mounting bilge pump and switch?

[gwp]

When I did this in my c30, I found plywood was between bilge floor and keel. Anyone know if the c34 has similar design? Just need to drill deep enough to let a screw get a bite. Thx

[Ken Juul]

I'm 99% sure that the only wood in the bilge area is in the mast step.  You should have a couple inches of glass to screw into.

[Ron Hill]

gwp : As Ken said "I don't think so".  I agree, but to make sure - empty the bilge of any water and let it dry out. 
Drill your pump mounting hole/s and fill it with silicone caulk, then screw in the stainless screw.  It should be sealed regardless. 

[pablosgirl]

Hi GWP,

On the 88' and earlier model c34s the keel box floor was cored with a piece of teak board, see this thread discussion http://c34.org/bbs/index.php/topic,3381.msg18608/topicseen.html#msg18608

I would recommend that you dry out the bilge, drill out a hole to fill with epoxy and then drill a tap hole in the epoxy for your screws to protect that wood core (see West System how to doc on "Bonding Fasteners & Hardware" http://www.westsystem.com/ss/use-guides/ Also seal the screws with a sealant when installing the pump.  You do not want to introduce any source of moisture into this core or you will end up with a very costly repair in your future.

Paul

[gwp]

Thx for info. Hull #568 so I got wood core. Just hope its dry....

[mtullier]

Use 4200

[Stephen Butler]

Approximately 5 years ago, we installed a bilge pump switch with a very short ss screw and used some 4200. The switch was centered in the bilge and we encountered no wood.  We were absolutely confident that we had not penetrated too far and that the 4200 was sealing everything well.  Subsequently, our vessel then toppled over while on the hard during hurricane Wilma, requiring the (fin) keel to be dropped and the keel bolts to be checked (per the insurance company) with no damage reported.  2 years ago, we were doing some cleanup and removed the bilge pump switch, with a resulting small but steady stream of water entering the hull.  We quickly replaced the screw and sat back to analyze the problem.  It turned out that water was entering the hull between the keel and the hull joint. We again dropped the keel to check/analyze the situation and then had the joint glassed/sealed/secured with large ss plates, etc.  We have a dry boat, but since that time, we are gun-shy and do not screw anything into the hull.  Rather, we now afix a thin piece of plastic to the bilge floor with 5400, onto which we screw whatever is needed.  Why take any chances.   

[wuchun]

You do not want to introduce any source of moisture into this core or you will endugg classic cardy up with a very costly repair in your future.

[gwp]

Intrigued by this info and have now dried and cleaned bilge. Was pleased to find what looked like the wood core removal and epoxy job described in link. Even found couple of small pieces of fiberglass skin with neatly ground edges down there. Also...the floor of bilge is a slightly different appearance than sides. I think i will drill very shallow oversize hole, epoxy, then redrill screw hole. Wuchun.....thx for the cool boot link! Ha

[Ron Hill]

Guys : Look at Paul's link that shows the keel to hull joint in the Catalina diagram I sent, most all of the C34s I seen have the bilge pumps mounted in the bilge aft of where the "hardwood" core is -- Just count the keel bolts and imagine the compartments.  
Anyway mine is!  A thought

[gwp]

Ron...I could be wrong but I think the wood core covers the entire bilge floor. Looks to me the diagram illustrates the completed job in the aft portion, and the factory condition in the foreward portion of bilge floor.

[Ron Hill]

Gwp : You are probably right, but as the drawing says - "Typical pre 1988 Models" & "Drawing by GD".
(drawn 10 Feb 1996)

If you are really concerned about drilling a hole, caulk it in place instead!  Just make sure that both surfaces are clean and use some 3M 4200 or silicone caulk.  A thought