Andy, I don't usually come over to the carpenters section but I see you have had twenty views and no answers yet. I don't usually have much to do with oils and that sort of thing, I think Wolfie is the man you want.

However I will attempt to answer your question.

Raw linseed oil is always good for oak. Oak is a dense wood and linseed oil (raw) takes a long time to dry so has plenty of time to soak in. It will however darken the wood a bit, but as you want that anyway it should be alright.

As regards the gaps on the window board (we are talking inside, aren't we) I suggest brummer stopping. The shop should have a small chart with the different shades available.

Push the brummer into the gap and level it off, Wipe any excess off with a damp cloth.  Thin the first coat of oil with a little white spirit to enable it to soak in and wipe on with a cloth. You can also use a paint brush and then wipe the excess oil off with a cloth.  

Leave to dry (could be a couple of days.)  When dry recoat with oil without thinning.  It is important not to scrunch up and leave any oily
rags lying around, as they can spontaneously combust. Open them out flat and leave in the garden, or better still put in a bucket of water.

If speed of drying is important then I suppose you can use something like Danish oil instead.

I'm not an expert in this, but I hpoe it helps.  If it is wrong we will soon get some more replies.

Hamilton & Cwatters,

Thanks for the replies.  I gotthe window installers to leave e a scrap of the oak they used.  I'll give all your suggestions a try before doing anything permanent to the house!

The red wine test is a very good idea!  My wife has a habit of having little red wine related accidents now and then!

Cheers for the advice.

That's the one Badger.  Consequently, we bought a red carpet and suite for our living room - if you can't avoid it happening in the first place, at least you can try to hide it!