Exterior siding finishes

[beetle]

Any opinions on Linseed oil and Turps as a finish for exterior siding, specifically Hemlock. I know it will have no UV resistant properties. Looking for a good finish that will allow the wood to age naturally and to keep it from turning that ugly black and/or gray.

[beenthere]

The "ugly black and/or gray" is mold, so something that won't let the mold grow will help. Bleach solution will help, but will need to be sprayed on a couple times a year most likely.

Used to use a mix of Penta, paraffin wax and mineral spirits but that was when we could get Penta. Some borax treatments may help but appears they also need application more often.

I understand that linseed oil is like candy to mold. So I would be cautious to use it without something added to kill mold.

The UV protects the wood from breaking down.

[beetle]

The Madison formula, that is what I had read other places. Linseed whether raw or processed ( boiled ) feeds mold and reguires a fugicide. Penta is no longer avaliable to us, and I would not want the toxic properties on a agg building anyway.

So we are looking for suggestions, we want a oil penetrant, not a Urethane or wax based product that lays on top and seals the surface. Anyone have experience with the multitude of commercial products out there?

Suggestions?