Period timber already preserved?

[dishman]

Hello, about to repaint some period (1930s) exterior timber.

The spec sheet for the paint recommends to apply a wood preserver first. As these are very old windows, am I correct in thinking some form of preserver would have been applied in the past?

Any harm in preserving them again?

 

[AronSearle]

Given that age, they are very likely made from naturally durable timbers.

Douglas fir if softwood, or oak if they are hardwood would be my guess.

No harm in preserving them again and no reason not to, if you have gotten to the stage of stripping existing finishes.

If you are only sanding existing finishes enough to take a new coat, then no point preserving them, only do so on bare timber.

 

[dishman]

Thanks..

Yes, I should have mentioned that they are indeed a good quality softwood (heart wood) of the period.

I intend to strip back to the wood as the current paint cracked/peeling and is non-existant. They don't seem to have any rot though as the wood is so good.

I was unsure if adding new preservative would have any kind of negative effect on them eithe rnow or in the future. Thanks for clarifying.

After much research I have decided to give superdec a go. The nice thing about this is that the wood grain still shows, even though I am using the opaque black gloss. Hopefully should look nice!