Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Tutorials & "How Tos" ... => Topic started by: philgg1946 on July 18, 2021, 08:04:14 pm

Title: putting a lithium grease into a propshaft housing
Post by: philgg1946 on July 18, 2021, 08:04:14 pm
I bought this launch last week ,any way jon test the motor packed in so I put a new motor and ECU in and there is a feeder on the prop shaft to add grease to lubricate the shaft while spinning, I PUT SOME HIGH TEMP WATER RESISTANT LITHIUM GREASE IN with a hyperdermic type container , I ran the motor and it seems ok when it's full will it need topping up after it's had a run ?  any help much appreciated Phil
Title: Re: putting a lithium grease into a propshaft housing
Post by: derekwarner on July 19, 2021, 01:28:33 am
Hi Phil.......it all depends on the vessel's past history %)  so If you were unsure you could consider

1. remove the shaft with the propeller still mounted [depending on design]
2. flush out any old or hardened grease.......[hardened grease will be evident in how far you take this]
3. check the outboard bearing and shaft journal surface areas
4. fill the shaft tube with grease from the propeller end, remount the shaft & cleanup any grease spillage in the hull...remembering you now know that new grease is in that all important location

Periodically put a bamboo skewer in the fill point to see how the level is
During or after a run, you will probably see evidence of air or water in suspension in the grease by the propeller.......this normal, just wipe it away. I say in suspension [bubbles] as you note the grease is a waterproof variety

I have found a blank plastic hypodermic needle shell [without the sharp >>:-( steel end] from the Pharmacy [for $1.20] is a convenient way to dispense lubrication grease or oils to model engines

Happy boating [with confidence that shaft lubrication is OK]

Derek 
Title: Re: putting a lithium grease into a propshaft housing
Post by: BrianB6 on July 19, 2021, 01:46:10 am
To flush out the old grease I put a small ball of cotton wool into to tube then push it all the way through the tube with the shaft.   Remember to put a piece of paper below the interior end of the tube to catch the old grease.   I try to do it about once a year after my tug sunk from not doing it for a few years.  :embarrassed:
I asked my local "vampire" Pathology nurse, for a couple of syringes when they still used them and still have them.   The large one with a length of plastic tube on the end is useful for getting the water out of difficult places
Title: Re: putting a lithium grease into a propshaft housing
Post by: philgg1946 on July 19, 2021, 09:31:26 am
Hi Brian and Derek, Thanks for the tips I'll give it a go, cheers Phil
Title: Re: putting a lithium grease into a propshaft housing
Post by: warspite on July 19, 2021, 11:21:35 am
I dont know if they still supply them, but nurofen childrens Calpol type medication used to supply a syringe for oral dispensing - no needle just place in the childs mouth and squeeze the piston and the meds go into the orifice  {-)  I use one to force the grease into the propeller end of the shaft - though its been a while since I last regreased the boats shafts as I haven't sailed anything for several years.
Title: Re: putting a lithium grease into a propshaft housing
Post by: Martin [Admin] on July 19, 2021, 11:27:31 am
 
Side Question: What advantages does Lithium Grease have over other / 'normal' greases?
Title: Re: putting a lithium grease into a propshaft housing
Post by: CGAux26 on July 19, 2021, 04:12:58 pm
I use Lubriplate water proof white lithium grease.  It comes in a squeeze tube, so I cut the end off to a size that fits against the outside of stuffing tubes.  Push the tube up to the stuffing tube and squeeze until new grease comes out the inside end.  Pick up the paper towels under both ends and DONE.  No syringes to load and clean up, far less wasted grease.  ;)

I re-grease my boats about yearly.  No leaks,, no shaft wear problems in 14 years and 5 boats.
Title: Re: putting a lithium grease into a propshaft housing
Post by: derekwarner on July 20, 2021, 12:54:03 am
Martin.....courtesy of Google...............


"Lithium-complex greases generally possess good stability, high-temperature characteristics and water-resistance properties"


So as designed for a range of Industrial applications, [pressure, speed & temperature] has the spin-off of being totally acceptable for general model engineering applications :-)) ...available in small quantities & only say 10% more expensive than a same sized tube of Standard base grease


Derek