Galley Sink drain assembly with plastic elbow flix

[Footloose]

Noah

I think the big improvement in how the drain runs is because I made a straight run down to the thru hull.  The way it was previously plumbed had a big loop in it much like an s-trap.  Not sure why it was there as there are no sewer gases to be had.  It is faster but not like at home.  For me it would not be worth the hassle to put in a larger thru hull.  I don't fill my sink more than a couple of inches and if it takes a couple of extra seconds to drain we let it happen.  Gravity is an amazing force. 

[Steve W10]

Noah,  personally I think reactivating an old thread and expanding on the exact same topic is the way to go.  It makes searching later (for other skippers with the same issue) that much easier; good one:).

If I recall I had to take off very little material to fit the new drains so I wouldn't worry about that too much; I understand your concern though.

My flow increased a little bit when upgrading just the hose, no thru-hull, but with my new set-up the biggest gain I had was making room for my microwave.  I think it's prudent to always add room when able, even if you're not going to use it right away.

Another benny was that the one sink didn't back up into the other anymore because when I plumbed mine I put the 90 deg connector further down.  Worked perfectly, got the flow happening right away and gave me even more space for the microwave; only takes about a foot more of hose.

Excuse the old 1/2" line there, it's all been redone...

Good luck whatever you decide.

Steve

[Stu Jackson]

Noah, I don't think it's the thru hull, it's the piping to it.  There are a few conclusions I can draw from the differences between my experiences and those of Fred, Steve, and Al Watson.

1.  The sink drains just fine with the existing thru hull.  If you're in a hurry, insert sailboat joke here.    Or do the macerator trick.    It's just NOT worth the expense to change the thru hull.  I don't think Al did either.  Dave & Fred are right.

2.  Steve's T fitting lower down would avoid some minor backup we get with ours.  This doesn't happen when there is a little water or just the faucet running.  It occurs when we empty a full pot of water.  So, we just put the plug in the other side.  The reason is his T is much lower than ours, good idea from Steve's experience.

3.  We had that foot pump for 15 years.  Anything that drains without that foot pump has been a blessing for us!  

4.  If you do this now, you'll never have to do it again, regardless of what drain you use, even if you're Methuselah.    Don't worry about future generations, really...

5.  Double clamp your hoses so they don't fall off, and use the time down under there by replacing all your plumbing hoses while you're at it.

Bar sink or Ambassador?   Your boat, your choice.  

[Noah]

Question: my 3/4 thruhull is Marelon.  I am running into a bit of a brain bend trying to find an "acceptable" 1-inch hose barb fitting that attaches to the thruhull. the P.O. used PVC 90 degree elbow to hose. PVC is technically a no-no at the thruhull. I can't find a Marelon 3/4 thread to 1-inch barb fitting. Bronze fittings have tapered threads not straight like Marelon so not a good match. Best I could find is nylon. Better than PVC, but still not marine surveyor-approved. Ideas?
Also, Does anyone have Bronze thruhulls on their boat?

[KWKloeber]

Question: my 3/4 thruhull is Marelon.  I am running into a bit of a brain bend trying to find an "acceptable" 1-inch hose barb fitting that attaches to the thruhull. the P.O. used PVC 90 degree elbow to hose. PVC is technically a no-no at the thruhull. I can't find a Marelon 3/4 thread to 1-inch barb fitting. Bronze fittings have tapered threads not straight like Marelon so not a good match. Best I could find is nylon. Better than PVC, but still not marine surveyor-approved. Ideas?
Also, Does anyone have Bronze thruhulls on their boat?

Noah,

I had the same situation on the 30.  I ended up going with PVC off the drain basket (somehow - it was 15 yrs ago!) and then to 3/4" hose, since the hull is 3/4 anyway.  Maybe that would work on the 34?   I thought there was 3/4" barbed drain available also?

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Cheers,
Ken

[Ron Hill]

Ken & Noah : FYI, the sink drain thru hulls (both Galley & Head) in my 1988 C34 will accommodate a 1" hose.

A thought

[Noah]

Not mine. The thru-hull(s) for galley sink, head drain and engine intake, are all Marelon 3/4-in. They don't make a Marelon 3/4 in. male thread to 1 in. hose barb, that I can find. I found one in Nylon and in bronze, only. Forespar's website says one can screw bronze tapered-thread fittings into parallel-thread Marlelon valves, using "thread compound and being careful not to cross thread" -- which risks wrecking my existing thru-hull. That is why I wondered about up-sizing to 1in. bronze or 1in. Marlelon thru-hull at next hull out.

