Flex Shaft Lubricants

[Drag Boat Bob]

As I get ready for testing several flex shaft lubricants, I thought I would share the ones that I have accumulated for testing.

Speak up if anyone has a special one they want thrown into the mix.

Even though this will not be a thorough scientific study, it will give me an idea on just which lubricants to continue using. I was switching around with a few different ones while prop testing and I believe it was complicating the results.

I plan on using one prop (for now) and using two sets of batteries, making two consecutive runs and recording the mph. I will attempt to test one lubricant each morning when the water is calm and no wind.

Here is the list: (thanks to those who have suggested some of the below)

Marine Wheel Bearing Grease (blue)
Grim Racer Speed Grease
Hob-E-Lube White Grease with Teflon
Hob-E-Lube Moly Grease
Tamiya Cera-Grease HG
Mobil 1 Synthetic Grease
Tri-Flow Synthetic Grease with Teflon
Lubriplate “Lube A”
Quantum Hot Sauce Reel Grease
Quantum Hot Sauce Reel Lube
STP (may thin this down)

Testing is still a few weeks away, so if you feel strongly about one, just say so.

[domwilson]

I'd like to see the results myself. Thank you for testing.

[detox]

I here grease on the prop shaft and thin oil on the flex or wire drive works great.


...

[Rex R]

ky gel...

[Fluid]

You may find that the same lube tested on consecutive days will give different speeds. That has to be the first step in your tests - varify that any speed differences you see are due only to the lube and not to the day, the particular pack you used, the temperature or charge of the packs, the water conditions, etc. It would be a shame to spend so much time on what could be a vaulable test program only to find the results are meaningless....

A few things to think about before starting:
- How will you keep the lubes from being flushed up into the boat while running? The test results will be useless if the lube doesn't stay in the stuffing tube.

- Are you using Teflon liners or not? If yes, how will the condition of the liner effect the results between the first and the last pair of runs?

- How will you know if a lube works great for thirty seconds then breaks down?

- What if the thicker lubes need to warm up a bit to give the lowest friction?

- Is a difference of one mph even significant?

- Is initial top speed the best thing to measure, or is amp draw or the ability to stay fast for a two minute race? You have to define what is meant by "best" before your testing begins.


FWIW, my favorite is Pennzoil Synthetic 75-90W GL-5 from Wally's.

http://www.pennzoil.com/#/transmission-fluids-and-gear-oil/synthetic-gear-oils

.

[Drag Boat Bob]

You may find that the same lube tested on consecutive days will give different speeds. That has to be the first step in your tests - varify that any speed differences you see are due only to the lube and not to the day, the particular pack you used, the temperature or charge of the packs, the water conditions, etc. It would be a shame to spend so much time on what could be a vaulable test program only to find the results are meaningless....

A few things to think about before starting:
- How will you keep the lubes from being flushed up into the boat while running? The test results will be useless if the lube doesn't stay in the stuffing tube.
Correct! We'll see which ones have staying power.

- Are you using Teflon liners or not? If yes, how will the condition of the liner effect the results between the first and the last pair of runs?
Yes. Once I narrow the field down to the top 2 or 3, I will repeat the test.

- How will you know if a lube works great for thirty seconds then breaks down?
I won't, but I really don't want a lube that doesn't last one run. Longevity is one of the qualities I am looking for.

- What if the thicker lubes need to warm up a bit to give the lowest friction?
Each lube will get (2) 3 minute runs. If it takes longer than that to 'seat in', then I guess I won't know.

- Is a difference of one mph even significant?
Not to me.

- Is initial top speed the best thing to measure, or is amp draw or the ability to stay fast for a two minute race? You have to define what is meant by "best" before your testing begins.
You are right. I wish I had an Eagle Tree data logger, but unfortunately I do not. I plan on taking temp readings on the stuffing tube, but I cannot control the ambient temp over the several days it will take to complete the testing. Just have to wait and see.

I plan to use two different packs (topped off) for each lube and plan on early morning runs when the water is flat and no wind. 1 lube per day.
I am mainly looking for: 1. Free up some rpm/speed; 2. Longevity (I get tired of removing the flex shaft after 2 runs).

