Water ballast construction

[alibi]

Hi all..... I'm building a "hard tank" setup in my ski boat for filling with water ballast to make the wake bigger, looking at building fibreglass tanks capable of holding 400lbs. Do I need to make these tanks out of vinylester resin or will polyester be fine? as this is not potable water. Bearing in mind that water will not be sitting in the tanks for any long period of time only when wakeboarding.

Cheers Mat

[TeddyDiver]

Yes you can do it with poly. Remember gelcoat on both sides and fasten the tank well in its place. Just make also strong baffles inside. Make sure all the plumbering is marine grade and properly installed :)

[apex1]

As an addition to Teddy´s comment:
do´nt forget a sufficient "manhole" to clean the tank from time to time, you otherwise host a biotope after a while.;)
Regards
Richard

[alibi]

cheers for the advice guys, do i need gelcoat both sides? if at all? just curoius? also what is biotope?

[apex1]

cheers for the advice guys, do i need gelcoat both sides? if at all? just curoius? also what is biotope?

I cannot answer to the gelcoat question (I never used Polyesther). The biotope I mentioned, meant, if you do´nt clean the tank, you grow algae, mold and fertile sludge after some time, and that stinks.

Regards
Richard

[TeddyDiver]

do i need gelcoat both sides? if at all?
Preferably.. though if you don't expect too much lifetime of the laminate a simple paint could do..