Holding Tank Installation - SailNet Community

   Search Sailnet:

 forums  store  

Quick Menu
Boat Reviews  
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Hatches and Portlights
Interior And Galley
Marine Electronics
Other Items
Plumbing and Pumps
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here

Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
Old 03-16-2012
QLite's Avatar
Junior Member
Join Date: Dec 2009
Location: Chicago area
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
QLite is on a distinguished road
Question Holding Tank Installation

I'm installing a 25 gal roto-molded Ronco holding tank in the v-berth area, just forward of the aft most bulkhead. The tank has been made to somewhat follow the shape of the hull. So as to evenly support the 200 or so possible pounds that the tank may weigh when full, I'm thinking of placing the tank where I want it and then spraying the 1"+ Great Stuff expanding closed cell foam all around the underside of the tank. Additionally, so as to not 'glue' the tank and foam to the hull I'm thinking of first laying down some mylar (aka 6 mil visquene) or large 30 gal style trash bags so as to create a mold release. I'd also tape this same plastic to the tank. After the foam has cured, I hope to lift out the tank and remove the foam plug mold and the hull lined plastic. Then I'll cut away where I need to for my outlet hose in the mold plug and just set the mold plug back into the hull. Then I'd install the tank with an aluminum flat bar bracket holding the tank to the bulkhead.

I've test sprayed some of the Great Stuff onto different plastics including a piece of wood coated with PVA on a part and vaseline on another part. The Great Stuff released pretty easily from the mylar and garbage bag the best, next best was the vaseline (will make a mess).

What does everyone think of this idea? If / when, some water or effluent gets in and or around the foam will it cause Mould and will I be able to clean it up? It seems to me, that having a uniform light weight mold is far better than some marine ply or heavy fiberglass matting. I expect the thickest (depth) of required foam would be about 4-5".

Thanks in advance for any suggestions or constructive thoughts.

Attached is a rendering of the hull section and tank used for fitting purposes.
Attached Thumbnails
Holding Tank Installation-holdingtank-v_berth.jpg  
Reply With Quote Share with Facebook
Old 03-16-2012
Lake Superior Sailor's Avatar
Senior Member
Join Date: Aug 2011
Location: Eagle River Wi.
Posts: 908
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 4
Lake Superior Sailor is on a distinguished road
Re: Holding Tank Installation

I think it would work well, remember to not block water way, by causing dam with foam..Dale
Reluctant Lady
Cal 28, 1967
Lake Superior
Where God got it done!
Reply With Quote Share with Facebook
Old 03-16-2012
Faster's Avatar
Just another Moderator
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 14,704
Thanks: 69
Thanked 197 Times in 189 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Re: Holding Tank Installation

Dale's got a good point.. keep the drainage clear. (maybe cut a lenght of PVC pipe in half lengthwise and put that down on the hull to create the channel - you could even epoxy it in place and leave it there to ensure that no moisture gets into the foam)

I like the idea.. one of our last boats had tanks anchored with foam, more or less as you describe, but didn't take the care that you're talking about and, as that stuff is wont to do, it expanded well beyond where it was needed taking up otherwise useful space. Spent quite a bit of time cutting a lot of it away, not an easy or tidy task.

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Reply With Quote Share with Facebook

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
O/I 41 holding tank tatoloco Morgan 4 02-01-2011 11:50 AM
Convert existing steel freshwater tank to blackwater holding tank? patrickstickler General Discussion (sailing related) 7 09-24-2010 07:55 PM
Flexible holding tank installation sarafinadh Gear & Maintenance 29 10-17-2009 07:46 PM
Dye in holding tank davidpm Gear & Maintenance 5 09-27-2009 12:05 PM
Holding Tank leterip Announcements and Suggestions Box 2 12-23-2008 10:03 AM

All times are GMT -4. The time now is 02:01 PM.

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.