Building an FRP Holding Tank & System - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #11  
Old 03-11-2009
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Glad to help... Post photos of the installation when you're done and let us know how it goes.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Quick reply to this message Share with Facebook
  #12  
Old 03-11-2009
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Quote:
Originally Posted by Deadeye View Post
Just an addition here - it sounds like you've got the answers you're looking for.

Sealand makes a carbon filter that you plumb into the vent to kill odors. From the ones I've seen (smelled...), they are probably 75% effective vs no filter. No idea what they cost though - for us it's just another service item.
Wouldn't recommend it, as it will restrict airflow drastically, leading to a stinky holding tank, leading to needing the filter... good ventilation is a better, and cheaper solution in the long run.

Quote:
In powerboats up to about 45', the 10 gallon Sealand holding tank is pretty ubiquitous here - I don't think I've ever been asked to install a bigger one.

FWIW I plan to build my own as well from epoxy and ply and the inner coating of epoxy will probably be laced with graphite to make it harder and more 'slippery'. I'd caution against using epoxy with mat because mat requires styrene based resin to dissolve into a 'mush'. It will physically work to build up bulk, but it's pretty wasteful of epoxy IMHO.

I used to work for a shop that built sportfishers to about 30'. They used a solid 'glass tank made over a triangular plug mold that fit in the forepeak against the stem. I always wondered why they gelcoated the outside but not the inside of the tank...ewwww.....
Chopped Strand Mat is usually held together with a binder that dissolves in the styrene found in polyester/vinylester resins. However, there are now some "epoxy" friendly CSM mat materials available. I prefer to build thickness with cloth, because it is stronger than CSM is.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Quick reply to this message Share with Facebook
  #13  
Old 03-11-2009
Bender of Nails
 
Join Date: Jan 2009
Location: West Coast BC
Posts: 66
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 6
Deadeye is on a distinguished road
SD, you make a good point (as usual) about the use of vent filters. What I've seen in boats that come back in the fall that have seen use during the season though, is that the pumpout process draws air into the tank regularly enough that the filters seem to work pretty well. Most folks with newer boats seem to be pretty thorough about rinsing the tank after pumping out as well. Your post does remind me of a caveat I should have mentioned when suggesting the filter in the first place. The Sealand tanks we use have them already, but if I were fabricating a tank, I'd definitely add a tanksaver valve. If that filter ever jams up after overfilling the tank it probably won't clear itself...

I agree with you on building up with cloth. The whole point of epoxies are that they are stronger in laminate so you need less. In a conventional layup, mat is there primarily as a means to add density to the laminate, like filling the weave between structural cloth layers or reinforcing what will become outside corners within a female mold. To use the same technique with epoxy demonstrates an ignorance of the material's advantages.
JMHO of course.

Matt, you were asking about level indicators as well.
Again with the Sealand stuff (not a shill, it's just what I've used most), their Tankwatch system is pretty idiot-proof. It uses a series of coloured LEDs to give you an indication of the tank's level. Their are a couple things to watch when installing them, but they work pretty well once set up. If you leave a long enough pigtail of wire (or use disconnects), it can be used as an inspection port /cleanout as well.
The Heart TankTender system takes a bit on the part of the user and costs a fair bit more, but there's only a 1/8" air line going into the tank and the same guage can read multiple tanks containing different fluids. Oh, and it requires no electrical power to run...

Regarding your concerns about inspection plate fasteners penetrating the tanks: you could either add a plywood ring to the top of the tank, which is what it sounds like you were alluding to, or you could use anchor nuts (tee nuts) and glass right over the bottom of them.
__________________
"Verbosity leads to unclear inarticulate things"
~Dan Quayle
Reply With Quote Quick reply to this message Share with Facebook
  #14  
Old 12-14-2009
Junior Member
 
Join Date: Dec 2009
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
RobinAtkinson is on a distinguished road
Tank size calculation

Quote:
Originally Posted by matt2 View Post
So for 2 people, 15 days between pump outs would make it
5*2*15=150 litres? -> divide by 3.8 to get 40 Gallons

So since 1000 cubic cm is 1 litre, to get 150K cubic cm the rough dimensions would be 100cm*15cm*10cm, which is workable.

What size tanks do other boats have?
Are there downsides to excessive tanks size?

Are folks happy or unhappy with your tank size?
100cm*15cm*10cm is only 15,000 cubic cm (15 litres). If you want 150 litres (150,000 cubic cm) you will need to increase the volume by ten times.
Reply With Quote Quick reply to this message Share with Facebook
  #15  
Old 12-14-2009
roline's Avatar
Cal 9.2 SilverSwan
 
Join Date: Jul 2000
Location: East Tennessee
Posts: 272
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 15
roline is on a distinguished road
My boat had a 10 gallon Vetus bladder tank that developed odor issues, I replaced it with a custom fabbed tank just behind the head to keep the hose length to a minimum. It is a 15 gallon epoxy and fiberglass tank. 12 layers thick with a slick coat on the inside and 45 degree fillets on all internal corners. It takes up 1/2 of the hanging locker, but the stowage that was consumed by the bladder is now usable. A HDPE tank would have been prefered, but I could not find on that fit the space and the cost of a new mold was too much $$$.
Attached Thumbnails
Building an FRP Holding Tank & System-holding2.jpg  
__________________
Cal 9.2 #19 SilverSwan
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Siphoning holding tank Sixbrothers Gear & Maintenance 18 10-25-2008 12:08 AM
holding tank removal gwhar Gear & Maintenance 4 10-03-2008 09:39 AM
Holding tank or Type 1 MSD for Cal 39 costaricanwannabe Cal 4 03-13-2007 07:10 AM
Holding tank jeanneau 51 Myblueheaven Living Aboard 3 05-25-2006 05:06 PM
Sealand Holding Tank System sjacovino Gear & Maintenance 4 02-08-2001 03:48 PM


All times are GMT -4. The time now is 05:07 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.