Replacing the hose between the propeller shaft stuffing box and shaft log tube - Page 4 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 


Like Tree7Likes
Reply
 
LinkBack Thread Tools
  #31  
Old 12-14-2011
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 6,981
Thanks: 0
Thanked 61 Times in 52 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
That is why a split coupling makes sense - the engine doesn't have to be moved.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #32  
Old 12-14-2011
jameswilson29's Avatar
Senior Smart Aleck
 
Join Date: Aug 2009
Location: Richmond, Virginia
Posts: 1,999
Thanks: 25
Thanked 62 Times in 57 Posts
Rep Power: 5
jameswilson29 is on a distinguished road
So after the split coupling is fitted and faced to the shaft, it can be split and re-attached without more fitting and facing?
Reply With Quote Share with Facebook
  #33  
Old 12-14-2011
Senior Member
 
Join Date: Feb 2005
Posts: 1,077
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 10
sawingknots is on a distinguished road
i would think so,just use a .002 feeler gage between the couplings while you realign the engine
Reply With Quote Share with Facebook
  #34  
Old 12-14-2011
Maine Sail's Avatar
Senior Member
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,247
Thanks: 9
Thanked 107 Times in 78 Posts
Rep Power: 15
Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice
Quote:
Originally Posted by hellosailor View Post
Maine, all this sticking the shaft in the coupling, lathing everything, not just "bolting it up"...is this akin to "blueprinting" an engine instead of just building it? Is this really necessary every time a shaft is popped off?

Or is it more for the folks who simply prefer ironed shirts to permanent press?
If you remove an old straight coupling and try to re-use with a poor fit, as in not a light press fit, you will:

A) Eventually ruin the shaft because the set screw and ss key are not intended to take ALL the load. Often times the key will also fit sloppy due to the layer of rust broken free and this will result in hard loading the key from forward to reverse. A loose coupling can actually shear a shaft.



B) Potentially lose the shaft




I have seen both of the above scenarios happen when old couplings are re-used. When Buck or Walters or others ship a straight or split coupling they are normally undersized for the standard shaft sizes so they generally need to be fitted or you likely won't be able to get them on. If you don't want to face it that is not as critical if you don't mind vibrations. In lots of shaft jobs I have had one coupling, that when installed onto the shaft, did not need to be faced. Your shafting shop should always be willing to check it BEFORE facing. This is about a $10.00 job if facing is nor required. I have seen new shaft / couplings off by as much as 0.012" and that is more than enough to cause some pretty bad vibrations.

Considering the time and expense involved in doing this job and the potential safety issues the fitting and facing is a small portion.

The Sabre 34 I just finished was a ONE HANDED job due to piss poor access. Took about double the time it normally takes while working like an amputee. Things you take for granted as a 2 minutes job, like tightening hose clamps, but only blind & one handed when they just want to spin around the shaft log hose add up for the owners to the point that they become costly jobs. I don't think the owner would have been happy to do it over again if we had issues because I cut a corner and chose not to check the face or tried to re-use an old coupling.

I'm lucky in that I have a very reputable prop shop who will not ship out a shaft and coupling without doing it right. There are many shops, especially on-line who think nothing of taking your money and selling you junk.

I had one customer who insisted on buying his own shaft from an on-line source. No problem, right..? It was $137.00 cheaper than my shop excluding shipping so that's justifiable, if we're comparing apples to apples.. When I saw it there were no signs of it being faced, it was way off, and the coupling literally dropped over the shaft. The set screws were not spotted into the shaft as is required under ABYC P-06 and the keys on both ends were terribly sloppy and it came without prop nuts. Also the key at the flange end was brass and it should be SS.

All that wrong in just one on-line prop shaft adventure.

I had to decline to install it noting the potential safety issues. I sent the customer to my shop and they were horrified at the sloppy workmanship so much so that they installed a new coupling, spotted the shaft, fitted and faced it and supplied new keys all for $80.00 including the new coupling. they're good guys. Customer was still ahead but then had to buy some prop nuts and the shaft grade was still unknown. At the price he paid I am nearly certain it was not AQ22 as they said it was. You can barely buy the raw shafting from WBM for what he paid for the whole lot.

Having seen the failures I have I do take shafting work pretty seriously.. As always with your boat you can always do what you want. All I can do is share what I've learned...
__________________
______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Reply With Quote Share with Facebook
  #35  
Old 12-14-2011
Maine Sail's Avatar
Senior Member
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,247
Thanks: 9
Thanked 107 Times in 78 Posts
Rep Power: 15
Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice Maine Sail is just really nice
Quote:
Originally Posted by jameswilson29 View Post
So after the split coupling is fitted and faced to the shaft, it can be split and re-attached without more fitting and facing?

Yes so long as it is new you're fine. If it gets a few years old and rusty, and you remove it, you'd be best to drop it at a machine or prop shop to have it re-checked. Most will check the fit and face for just a few bucks.
__________________
______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Advice: Replacing Stuffing Box Hose Piratesoul Gear & Maintenance 17 07-20-2011 04:25 PM
shaft log hose gulftex Gear & Maintenance 5 03-23-2009 03:27 PM
Propeller Shaft Packing Material mightyhorton Passport 0 12-07-2008 11:04 AM
Recommended hose for stern tube to stuffing box GBurton Gear & Maintenance 10 03-18-2008 09:50 PM
Propeller shaft woes............. clayjay Gear & Maintenance 24 03-13-2008 08:17 PM


All times are GMT -4. The time now is 03:46 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012