Can a prop be too far gone?

[BobM]

Shaft

Hermit,

Check out this link. Even if you can make one for $100, you may wish to consider them as they are in the business and have good prices. I ended up paying about the same money to have my old stuff refurbished. In hindsight, I should have bought new from them and kept my old stuff as spares.

http://www.deepblueyachtsupply.com/

 

[Hermit Scott]

haul out

I will be hauled for approximately 10 days. I hate that stuffing box. If you read the other post about my 40 mile journey, I forgot about the packing nut falling off the stuffing box and water filling up the whole bilge. I want a mechanical seal.
If I can get it in the dimensions needed I will replace the cutlass with a plastic linear bearing from Igus. They are absolutely amazing. And they will send me one for free.
There is alot to do. You just gotta go down the list and knock it out.

 

[Stu Jackson]

Before You Buy That Prop

check what's the best for your boat at www.catalina30.com. You may not even have to ask on their Message Board, just look it up on their 'site. 2 bladed diameters would be the same as 3 blades, but maybe not the same pitch as a 3 blade. The diameter is governed by the distance the prop is from the bottom of the hull after it leaves the strut.

 

[Maine Sail]

Please slow down...

Tim R. posted that also. I did check them out. I gave them a call; they didn't have the exact match as the prop list says, but as TT238599867 has pointed out, it may not be the best for my boat anyway. They did have a 2 blade prop that was the same diameter and pitch though, and I will probably call and get that one tomorrow. Thank you for that link guys, those are the cheapest props on the net unless you can get lucky on ebay somehow. I just don't have the time to wait for that right now. So it will be $80 shipping included.

SO...my prop shaft looks the same nasty pink color as my broken prop. I assume it's toast too? I can make one out of 316 stainless for around $100-150. Do I want to make it out of 316 or doI want to make it out of the nibral as Ross pointed out that his prop is made of? How does 316 do submersed with zinc on it?

I'm going to fix that after I put it back in the water though. I figure I can slide the prop shaft out and have some one put a plug in the packing tube. Then slide it back in and have them take the plug out while I slide the shaft in. Is that how it's done in the water?

Hermit,

Please slow down. Prop shafts are NOT generally replaced in water. There is a LOT more to it than just sliding it out of the coupling. I've replaced many, many prop shafts and I would never, ever consider this as a in water job even in an emergency.

You'll pay now or you'll pay later by rushing it..:cry:

Here's some advice:

#1 Call Catalina tell them the engine/boat model & hull # you have and they will tell you what the correct two and three blade prop sizes are!!

#2 Prop shafts are generally made of Bronze or Aquamet 22 which is not 316 Stainless. Catalina has the best prices on new shafts period!!!! Trust me on this one I have replaced prop shafts on two Catalina's. They own their own machine shop so their costs are low.

#3 You will want to "lap fit" the prop to your shaft before installing it. This can be done quite easily with some lapping compound or any prop shop can handle it.

#4 You must first have the old shaft out so you can measure before ordering. You will also need a new coupling as they should never be reused without first being fitted and faced to the shaft. The old coupling will lose material due to rust when you pull the old shaft out, if you can get it out, and it will be virtually useless if it's older than a few years. Couplings are cheap and Catalina will fit and face a new shaft to a coupling and ship it out. The last one I bought for my C-36 was about $190.00 with coupling delivered across country. Keep in mind that prices on metals have soared so it will likely be more than that today.


Please don't rush out and buy the first two blade that matches the specs of your three! It will most likely be the wrong size. Also the prop in your photo is likely NOT original equipment and it too was probably not sized correctly as many do as you are attempting, finding a close enough is good enough fit.

What engine do you have in your C-30??

P.S. Please don't try to reinvent the wheel or cutlass bearing. They are cheap and they last a LONG time. The flutes are designed to not only cool and allow additional water lubrication but to also clear sediment and debris that can ruin a shaft very quickly. Also the rubber in cutlass bearings is flexible to some degree, and for a reason. This rubber has some give to absorb slight shaft misalignment issues due to torque, motor mount flex or just misalignment. A hard solid plastic will be much less tolerant of these alignment issues and will transmit vibrations through the hull with potentially very annoying cycle frequencies. It could perhaps also damage the strut mounting if the vibration is bad enough.

