Hobie Cat Forums

It is currently Wed Jul 30, 2014 12:14 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Fri May 22, 2009 5:22 pm 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 8910
Location: Oceanside, California
Thanks roadrunner!

Note: This is the first of three parts dealing with the Mirage Drive.

Part II has to do with lubrication points:

http://www.hobiecat.com/community/viewtopic.php?f=60&t=12576

Part III is about inspecting and adjusting the Drive:

http://www.hobiecat.com/community/viewtopic.php?f=60&t=12578


I decided to test three popular lubes -- the ever popular WD-40, my favorite Breakfree, and Rynkster's dealer's favorite silicon.

Initial characteristics: WD-40 is a thin, penetrating oil that displaces water. It feels moderately slippery between the fingers. BreakFree has a little higher viscosity (thicker), comes out in a foam, has friction modifiers and is very popular in the gun world. It feels thicker and slipperier. Silicon is a dry friction reducer that has a liquid carrier for penetration and distribution, which evaporates in short order. It feels squeaky between the fingers.

This first pic shows each sprayed on a vertical sheet of ABS plastic:
Image

Within five minutes the liquid carrier for the silicon had evaporated. After two hours (below) a portion of the WD-40 had also evaporated.
Image

A gentle stream of water was applied to the plastic sheet, washing away the BreakFree, but not the remaining WD-40 (surprise!):
Image

Talcum powder was distributed on the entire area to detect any remaining oil. This would simulate dirt, mud or debris in the water. After being blown off with an air hose, it stuck almost exclusively to the WD-40 sample (below):
Image

Again, water was applied. The remaining talcum washed off all but the WD-40. It had congealed with water and oil to form a sludge (below):
Image

Results and interpretation: The silicon has no corrosion protection, is not a particularly great friction reducer, and had little to commend it. The dealer, IMO, is misinformed. Whereas it's essentially useless on the Mirage Drive, it is the best lube (and only one I would use) for the Twist & Stow rudder -- it flushes and frees up the mechanism without any sludging effect or attracting any dirt or grime.

WD-40 is acceptable. It penetrates, displacing water (as most petroleum based products do) and offers protection against corrosion. It's biggest shortcoming in these tests, is its tendency to retain and accumulate small particulates. This could increase wear.

Breakfree offers superior penetration into wear points because of its foaming action (doesn't run off so fast). It seals and coats the parts better than WD-40 because of its higher viscosity. It lubes better because it contains friction modifiers. It washes free rather than turn to sludge in water. I have a six year old drive that has been maintained with BreakFree since new. It has been used in salt water as well as fresh water. As you can see below, it still looks excellent and runs like a top:
Image

Or maybe I'm a bit biased. I'm sure there are equally good or better lubes available, but at least among these, you can see what works and what doesn't work, and why. 8)

by "roadrunner"

Part II has to do with lubrication points:

http://www.hobiecat.com/community/viewt ... 60&t=12576

_________________
Matt Miller
Director of Parts and Accessory Sales
Hobie Cat USA


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group