FWIW, my favorite is Pennzoil Synthetic 75-90W GL-5 from Wally's.
I'll see if I can pick some up.

http://www.pennzoil.com/#/transmission-fluids-and-gear-oil/synthetic-gear-oils

.

If you have another idea on the methodology, please let me know.

[MarkJnK]

I think Drag Boat Bob is doing us all a great service here, and while the methodology might not be lab-certified, I think it will still be good info, and I thank him for the time he is taking to share his results.

[MT-Tank]

science fair project!

This will keep you busy for a while!

Seriously, you may want to consider setting up a 'lab' experiment to save yourself time and get a better result by reducing variables. Consider:

• deep plastic tub with lid to contain water splash
• an old brushed motor (eliminates an ESC by allowing a direct connection to power)
• 'constant' power source like a car or marine battery
• prop sized to allow motor to spin up to target RPM's
• ammeter to check current draw

Since the only variables would be lube and temps of motor and shaft it would be easy to do all the testing quickly. Remember, the motor and prop can be small. We don't need to push the water, just spin up the shaft!

Even if you go ahead with field testing you may want to first test to see if the first or second run has an advantage by repeating runs with the same lube. If there is a difference then each day's test could start with the same 'control' lube followed by the 'test' lube. This would also 'flush' the 'test lube 1' with the same 'control' before trying 'test lube 2' (Test 1 doesn't influence Test 2, etc...)

Sounds like fun any way you do it (if you are a scientist like me...)

Paul

[Bill-SOCAL]

I use Mercury Quicksilver 2-4-C lube on all my flex shafts. Seems to work fine for me.

[domwilson]

I think Drag Boat Bob is doing us all a great service here, and while the methodology might not be lab-certified, I think it will still be good info, and I thank him for the time he is taking to share his results.

I agree.

[Drag Boat Bob]

This will keep you busy for a while!

Seriously, you may want to consider setting up a 'lab' experiment to save yourself time and get a better result by reducing variables. Consider:

• deep plastic tub with lid to contain water splash
• an old brushed motor (eliminates an ESC by allowing a direct connection to power)
• 'constant' power source like a car or marine battery
• prop sized to allow motor to spin up to target RPM's
• ammeter to check current draw

Since the only variables would be lube and temps of motor and shaft it would be easy to do all the testing quickly. Remember, the motor and prop can be small. We don't need to push the water, just spin up the shaft!

Even if you go ahead with field testing you may want to first test to see if the first or second run has an advantage by repeating runs with the same lube. If there is a difference then each day's test could start with the same 'control' lube followed by the 'test' lube. This would also 'flush' the 'test lube 1' with the same 'control' before trying 'test lube 2' (Test 1 doesn't influence Test 2, etc...)

Sounds like fun any way you do it (if you are a scientist like me...)

Paul

Wow! I think I underestimated the interest in this undertaking. I have decided to limit it to 10 lubes (I have a list of 11 right now). The list has gone through many changes (Thanks again for everyone's input!) and I think I have as much as I can handle right now.

Doc's idea is certainly a more efficient method of testing, but I want to have some fun driving as well. Even if my results don't produce any viable data, I will still have fun doing it.

Maybe Doc could pick up where I leave off and we can post and maintain an updated list of the best lubes and the ones that produce the best price/benefit ratio.

Anyway, now more than ever, I am curious about what will come out of this test.

[Drag Boat Bob]

I should have mentioned that during prop testing, I used a few different lubricants which produced noticable differences in speed with the same prop.

I really have no doubt that the shaft lubricant can mean a difference of 3-4 mph.

I think this is going to be fun...

[Drag Boat Bob]

I use Mercury Quicksilver 2-4-C lube on all my flex shafts. Seems to work fine for me.

Bill,
I wondered about that one too.

There are two very interesting lubes that did not make the list due to financial considerations (and the perceived price/benefit ratio):

1. Neo Synthetic Grease (seems NASCAR likes it)
2. Mercury Special 101 Lubricant

Bob

[Bill-SOCAL]

Iuse it on both gas and FE boats. Served me well.

[domwilson]

Iuse it on both gas and FE boats. Served me well.

Where do you get that from?