Catalina 34

General Activities => Main Message Board => Topic started by: Roland Gendreau on December 30, 2018, 06:42:51 PM

Title: Propeller reconditioning
Post by: Roland Gendreau on December 30, 2018, 06:42:51 PM
I have an m25xp and the standard 3 blade fixed prop.   I don't have any particular problem with vibration or performance with the prop.   However I was wondering whether it is worth having the prop reconditioned as it is 26 years old.   I don't see any noticeable deformity of the prop blades or any significant dings or worn areas.  In searching thru the message board and wiki, I don't find a lot of discussion on the topic.  So those who have had their props reconditioned, please let me  know what your experience; was there a noticeable reduction in vibration or increase in performance?

Thanks



Title: Re: Propeller reconditioning
Post by: scgunner on December 31, 2018, 07:21:00 AM
     Roland,

        When it comes to props there's no such thing as an insignificant ding. If it's 26yo it's not a bad idea to take it to a prop shop and get it tuned up. They might even be able to put a little more twist into it to improve performance if that's what you're after.
Title: Re: Propeller reconditioning
Post by: Breakin Away on December 31, 2018, 08:20:33 AM
Thanks for starting this thread, as I was going to do the same in a couple of days. I've had my boat for 2.5 years and never pulled the prop. I don't know how long PO left it on without pulling. I borrowed a puller from AutoZone's free loaner program. After 3 days of cranking, tapping, penetrating lube, heating the hub, applying ice cubes to the shaft, I finally got it off this morning. Obviously I'm now looking for suggestions about anti-seize compounds for the future.

I'm in exactly the same situation regarding reconditioning. Condition seems fine, but I'd like to have it checked out professionally just to be sure there are no signs of corrosion problems, etc. I'd love to have recommendations for good prop shops. Near Philadelphia would be nice, but I could go down to DelMarVA or Annapolis if needed.

The prop was clean when I bought the boat, and the yard put on a coat of Pettit "Prop Coat Barnacle Barrier", and I've cleaned and sanded smooth each year, then re-applied another coat. The sanding was thorough (all oxides removed, down to a very smooth gray surface), but was not done all the way to bare metal (since this stuff REALLY bonds strongly to the metal and is hard to remove). Its antifouling performance has gotten a bit worse each year, with about a hundred barnacles at the end of last season (typically near the hub and on the shaft, not as much on the blades). I'm not sure if it's just the water conditions were worse or the fact that I didn't remove it the paint all the way between re-applications.

Bottom line, I'm ready to try something else to reduce hard growth. I have friends who swear by PropSpeed, but at $300 for 200 ml it's a bit rich. I'd be interested in hearing of lower cost alternatives and/or suggestions of prop shops who could do the application. Maybe if they buy the PropSpeed (or alternate material) in bulk and do several props at a time, they might be able to do it for less than $300 including labor.

I'm open to suggestions, since this is a bit more complicated than the outboard props that I've dealt with in the past.
Title: Re: Propeller reconditioning
Post by: mark_53 on December 31, 2018, 10:36:56 AM
$300 for a product that doesn't do the job sounds like a waste of time and money to me.  How long do you keep the boat in the water?  Salt or fresh?  How long does it sit unused?  My experience in brackish water has been the longer the prop has not been moved, the more barnacles will collect.  I use no prop coat. Boat was in the water from June through October with no barnacles.  Maybe start the engine to spin the prop at least once a week.  Another option could be another marina.

Oh, and as far as reconditioning goes, I would suspect if your already doing hull speed, you won't see much if any performance increase.
Title: Re: Propeller reconditioning
Post by: Breakin Away on December 31, 2018, 11:26:47 AM
I guess I need to be more clear.
$300 for a product that doesn't do the job sounds like a waste of time and money to me.
Yes, it would. But I never said that. Barnacle Barrier ($30) was OK at first, but not as good lately. This could be due to environmental factors or my improper application. PropSpeed is a different product that has gotten very good reviews from my friends.

How long do you keep the boat in the water?  Salt or fresh?  How long does it sit unused?  My experience in brackish water has been the longer the prop has not been moved, the more barnacles will collect.  I use no prop coat. Boat was in the water from June through October with no barnacles.  Maybe start the engine to spin the prop at least once a week.  Another option could be another marina.

