T&T: Vented loop

[Steve Sipe]

I am working my way through an extensive bug list on our '99 Solo we 
just took delivery of.

One of the items high on the list was both heads, which reeked worse 
than any bar urinal I've ever worked on, and I'm a master plumber.

After thoroughly cooking them out with a quart of full strength muriatic 
acid, and rebuilding both, the reason for the condition has become 
apparent.  The intake has a vented loop between the thru-hull and the 
pump suction. Every time the pump runs, the vent on the loop opens, 
breaking the suction to the pump, and seriously limiting the amount of 
water for flushing. The heads never quite clear, and urinary salts have 
a perfect environment to build. There was a minimum of 1/8" buildup on 
the surfaces of the head. In my business, we refer to it as 
"pi**-crete." Nasty stuff.

Any one have a solution for the vented loop problem that will enable the 
heads to flush properly? For now, when we're aboard, I'm just putting a 
tab of masking tape on the loop vent inlet, the improvement is 
remarkable. Removal of the tape is on the checklist when we leave the boat.

The long range solution will be to replace both heads with freshwater 
flush Tecma or similar, not sure I want to spring for vacu-flush, the 
Tecma is rated pretty high, not sure if it's worth nearly double the 
cost to go to the vacu-flush.

Steve Sipe
43 Solo
Upper Chesapeake