livewell/bilge pump question

Hey guys. I am planning on doing my livewell similar to Perchin's. I like the idea of pumping the water out instead of depending on an overflow system. I have included a quick sketch of my design (sorry, i truly am terrible at Paint). The only problem is that I just found in my pump instructions not to have any point of the plumbing below the pump. From Attwood's website:

"HOSE CONNECTION INSTRUCTIONS
IMPORTANT: To prevent airlock, hose must rise continually upward
to the thru-hull connector with no dips or sharp bends. Support hose
if necessary."
https://www.attwoodmarine.com/userfiles/store/product/files/990/69390-a-tsunami-bilge-eng.pdf

Do you think that running the plumbing below the pump would be an issue, like the instructions say? I really would like everything to be below the floor, and then come back out of the floor right at the stern and run up it to a thru-hull.

Nobody?

Well, since the manufacturer states that it's not a good idea, it would seem they would have good reason for doing so. I guess your best bet would be to test it out in a way that would simulate what you want, but is easily changed if it doesn't work out.

Could you run the plumbing to the side of the boat instead of out the back? Or maybe instead of up, down, then back up again, could you have your connections at the bottom of the livewell? At least this would be closer to suggested by the manufacturer.

Skidz

Skidz said:

Well, since the manufacturer states that it's not a good idea, it would seem they would have good reason for doing so. I guess your best bet would be to test it out in a way that would simulate what you want, but is easily changed if it doesn't work out.

Skidz

Click to expand...

Yea, I had the same thoughts.

You gave me an idea though...Instead of sitting the livewell on the floor, I could cut a hole out of the floor for the livewell to actually sit in it, directly on top of the hull. That way the downward slope would be little, if any at all. As far as running the plumbing out the side, that would be ok, except the livewell will be a stand alone unit in the middle of the boat. I was hoping to have walking space around all four sides of it. I definately don't want any exposed plumbing running across the floor! I think sitting the livewell below the floor might just work though.

Im going to cut a hole in my floor & set my livewell in it. Then im going to use the cooler drain to attach my livewell fill hose to.

Ok, so I never did find out if the air-lock of doom scenario would take place if I dropped the plumbing below the pump. But, as Skidz said, there was probably a reason the manufacturer said not to do it. So I put a little brain power into the dilema and came up with this.

It's a little different than my previous plan. Basically, the plumbing will run on top of the floor for about two feet between my livewell and rear deck. I didn't originally want the pipes on top of the floor for aesthetic and safety reasons, but I am going to frame a small housing around the pipes to protect and hide them. I'm happy with the compromise.

However, this means I am going to plumb through the cooler near the bottom, instead of above the water like as originally planned. How in the heck do I do it? I see double ended thru-hull fitting listed for sale online, but they only are made for up to 1-1/8" hulls. My cooler was apparently designed to keep human organs viable in the Saraha Desert for months at a time, sans ice refills. It is about 2 1/2" thick. So how do I do it?

why cant you mount the thru hull pump closer to the bottom of the boat? This way it would be a straight shot across the bottom, and then up to the top of the cooler, back above the waterline. I believe you will have problems if you dont keep the fill tube above the waterline.

perchin said:

why cant you mount the thru hull pump closer to the bottom of the boat? This way it would be a straight shot across the bottom, and then up to the top of the cooler, back above the waterline. I believe you will have problems if you dont keep the fill tube above the waterline.

Click to expand...

Perchin, I think one of us is misunderstanding the other. Did you think I was drawing the fill system? My drawing is of the bail/recirculator system. The only difference between my planned system and yours is that I am running the bail line out of the transom, not the side.

I didn't draw the thru-hull pump and fill lines to keep the drawing simpler.

Haha :LOL2: ...yeah I misunderstood.

My bail line is above the waterline and aldo above the pump, and I have had no problems.

perchin said:

Haha :LOL2: ...yeah I misunderstood.

My bail line is above the waterline and aldo above the pump, and I have had no problems.

Click to expand...

Thought so :wink: I like how your bail line is short and sweet out the side of the boat, but I want to be able to walk around the sides of my livewell without having to step over anything.

Anybody know how to make a water proof thru-hull connection through a 2" thick cooler? Maybe its as simple as drilling a hole, coating the inside of the hole in 5200, pushing the PVC through, and then adding more 5200 around the PVC where it goes into the cooler.

Bump.

"Anybody know how to make a water proof thru-hull connection through a 2" thick cooler? Maybe its as simple as drilling a hole, coating the inside of the hole in 5200, pushing the PVC through, and then adding more 5200 around the PVC where it goes into the cooler."

Anybody?

Yep, that would work.

I think that would work also. Would you be using the thru hull connector that came with the pump or something different? If it was me, I would go to lowes or HD and get the size you need in a slip joint style. When you coat the inside flange with 5200, have your pvc glue ready and another flange for the outside. Get some all thread and a couple of nuts and washers, and tighten them up through the hole, letting the pvc glue and the 5200 set a good tight bond. Then you can use the outside flange to reduce or expand the remaining plumbing any way you want.