Oh, and as far as reconditioning goes, I would suspect if your already doing hull speed, you won't see much if any performance increase.
My location is in my signature. Brackish water, salinity level varies with rainfall. In the water April-October, on the hard off-season. We've had extremes of drought and floods in the past two years which have caused salinity fluctuations. Due to work and travel I'm away for 6 days at a time, sometimes two weeks. I do spin the prop in the slip if I can't go out.

My bottom paint has been 100% effective at preventing hard growth.

My request for advice has nothing to do with trying to exceed hull speed, which I get to fine. It's only about having a maintenance-free prop that doesn't corrode or load down the engine unnecessarily due to hard growth. It's also about maybe leaving the boat in through the winter at some point in the future, which is why I'd like to do a little better than I am now. I'm open to suggestions.
Title: Re: Propeller reconditioning
Post by: Breakin Away on December 31, 2018, 11:51:31 AM
I just learned about a very new product that claims similar performance to PropSpeed at much lower cost:

http://www.propglide.com/

Searching this site yields no hits. I'd appreciate any comments people here might have.
Title: Re: Propeller reconditioning
Post by: Ron Hill on December 31, 2018, 12:37:10 PM
Guys : I wrote a Mainsheet tech note article explaining why you should take your prop to a shop that uses "Prop Scan".

I also wrote an article pointing out that Catalina installed engines of 21, 23, 30 and 35 HP.  However, Catalina always installed the same 3 bladed prop of 15" x 9" pitch!!!!!!  Most owners with the M25XP engine re-pitched to 10".

I re-engine to a M25XPB and a 3 bladed 11" pitch prop and was very happy. If there had been enough room I would have re-engine to a M35BC engine with a repitched 3 bladed 15"x 12" prop!!

So you be the judge.

A few thoughts

Title: Re: Propeller reconditioning
Post by: Breakin Away on December 31, 2018, 01:03:03 PM
Guys : I wrote a Mainsheet tech note article explaining why you should take your prop to a shop that uses "Prop Scan".

I also wrote an article pointing out that Catalina installed engines of 21, 23, 30 and 35 HP.  However, Catalina always installed the same 3 bladed prop of 15" x 9" pitch!!!!!!  Most owners with the M25XP engine re-pitched to 10".

I re-engine to a M25XPB and a 3 bladed 11" pitch prop and was very happy. If there had been enough room I would have re-engine to a M35BC engine with a 3 bladed 9"x 12" prop!!

So you be the judge.

A few thoughts
Hi Ron, thanks for your comments. Too bad I'm on the hard, because if in the water I'd go out and test my RPMs at full throttle, since I think that's the ultimate test for whether re-pitching is needed. I'll keep that in mind for next season.

But I am a little puzzled why a M35BC engine should have only a 9" diameter prop. Did I misread something?
Title: Re: Propeller reconditioning
Post by: Ron Hill on December 31, 2018, 01:35:27 PM
Breaking : In a number of articles, I wrote (and confirmed by Jerry Douglas) that it is the builder of the hull that determines the diameter of the prop - so the prop does not cause "buffeting" against the hull.

I'm no engine Guru, but I can't believe that an engine that has over 70% more HP needs the same (low torque) pitched prop as the same smaller HP engine!!   

Hope that answers your question. 

A few thoughts
Title: Re: Propeller reconditioning
Post by: Breakin Away on December 31, 2018, 01:49:41 PM
Breaking : In a number of articles, I wrote (and confirmed by Jerry Douglas) that it is the builder of the hull that determines the diameter of the prop - so the prop does not cause "buffeting" against the hull.

I'm no engine Guru, but I can't believe that an engine that has over 70% more HP needs the same (low torque) pitched prop as the same smaller HP engine!!   

Hope that answers your question. 

A few thoughts
I fully agree, but you seemed to be suggesting that a M35B motor should result in reducing the prop diameter from 15" to 9". Either I misread it, or you have a typo.

My other unrelated comment was not addressing prop diameter. It was addressing pitch adjustment of a prop of the manufacturer's selected diameter. The procedure I always heard was to run at full throttle and compare to engine spec, then adjust pitch if out of spec. Obviously certain specialized needs could justify higher or lower pitch, but care should then be taken to ensure you're not under-revving at idle or over-revving at full throttle.
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 01, 2019, 09:27:31 AM
Breaking : I set my low idle @ 1000rpm (why shake your teeth out? and you also get better output from the alternator) I usually cruise @ 80% power about 2400rpm.

Sorry for the 9" typo  :cry4` 

What is MOST important is that you take your prop to a shop that has PROP SCAN!

