Filling the bilge sump on E-29

[maggie-k]

Hi all . It's noted the deep sump on the aft of the keel on E-29s is a weak point . I am looking at filling mine and am looking at options in material. Foam was the first thought but then I considered cement as it is used in a lot of keels with an epoxy cap on it . The slight added ballast wouldnt hurt either. What is your opinion.

Eric

 

[Randy Rutledge]

I have the same concerns. The thread on the E27 Achilles keel has much discussion on this subject, I am left with the opinion that if the keel is compromised in the area of the encased lead ballast that there would be a path through that area for water to enter the boat. It would appear that the lead is lowered and bonded into the forward keel compartment and the deep sump is a separate compartment on the back of the ballast section. If you are to eliminate the problem the lead would have to be sealed to the hull at the top of that compartment and then deal with the rear compartment. I think leaving the rear compartment as a deep sump but walling it off near the top with a shallow sump that has a threaded fitting for a plug to be used in case of a leak in the lower compartment.
I plan to look at this, this weekend while hanging out on the boat. Attached are rough drawings of what I have in mind. The shallow sump with an auto pump would evacuate the icebox drainage and the prop shaft leakage. The hole would vent the deep sump and allow for it to catch water if the auto pump failed. I like the deep sump as a safety keeping the sole dry, don’t like the ice box gunk in the deep bilge.

What do you think and will this work? Any ideas on sealing the top of the lead ballast area to the hull???

 

[Randy Rutledge]

I will try again to attach the drawings

 

[Randy Rutledge]

round three

 

[maggie-k]

Hi Randy my thoughts are similar but I am looking at filling the deep sump with cement (commonly used for balast) but leaving an area in the cement for a shallow sump . The cement would be covered with Fibreglass Cloth and epoxy then painted . This should eliminate any pathwway for water into the boat from the keel. I was considering foam but it has no real advantage over cement . Cement does not require a clean dry environment to set and that deep sump would be very difficult to clean and dry perfectly. Cement would also give the thin glass at the aft of the keel a solid support thus increasing it's resistance to impact

 

[Art Mullinax]

Where's mine

My 71 E29 doesn't have this sump (hole) you folks are referring to? Under the ladder is an access panel, under this panel is an area for bilge pump to sit. No deep sump unless the PO filled it in (which I doubt).
Also, If you decide to use cement, try the liquid latex additive used with tile grout. It's waterproof and dries harder than regular cement and water...

 

[maggie-k]

Art that's interesting that you don't have the sump perhaps it's just later years. Under the access I also have a bilge pump the sump is about a foot aft of that . Thanks for the tip on the additive
Eric

 

[Sean Engle]

Questions...

A few questions on this topic....

• If you use cement - how much will it require to fill?
• Given that amount of cement, what about the heat generated when it's curing - what is the potiental for damage to the existing glass/lead structure?
• Will the existing sump walls be able to bond (for lack of a better term) with the cement - or will you need to consider somekind of a mechanical connector (thinking of tiny reinforcing rods, somehow joined to the sump walls)?
• What will the added weight do to the way the boat sits in the water, and behaves under sail?
• What about air pockets that might develop in the cement - will you vibrate them out?

You might want to enlist the opinions of someone who works with ferro-cement construction to deal with some of this...

//sse

 

[maggie-k]

Hi Sean the answers to your questions are
About 40 pounds of cement.
Cement does not heat appreciably when setting. Not an issue.
Using a thin mix bonding cement you will get some adhesion to the walls however this will be exceeded by a mechanical lock that will be formed by the cement flowing into irregularities. In other words when it sets it's in to stay.
The weight increase will be around 50 pounds. I have sailed with the sump full of water when the pump in the sump would plug with no noticable effect on trim or otherwise. That would be about the same weight.
Air pockets ? who cares . They will be minimal as a thin mix would be used and it would have to be flowed in , in small quantities due to the limited access.
Water does not weaken cement in fact it sets harder when wet. It does not have to "dry out"

I was in touch with a boat builder about this and he sees no problems in proceeding with the project . He informed me that many boats with integral keels have cement poured around the lead balast then are capped off with glass. Bruce Roberts designs and Spencer yachts did this I am told.

I intend to cover the works with cloth and epoxy.

I will keep a photo log of the project if I go ahead with it

Eric

 

[BrianP]

I own the 27 with the bottom of the sump knocked out (hang loose ). With the completion of the repair being completed within the next 3 weeks I have given great thought to this. I have come up with a bilge solution on this if a major hit was to ever occur again. I plan on leaving the sump wich the bottom is now all grp up from bottom about 8 inches. I have taken cardboard to cut templates for creating a sealed hatch over sump. what I have planned is to create a cover with a sealed lid to the top but to leave a 800 gph bilge in the bottom but still accessable with stainless steel latches on cover with a sealed fittinging in the cover for 3/4 hose from bilge. I will also have a 500 gph and 1500 gph just forward of sump to handle ice box and other... The sealed cover is actually not to hard to do with a good glass man to set it in place. If this is the route I go I will post pics. -----Brian

 

[Sean Engle]

Sounds interesting Eric - I look forward to seeing the pictures! I've been thinking about pouring a rat slab in our crawl space (at the house) for about a year now...and find the issues with concrete quite interesting...

