# Transom thru hull? Plastic/Polyurethane vs Bronze fittings?



## heman (Dec 7, 2010)

First off, I have a 14 ft Duroboat (aluminum boat of course).
i'm working on a live well setup and i've decided to go ahead and drill a hole in the transom area for my livewell pump

I have one of these.. 






i also have of one these pumps I am going to use.






So my questions.
1) Is this polyurethane/plastic through hull/transom piece ok to use? Or should I be using one of those bronze fittings (just read about these through my internet research, and I assume it's for the bigger boats)?
2) The pump says it can be mounted through the transom, I dont think I wnt to do that in case it breaks or what not, your thoughts?

My plan was to drill the hole and use the plastic through hull/transom fitting and seal with the 3M stuff everyone's mentioned.
Then i'd like to have a ball valve (from home depot) sit between the fitting and the pump. Then then pump wld run to the livewell (igloo cooler) sitting in the front of the boat.

thanks for any advice/recommendations.


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## LonLB (Dec 7, 2010)

Most factory boats using those pumps mount thru the transom. I've installed quite a few on Fiberglass boats. I would go that route, just to simplify things.

Drill your hole in the transom, below the water line. Use a good dose of 5200 sealant, slide it thru the hold from the inside, tighten down the nut, and your almost done.

Trim off all but 3/4" of the threaded portion, and then screw on a strainer. They make them just for livewell pumps.



Technically you could use the plastic fitting about, but by doing so you still have a hole in your boat, AND you introduce two more places for leaks at the hose clamps from that fitting to the pump.

And you could suck in some junk into your pump and cause it to wear out or even jam the impeller.


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## 89Suburban (Dec 7, 2010)

I like the ball valve idea, but you still want to make a strainer for the intake.


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## heman (Dec 7, 2010)

thanks guys.. i'll def pick up a strainer today from BPS.. 

so the plastic/polyurethane fitting is ok to use though? I dont have to upgrade to brass?


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## 89Suburban (Dec 7, 2010)

Plastic is the way I would go. :wink: You got to put a thru hull for the drain in too don't ya??


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## LonLB (Dec 7, 2010)

Sometimes brass fittings are used, but I've only seen them mounted under the boat....Usually for a water pickup for an A/C unit.


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## heman (Dec 7, 2010)

89Suburban said:


> Plastic is the way I would go. :wink: You got to put a thru hull for the drain in too don't ya??



ok cool.. thanks guys.. i'll keep the plastic one. 

I was trying to debate whether I want to have the overflow/drain run to the back as well or run it off the side. 
I think the top of the cooler sits even with the bench seating.






and it sits near the front half of the boat.. like this






from my reading through the forums.. if i put the overflow coming out a couple inches below the top of the cooler and run a hose to the back.. I shld be ok?


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## 89Suburban (Dec 7, 2010)

Yeah, overflow is good for self leveling in the tank and recirculating fresh water into the livewell. You can also ball valve the system to circulate tank water or with fresh outside water. My boat has a 3 way tee with a ball valve to do just that. 

Theoretically, you can use a three way ball valve as an intake, a recirculator, and a tank drain all in one and using only one thru hull port if you plumb it right. But the overflow drian must have a separate drain for itself in the transom or side of the boat. You also might want to screen your drains inside the livewell tank so no bait fish or fish parts or dirt get clogged in the drain lines on the way back out. 

You ever throw a few smallmouths in a live well and see the stuff they cough up? :shock:


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## perchin (Dec 8, 2010)

You should not need the thru-hull barb for the pump...the pump itself mounts thru-hull. :wink: Now I did use the thru-hull barb for my bail line though...here are a few photos of my set-up... I didn't want to deal with the over-flow headache, and came up with a much simpler way.




I came up with this style of replenishing the fresh water from time to time. I'll just shut off the areator and turn on the bailer, while running the feed pump to recirculate some fresh water. Also this allows me to drain the livewell when done fishing.


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## LonLB (Dec 8, 2010)

I like the valve setup, keeps from needing a bailing pump, and a aerator pump.....


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## 89Suburban (Dec 8, 2010)

Nice setup perchin.


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## perchin (Dec 10, 2010)

89Suburban said:


> Nice setup perchin.



Thanks :mrgreen:


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## bassboy1 (Dec 10, 2010)

I know it has been mentioned that plastic is the answer, but the reason why is that bronze is primarily made up of copper and tin. Copper is the reason we say not to use pressure treated wood in an aluminum boat (dissimilar metals corrosion). You definitely don't want a bronze fitting touching an aluminum hull.


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## heman (Dec 11, 2010)

bassboy1 said:


> I know it has been mentioned that plastic is the answer, but the reason why is that bronze is primarily made up of copper and tin. Copper is the reason we say not to use pressure treated wood in an aluminum boat (dissimilar metals corrosion). You definitely don't want a bronze fitting touching an aluminum hull.



thanks.. this was more what I was looking for.. a why to the question. 

Although I love how we can get off tangent and the ideas just flourish. Thanks to everyone. Will probably be doing some drilling on my boat this wknd, gotta find the right size hole saw bit.


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## tripleup05 (Jan 4, 2011)

Perchin, I plan on doing my livewell very similar to yours. Who makes those pumps, how many GPH are they, and how much $? 

Thanks!


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## perchin (Jan 4, 2011)

tripleup05 said:


> Perchin, I plan on doing my livewell very similar to yours. Who makes those pumps, how many GPH are they, and how much $?
> 
> Thanks!



The thru-hull pump is an "Attwood Tsunami 800GPH Thru-hull" and cost me $43.00. (came with the screen). The pump inside the cooler (livewell) is whatever brand Walmart had at the time. It only cost me like $12.99 and is a 600GPH pump.

Hope this helps sir. :wink:


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## tripleup05 (Jan 4, 2011)

perchin said:


> tripleup05 said:
> 
> 
> > Perchin, I plan on doing my livewell very similar to yours. Who makes those pumps, how many GPH are they, and how much $?
> ...



It does! Thanks you!


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## tripleup05 (Jan 4, 2011)

Sorry to hijack the thread, but hopefully some others will find this info useful...

Is there any need to use hard PVC, or can flexible tubing be used for the entire drain and fill lines. It looks like Perchin used a combo of flexible tubing and PVC.


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## danmyersmn (Jan 4, 2011)

tripleup05 said:


> Sorry to hijack the thread, but hopefully some others will find this info useful...
> 
> Is there any need to use hard PVC, or can flexible tubing be used for the entire drain and fill lines. It looks like Perchin used a combo of flexible tubing and PVC.



Flexible tubing can be used for all of the lines if you like. That's how many rigs are setup. I used PVC under my floor with flexible tubing at each end.


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## msumoose (Jan 4, 2011)

Use the plastic. The brass can cause galvanic corrosion much like the copper in treated wood. Unless you want to add a grounding system and a magnesium anode... :shock:


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## mmf (Jan 4, 2011)

never use bronze or copper against an aluminum hull, will react and corrode!. Use NYLON thru the hull fittings. If you run a livewell pump with it's plastic (not nylon) tube thru the hull you take a chance of something sliding and hitting the pump and braking it off or just a freak accident, and you will take on water fast!. The nylon fittings will not dry rot like the plastic ones will either. Me, myself, will never one of those livewell pumps thru my hull, too many bad experiences.


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