thru-hulls, pumps, and assorted bilge stuff

[CamB25]

I have my eternal project back in the driveway for the 2016 building season. I've been working in the bilge/transom area designing plumbing layout, bilge pump locations, etc. before I permanently mount the "transom module" Looking for your thoughts on a few issues:

Bilge pumps:
I bought 2 1500 gph Rule pumps with separate switches. I plan to mount one on the keel line an inch or two forward of the transom. The other will be a backup pump mounted higher than the primary pump, probably just above the height of the primary on the deadrise of the hull on an angled pad. Each pump will discharge above the water line separately on either hull side. There will be a 12" rise over water line in the discharge hoses before dropping back down to the thru-hulls which are a few inches above water line. 1 1/8" hose. The entire boat drains to the aft bilge. There are no water traps anywhere. Sound reasonable?

Live well and washdown pumps:
I built a 20 gal live well in the "transom module" and I want to have a raw water washdown somewhere on the boat. Not sure how to plumb these. Questions:
- 1 thru-hull with a "T" to each pump?
- thru-hull through the transom or running surface of the hull? small scoop?
- what size?
- Bronze?
- strainer/filter before the "T"?
- any recommendations on brands? Groco? Buck Algonquin?

All input appreciated! thanks!

Cam

[Navatech]

Depending on the hose you use (the el-cheapo corrugated is the worst, the smooth sanitation like hose is the best), the total length of the hose, the number of bends in the hose and the head (height difference between the pump's inlet and the discharge overboard) you might be getting only 4-5 hundred gallon per hour from those pumps... OK for dewatering of nuisance water but not that much if you have an emergency (e.g. a burst engine intake hose)...

Personally I would prefer a single through hull for every user... Having said that, a salt water wash down can be easily combined with a live well... In fact, they can even use the same pump... I would definitely put in a strainer and use bronze for the through hull...

[scot]

my eternal project

My boat resembles that remark :-)
Keep poking away at it, it will float one day. Being in the south, I have a 3 month head start on the "building season". Hopefully one of these days this time of year will be boating season.

Keep the bilge pump thru hull as low as you feel comfortable. The additional head of a high mounted thru hull takes its toll on pump capacity. As stated, use good hose and keep the bends to a minimum and the bend radius long. Avoid sagging discharge hoses, the sage will always hold water and grow stuff.

[Tony Meola]

Cam

If Lilco jumps in he will tell you to have at least two 1500 or bigger, one stern one forward. He would also tell you to put a 500 GPH pump in the stern mounted as low as possible to take care of the nuisance water and then to mount the 1500 higher than the 500 for that unexpected moment when you need it.

In fact Bob will tell you to use 3 1500 GPH and then to have a crash pump set up.

[mike ohlstein]

In fact Bob will tell you to use 3 1500 GPH and then to have a crash pump set up.

That's what I have.... And 25 feet of hose under the dinette for the crash valves, so that I can reach any corner of the boat. I actually have three way valves on both engines and the generator. They make winterizing a breeze.

[Joseph Fikentscher]

I have two in the stern and one forward. The two in the stern work off one switch so that either float will turn on both pumps. The forward is on a separate switch. I test the forward pump regularly since the bilge water never gets up that far. Rewiring this year so new switches are in order.

[CamB25]

You guys are killin' me! Who names their boat "Roly Poly" !!! Engine intakes? Not me! Outboard power, man! Egg beaters rule!

I'll take some pics if it stops raining...

[Yannis]

There will be a 12" rise over water line in the discharge hoses before dropping back down to the thru-hulls which are a few inches above water line.

If I understand you want to make a siphon on the discharge hose?
This is necessary for a toilet bowl discharge; for a bilge, though,I don't think it's necessary. What do others think about this?

[CamB25]

For the bilge pumps I used Pascoes recommendations
http://www.yachtsurvey.com/bilge_pumps.htm

The thru hull discharges are not very high off the water line. The riser loop is intended to prevent backflow.

I am using hose with a smooth inner wall to reduce resistance

Happy Friday!

[scot]

Who names their boat "Roly Poly"

It's a Texas thing and also an insider family joke. You have to know a little Bob Wills to get that one. :-)

[CamB25]

Wow! That's an old timey tune. Inspirational with a couple of edits:

Roly Poly
Daddys little Bertie
Bet she's gonna run real nice some day!!

YeeeeHaw!

[scot]

hahaha you got it.

"Daddy's little fattie" applies well to a 10ft wide 25 ft boat. I tormented my daughters growing up with Bob Wills music. Always played it on road trips. Now I have two 30 year old daughters that can sing practically every verse of all of his music lol. They both got a huge kick out of me naming the boat "Roly Poly". If the kids like it, the wife likes and it has sentimental value in the family, we have a winner!

For those unfamiliar with the original "Texas Swing"... enjoy> https://www.youtube.com/watch?v=f_9Vw3XKe54

[bob lico]

number one all bilge pumps must exit as high as possible like just under gunnel,must be 316-SS. does not matter stern drive,inboard,and outboard actually taught by outboard people; jupiter,everglades,regulator. lets sit back and think not copy other boats . why in Gods name would i constantly recycyle a 3700 GPH bilge pump for 1/32" rise in rain water??????????? so we find the lowest point under cockpit floor (under stairs to companion way) and place 500gph pump in the angle of the 24 degree dead rise on the very bottom of the lowest point in boat .this will do 90% of your bilge water removal. next mount a 1500gph pump on pvc board 1" higher,next place on bottom of at transom at stern bilge two 3700 gph pumps on on bilge vee and the other 4" higher. backing down on tuna,swordfish and you put one a wave over the stern. i will not get into doomsday water removal but as Mike indicates you may need this to get everybody in life raft and eject E-perp,sent may day and give exact location to those on radio.my 5 pumps (one forward on other side of watertite main bulkhead) are separated on isolated 3 bank battery system plus another 110volt pump off generator. to the day i die i will not forget floundering in the Pacific ocean after a race boat cat. came apart at 100mph on a practice run with nobody around except those "big fish with big fins and teeth-------------amen