may have taken more wood of one side than the other which may be causinf an imbalance in the moisture content of the wood. ie. if it gets drier as you go towards the center then the side with more planed off will be drier than the other, over time they will equal out so one will gain or loose more moisture than the other.
After further thought I think this may be the problem.

When I flattened the boards the second time I basically tried to keep them as thick as possible and to that end only tried to remove material at the ends of the concave side and the middle to the concave face - should I have taken more off each entire face to get a more even board?? I'm assuming that it's the centre of the concave face that is causing the problem by "pulling" the ends in...

Any idea how long should I leave them to settle this time??

Thanks
Mike
 

jasonB

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Mike B":29d6mzd5 said:
When I flattened the boards the second time I basically tried to keep them as thick as possible and to that end only tried to remove material at the ends of the concave side and the middle to the concave face - should I have taken more off each entire face to get a more even board?? I'm assuming that it's the centre of the concave face that is causing the problem by "pulling" the ends in...
Thats the only way you can get them flat by taking it off the high spots so your method is correct. It could be either side one loosing moisture if the boards were not dry enough or the other side taking in moisture if the boards were overdried.

As to how long, well just keep checking them until you see no more movement. They would be better stored flat on battens with sticks between the boards and taped together or weighted down to stop them springing apart.

Jason
 

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