Depth and fragility of hollow bilge

[Bev & Billy on Sta-sea-dawn]

Hey everyone...I have been off the site for a while...I just almost sunk my 365 with the sump opened on a hard grounding. I broke several of my own rules...I had sea tow and the tide in my favor if I had waited for either.......I was on a pivotal hard rock directly under the hollow bilge sump.  I let a gung-ho big power boater put a line on the boat and ignore my instructions.  Hence, proceeded to pull me in a circle twice like a top.  By the time I got the line off the hidden damaged was done.  The tide lighted and sea-tow nudge me off easily.  I notice the auto-bilge cycling but did not pay attention.  I had to get grand kids home by dark so I rushed off after minor stowing of gear.  I returned the next day to stow sails and check dock lines.  I did not hear the pump cycling about every 10 minutes.

Three days later when the starting battery that I had the auto pump connected to died.  My shore charger was on the house bank running my refrigeration. The water in the bilge got high enough to compromise the work I was doing on the galley sink.  I had the drain that goes to the cockpit drain disconnected.  The vessel was going down by the bow.  Quickly.  The marina manager notice the changing water line and stuck a huge bilge pimp in her and restored the water line.  After frantic trip to the marina, I cranked the Perkins and motored for 2 minutes to the lift and hauled the vessel.  Finding the gash in the layers of glass on the keel.  So you can sink you boat if you do not use common sense and due diligence.

So, after repairing the keel with many layers of glass and resin, adding 2 inches of alternating cloth and fiber glass resin in the bottom of the sump and a new bottom job, in the water with a dry sump. 
I had to drain the v-drive...transmission...motor oils.

My question is what was suggested in an old thread......filling the sump and sealing it at a smaller area for the sump pumps.  What material would the members suggest using to fill the compartment..does it need to be hydralic and sand...or regular cement. Is there any thing better?......Open to suggestions......heed this and do not do what I did........billy

[INCOMMUNICADO]

Billy,I have thought about this project in the past this is what I came up with.Clean the bottom of the sump very well then rough it up with sander or sand paper what ever you can get to it with.Then do the same to the remainder of the sump to the height you would like to raise it.Next use acetone to clean well.Next put two to three layers of fiberglass with epoxy resin with about a two inch overrun up all four sides.Let that cure then use  two inch thick foam cut to shape and pressed to your first layer of glass.Then repeat this process until you reach the height you desire.This may be a great deal of work but you will have a stronger light and permanent job.Only my two cents Allen

[Bev & Billy on Sta-sea-dawn]

what kind of foam...that will not react with the resin....?

[INCOMMUNICADO]

I think the correct foam to use is urethane.Allen

[Bev & Billy on Sta-sea-dawn]

I am going ot put that plan in motion...will up date topic...but it is going to be really hard getting down into the bilge

[slokat]

I would use pour foam, instead of pieces. Use the densest that you can find, will fill void perfectly, plus it bonds to fiberglass.

[Dale Tanski]

I would agree with Allen.  Here is a web site that has what you are looking for. 

http://www.fibreglast.com/product/2_Lb_Polyurethane_Mix_and_Pour_Foam_24_25/Foam?gclid=CLP7r_axnLICFQJp4AodBxAA3Q

Good luck...

Dale

[Bev & Billy on Sta-sea-dawn]

Tahnk you all...the pour foam sounds like the way to go....

[slokat]

You can sculpt it immediately after cure & then fiberglass over it.
Really easy to work with, hardest part is guessing volume, but easy to cut cured excess or pour in a little bit more.

[POG]

Use concrete, of course.  It is heavy, cheap, loves mating with fiberglass and adds stability as opposed to foam.  Clean well (I used a small grinder on a stick and MEK solvent) and put in some layers of glass first.  Fill with concrete to desired level (about 6" up - you still need a bilge to hold water in bad weather etc).    After the concrete has set and dried add about 5+ layers of glass over the concrete and up the sides.  If you go back to one of my postings dated March 1, 2011, about the Paragon clutch under the heading "Clutch slip - Prop pitch" , I posted some pictures of my own work on the bilge when the subject veered off sideways and away from the clutch.  If I did it again I would add some wire mesh in the concrete to make it much stronger and less prone to crumbling if grounded.

The fact that the hollow back tip of the keel is the deepest part of the boat under water makes it an Achilles heel and is not great, though the P 365 is not by any means the only boat with this less desirable construction.