[KWKloeber]

Not mine. The thru-hull(s) for galley sink, head drain and engine intake, are all Marelon 3/4-in. They don't make a Marelon 3/4 in. male thread to 1 in. hose barb, that I can find. I found one in Nylon and in bronze, only. Forespar's website says one can screw bronze tapered-thread fittings into parallel-thread Marlelon valves, using "thread compound and being careful not to cross thread" -- which risks wrecking my existing thru-hull. That is why I wondered about up-sizing to 1in. bronze or 1in. Marlelon thru-hull at next hull out.

Noah, if you are just a little careful you won't cross thread the female valve threads. 

The difference in the threads is that parallel threads do not tighten and seal by "interference" (they use a sealing gasket or O-ring.)  So it's a little more difficult to seal the "valley" of thread spiral (which is present no matter whether it's parallel or tapered thread -- only "dry seal" NPT threads have an interference fit on the thread "peak" and "valley", so don't they need pipe dope or teflon to seal the cavity created -- which is why "dry-seal" thread is typically used on engine gauge senders.)

Anyway that said -- I have a glass-reinforced-polypropylene (eg, generic "Forespar Marleon") 3/4" tapered MNTP x 1" straight hose barb that you are welcome to try threading into the valve -- the plastic won't cut the female thread on the valve and cross thread like sharp bronze thread would.  Just PM me your address and I can drop it in the mail it to you tomorrow.

Ken

[Stu Jackson]

Noah, I would strongly discourage the use of "metal" thru hulls on our boats.  Why mix & match?  Somehow it seems unnecessary simply because of a connector.  Perhaps I am missing something, but the previous writeups have all explained how the connectors are made.  I must admit, not being near our boat to be able to check since I'm now up in Canada visiting my father-in-law, that I simply used the existing hose connection to my thru hull.  Good luck.

[Fred Koehlmann]

I'd have to agree with Stu. Keep the existing thru-hull, especially if its working just fine (i.e. not leaking). I also just connected to the existing hose. I did cut it down for my new drains but I made sure that my connection was still above the static water line.(See the black marker line between the loop hose for the shower and fridge pump-out line) The double clamps connect the hose to about an inch or two above that line.

On a slightly different note, none of our thru-hulls (on Dolphina) are metal. My understanding is that if we had metal fittings, we would also need to ground them or something. I'm not remembering the term right now (maybe "bonding").

[Stu Jackson]

On a slightly different note, none of our thru-hulls (on Dolphina) are metal. My understanding is that if we had metal fittings, we would also need to ground them or something. I'm not remembering the term right now (maybe "bonding").

Yes, Fred, that's what it's called.  Here's the "classic" discussion about this from Stan Honey.  Who is also the guy who brought us not only the yellow line markers in football games on TV, but the tremendous TV coverage of the Americas Cup.

http://www.westmarine.com/WestAdvisor/Marine-Grounding-Systems

Noah, "Don't mess with success?"    Marelon is just fine.  All my thru hulls work just fine, only had to replace the big head valve many years ago.  Also suggest folks read the Critical Upgrades, there's one there for the newer Marelon valve construction details.

[Footloose]

Fred

How did you get the drawer to fit after you installation with schedule 40 pipe?  I tried to do it that way but ran out of head room for the drawer.

[Fred Koehlmann]

@Footloose,

I did have to cut out the corner a bit more, but that was more because I made the hose go down more directly into the back corner. The shelf goes in and out on a diagonal. I raise the port side and then out she comes. 

[Fred Koehlmann]

@Footloose,
Sorry, I just realized that you mentioned "Drawer" and not "Shelf". Silly me. 
Dolphina is a 2002 MkII and we only have doors in front of the sink. the drawers are at the starboard side of the galley. The white wall beside the drain clean-out is the cabinet box for the drawers.
Cheers, Fred.

[Noah]

My boat is a Mk I, so no room for big black pipe above drawer (I believe?)  As far as just using EXISTING fitting on my thru-hull... The PO had remove whatever "proper or original fitting" was there and installed a Gray PVC elbow contraption to a non-barbed 1in. PVC pipe that had 1in. hose, single clamped on. None of that is acceptable (to me) to have on my boat, especially below the waterline--hence the search for the elusive 3/4 pipe to 1in. hose barb in Marlelon. Ken (thanks!) sent me a suitable generic one that should work and I will install it  this weekend. I am still trying to decide whether to use the Ambassador drains, which will be easier--plumbing-wise, except for having to grind away the holes in my sink with a Dremel to make them fit. Or, use the bar sink drains, which fit, but will require some PVC work and reducers to connect the 1in. hose. I kind of like the bar sink drain idea, as the bigger PVC pipe will hold more water so should drain the sink faster?? Decisions, decisions...