Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 01-06-2013, 20:21   #31
Wayfaring Mariner
 
captain58sailin's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Homer, AK is my home port
Boat: Skookum 53'
Posts: 4,045
Images: 5
Re: Reboring and Rekeying a Prop

+1 For lapping the taper, the more surface contact the better. Take your time to get a good fit and it will save you more problems later.
__________________

__________________
" Wisdom; is your reward for surviving your mistakes"
captain58sailin is offline   Reply With Quote
Old 01-06-2013, 20:52   #32
Registered User
 
sww914's Avatar

Join Date: May 2009
Location: Punta De Mita
Boat: Vagabond 39 Hull # 1
Posts: 1,842
Re: Reboring and Rekeying a Prop

Quote:
Originally Posted by Chas Erwin View Post
I always wonder how does FastBottoms do a well lapped propeller install?

Charles
Underwater!
Sorry, I couldn't resist.
__________________

__________________
Steve
http://www.landfallvoyages.com
sww914 is offline   Reply With Quote
Old 01-06-2013, 21:04   #33
Registered User

Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
Re: Reboring and Rekeying a Prop

I don't care how well ya lap em ! 99% 100% they still need a keyway ! I don't much care who you are thats a fact !! You show me a prop installed without a key that will not slip under power sooner or later and I will gladly change my opinion! Ive been doing these type if machine jobs for over 50 yrs and I can't ever remember one ive done that did not work properly ! Thats my 2 cents
__________________
Bob and Connie
bobconnie is offline   Reply With Quote
Old 01-06-2013, 21:24   #34
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Reboring and Rekeying a Prop

Well, what does that say, your work needs a key? Let's give you the benifit of doubt and say you should really have a key if you want your job to last for many years without any attention or it's a boat and it's bound to fall apart so you need a key.
__________________
Guy is offline   Reply With Quote
Old 01-06-2013, 21:25   #35
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Reboring and Rekeying a Prop

If the extremely small surface area of one side of a key was transmitting the drive then we could all reduce the size of our prop shafts to have the same power transmission characteristics as the key.
Just my 2 cents worth, I'm not a machinist but am a marine and mechanical engineer.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 01-06-2013, 21:31   #36
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,592
Re: Reboring and Rekeying a Prop

Quote:
Originally Posted by Guy View Post
Well, I've heard white lead should put on the shaft to make it so you could remove it someday. After all you do have a Key. Ask fastbottom about removing stuck props underwater.
The tolerance between prop bore and shaft taper are tight enough that adding any lubricant to ease future removal may, in fact, cause the prop to not seat properly.

You don't want the prop to come off easily. That's why God invented the prop puller.
__________________
fstbttms is offline   Reply With Quote
Old 01-06-2013, 22:15   #37
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Reboring and Rekeying a Prop

No that is not true. White Lead is not a lube but a anti-seize compound that prevents a metal to metal seizing.
__________________
Guy is offline   Reply With Quote
Old 01-06-2013, 22:25   #38
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,592
Re: Reboring and Rekeying a Prop

Quote:
Originally Posted by Guy View Post
No that is not true. White Lead is not a lube but a anti-seize compound that prevents a metal to metal seizing.
Umm... sorry, but yes, it is true. Whatever its purpose, you don't want anything between the mating surfaces. The prop is not supposed to come off easily. That's the whole point.
__________________
fstbttms is offline   Reply With Quote
Old 01-06-2013, 22:45   #39
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Reboring and Rekeying a Prop

I suppose if you had only 75% contact you would be right However we have been talking about 100%. At 100% you would have 0 chance of getting it off because it would pretty much be a metal to metal siezed joint. Hense the key and a loose joint. No one is sayiing it would come off easly if you used anti-seize compound. You would however be able to get it off. Perhaps you have had foggy goggles the last time you removed a prop that had put on using anti-seize compound but it's very thin. We are talking micro thin after everything is torqued up.
__________________
Guy is offline   Reply With Quote
Old 01-06-2013, 22:59   #40
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Reboring and Rekeying a Prop

The propellor is held in place by friction between the mating surfaces (taper) The friction is maintained by the propellor nut. The key is there primarily to stop any relative movement between the prop & shaft on initial tightening. This movement would cause galling and destroy the properties of the taper. Any antiseize or lubricant introduced between the mating surfaces will decrease the friction properties of the joint and potentially lead to rapid failure. Personally I prepare all tapered couplings after lapping or blueing by wiping with high evaporation solvent such as acetone then drying with a clean rag.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 01-06-2013, 23:10   #41
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,592
Re: Reboring and Rekeying a Prop

Quote:
Originally Posted by Guy View Post
Perhaps you have had foggy goggles the last time you removed a prop that had put on using anti-seize compound but it's very thin. We are talking micro thin after everything is torqued up.
Knowledgeable professionals do not put anything on the mating surfaces of the prop and shaft prior to installation. But hey- knock yourself out. It's your prop.
__________________
fstbttms is offline   Reply With Quote
Old 01-06-2013, 23:15   #42
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Reboring and Rekeying a Prop

I don't often flex my professional muscles on here but those advocating antiseize on a tapered coupling are seriously misinformed and are giving dangerous advice.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 01-06-2013, 23:28   #43
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Reboring and Rekeying a Prop

Sorry Pete but I am also a pro so flex away to no avail.
Mike
__________________
Guy is offline   Reply With Quote
Old 01-06-2013, 23:35   #44
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Reboring and Rekeying a Prop

The overwhelming body of evidence and best professional practice is against you on this.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 01-06-2013, 23:37   #45
Registered User

Join Date: Jul 2011
Boat: Rafiki 35
Posts: 55
Re: Reboring and Rekeying a Prop

how did we get here from my op????
very intresting indeed.
Isn't there a standard procedure?
__________________

__________________
mikogold is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:55.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.