Oak Panel bowing

[dchallender]

I'm in a bit of a pickle and need some help !!!

I've just bought some oak panels 28mm thick x 1800mm for a worktop for a welsh dresser for a friend, they have happily aclimatised over the last couple of weeks in the workshop however we've had a cold spell and the boards have bowed.

One is like a banana with a deflection of about 15mm over a distance of 600mm width. The other is only about 2mm deflection and can be pulled in for the worktop.

Does anyone know of a way I can get the boards back to shape?

I was thinking of bringing them in the house where it is warmer and clamping between timber to try to bring them back into shape.

First time this has happened to me as the workshop temp is normally pretty consistent

Any ideas would be gratefully received

rgds

Darren

 

[WellsWood]

Darren, the answer may be in the way that they were stored rather than the change in the weather. If they have been unevenly exposed to the change in humidity, by for example leaving them on the bench one on top of the other so that only the top face is exposed, I'd suspect an uneven take up of moisture from the atmosphere causing one face to expand more than the other. Board materials like this need to be treated extremely carefully in this regard until finished and installed, and should be stacked "in stick" with battens to allow the air to circulate freely to both sides.
It's extremely unlikely you'll be able to force them back into shape by clamping, but in the past I've had some success with wetting both sides thoroughly and allowing them to dry evenly. This may not be necessary in your case, try putting them in stick and give them a couple of days to acclimatise, you might find it'll come back all on it's own.
Of course all this assumes the panels were well made in the first place, if not you may be scuppered. If the movement is the result of ongoing drying/stress releasing from timber that was jointed too soon after resawing/planing then there's going to be very little you can do to correct it other than rip it back into its constituent boards and start again (DAMHIKT )

Hope this helps

 

[dchallender]

Thanks Mark - I'll leave them for a couple of days and see what happens, I only moved them for 2 days to another location and they bowed !! so with any luck they may go back as you mentioned.

If not they may make good runners for a rocking horse !!

 

[lugo35]

you could get them back by coating the concave side with a varnish and then drying them out, the other side will shrink and pull them straight.

wether they will stay that way is another thing??


have tried this on some pine boards it did work but they did cup again eventually :?

 

[Argus]

.

Wide Oak boards are always susceptible to bowing, unless they are very carfully cut (on the quarter) and dried. I don' think there is any guarantee that they will stay in a stable, flat shape in use if the ambient humidity changes radically - so they may cup later in life.

Unless grain figure is a feature, I usually make up wide boards by gluing oppposed boards, no more than 4" wide. This is for a typical table top, anything up to 3 feet wide or even more

You may need to re-saw the existing board, plane it flat and re-assemble it as above - I don't think that you will get an existing cup out.

.

 

[dchallender]

Just to let you know I managed to fix the issue I restacked them with sticks monitored the air temp and they went back by their own accord, not 100% but a lot better than they were.

Thanks for the help as always

Darren

 

[WellsWood]

Really glad everything worked out Darren. Will we get to see the end result?

 

[dchallender]

Mark

I hope that I'll be able to get some photo's onto the site fairly soon, I have a list of projects now photographed that I haven't managed to get on there, ranging from a timber framed oak door canopy to a welsh dresser which the oak board are going onto to

Bear with me work keeps getting in the way the plan is to get it on there at xmas

Thanks for the advice it saved me a lot of hard work

rgds

Darren