Propeller reconditioning

[Ron Hill]

Guys : Be where of a "sailor" Michigan Wheel prop as it is not the same Sailor prop used by the Catalina factory!!  The cord of each blades is much larger.

A thought

[Breakin Away]

Guys : Be where of a "sailor" Michigan Wheel prop as it is not the same Sailor prop used by the Catalina factory!!  The cord of each blades is much larger.

A thought

Judging by the pictures, we have the original "Sailer" 3B prop. The Sailer 2, Sailer 3, and other models have larger blades with more driving efficiency (at the expense of sailing speed).

In seeking other examples, here's one that I found of someone whose prop was over-pitched at 15"x12" on his M35B:

http://c34.org/bbs/index.php/topic,221.0.html

It's sort of an apples to oranges comparison, since it's a folding prop that may have very different resistance on the shaft. But it is one example of 12" pitch (though probably 2-blade) that appears to be too much resistance.

I'm still trying to decide whether to re-pitch to 10" or  11". With a new freshwater pump and antifreeze change this off-season, I'm concerned that if my engine overheats I won't know whether it was the prop, water pump, or improper coolant fill. I may be changing too much at once.

[Noah]

Here is a pic of my old Michigan  "sailer" 15x9 prop that I have since replaced with a Flexofold folding 3 bladed 15x10

[Breakin Away]

Here is a pic of my old Michigan  "sailer" 15x9 prop that I have since replaced with a Flexofold folding 3 bladed 15x10

It's interesting to see that brand new anode on your strut. My strut has no anode, and I've always wondered if it should, since it seems to be isolated from the rest of the drivetrain. (Since getting the boat I've coated it with Pettit's zinc paint.) Do others here have anodes on their struts? Is there a Tech Note on how to properly install an anode there?

[Noah]

Breakin- IMO all bronze struts require an appropriate anode for type of water (salt, fresh, brrakish, etc.). Make sure there is no paint between strut and anode and that the anode in on TIGHTLY. You can use dielectric gel/grease on contact bolt/nut. Simple.

[Stu Jackson]

>>>>>>>>>>>>>>>>>>>>>>
It's interesting to see that brand new anode on your strut. My strut has no anode, and I've always wondered if it should, since it seems to be isolated from the rest of the drivetrain. (Since getting the boat I've coated it with Pettit's zinc paint.) Do others here have anodes on their struts? Is there a Tech Note on how to properly install an anode there?

There is no tech note that I recall on strut anodes.  I just checked the Knowledgebase for both strut and anode, nothing.

This is basic stuff not related specifically to C34s.  Any diver and/or qualified boat yard should do this without even asking.

Calder's most likely discusses it, too.

[KWKloeber]

BA,

There's discussion here on strut anodes and how to install:

https://c34.org/bbs/index.php?topic=1579.0

-k

[Breakin Away]

I don't have an anode on the strut. The surveyor didn't note it as an issue, so I neglected it until recently (aside from annual zinc paint). I don't recall seeing them on my neighbors in the boatyard.

I'm no expert, but I suspect that some boats have the struts internally bonded to a master anode, so don't need a dedicated one. Catalina appears to be different from others in this respect. It also looks like Catalina's struts are glassed in, not bolted on (and therefore not replaceable). Is that the same for all makes of boat?

I am in a DIY boatyard, so there's nobody who is going to do anything without even asking. I do it, or it doesn't get done. I learn as I go. This goes to the top 3 on my list before I splash.

My Calder and Casey books are on the boat - I'll have to check them out next time I'm there.

Noah - Could you specify the diameter of your anode, if you remember? It will save me an extra trip to the boat. Also, your picture looks like it's through-bolted. Please correct me if I'm wrong.

These appear to be sold as rudder anodes. If there's a better design spec, please let me know.

[Noah]

I believe any approx. 2-3 inch clamshell-style rudder trim tab anode will do ya. Yes it is thru-bolted with captive hardware included.

BTW—C34 struts are "replaceable", albeit a big expensive job—it is thru-bolted, bedded, and glassed in. I just replaced mine in Oct. and coached another fellow C34 member on the east coast who had to replace his just a couple of weeks after mine, due wrapping a line around his prop and it torking strut causing cracking/leaking at hull joint. That photo is of my NEW strut. My situation for replacement is another story saved for a later write-up

Hope you never need a strut but Catalina Direct sells the replacement strut and has a factory install diagram on their site as well..

.

[Breakin Away]

New prop info today: First, I re-checked my survey, and my motor at full throttle was 3400 RPM, not 3800. I don't know how I had misread that before. That will make me a lot more conservative in re-pitching my 15"x9" prop. If I adjust it at all, it will be to no more than 10" pitch.

I spoke to Catalina today to ask why they shipped boats with the same 15"x9" 3B props, even as their motors grew from 21 HP to 35 HP. There are several explanations, the most significant of which is that the lower power motors had higher gear reduction ratios on the transmissions. (M35B/Hurth HBW100 has 1.79:1) So the lower power motors were spinning the prop slower. He also thought some of the HPs that I mentioned were continuous while others were peak/intermittent, so that the difference between a M25 and M35B is less than the 70% that someone mentioned previously. Third, he said that they are probably conservative with blade pitch because different people load up their boats differently than others, and as Mainesail reminds us, it's better to be a little under-pitched than over-pitched. A 15"x12" prop might work fine for one person, but might lug the motor for someone who weighs their boat down heavily and/or puts on a super big alternator. He also mentioned three models of Yanmar motors that they had put into the C34, all of which had 15"x12" props, but had gear ratios as high as 2.6.

Soon I'll call Westerbeke and try to see how they set their governors. I'm still curious if my surveyor's observation of 3400 RPM is outside the limit set by the governor.

[KWKloeber]

R,

<<they set their governors.>>

"How" (physically) it works, or at what RPM its supposed to hold??

Note the  HP/RPM curves to compare (and prob the recommended RPMs) **should** be shown on the Universal/Westerbeke "cut sheets" for each engine that I put on w/the wiki Manuals.  and are in the Service Manual.

[Breakin Away]

R,

<<they set their governors.>>

"How" (physically) it works, or at what RPM its supposed to hold??

Note the  HP/RPM curves to compare (and prob the recommended RPMs) **should** be shown on the Universal/Westerbeke "cut sheets" for each engine that I put on w/the wiki Manuals.  and are in the Service Manual.

I want to ask them what RPM it's set for, and compare that with my surveyor's observation of 3400 (corrected from my prior incorrect posts).

I've reviewed a bunch of documents for the various models of engines, and maximum RPM varies from 2800 to 3600. The B-series pretty much seems to be a 3000 recommended maximum for all sizes.

[Ron Hill]

Breaking : There is NO-ONE that had more "stuff" on their C34 that I did!!!!! People always said that if I had another hull, engine, mast and boom - that I had enough spare parts to make another C34!!

As far as a super Large alternator, most all of us have limited that alternator output to about 80 or 90 amps - you don't need any more!!
Most all of the Hurth Xmissions on the Universals are about 2:1.

A few thoughts

[Bobg]

I had my 3 blade prop repitched from 9 to 10, boat speeded up a little and then started to slow down throughout the summer, instead of 6 knots at 2300 RPM  i am now at 4.8 to 5 knots, calm  seas, no extra weight, I have investigated a few things, and a few more to go, but is it possible too much pitch can damage or cause the transmission to slip?  could be just coincidental that something else is going on with my boat to make it slow down right after the prop was repitched.

[Noah]

Bob-what motor and transmission do you have?