I am looking for the best stripper to remove penofin on tamarack where it has not already failed. The surface is splotchy with gray - open areas and areas, mostly vertical, where there is a superficial coating and a natural color beneath.

Can I get samples to test out. Biodegradable and non injurious is important.

Then also, any advice for cleaning and treating with a new product. Looking for a semi transparent grey that will penetrate and be easy to follow up yearly or bi-yearly.

Since it is all going gray anyway I don't want to fight it, but instead match it more or less in an attractive way.

Vermont climate in full sun and snow.

Penofin is fairly easy to remove with a wood stripper and any of these brands will work effectively:
Wood Deck Strippers

Make sure that you use a wood brightener when done to neutralize and brighten the wood. Both the Strippers and the Brighteners are biodegradable. Unfortunately we do not have any samples.

Penofin makes some very nice gray colors:
Penofin Original Blue Label Oil Wood Finish

As well as Defy Epoxy Stain:
Defy Epoxy Fortified Professional Deck Stain