As Stu usually says "It's your boat" and Ron adds - "It's your prop"!!

A few thoughts
Title: Re: Propeller reconditioning
Post by: Roland Gendreau on January 04, 2019, 03:14:51 PM
Ron

Finding the article you wrote on why I should go to a shop with Prop Scan will take some digging.
To save some digging, can you just tell me why and about how much does it cost?

I found the Prop Scan website, but their dealer locator does not work.  Anyone know of a shop in Rhode Island?

Roland

Title: Re: Propeller reconditioning
Post by: Breakin Away on January 04, 2019, 08:30:02 PM
I found the Prop Scan website, but their dealer locator does not work.
I'm not sure that it doesn't work. It looks like they've lost a whole bunch of dealers, and that there are huge areas of the country with no coverage.
Title: Re: Propeller reconditioning
Post by: Bill Shreeves on January 04, 2019, 09:35:36 PM
Breakin'   I used a very good prop shop, Atlantis Propeller, just across the river from Philly in Cinnaminson, NJ. in 2017.  The owner, Ray was great to work with.  I got my new SS prop shaft from them.  Great to work with and I just dropped off a friends prop to be tuned up a couple of weeks ago.  I heard somewhere that they do the prop work for Cherubini which is very close to them.  BTW, they loan out their "real deal" prop pullers.

http://atlantisprop.com/
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 04, 2019, 10:01:56 PM
...I also wrote an article pointing out that Catalina installed engines of 21, 23, 30 and 35 HP.  However, Catalina always installed the same 3 bladed prop of 15" x 9" pitch!!!!!!  Most owners with the M25XP engine re-pitched to 10"...
Hi Ron, thanks for your comments. Too bad I'm on the hard, because if in the water I'd go out and test my RPMs at full throttle, since I think that's the ultimate test for whether re-pitching is needed. I'll keep that in mind for next season...
Rather than wait for next season, I did a little research. I remembered that the maximum RPM was tested during the survey/sea trial when I bought the boat 3 years ago. (I have not gone anywhere near full throttle since, though I now realize that I should occasionally to knock off any carbon deposits.) I checked the survey report and he noted a maximum RPM of 3800. (I didn't know enough at the time to realize that it might be abnormally high)

The service manual does not say what the maximum RPM of the M35 should be, except that the horsepower is rated at 3000 RPM, and I assume most manufacturers rate their motors at the max recommended RPM. Then, after some more digging, I found a 2004 product brochure for Universal's B-series motors, that said made it clear:

Quote
Universal recommends a propeller that will allow the engine to turn 3000 RPM underway at full throttle

So it's pretty clear that my prop should be re-pitched to account for the higher power of the M35B motor, just as Ron suggested. I'll probably give Ray at Atlantis a call to discuss.

...or maybe it's time to think about a feathering/folding prop. Which brand do you guys like best? I want a design that also reverses effectively, since it's critical for dock maneuvering.
Title: Re: Propeller reconditioning
Post by: Noah on January 05, 2019, 09:01:45 AM
Check you tachometer for accuracy before you make you decision to repitch based upon an assumed RPM of 3800.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 05, 2019, 09:38:18 AM
Check you tachometer for accuracy before you make you decision to repitch based upon an assumed RPM of 3800.
I checked it a few weeks after survey (and annually since). Spot on.

EDIT: To be clear, I've only tested up to about 2400 RPM, but everything is accurate and linear. I'm not sure I want to be around the motor when it's spinning at 3800 RPM.
Title: Re: Propeller reconditioning
Post by: Stu Jackson on January 05, 2019, 03:05:34 PM
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
...or maybe it's time to think about a feathering/folding prop. Which brand do you guys like best? I want a design that also reverses effectively, since it's critical for dock maneuvering.

"Best" rarely works when talking about boats, which are inherently compromises, right?

I'd bet that if you typed "feathering+props" in the search bar you'd find lots and lots of comments.  Which, inherently, would be all over the place, for different and individual reasons.  There haven't been any new ones made in many years.

Good luck.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 07, 2019, 08:46:40 PM
I called Ray at Atlantis Propeller today and had a talk about my prop. Like Noah, he expressed some skepticism that my motor could have been actually revving at 3800 RPM, noting that the governor should prevent this. I'm so clueless about this stuff that I didn't even know that my engine has a governor, but after reviewing the service manual I know it has one, but I'm still pretty clueless about how it actually works. It seems it has to do something with springs interacting with the centrifugal force of the governor shaft to increase/decrease fuel flow if centrifugal force decreases/increases when load increases/decreases. But I digress.

