We have been building aquarium stands and hoods for a while. A larger company wants us to build all their saltwater stands and hoods. We did one (400 Gallon Tank) about 9 months ago. The hood is showing some discoloration which looks the hickory is turning a grayish color. This in on the inside of the hood only. It feels rough like salt is forming on the finish. We have used conversion varnish on these. Should we consider 2k poly or is there something else that would possible extend the life of the finish on the inside of the hoods. The outside of the bases and stands are all fine. Sorry for the long explanation. Thanks

I have only built a few for friends over the years including one for my personal 600g saltwater tank. I have always used high quality white exterior house paint on the inside of the hood. Most salt water tank lighting is high power and high UV so nothing is going to last that well in those conditions. I figured house paint is thick and as made to withstand harsh conditions better than any clear finish I use on my day to day projects. It seems to be holding up well after all these years.

Thomas,

What do the boatyard folks use on their teak and mahogany that is exposed to the elements?
I would think about the west system for the interior of the hoods at any rate as a start.

shenendoah, I understand that completely. I have built my fair share of strip built kayaks and canoes. West System is a great answer, however: West system in expensive in initial cost and in time for application. We have used RANKA also but it is just too expensive for this application. Funny how people with large aquariums want the best of everything except the stands and hoods. That is where they want to cut corners. Thanks for the response.

Could you bond something simple like FRP or equivalent (inexpensive) to the interior of the hood after a few coats of finish? There would be some slight balance issues but if you used a flexible adhesive to bond I'd imagine you'd be fine. Bonus would be a basically impervious interior.

Mark B
That is a good idea I had not considered. It caused me to think about "maybe" even trying something like spray on bed liner used in the auto industry. I am going to look int the frp further. Thanks

Id think one heavy wet coat of finish on the interior (leave it rough sanded so it still has some tooth but blast a coat of finish on it anyway, then if its just flat faces, the FRP bonded to five interior faces and silicone caulk the corners and be done. Highly reflective, keeps water off the wood. Its an added step and added cost but...

I did a saltwater tank cabinet below and hood above out of 100% solid walnut and I used Ilva solvent based 2K acrylic urethane, but put a coating of isolante on before I put the sealer and topcoat on and it’s been a year….no call for issues

For the wood tank canopies I have built I found that epoxy was really the only thing that would stand up. I built aquarium stands many years ago when I was younger including some that were wood and in those I used epoxy as well to seal the inside surfaces and it was a great solution. Fiberglass was another thing that I used