CD36 refit/repair advice needed

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Greg Kozlowski

CD36 refit/repair advice needed

Post by Greg Kozlowski »

I am the new owner of a 1979 CD36 which I am now refitting. Any advice on the following items would be very much appreciated:

1. Aft water tank in bilge:

This water tank is cracked on top. It is accessible for repair, but I have no idea what it is made of ( seems like some sort of rubbery plastic) and what kind of repair would seal this crack. I have a feeling that epoxy might not stick to this material. Any suggestions?

2. Propellor:

I want to replace the 2 blade 15 by 15 propellor with a 3 blade prop.
The engine is a Perkins 4-108 with a Hurth transmission. Any suggestions from CD36 owners on what 3 blade prop works well
for them?

With many thanks,
Greg Kozlowski
koz@seijo.ac.jp



Koz@seijo.ac.jp
sam

Re: CD36 refit/repair advice needed

Post by sam »

Greg, re the prop. there are several places on the web that make props and offer a prop analysis program to help you select the right one. If you do a search on props or similar you should find them. The one I bought from was General Propeller in Fl. (I bought a shft for my 40) Very happy, they were knowledgeable and prompt.
Matt Cawthorne

Re: CD36 refit/repair advice needed

Post by Matt Cawthorne »

Greg,
By 1982 the water tanks had been moved out of the bilge so I have no advice there, but I have spent time messing with my 3 bladed prop and have some recommendations there.
Cape Dory 36's eventually were supplied with 15RH14 3-bladed props. I did speed trials with the Patricia Louise in smooth water and found that the 14 inch pitch on this prop was too high to allow the engine to develop its full power. The engine RPM was limited to about 2800 rpm. This is not a problem in smooth water because this combination would take you right up to hull speed. It would, however, leave you unable to take full advantage of the engine to power off of a lee shore or to drag yourself off of a sandbar if needed. I sent the prop to a prop shop and had it re-twisted to a 12 inch pitch and I can now run the engine at the higher RPMs which will allow more full utilization of the engine. The pitch could even stand to be a little lower, but I am content with the existing setup. The disadvantage is that it causes the engine to run a little faster and more lightly loaded all of the time. If run too lightly loaded a diesel can carbon up. I have not had any problems of this sort yet.
The 3 bladed prop that I have has a low disk area ratio (DAR). It causes less drag than a motor boat prop. Keep this in mind if you get a 3 bladed prop, because you will want the lower drag if possible.

Have fun with your new boat. I have been very happy with mine.

Matt

Greg Kozlowski wrote: I am the new owner of a 1979 CD36 which I am now refitting. Any advice on the following items would be very much appreciated:

1. Aft water tank in bilge:

This water tank is cracked on top. It is accessible for repair, but I have no idea what it is made of ( seems like some sort of rubbery plastic) and what kind of repair would seal this crack. I have a feeling that epoxy might not stick to this material. Any suggestions?

2. Propellor:

I want to replace the 2 blade 15 by 15 propellor with a 3 blade prop.
The engine is a Perkins 4-108 with a Hurth transmission. Any suggestions from CD36 owners on what 3 blade prop works well
for them?

With many thanks,
Greg Kozlowski
koz@seijo.ac.jp


mcawthor@bellatlantic.net
Greg Kozlowski

Re: 3 bladed prop

Post by Greg Kozlowski »

Hi Matt,

Thanks for the advice on going with a low DAR 15RH12 3-bladed prop.
Would you by any chance have a contact no. for a manufacturer?
With thanks,
Greg



koz@seijo.ac.jp
Roald Horton

Re: 3 bladed prop

Post by Roald Horton »

Greg,

I replaced my prop with a 3 blade 15X12 from Essex Machine Co. in Essex, CT. They were the OEM for all the Cape Dorys. Any of the many prop machining companies can supply you with a prop including most of the local prop shops. The manual supplied with the boat should have Essex's address.

Roald Horton
"SeaScape" CD36

Greg Kozlowski wrote: Hi Matt,

Thanks for the advice on going with a low DAR 15RH12 3-bladed prop.
Would you by any chance have a contact no. for a manufacturer?
With thanks,
Greg


roald@toad.net
Greg Kozlowski

Re: 3 bladed prop

Post by Greg Kozlowski »

Roald,

Many thanks for the info.

Greg Kozlowski
"Sherpa" CD36
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