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General Category => General Scroll Saw Talk => Topic started by: PaulK on December 12, 2010, 02:31:10 pm

Title: Wood warping when oils and polishes are applied - any tips?
Post by: PaulK on December 12, 2010, 02:31:10 pm

Hi -

I have had several occasions where a pattern has cut really well and everything looks great. Then I start to use an oil or polish finish and the wood starts to distort. This is when using hardwoods. Birch ply seems so much more resilient of course.

One approx.1mm thick Joseph's crook on a nativity scene went from completely straight to a series of curves in a very short time - thankfully I packed it both sides with thick cardboard and it dried perfectly straight again.

On another thin Oak box I made as a Christmas present, the flat rectangular lid arched beautifully, once it was oiled, and never recovered.

I do plan pattern layout and try to choose grain direction to best suit the piece.

Anyone got advice on how to reduce or stop the problem please?

I very often miniaturise patterns, so a larger pattern with 1/2 inch wood I make half size and use 1/4" wood. This doesn't help.

Hope to benefit from your ideas and experience.

Thanks - Paul,

North East England

( not Grampa )

Title: Re: Wood warping when oils and polishes are applied - any tips?
Post by: dgman on December 12, 2010, 03:32:35 pm

Hey Paul, Two things come to mind. Are you using kiln dried hardwoods or are they air dried? If air dried, the wood may not be dry enough.
Are you milling your own wood? When I plane wood to thickness, I make sure I plane equal amounts on both sides to allow for equal moisture absorption. Then I allow air to circulate around the board to allow the moisture to equalize in the board.
Other than that, I can't think of any reason your boards are warping when oil is applied.

Title: Re: Wood warping when oils and polishes are applied - any tips?
Post by: Rightarm on December 12, 2010, 05:20:06 pm

   sorry. I have not ran into that problem yet. I don't have any idea. Dave 8)

Title: Re: Wood warping when oils and polishes are applied - any tips?
Post by: dunk on December 12, 2010, 05:28:44 pm

I actually had a board warp on me while in contact with my saws table the other day.  I think it was due to the damp cold air.  After it was cut I took it indoors and it relaxed to it's flat state again.  I have had a few things warp when oiled but they usually go back to their flat state as well.

Just one of those things this time of year I'm afraid.

Title: Re: Wood warping when oils and polishes are applied - any tips?
Post by: KarlB on December 12, 2010, 05:40:52 pm

One consideration is finishing both sides of your project evenly.  In our shop if our finishers don't finish the back side of a wood plank let's say, the board will warp.

Karl

Title: Re: Wood warping when oils and polishes are applied - any tips?
Post by: PaulK on December 13, 2010, 02:31:20 pm

Thanks Everyone -

I have been working in very cold damp conditions with 15" of snow outside and it's been giving me quite a few problems, generally.

Almost everything you all said is valid, and I need to take more care in both wood and finish preparation along the lines you suggest.

Thanks for your help.


Regards - Paul