The Igus linear bearings are fluteless so all it would take is a couple pieces of sediment stuck in there to potentially destroy a new shaft... Cutlass bearings can be had for about $40.00 - $50.00 depending on the supplier. This is a very common one for a 1" shaft - 1" Cutlass Bearing (LINK)

 

[tommays]

"plastic linear bearing from Igus"

They dont have the metal jacket that a cutlass bearing has and will fall out


It is really hard to find shaft even TGP that would not require secondary work to get it straight enough to be vibration free :cussing:

 

[Hermit Scott]

prop

The bearing is fluted, is held in place by retaining clips and self aligning, but cutlass bearings are so cheap why experiment?
Does any one know of a prop calculator that will accept the variables Displacement, Horse Power, RPM, Gear ratio, Length at waterline, diameter, number of blades and yeild pitch? ALL the prop calculators I can find are for calculating slip or thrust or something else other than being used for prop selection.
The C30 website had everything else readily availabe, except prop selection.
The engine in my boat was not stock. It is a refit. 12 Hp diesel. 10 continuous hp @ 1518 RPM. with a 2:1 gear reduction. 25' on the water line and 11,200 lbs. including gear people and beer. I tried to contact Catalina, it ended up being an email request. I sent it.
It's weird how some people are adamant about 3 bladed props while others are just as adamant about 2 bladed props. Is it that 3 blades provide more thrust while 2 blades have less drag? I'd be more interested in thrust with this small of an engine. If I have to choose that is the compromise I would rather have.
I need the correct prop. I wanted to have it ordered today so I can put it back in the water next week. I may have to take an extra week.

 

[Ross]

Re: prop

Hermit , The drag that you will get from a third blade will be equivilant to dragging that size piece of material through the water. What something about the size of your hand stuck into the water?
Try this link. you will have to pony up 25 bucks for a membership but for my mind it is worth it.
http://boatdiesel.com/index.cfm?CFApp=19&

 

[TT23844]

Hermit - As I mentioned in an earlier post, Michigan Wheel has an on-line service for calculating the correct prop for your boat/engine.
http://www.miwheel.com/
Click on the "Prop it Right" button & enter the relevant data. You'll need to know the LWL & beam at WL, engine HP at rated RPM , gear reduction, shaft size, distance from the shaft to the hull at the location of your present prop, etc. etc etc.

 

[Hermit Scott]

prop

Thanks for the link but they take up to 3 weeks to respond.

 

[Ross]

Thanks for the link but they take up to 3 weeks to respond.

I tried this link this morning about 8 o'clock. I submitted the information they requested and when I returned a few minutes ago the analysis was in my inbox.
I was pleased to know that they considered my prop to be close enough to ideal that they recommended a 14x12 in place of my 13x13. Their explanation was a little more thrust and a little less slip. I paid about 212 dollars for my 45 year old nibral prop including the cost for repitching and their price for the new prop is $682 plus shipping, handling and tax.

 

[Hermit Scott]

prop

I submitted one to them and one to catalina. Hopefully they will respond before Monday. I am going to my boat for a couple of days, to mary kate on and off and try polishing the topsides. Then work on the bottom. I will pull the prop shaft too and take some pictures, so you guys can see what 5 years with no zincs does to a prop shaft.

 

[Hermit Scott]

prop

The prop estimator got back to me and recommended a 13" diameter 9" pitch with 3 blades. That prop is even bigger than the original.

 

[Hermit Scott]

Catalina

I emailed catalina last week, robert butler in service, no reply. I called catalina today about the prop and prop shaft. They weren't much help; unfortunately they are not keeping up with exact specs on their old boats. I asked the engineer/service/whatever guy about a new prop shaft. He told me that prices have tripled in recent years, but all props installed on catalinas now are 316 stainless, and the props are nebral. Their prices for cutlass bearings are 1 1/2 times what they are on SBO. Then he referd me to a company with the most expensive props sold on the internet. Nice fellow but it's hard to be impressed with catalina when dealing with my 'old boat'.
I was so busy with the bottom job that I didn't pull the shaft. I seriously regret that decision. I am going to do a new post about that.

 

[Hermit Scott]

Shaft

I pulled the shaft. Well I tried to pull the shaft, I ended up just cutting it in two with a thin grinding disc and letting it fall apart.
I got one of those 'slam rods' with the 5 lb. weight on it and put 2 prop nuts on and gave it all I had and slammed the weight to the end of the rod and it ripped the threads clean off of the prop shaft! The threads were inside the nuts laying on the ground. At that point I decided the shaft was trash along with the prop.
I ordered a new cutlass bearing, bought a prop on Ebay and hopefully getting a used shaft from minnies. By the way if they have what you are looking for, they are the cheapest with out doubt.
My only problem is I had a 12 LH 10 and the one I bought is a 12 LH 12. I am going to go ahead and install it as is, and see how it preforms. If it's too much, which it probably is, a prop is a job done easily in the water.
THe toughest part of the prop shaft is getting the flange and the shaft seperated. This is not a job done in the water unless you can easily seperate the flange and prop shaft. I don't recommend replacing a prop shaft or cutlass bearing in the water.
The one pic is my rotted shaft. lol
The other is the transom after wet sanding and compounding, the maine sail way. I removed the old name, I can't seem to get rid of the yellow under the name though. I thought some one had painted the transom, it turns out they gel coated the transom, apparently over another name.
I didn't do the ritual, so posidon, the easter bunny and the boogie man will be visiting me tonight.

