holding tank capacity

[Kevin O'Rourke]

I recently purchased a 1983 Catalina 30 where would I find the tank fill capacity, remember I'm new

 

[Victor Robert]

The old fashioned way

If all else fails, find a five gallon bucket, water hose, funnel, and start counting till you see the overflow through the breather opening.This will give you the 'actual' capacity as opposed to any 'spec' figure.

 

[Peggie Hall/Head Mistress]

You'll prob'ly have to measure it

If the tank is rectangular, it's easy: length x width x height in inches, divided by 231. If it's not rectangular you'll need some math skills to determine the number of cubic inches, then divide your answer by 231.That'll prob'ly give you some strange number like 26.364...or 16.86345...which means you have a tank with a useable capacity of 25 or 15 gallons. Why? Because you're measuring outside dimensions--so you have to deduct for wall thickness--and you can't use every last cubic inch of any tank without overflowing the tank out the vent. So the USEABLE capacity is anywhere from 5-10% less than the outside dimensions indicate.And btw, when shopping for a tank, the nominal size IS always the useable capacity.

 

[Peggie Hall/Head Mistress]

Actually, the "old fashioned" way is deceptive

Because the actual useable capacity is less by a gallon or even more, depending upon tank size (the smaller the tank, the less useable capacity) more than it takes to overflow the vent.