I told him I'd do some homework and bring the prop by next week when I'm back home near Philly . In the meantime, I need to decide whether I should request any modifications to the prop. I assume that I have the standard 15"x9" three-blade prop (with pretty narrow blades) that Catalina supplied, and I'm sure he'll verify dimensions and pitch and tell me if it's something other than 15"x9". Since the boat is winterized on the hard, and I do not want to do multiple short hauls to seek perfection, I'd like to take the long-term view and get the prop little better for the coming season (i.e., RPMs closer to 3000), then verify top RPM after launch in the spring, then have him do a final prop adjustment (or replacement) while hauled out a year from now.

I'm always inclined to leave well enough alone, especially since Mainesail says too little pitch is better than too much. But knowing that I have the more powerful M35B engine, and reading here that there are people with M25XPBs who upped their pitch to 15"x10", I wonder if I shouldn't have him up the pitch on my prop to 10" (assuming, of course, that it hasn't already been increased). Then I'd check my max RPMs next spring, verify it with the strobe (since I haven't used the strobe above 2400 RPM), and do the final adjustment while on the hard in a year.

What do you guys think? Of those of you who have the MkII/M35B combination with 3-blade prop, what prop size and dimension do you have? Have you verified that it achieves a max RPM of 3000?
Title: Re: Propeller reconditioning
Post by: Roc on January 08, 2019, 04:16:03 AM
Roland,
I have found that not too many shops use Prop Scan.  There might not be any in Rhode Island.  You may need to ship it to whatever closest one you find.  That's what I did.  Shipping the prop is not that expensive.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 08, 2019, 05:17:06 AM
http://oceanpropsri.com/

Quote
New England’s first prop repair shop with Prop Scan™
Title: Re: Propeller reconditioning
Post by: Roland Gendreau on January 08, 2019, 11:41:06 AM
Thanks for finding the Rhode Island prop shop Breakin.

I emailed them to confirm they had prop scan and got an estimate of $250 to $280 to recondition the prop.  The prop scan inspection is free.  It is interesting that all the testimonials they post on their web site are from large power boat owners.   



Title: Re: Propeller reconditioning
Post by: Ron Hill on January 08, 2019, 04:46:14 PM
Breaking : Re read my post which said that MANY people with the M25 XP engines (usually in the MK1 C34s 1987-1991s) upped their 3 bladed prop pitch from 9" to 10".
 
I did that I took my 3 bladed 15"X 9" to a local prop shop and asked them to repitch to 10". 
As I mentioned in my Mainsheet Tech note article, many years later (4-6? years) I took it to Black Dog Props (that used Prop Scan) to have them recheck my prop.  They found all 3 blades repitched differently!!!!!!  I had asked them for 10" and they told me that a couple of the blades were pitched to over 11" !!!!  They asked how the engine was doing and I said OK; so they suggested 11" on all blades so that's what I did.  That screwed up prop was on the boat when I went south for 9 months and I'll guess it had a couple of thousand hrs running time!!

So when I reengined to the newer M25XPB with 3 more HP the boat really took off!! Cruising @ 2300-2400 rpm.  So that's why I say with a 35 hp engine you should easily be able to handle 11" of pitch.

It's your boat so do what you want, but do NOT take your prop to a local prop shop - they will pull out a (well worn) 10" or 11" pitch block and then mallet your blades into submission. They do not have the capability to "calibrate" and/or "measure" each blade to make sure that each is "in spec" - from hub to tip!!
 
However,PLEASE just read the articles that are published and already out there!!  :cry4`

A bunch of thoughts

Title: Re: Propeller reconditioning
Post by: Breakin Away on January 12, 2019, 10:45:54 AM
Thanks, Ron. That’s EXACTLY the type of advice I’m looking for. I’ll also check out your articles, but it sounds like my M35B should easily handle 15”x 11” without lugging the motor. I’ll probably request this to start, and maybe request further tweaks next off-season.