How are you going to mix it (what I mean is - do you have the capacity to mix the entire batch in one setting)?

Good luck!
//sse

 

[rwthomas1]

This may sound insane but how about using epoxy mixed with lead shot to fill the keel sump? It will add extra ballast as well as being extremely strong and will bond well with the fiberglass sump. I got this idea from building model boats as that is what I use to fill the keels on the models. Granted this will take a lot of lead and epoxy so maybe you don't fill the entire sump just partway? Regarding the heat generated by the epoxy while curing, this may pose a problem as you would want to damage anything by overheating it. Consult with the epoxy companies and see what they recommend. Likely it will be an extremely slow curing hardener. RT

 

[maggie-k]

HI Seth:
The more I research it the more concrete apears to be the solution hell they build hulls out of the stuff. My plan would be to do it one mix having a helper pass it down to me about a quart at a time as access allows . I could move it around with a long stick . The plan is to pour to about 2 inches from the top of the sump and embed a foam block about 3x5 inches 1 in deep into the surface to provide a place for a pump when it's removed after the cement has set. I will put some 1/2 in starboard in the base of the 3x5 area prior to the epoxy and cloth to allow a base to screw the bilge pump to.
Hi Rob
The problems with epoxy are heat developed I think the slow kicking stuff would solve the problem as you suggested , price, around $100 a gallon you would need about 4to5 gallons , bonding is dependent on a clean dry surface which would be very difficult to acquire in the sump where old oil and diesel live. Cleaning access is very limited. I was considering throwing in chunks of lead in the concrete mix just for balast fun.
Eric

 

[Art Mullinax]

Keel Question

Since we are discussing Keels maybe Seth or someone can answer a question? Did Ericson ever use lead shot in the keel rather than a cast lead ingot set inside the hull? Seems that when I really clean the bilge, I keep finding lead shot about the size of a #7 or #8 bird shot.

 

[Randy Rutledge]

I just pulled my head out of the two access holes in the sole. The lead is covered with a layer of fiberglass and the deep sump is going to take a little work to get the cover glassed in. My drawings are not to true layout, the deep sump is behind the rear access panel in the sole under the front of the engine compartment bottom, the cover would have to be installed in an area with a height of about six inches.

Filling would be easier, I don't like the concrete idea, no turning back from concrete, epoxy the cost would be very high and the heat problem. foam in layers would work and not cause a heat problem, also just glassing over with no fill would solve the problem but water could be in there and get a real problem when hauled for the winter unless a pickup tube were incorporated like the original sure-flow pump install.

We have enough people thinking on this to get to the best repair.

 

[NateHanson]

You could just glass it in, and add a threaded bronze garboard plug fitting in the bottom of the sump. That way if there were water getting in there it would be easy to drain. I don't usually like garboard plugs because I consider them a liability that's not worth the convenience, but in this case there would be an extra layer of glass even if the plug failed.

 

[Bob in Va]

Lead shot info

I am just finishing up a centerboard that will have about 60# of lead shot filling pre-formed openings, for weight. If anyone does elect to go that route with filling their keel void, I offer the following observations: Get the void area as clean as you reasonably can, but once the shot/resin mix sets up, it's adhesion to the surrounding surface isn't that important since it will be conforming pretty exactly to the space. Use polyester resin - it is plenty strong enough to glue the shot together and at about a third the cost of epoxy, and will fill the spaces between the shot just as well. Do the job in several pours, so as to keep the temperature under control as it kicks off. If you mix up more resin than you need for one pour, refrigerate the rest, then mix and pour as needed - I found that about 10 lbs of shot at a time made a good mix for my purposes. Put the amount of resin needed for one application into a container, pour in the appropriate amount of shot, stir it up a little, add resin or shot as needed, then go to it. The slurry will pour with about the same consistency as concrete and will go into every opening of any size - you don't have to worry about air pockets.

 

[Sean Engle]

Does it make any difference if he's hauled out or not when this happens? I would think the cooler temps would be better for the heat (assuming the route suggested) - but what about water being present? He would have to dry the sump out, no?

//sse

 

[maggie-k]

Bob I fail to see the advantage of polyester resin over cement. One is a lump of plastic one stone. Water does not affect either negatively. They both flow the same during placement . They both can be infused with lead shot . They both don't depend on adhesion but more so friction to stay in place. Price wise Cement is far less.

I had lunch today with a boat designer with about 25 years experience and we discussed the void in the keel. His conclusion for the existance of the unreasonably deep sump was built it room in the keel for a "fudge factor" in the design on the correct balast . Unlike bolt on keels integral keels can't be changed in volume so designers create more space than required just in case . He was surprised it was not foamed in at the factory. We crunched the numbers on the E-29 and he was of the opinion a bit more balast would not hurt the E-29 . Just thought I would pass this along. It would be interesting to know if this was in the design plan.

 

[Randy Rutledge]

Remember that the 29 has 300 pounds of additional balast added in front of the compression post under the sole, this would indicate that the bow was to light in someones opinion. adding to the rear would counter that.
Tacking in heavy air my 29 noses down hard unless I do a very good job of sail trim the rearward weight might help that.

Just more food for thought.

Whatever we do we should plug the hole.