Problems finishing cedar window frames

Can anyone give me some tips on applying clear oil/poly to old cedar window frames.
I've got the cedar ready for coating which turned out to be a real pain - after scraping the old paint off, the sand paper clogs up after only a few seconds use.
Anyway, I've bought some Rustin's Danish oil to do the job but after applying a test coat to a hidden part of the frame I'm disappointed with the results - what I was hoping for is a resonably light finish but (after a couple of coats) the cedar has turned a very dark, dull colour.
The instructions on the tin suggest wiping cedar with white spirits first but I didn't have any - would this have made a difference to the result? Or is it worth applying some sort of sanding sealer prior to coating?
Perhaps I should use water based poly to achieve the light finish I'm after.
Any tips/suggestions appreciated.

cheers

Tim

Hi Tim,

Oil will always darken timber. As for cedar, it will always darken when a finish is applied, doesn't really matter what sort of finish - oil, poly, shellac or just wet with water even.

the best thing I can suggest, is that you test the finishes on some scrap cedar first to see what they do to the cedar colour-wise.

Good luck

Wendy

Him,

You might find something of use in this old thread.

https://www.woodworkforums.com/showthread.php?t=19298

Cheers
Luke

Quote:

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Originally Posted by tims

Can anyone give me some tips on applying clear oil/poly to old cedar window frames.
I've got the cedar ready for coating which turned out to be a real pain - after scraping the old paint off, the sand paper clogs up after only a few seconds use.
Anyway, I've bought some Rustin's Danish oil to do the job but after applying a test coat to a hidden part of the frame I'm disappointed with the results - what I was hoping for is a resonably light finish but (after a couple of coats) the cedar has turned a very dark, dull colour.
The instructions on the tin suggest wiping cedar with white spirits first but I didn't have any - would this have made a difference to the result? Or is it worth applying some sort of sanding sealer prior to coating?
Perhaps I should use water based poly to achieve the light finish I'm after.
Any tips/suggestions appreciated.cheersTim

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As far as I am aware white spirit is just a cleaner ,I don't think it changes or lightens the wood. Try reading here
http://en.wikipedia.org/wiki/White_spirit

What is generally used is Oxalic Acid which bleaches the timber lighter. You might find something useful here
http://alsnetbiz.com/homeimprovement/oxalic_acid.html

Cedar is valued for its properties of strength with durability , of lightness when we didn't have trucks , and of its beauty amongst others . Cedars contain a silica (sand) which wears down the mandibles of ants (white ants too) so they choose other wood to eat.

I have been a fan of the Sikkens finish system for WR cedar for more than 30 years. As has been said cedar will darken whatever you put on it, but I have found the best 'natural' look comes from i or 2 coats of Sikkens Cetol HLS 077 (pine/oregon - ie: natural) followed by two coats of Sikkens Supernatural 07 (natural) http://www.tenaru.com.au/.

Like all exterior finishes in Oz harsh sun with heat & UV makes re-coat necessary every 2-3 years on northern and western exposed areas and after 4-5 year on others. I have windows that have been simply re-coated and are still in excellent condition after 25 years and more.

Like all exterior coatings if you allow maintenance to fall off and the surface breaks down you will need to re-sand to bare wood and start again so it pays to look after them.

BTW - DO NOT use oxalic acid on WR cedar unless you are trying to remove the silver grey colouration of aged cedar and make sure that anything you use is well dry before you try to apply any coatings. On your description you have already done sufficient preparation, you just need to try out a few samples to see what is the best option to give the colour you want. WR cedar when coated will be close to the colour it is when wet. It varies widely- from very light pale yellow/cream to the more usual red/brown to very dark burnt brown. As with all timber you can darken a lighter shade, but it is hard if not impossible to lighten a darker one and attempts will end badly. The reflective properties of the Sikkens Supernatural (which has low sheen 'deep' finish) gives the appearance of a slight lightening on WR cedar.