Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: returnee on December 14, 2010, 12:07:59 pm

Title: sealing a propshaft
Post by: returnee on December 14, 2010, 12:07:59 pm
Can anyone tell me how to stop water from coming up the propshafts on the yorkshireman
Title: Re: sealing a propshaft
Post by: BigA on December 14, 2010, 12:13:15 pm
Keep it full of grease or oil - re-oil regularly - oil, being less viscous, will seep out eventually.

Make sure the bearing at the wet end is secure. Perhaps consider using a PTFE (flat) washer between the prop and beaing/shaft end?

A.
Title: Re: sealing a propshaft
Post by: Martin (Admin) on December 14, 2010, 12:49:21 pm
Check that there is as little play as possible between the prop tube end and the washer and the prop nut.
 If it's an old (aged) model, it could be that the bearings are worn....
Title: Re: sealing a propshaft
Post by: nhp651 on December 14, 2010, 01:08:28 pm
Just doing mine on my Big Clyde class lifeboat..........I use Vaseline mixed with carbon powder that I bought at an engineers years ago............gives great lubrication and water tightness......but even so I still get slight weepage if the boat is in the water for longer than a couple of hours.
neil
Title: Re: sealing a propshaft
Post by: roycv on December 14, 2010, 04:05:20 pm
Hi all, vaseline can get very viscous, especially when cold, but if you use the following mixture it works well.

1 part Vaseline, 1 part WD30,1 part 3 in 1 oil.
It mixes into a less viscous version of vaseline.  Stays where it is put, works well when it is cold.
good luck
Roy
Title: Re: sealing a propshaft
Post by: davidm1945 on December 14, 2010, 05:14:47 pm


1 part Vaseline, 1 part WD30,1 part 3 in 1 oil.


WD30?....Is that WD40's little brother?   %)

Dave.
Title: Re: sealing a propshaft
Post by: roycv on December 14, 2010, 05:29:53 pm
Hi I think it must be so if you can't get WD30 then WD 40 will have to do!
Roy
Title: Re: sealing a propshaft
Post by: returnee on December 14, 2010, 07:00:55 pm
Thanks for all the info , will give the 3 in 1 a try
Title: Re: sealing a propshaft
Post by: class37 on December 14, 2010, 07:25:36 pm
I use copper slip, tin from halfords will last a couple of lifetimes.

Take propshaft out and half pack tube from propeller end with copper slip, then slide the shaft back in, turning it as it goes in, keeping some pressure on the open end which forces the copper slip down the side of the shaft between it and the tube wall, then allow excess to push out as shaft goes right through tube. wipe off all excess copper slip and fit washers and nuts.

Haven't found that water gets into/ mixes with the copper slip, and haven't noticed any evidence of the copper slip leaking out of the tube to contaminate the water.

Shaft is free turning, so there doesn't seem to be any friction.

cheers

alan
Title: Re: sealing a propshaft
Post by: Peter Fitness on December 14, 2010, 08:49:55 pm
The question of oil versus grease has been debated on many occasions. Those in favour of oil point to the fact that oil offers less resistance than grease (or grease like substances) which is quite true but, for practical purposes the difference is negligible. It may be a problem in high speed craft where every RPM is vital, but for most models the extra battery drain would be minimal. I have always used grease of the outboard motor variety which, to all intents and purposes, is waterproof, and have never had a problem with water getting into a hull via the prop tube.

However, in my opinion there is no "right" or "wrong" method, it's whatever works for you.

Peter.
Title: Re: sealing a propshaft
Post by: Mankster on December 14, 2010, 09:13:53 pm
I wonder if anyone with surface skimmers has taked a leaf out of what model submariners do. No leaks, no real maintanence.
http://www.engel-modellbau.eu/catalog/product_info.php?cPath=92_93&products_id=539
Title: Re: sealing a propshaft
Post by: RaaArtyGunner on December 15, 2010, 12:25:55 am
I wonder if anyone with surface skimmers has taked a leaf out of what model submariners do. No leaks, no real maintanence.
http://www.engel-modellbau.eu/catalog/product_info.php?cPath=92_93&products_id=539

Makes interesting commentary and point regarding wear of brass v stainless
Title: Re: sealing a propshaft
Post by: Mankster on December 15, 2010, 12:27:56 pm
Yes I dont think anyone uses brass shafts anymore for that very reason (and they bend easily too)
Title: Re: sealing a propshaft
Post by: cosmic on December 15, 2010, 12:36:33 pm
Dow Corning High Vacuum Silicone grease. Cannot wash out with water.
Title: Re: sealing a propshaft
Post by: returnee on December 15, 2010, 02:39:42 pm
Thanks Cosmic. you fellows have given me a grest many ideas.
Title: Re: sealing a propshaft
Post by: RaaArtyGunner on December 15, 2010, 10:47:28 pm
Yes I dont think anyone uses brass shafts anymore for that very reason (and they bend easily too)

Good to know  :-)) :-))
Title: Re: sealing a propshaft
Post by: Peter Fitness on December 16, 2010, 04:53:13 am
We have one member in our club who always uses brass shafts and swears by them. Others tend to swear at them. I much prefer stainless steel.

Peter.
Title: Re: sealing a propshaft
Post by: davidm1945 on December 28, 2010, 05:52:26 pm
Keep it full of grease or oil - re-oil regularly - oil, being less viscous, will seep out eventually.

Make sure the bearing at the wet end is secure. Perhaps consider using a PTFE (flat) washer between the prop and beaing/shaft end?

A.

Hi, BigA (or anybody else!),

    Any ideas where I can get M4 PTFE washers in small quantities?

Dave.
Title: Re: sealing a propshaft
Post by: cosmic on December 28, 2010, 06:38:09 pm
Hi, BigA (or anybody else!),

    Any ideas where I can get M4 PTFE washers in small quantities?

Dave.

You might try bestrcdeals.com. I know that they carry insulating shim washers in metric sizes. I think they are made by Integy.
Title: Re: sealing a propshaft
Post by: Tom Herman on December 28, 2010, 07:52:22 pm
Hi there,
I have a twin screw model tug.....the shaft ends have been made to accommodate suitable "O" rings.   It will keep the lubricant in and the water out!
Tom