Atlantis Prop is about the only shop within 40 minutes of my home. Their website also says they have prop scan. Are you aware of any reason not to use them instead of Black Dog?

http://atlantisprop.com/
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 13, 2019, 01:32:09 PM
Breaking : It's the process "Prop Scan" that is important - measuring multiple zones of the prop.  I have no reason that Atlantis shouldn't use it as well as BlackDog does.   :D

My thought
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 13, 2019, 01:37:31 PM
Breaking : It's the process "Prop Scan" that is important - measuring multiple zones of the prop.  I have no reason that Atlantis shouldn't use it as well as BlackDog does.   :D

My thought
Thanks, Ron. I found your 1991 Tech Note where you took it to your local shop, but having a hard time finding the article from several years later where you went to Black Dog. Do you have a link?

I'm also interested in hearing from anyone else with a M35B motor. What diameter/pitch do you have on your props? What is your maximum RPMs?

I'll be taking my prop to Atlantis sometime this week, so would like to know other owner experiences.
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 13, 2019, 04:14:23 PM
Breaking : For the last time - if you have a prop larger than 15inches diameter, you are most apt to get hull buffeting!!

Your boat, your choice

A thought
Title: Re: Propeller reconditioning
Post by: Bill Shreeves on January 13, 2019, 04:35:38 PM
Atlantis uses Prop Scan and you'll walk away with the output of the scan for your reference.  I installed a new 3-blade sailor 15x10 on my boat two years ago and I'm very happy with it.  I typically cruise between 2,300 & 2,400 RPM.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 13, 2019, 04:53:43 PM
Breaking : For the last time - if you have a prop larger than 15inches diameter, you are most apt to get hull buffeting!!

Your boat, your choice

A thought
No repetition needed. I have no intention to buy a different diameter prop, and don't recall ever saying I would.

I just want to know what other people have on their boats so I can request an adjustment by Atlantis. They're very reluctant to increase pitch by more than 1" in one shot, so if PropScan says I have the factory default 15"x9" prop, I'm going to have to push him a little to increase it to 15"x11". If there's clear experience from multiple people that 15"x10" is still too little pitch for an M35B, it will help raise my confidence to push him to go to 11" pitch.

Last I checked, most prop shops don't have the technology to increase the diameter of someone's existing prop.  :D  But if by some chance someone here has a smaller or larger diameter,  I want to know about it.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 13, 2019, 07:06:41 PM
I finally managed to get the right search terms on Google to bring up the correct Tech Notes. Since Roland has also had some problems finding the right articles, here's a quick chronological summary of documents that I found:


Everything I see suggests that 15"x11" (which ran well on both Ron's M25XP and M25XPB) would not overload any M35B. However, it's still a small data set, and most people who report data give their cruising RPM, not their maximum full-throttle RPM which is what Westerbeke uses as their guideline for correct prop pitch. So any other data from M35B owners would be helpful (especially if you've tested your maximum RPMs).

If Atlantis prop pushes back too hard, I might go to Black Dog, since it sounds like they've done this before with the Catalina-supplied Michigan Wheel 15" "Sailer" props. I expect that all these guys do 95% of their business with powerboats, so experience with our sailboats could be a differentiator.
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 14, 2019, 03:04:23 PM
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
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 16, 2019, 07:27:50 PM
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.
Title: Re: Propeller reconditioning
Post by: Noah on January 16, 2019, 08:49:21 PM
Here is a pic of my old Michigan  “sailer” 15x9 prop that I have since replaced with a Flexofold folding 3 bladed 15x10
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 17, 2019, 07:41:14 AM
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?
Title: Re: Propeller reconditioning
Post by: Noah on January 17, 2019, 09:38:29 AM
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.
Title: Re: Propeller reconditioning
Post by: Stu Jackson on January 17, 2019, 10:45:10 AM
>>>>>>>>>>>>>>>>>>>>>>
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.
Title: Re: Propeller reconditioning
Post by: KWKloeber on January 17, 2019, 11:53:24 AM
BA,

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

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

-k
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 17, 2019, 11:54:13 AM
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.
Title: Re: Propeller reconditioning
Post by: Noah on January 17, 2019, 01:20:39 PM
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 :cry4` 8)

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

.
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 17, 2019, 08:33:49 PM
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.
Title: Re: Propeller reconditioning
Post by: KWKloeber on January 17, 2019, 10:29:51 PM
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.

Title: Re: Propeller reconditioning
Post by: Breakin Away on January 18, 2019, 05:21:21 AM
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.
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 19, 2019, 02:01:35 PM
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
Title: Re: Propeller reconditioning
Post by: Bobg on January 20, 2019, 10:12:42 AM
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.
Title: Re: Propeller reconditioning
Post by: Noah on January 20, 2019, 01:17:15 PM
Bob-what motor and transmission do you have?
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 21, 2019, 09:15:48 AM
Noah : Unless Bob has "reengined", he should have a M25XP engine with a Hurth 50 Transmission.

