Oak Exterior Door

[Anonymous]

We had an front door made from Oak approx 12 months ago, it did have a coat of some appropriate preservative, however, we never got around to completing a second coat before the wood became stained 'black'

The door appears very dry now.

Any advice would be appreciated.

John

 

[Anonymous]

There is no appropriate preservative for oak. It contains enough tanins and other chemicals to put the fungi and small creepy crawlies off their lunch. If you painted it with some manmade biocide it would not soak in very far but just leave a toxic film on the surface to rub off on your children's fingers. The surface of oak, when exposed to the the weather and particularly to UV light from the sun, does open up to form a rough 'dry' looking texture.

Try rubbing linseed oil into it.

 

[Anonymous]

P.S. the 'black' staining results from a chemical reaction between tannin and iron. Same stuff as was used to make ink. Thye used to use crushed oak galls and iron sulphate.


How to make ink from oak

 

[Anonymous]

Biff has explained, oak and paints do not go together very well because of the tannic acids.
This is very true on exterior use as without VERY regular applications the oak will want to take on it's natural aged colour, silvery grey.

This looks lovely on old buildings !!.

 

[Anonymous]

Pardon Middi, but I don't think paint was involved in this door. I was just having a little rant about 'preservatives', aka poison.

 

[Anonymous]

Quite right, I generalised about your comment instead of being specific.

I am usually quite accurate at executing with my hands most practical tasks that my brain dictates, unfortunately this does not apply when my "finger" is on a computer keyboard, a lot gets lost in the translation somehow.

( strange, I use all ten when playing the accordion)

 

[Anonymous]

Hi John

Oak needs no preservative.

If it is South facing, exposed or near to a busy road (acid deposits) then you may want to stop it from cracking and discolouring. Er one coat of anything is never enough!

Sounds like you have iron staining. It will need a good sand. You may have to bleach the "iron mold" out. Please don't use the normal two part (A and B) bleach this RUINS the patination, best left to the hairdressers. You can use washing soda followed by hot oxalic acid, this is much gentler.

If you want a nice durable finish then you can try something like a good yacht varnish. I use the International brand. I seal with shellac (two coats) then apply six coats of varnish on top sanding all the way (VERY thin coats) looks very nice in satin or matt. In theory you should recoat clear finished exterior woodwork every year.

Regards

Toby