 

[bonaroo5698]

Re: totaled

i have a number of lightly used props that might fit your boat. if interested, send me the size and pitch which should be stamped on the prop as well as the rotation L or R which should follow the number.

the prop stamp should look something like:

"19x6 RH" (this is just an example)

if interested, email me back.

bukerr@cox.net

 

[Hermit Scott]

bonaroo

Bonaroo, I need a prop shaft now. The prop I have will work, if it is pitched too much I will have it bent to a 10" pitch. But thank you. IF you have a 12LH10 I may definitely be interested though. Let me know.
I destroyed the flange that mounts the end of the prop shaft to the engine, so now I need one of those. I thought it was a straight through 1" but it was a taper. I tried to press the shaft through to loosen it up, and bent the flange. SO...I now need a 57"-1" diameter prop shaft and a flange.
I am still going to have a prop shaft made. I am going to buy aquamet 17 or 19 and take it to a machine shop and have them machine the ends. Something is wrong with the price of something when you can have it custom made for half or a third of the price retail. Whose making all the money with these things? The retailer, the wholeseller or the manufacturer?
Mainesail's prediction about the shaft coupling being trash was correct. If you read this though maine, the guy at catalina told me the prices tripled in the last few years for prop shafts. He also told me they no longer made them from aquamet, but 316. That's jsut one guy so I am skeptical until I hear it from 2 or 3 different sources.

 

[Maine Sail]

I pulled the shaft. Well I tried to pull the shaft, I ended up just cutting it in two with a thin grinding disc and letting it fall apart.
I got one of those 'slam rods' with the 5 lb. weight on it and put 2 prop nuts on and gave it all I had and slammed the weight to the end of the rod and it ripped the threads clean off of the prop shaft! The threads were inside the nuts laying on the ground. At that point I decided the shaft was trash along with the prop.
I ordered a new cutlass bearing, bought a prop on Ebay and hopefully getting a used shaft from minnies. By the way if they have what you are looking for, they are the cheapest with out doubt.
My only problem is I had a 12 LH 10 and the one I bought is a 12 LH 12. I am going to go ahead and install it as is, and see how it preforms. If it's too much, which it probably is, a prop is a job done easily in the water.
THe toughest part of the prop shaft is getting the flange and the shaft seperated. This is not a job done in the water unless you can easily seperate the flange and prop shaft. I don't recommend replacing a prop shaft or cutlass bearing in the water.
The one pic is my rotted shaft. lol
The other is the transom after wet sanding and compounding, the maine sail way. I removed the old name, I can't seem to get rid of the yellow under the name though. I thought some one had painted the transom, it turns out they gel coated the transom, apparently over another name.
I didn't do the ritual, so posidon, the easter bunny and the boogie man will be visiting me tonight.

Hermit,

Please, please, pleas do yourself a favor and DO NOT use a slide hammer! You can literally split your trannie casing apart and at a minimum damage the bearing races and bearings them selves. Slide hammers are NOT a good idea unless the shaft is NOT connected to the tranny. The only time a slide hammer should be tried is if the shaft is out of the boat!

If you ripped the threads off the prop shaft you may have done some damage to the tranny..

P.S. the yellow under the name will only go away with time and UV exposure. DO NOT try and wet sand it out as it is very deep into the gel... UV is your best friend and it will diminish in good time. Shine it up, put the new name over it and in a year or two you will barely notice it. I know it's a pain but there really is nothing but good old UV and time to even things back out.

 

[tommays]

The new shaft will need to be checked in V-blocks

Most SS shafts are not that straight and will need some help because even .002 run out in the middle of the shaft will cause vibration at some RPM

 

[Hermit Scott]

tranny Maine Sail

I had thought about the damage to the transmission, so I tried pulling it out just slamming it by hand against the tube. Now I will have to do a little fiberglass repair to that before I install the packing housing. And I thought the shaft would pop right out. Fortunately the bearings are cheap in the transmission case and not a problem to replace. I will find out when I crank it over and try to run it and test out the new prop.
The shaft I am going to buy will be straightened when I buy it. It's from a prop shop. I can do better on the machining cost though. I guess it will be aquamet17, I will see if the guy will give me reasonable deal on some 19 or 22.
Ripping the threads off was probably a good thing, that absorbed all the shock.
Monday, I will continue on the top side polish. I tried to use a cheap synthetic wool pad to do the compounding. Then I put a real wool pad on and it was 10 times less work with better results. I bought all body shop compound polish and pads. And I got the collonite fleet wax.
Maine sail, I have your long post saved titled 'there are no short cuts in life' After you compound, then finesse it, then McGuires #09 do you do something after that? Do you use a glazing, like a number 10 rated cut McGuires product or #9?

 

[Maine Sail]

Ouch..

so I tried pulling it out just slamming it by hand against the tube. Now I will have to do a little fiberglass repair to that before I install the packing housing.

Ouch!!:cry:

And I thought the shaft would pop right out.

That is far more rare than actually needing to press it off or cut it off.