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Bladder Type Holding Tank #6990
02/26/09 09:36 AM
02/26/09 09:36 AM
Joined: Apr 2003
Posts: 649
Marblehead, MA
dbows Offline OP
Senior Member
dbows  Offline OP
Senior Member
Joined: Apr 2003
Posts: 649
Marblehead, MA
Are bladder type holding tanks in the same spot as my rigid tank an acceptable alternative?

Thanks,
David


David Bows
Mallorca - Hull# 397
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Re: Bladder Type Holding Tank [Re: dbows] #7000
02/27/09 05:20 PM
02/27/09 05:20 PM
Joined: Mar 2003
Posts: 155
Annapolis, MD US
LChristy Offline
J/30 Class Measurer
LChristy  Offline
J/30 Class Measurer
Joined: Mar 2003
Posts: 155
Annapolis, MD US
David

Is your old tank defective? I will take this up with the rules committee and get back to you.
Larry Christy

Re: Bladder Type Holding Tank [Re: LChristy] #7018
03/02/09 07:31 PM
03/02/09 07:31 PM
Joined: Apr 2003
Posts: 649
Marblehead, MA
dbows Offline OP
Senior Member
dbows  Offline OP
Senior Member
Joined: Apr 2003
Posts: 649
Marblehead, MA
Defective? No just getting close to replacement time and was thinking the bladder would be a simpler install and probably a simpler thing to replace in the future.


David Bows
Mallorca - Hull# 397
~~~~~_/)~_/)~~~~_/)~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~
Re: Bladder Type Holding Tank [Re: dbows] #7083
03/10/09 03:54 PM
03/10/09 03:54 PM
Joined: Mar 2003
Posts: 155
Annapolis, MD US
LChristy Offline
J/30 Class Measurer
LChristy  Offline
J/30 Class Measurer
Joined: Mar 2003
Posts: 155
Annapolis, MD US
Ok give me a few days. Is there a deadline?

Re: Bladder Type Holding Tank [Re: LChristy] #7085
03/10/09 04:11 PM
03/10/09 04:11 PM
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Steve Buzbee Offline
Senior Member
Steve Buzbee  Offline
Senior Member
Joined: Apr 2004
Posts: 457
Highland Park, NJ
I would guess there might be a pretty significant weight difference-those plastic tanks are pretty heavy (nothing like excess weight in the pointy end!)


Steve Buzbee
Blue Meanie J/30 #485
Re: Bladder Type Holding Tank [Re: Steve Buzbee] #7086
03/10/09 04:15 PM
03/10/09 04:15 PM
Joined: Mar 2003
Posts: 155
Annapolis, MD US
LChristy Offline
J/30 Class Measurer
LChristy  Offline
J/30 Class Measurer
Joined: Mar 2003
Posts: 155
Annapolis, MD US
Dbows
What is the weight of your proposed bladder replacement?
Larry Christy

Re: Bladder Type Holding Tank [Re: Steve Buzbee] #7087
03/10/09 04:54 PM
03/10/09 04:54 PM
Joined: May 2007
Posts: 2,669
Portsmouth, RI
Rhapsody #348 Offline
Past J/30 Class President
Rhapsody #348  Offline
Past J/30 Class President
Joined: May 2007
Posts: 2,669
Portsmouth, RI
Actually, the empty polyethylene tanks are very light when empty (~15 pounds for 15 Gal tank). A bladder tank of similar capacity is about 6 pounds. Just look at the shipping weights in a Marine catalog for the ballpark comparison. The weight is in the stuff that fills it up! That's comparable to water or ~ 8.4 pounds per gallon.

I don't thing this is a weight issue from a class rules standpoint, but Larry will have to weigh in (pun intended...)

For my money, I want my stuff in a rigid walled polyethylene tank, not some bladder.

Re: Bladder Type Holding Tank [Re: Rhapsody #348] #7088
03/10/09 05:04 PM
03/10/09 05:04 PM
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Steve Buzbee Offline
Senior Member
Steve Buzbee  Offline
Senior Member
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Ahhh, but the weight differential increases as the tanks get bigger. A 25 gal polyethylene tank weighs in at 44 pounds (at least according to a Defender Industries listing) while a 25 gal bladder type is still about 6 pounds. I have no idea how big those holding tanks are, but I'm pretty sure they are more than 15 gallons. 36 extra pounds carried well forward is some very serious weight-recall the debate over the stove which is carried much closer to midship and weighs in at only ~12 pounds.

If replacement was permitted, I know I would consider swapping out for the lighter tank setup-I race a bunch of J-29's in PHRF, and weight in the ends is deadly.


Steve Buzbee
Blue Meanie J/30 #485
Re: Bladder Type Holding Tank [Re: Steve Buzbee] #7089
03/10/09 05:24 PM
03/10/09 05:24 PM
Joined: May 2007
Posts: 2,669
Portsmouth, RI
Rhapsody #348 Offline
Past J/30 Class President
Rhapsody #348  Offline
Past J/30 Class President
Joined: May 2007
Posts: 2,669
Portsmouth, RI
Steve - the holding tank is about 14 gallons - you can measure the dimensions and calculate the volume. Think of your 25 gallon analogy above. Cut a 55 gallon drum in half (take the smaller half) and that would be about the size of a tank you describe. No way that sucker fits in the v-berth!

We're talking about a 10 pound differential here on dry weight between a bladder tank and a poly tank. If you store a gallon of fresh water (or beer) that's pretty close to the weight differential. You'll get more mileage out of keeping the tank pumped dry.

Re: Bladder Type Holding Tank [Re: Rhapsody #348] #7090
03/10/09 05:41 PM
03/10/09 05:41 PM
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Steve Buzbee Offline
Senior Member
Steve Buzbee  Offline
Senior Member
Joined: Apr 2004
Posts: 457
Highland Park, NJ
No way you'll get me to store a couple of gallons of water forward of the head area! And I don't think I agree with your estimate of the size of the tank-I figure the tank is (at the top) about 3' wide aft, 1' wide forward, and about 3' long. That would be a top surface area of a little over 5 square feet. So conservatively, figure 5 cubic feet of volume (the tank is deeper than one foot, but tapers quite a bit). A gallon of water occupies .1337 cu. ft, so I would estimate 5/.1337=37 gallons.

I can't believe I just wasted so much time on...waste.


Steve Buzbee
Blue Meanie J/30 #485
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