Fuel tank inspection ports

I am wondering if it would be acceptable to use plastic deck plates for inspection ports in my fuel tanks.
http://www.marinesurplusinc.com/servlet/Categories?category=Hatches+%26+Deck+Plates
I will have 2 tanks of 200 - 300 liters each with 2 baffles so 6 inspection ports in all. The Gucci Seabuilt ones are mind-numbingly expensive(http://www.seabuilt.com/pricing.php) and it occurs to me that all one needs is a good seal. Anybody using plastic deck plates?

Mike

 

In answer to my own question, I am thinking it would probably be better to cut a simple plate out of 8mm aluminum and fasten it down with neoprene or similar gasket. Not much difference (if any) from Seabuilt but much cheaper!

 

Leaky ports

What are your tanks made of, and are your ports on top or below the fuel level? Unless a port seal is O-ringed the gasket/sealer will leak if exposed to fuel. Even a small amount of seepage is very unpleasent. Sealing the port flange to the tank is often the hardest part. bruce

 

ABYC would frown on plastic plates. Theoretically they, as part of the fuel tank, would have to pass a fire test, which the plastic plates would likely fail. Your aluminum plate idea makes a lot more sense.

 

Tanks will be aluminum with the ports on top. I had not considered fire, metal is sounding better all the time. Looking at the Seabuilt ports I think it would be fairly straightforward to build my own using the same design. Concerning the inner ring with the bolts attached, could this be epoxied in place or would it have to be welded?

http://www.seabuilt.com/index.php

 

Mike, if the tanks arent built it's easy just to get the builders to do the ports like the ones you link to.

Had a couple done last year and thats how they came as standard

Tanks only cost about $250aud each

Port frame is welded in