I bought a 1994 2556 in January, and have finally gotten some time to work on fixing it up. They survey recommended replacing the plastic thru-hulls. So I tried tugging on one of the hoses under the cockpit to see how bad it was. The thru-hull snapped right off. Okay... glad that happened while I was testing and not on the water. I've ordered a bunch of new thru-hulls (chrome-plated bronze $$). But I figured this would be a good time to learn what the heck all these thru-hulls are for. Based on pictures I can find online, the thru-hulls seem to be fairly consistent for the 1991-1994 models.
Starting from the left of this picture of the starboard side:
[img size=800]http://solandri.com/misc/IMG_7005.jpg[/img]
S1 - plastic 3/4". I'm guessing the bilge? Hose goes underneath engine.
S2 - plastic 3/4". Hot water tank? Hose goes behind holding tank.
S3 - plastic 1". Holding tank vent.
S4 - plastic 3/4". Water tank? Hose goes behind holding tank.
S5 - metal. Fuel tank vent?
S6 - plastic 3/4". Head sink drain
S7 - metal. Another fuel tank vent?
S8 - (not in picture) plastic 1 3/8" (not exactly sure of size). Galley sink drain
S9 - (not in picture) plastic 3/4". Anchor locker drain.
Port side (not pictured - only one)
P1 - plastic 3/4". Leads to pump underneath the under-dinette berth. I'm guessing this is for a bilge amidships?
Does anyone know for sure what S1, S2, S4, and P1 are?
Are both S5 and S7 fuel tank vents?
How do you access the S8 thru-hull? I can see it's for the galley sink drain, but the cabinetry totally blocks my ability to reach or crawl in far enough to access it from the inside. Maybe remove the stove to access it from above?
Also, there are four cockpit drains which lead to scuppers on the transom. Should I consider replacing these too?
---------------
Edit: Summary of answers for future reference.
S1 - plastic 3/4". Bilge pump.
S2 - plastic 3/4". Fish locker drain (older models), flybridge drain (newer models).
S3 - plastic 1". Holding tank macerator.
S4 - plastic 3/4". Shower sump.
S5 - meta vent. Holding tank vent. (Recommended to replace with open marelon vent).
S6 - plastic 3/4". Head sink drain
S7 - metal vent. Fresh water tank vent.
S8 - plastic 1 1/2". Galley sink drain
S9 - (not in picture) plastic 3/4". Anchor locker drain.
Port side (not pictured - only one)
P1 - plastic 3/4". Bilge amidships, underneath cave.
Transom, port side (not pictured)
T1 - metal vent. Fuel tank vent.
Starting from the left of this picture of the starboard side:
[img size=800]http://solandri.com/misc/IMG_7005.jpg[/img]
S1 - plastic 3/4". I'm guessing the bilge? Hose goes underneath engine.
S2 - plastic 3/4". Hot water tank? Hose goes behind holding tank.
S3 - plastic 1". Holding tank vent.
S4 - plastic 3/4". Water tank? Hose goes behind holding tank.
S5 - metal. Fuel tank vent?
S6 - plastic 3/4". Head sink drain
S7 - metal. Another fuel tank vent?
S8 - (not in picture) plastic 1 3/8" (not exactly sure of size). Galley sink drain
S9 - (not in picture) plastic 3/4". Anchor locker drain.
Port side (not pictured - only one)
P1 - plastic 3/4". Leads to pump underneath the under-dinette berth. I'm guessing this is for a bilge amidships?
Does anyone know for sure what S1, S2, S4, and P1 are?
Are both S5 and S7 fuel tank vents?
How do you access the S8 thru-hull? I can see it's for the galley sink drain, but the cabinetry totally blocks my ability to reach or crawl in far enough to access it from the inside. Maybe remove the stove to access it from above?
Also, there are four cockpit drains which lead to scuppers on the transom. Should I consider replacing these too?
---------------
Edit: Summary of answers for future reference.
S1 - plastic 3/4". Bilge pump.
S2 - plastic 3/4". Fish locker drain (older models), flybridge drain (newer models).
S3 - plastic 1". Holding tank macerator.
S4 - plastic 3/4". Shower sump.
S5 - meta vent. Holding tank vent. (Recommended to replace with open marelon vent).
S6 - plastic 3/4". Head sink drain
S7 - metal vent. Fresh water tank vent.
S8 - plastic 1 1/2". Galley sink drain
S9 - (not in picture) plastic 3/4". Anchor locker drain.
Port side (not pictured - only one)
P1 - plastic 3/4". Bilge amidships, underneath cave.
Transom, port side (not pictured)
T1 - metal vent. Fuel tank vent.
Comment