Acrylic to teak sealant / Varnish before or after?

[Blitz]

It is time for my companionway sliding hatch to be redone after 30+ years. It is constructed with the smoked acrylic (or Lexon) is sandwiched between teak with self tapping screws.

I have taken the whole thing apart, cleaned the teak and am ready for the next steps which would be varnishing the teak and reassembly with sealant.

What would be the best sealant to use - Dow 795 (black) or Butyl Tape (Grey color may be visable through Acrylic) or one of the Boat Life products?

Also, should I seal (using West System 207 hardener/ 105 resin) and varnish before applying sealant or after only on exposed teak of hatch?

Thanks for the advice.

 

[Blitz]

Boat Life responded to me and said best sealant to use is their Life-Calk® Polysulfide, and it should be applied first before varnishing. It comes in black so it won't stand out so that is good.

I was reviewing many posts and it would seem that the Dow 795 or 791 might be the better choice.

Is there any way to be able to tell if the previous sealant used was Polysulfide or silicone?

 

[Brian S]

I think I would use 795 over marine sealants. Sealants don't always play nice with plastics. 795 is used to glue plexi port lights on cabins, so that would probably work ok for wood trim. It's also a structural adhesive used to glue glass panes in to window frames on buildings, so it would probably adhere well.

If Boat Life says the polysulfide will work with plexi, then I guess you're good to go either way.