Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: RHBAKER on September 29, 2015, 10:29:03 pm

Title: PROPELLER SHAFT SEALING
Post by: RHBAKER on September 29, 2015, 10:29:03 pm
I have plain brass bearing propeller shafts on a tug model and find an excessive amount of water ingress up the shafts. Has anybody found a lubricant or sealing compound that can be injected into the shafts to improve sealing?
Title: Re: PROPELLER SHAFT SEALING
Post by: Martin (Admin) on September 29, 2015, 10:39:26 pm
 
"excessive amount of water ingress up the shafts"

I would say there is something seriously wrong with your shafts or bearings!!
Title: Re: PROPELLER SHAFT SEALING
Post by: malcolmfrary on September 30, 2015, 08:56:41 am
It sounds like either wear and tear has happened giving unwanted clearance, or they were made like that.  A pair of thrust washers at the prop end with an "O" ring between them plus some silicone grease in the bearing and trapped in the washer-ring arrangement will help.  If you use silicone grease, remember that repainting anywhere near where it manages to spray is unlikely to work.  Silicone residue is an absolute sod to get rid of.
Title: Re: PROPELLER SHAFT SEALING
Post by: morley bill 1 on September 30, 2015, 09:40:43 am
Hi I always fill my prop shafts with sapphire grease it is from the car industry waterproof and low friction ...Bill..
Title: Re: PROPELLER SHAFT SEALING
Post by: Seaspray on September 30, 2015, 09:42:58 am
Mic your I.D. of the bearing and the O.D. of the shaft. If there is a marked difference buy a new prop shaft, pop out the bearings in it and fit them into the old shaft. Fit the new centre shaft into the old tube in the boat.

If that doesn't work you can try a tufnol bearing
Title: Re: PROPELLER SHAFT SEALING
Post by: RHBAKER on September 30, 2015, 02:53:49 pm
Thanks for all the suggestions.
Have dug a little deeper and found that the thread on one shaft is cut marginally deeper than the other, increasing the end float. Have tightened this up and will try again.
There is very little sign of any wear, so the grease or silicon suggestions are next if the end float reduction does not resolve the problem.