This is a classic problem of dissimilar metals. The chromate is the
sacrificial metal in the primer. As it deteriorates first, the aluminum is
saved. The best product to use is a fluid resistant strontium chromate
epoxy primer. It is resistant to the water and when it intrudes, the
chromate is the first to go.Here is a link to the product information.

http://www.shieldfinishes.com/nauticoat_epn1y1.asp

Thanks
Bruce
"Paul Oman" wrote in message
...

I need to coat the inside of an aluminum pontoon with zinc chromate, in
order to do this it must be thinned. What solvent can be used to thin
zinc chromate?


use an aluminum filled moisture cured urethane (MCU) and/or an epoxy
paint.

paul oman
progressive epoxy polymers


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