A thought
Title: Re: Propeller reconditioning
Post by: Bobg on January 21, 2019, 10:18:07 AM
Thanks Ron, yes I have the 25xp with the Hurth 50.  it is a 2;1 reduction, using a handheld laser  with reflecting tape on the crank pully and output shaft on the tranny, I read 50 RPM low at all speeds, i;e at 2000 rpm, I get 950 on the transmission shaft, never did check it before my prop re pitch, 50 rpm below half rpm probably not enough to reflect that much speed loss, can't turn the prop by hand while on the hard in gear, (one of the tests that was suggested to do on the tranny)
 just wondering if its a possibility that a over pitch prop can cause the transmission to start slipping.  Is it something to consider when re pitching prop?
Title: Re: Propeller reconditioning
Post by: Breakin Away on January 21, 2019, 10:32:18 AM
My spec sheet says Hurth 50 is 2.05:1 ratio. If correct, that accounts for half your discrepancy.

I’m not an expert at this, but I can’t imagine turning over the motor by turning the prop (especially at 2:1 nominal ratio) unless you have a compression release lever, and I don’t think Universals have those, do they?
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 21, 2019, 02:43:53 PM
Breaking : FYI, both the M25 & M25XP have compression release levers!!

A thought
Title: Re: Propeller reconditioning
Post by: Noah on January 21, 2019, 03:00:54 PM
Ron— curious did you or anyone  every successfully try to hand crank one?
Title: Re: Propeller reconditioning
Post by: Ron Hill on January 22, 2019, 02:29:53 PM
Noah : Don't know about the hand cranking, but I do know of someone that had a low battery start.

He hit the starter spinning the engine with compression release lever open and then closed it - causing the flywheel to continue to turn and it started the engine!!!
He's the same guy that showed me how to by pass the starter solenoid, by laying a long screwdriver shank on the threads of the starter  solenoid and then touching the engine block.  The starter immediately turns the engine over - don't leave the screwdriver on the block for more than a second!
 
He was an older gentleman ( had an early 1986 C34 M25) and was a line chief on B17s during WWII. 

A few thoughts
Title: Re: Propeller reconditioning
Post by: Breakin Away on February 23, 2019, 08:28:00 PM
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 :cry4` 8)

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

.
Just curious, since it is through-bolted, what is the bolt material? That might affect my selection of anode material for the strut.

As I mentioned previously, my boat is currently protected by zinc anodes, but I am considering switching to aluminum, since our ever heavier rains in the upper Chesapeake have reduced the salinity level significantly over the last couple of seasons. If we get a drought, the aluminum will still protect, it just won't last as long. But since I haul out every winter, it should last through the season and provide better protection. It's just a pain to find every one of the anodes in Al, especially the HX pencil. What do you other guys north of the Chesapeake Bay Bridge use for anode material. Zn or Al?

Finally, regarding my prop work, Atlantis has had it over a month but not done yet. He likes to do all the sailboat props in one batch because he has to change the machine to accommodate the smaller hole size in the props. I told him to check, clean, and true it up, but not to adjust the pitch at all. I want to re-verify my full throttle RPMs with a strobe this season before making any change in pitch.
Title: Re: Propeller reconditioning
Post by: Noah on February 23, 2019, 08:38:11 PM
The strut and bolts are silicon bronze.
Title: Re: Propeller reconditioning
Post by: Bobg on March 04, 2019, 08:50:24 PM
Ron..I'm.curious on what you meant on starter solenoid threads to engine block via a screw driver shank..do you mean the battery positive post on the solenoid then touch the engine block?
Title: Re: Propeller reconditioning
Post by: KWKloeber on March 05, 2019, 06:34:10 AM
Bob

To bypass the solenoid switch you bond the two large threaded terminals together. The upper being the input to the solenoid (“B post”; battery cable) and the lower being its output to the starter motor.

(https://www.nationsstarteralternator.com/v/vspfiles/photos/153400-9900-2T.jpg)

If you bond “B” to the engine it’s a dead short and will probably weld the screwdriver tip to the engine.

To bypass the start switch you bond “B” (or any power source) to  “S” (the 1/4” quick disconnect terminal.)