prop and shaft anti-fouling

[yotphix]

Rick, Propspeed does work as promised. Nicks from debris just present as a scratch to which growth can attach if large enough but don't seem to grow. I recently redid the propspeed on the large motoryacht I work on and after two years in the water it was showing minimal growth. The worst was in the hard to reach places that the last guy did a bad job of coating! The only reason i replaced it was because we were out of the water anyway, the growth alone didn't yet warrant it.

It was easy to do, just be thorough at each step. For the Monster 36" screws and 3" shafts i was doing, two people were required to move fast enough but you won't have any trouble. Removing the old Propspeed was the hardest part!

I will definitely be putting propspeed on the next time I have a sailboat in saltwater.(I sail OPB through a club for now since I'm stuck on the luxury yacht!)

[hellosailor]

SkiprJohn, offhand I don't remember the clearance rules but IIRC it may be not less than 10% of the prop diameter, so your 3" clearance would work for the typical sailboat prop. IIRC--and I don't always.<G>

[GordMay]

Dimensional Standards and Tolerances for Propeller Shaft ends, Propeller Hubs, Keyways and Shaft Couplings (in accordance /w SAE, Standards J755, and J756) are found in:
ABYC Standard “P-6"
Propeller Shafting Systems: (23 page PDF)
Goto: http://www.abycinc.org/committees/P-06.pdf

“Aqualoy” Marine Shafting has an on-line tutorial, based upon ABYC Standard “P-6", which provides a wealth of technical information.
http://www.gpcprop.com/PDF%20Files/aqualoy.pdf

See also: Society of Automobile Engineers (SAE) standards:
SAE J755 - Marine Propeller-Shaft Ends and Hubs
SAE J756 - Marine Propeller-Shaft Couplings

[SkiprJohn]

Aloha Gord,
Thanks for the informative articles. I'm going to pull the shaft today and then take it to a machine shop for a crop and new key way.
Kind Regards,
JohnL

[delmarrey]

I purchased the Aqualoy 19 when I machined my shaft. I would have liked the 22 but it was not available on such short notice. Even at that it was $20 a ft. for 1" OD. It does machine nice, we'll see how it wares.

In their "Instruction Procedures" I noticed the statement " Since a 100% fit is not always possible, an effective seal such as waterproof grease should be used to exclude water. This seal will also protect against dissimilar metal corrosion.. That seems to contradict the statement proceeding, which instructed how to get a uniform fit by lapping.

Oh well! It seems nothing is perfect So, apparently if one has a sloppy prop fit "Use Grease". And for protection against corrosion, I doubt it!!!

John,
I'm glad you decided to shorten the shaft. The ABYC must have printed those spec's for a good reason. It seems anytime one changes from the original design one has to go through a series of "what if(s)" before a final installation is done.

[SkiprJohn]

Aloha All,
I took the shaft into a machine shop, had 2 and 3/4 inches lopped off and a new keyway cut. They also gave me a new stainless key. Nice of them. It cost me an extra two days and $55 but it will fit better and bring the prop hub within two inches of the back of the cutlass bearing. Just out of curiosity, is that a comparable price for the job?
I'm on an outer island and there are very few machine shops to choose from. The nearest marine shop is 100 miles away. The one I chose was only 15 miles away.
Kind Regards,
JohnL

[Big Moe]

Dear Jentine:

This is the translation:

VELOX for antifouling
propellers, axles, etc. feet aft. "What I believe the contents to be
is "composed of tributyltin compounds, triphenyltin acetate,
etilglicole

[hellosailor]

Moe, I think you've posted to the wrong thread.

And fwiw tributyl tin may be universally banned by now.