My buddy just gave me two oxen blocks http://www.oxenblocks.com/ for my spinnaker addition on my N5.2. One works well and the other feels pretty stiff. I read on the mfg website that the 1st gen used lots of grease, but I cannot find anything on lubricating these. I see it has lots of o-rings. Any ideas on what to try other than sending it to Murray's for $60+shipping+parts?

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FYC, Nacra 5.2 "Chris's Flyer" & Nacra Playcat & Farrier Tramp
Previously owned: Trac 14, H14, H16, H18, N5.0, G-cat 5.0
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i find yelling at gear that is now working is very satisfying - doesn't help much though

besides that when my harkens were acting up they advised me to soak in reaaaaly hot water to desolve any salt crystals / sand in the block - NOT BOILING water though

also - i have no idea if this is a good idea on oxen blocks but worked well for my harkens

Being that this is very similar in construction to a winch I guess I will follow Practical Sailor's advice for winch paw lubricating. https://www.practical-sai…/penny-pincher-pawl-lube

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FYC, Nacra 5.2 "Chris's Flyer" & Nacra Playcat & Farrier Tramp
Previously owned: Trac 14, H14, H16, H18, N5.0, G-cat 5.0
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If it’s not functioning smoothly, I would recommend sending it to Murrays for servicing. I used those blocks for many years on the Hobie 18 jib. They work well most of the time, but also have a tendency to fail without warning at the most inopportune time. When that happens, they can lock up and not allow the sheet to release. I ended up switching back to the standard Harken blocks, but if I were to continue using the Oxens, I think I’d get in the routine of having them serviced on a regular basis.

sm

I got the blocks working smoothly now. I did not do a full tear down (though I tried). I was not able to get the side of the pulley open. I tried rasping on the shaft with a screw driver handle on the opposite side and it did not budge.

There was plenty of grit around the seals so I cleaned it up with a toothbrush. I was missing an o-ring on the main bolt, but I had generic spares in the shop and replaced it. For lube I used 75W-90 SAE gear oil. I heated it on an electric burner in a stainless steel measuring cup and poured a little into the gap at the shaft with seal removed. I put my shop vac on the backside and sucked in the oil. My worst block went from unable to spin in my fingers to rolling several turns with ease.

Overall a super easy job. Oiling once a year should be sufficient to stave off the ~$60 each rebuild for a few years.

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FYC, Nacra 5.2 "Chris's Flyer" & Nacra Playcat & Farrier Tramp
Previously owned: Trac 14, H14, H16, H18, N5.0, G-cat 5.0
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I have a set. The sheaves are worn to the point of not being able to hold a line. I tried to take the worst one apart and it was nearly impossible. I did get it apart. I laid it on a vise and whacked it with a two pound hammer.
Surprising all the innards are intact and function with no trouble and I was able to put it back together again. It works fine, but it’s still not usable because I didn’t replace the sheave.

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Tim
Collierville (Memphis), TN
Supercat 15--sold :(
Hobie monocat--given
Vanguard 15--traded for...
Nacra 4.5--sold
Nacra 5.7
Hobie 14–sold to make room for...
Supercat 17–sold
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I've been a 100% Oxen convert for about 35 years now - I use them on main and jib on every cat I've owned except for the Tornado, where they couldn't be used on the jib because the horse slopped around too much. Routine maintenance isn't tough once you've familiarized yourself with the gutz.

Removing the cover from the sheave isn't hard. Nowadays I have a hydraulic press, but before that I used a bench vise - or even just got my weight over it and pushed firmly. You don't need much for a jig - a jar lid of suitable size and depth will do fine. Assuming there isn't a problem with the core, I just pop all the parts into the ultrasonic cleaner with some detergent, then give them a rinse, dry, and reassemble with lots of FOOD-GRADE, PLASTICS-SAFE silicon spray (Chesterton 660, CRC, etc.). Beware of automotive or hardware-store silicons - you can find out the hard way that some (like Jig-A-Loo) also contain solvents that attack plastic.

There are some parts that will fail over time, in particular the trip lever standup spring, one end of which has a right-angle bend that fits into the hole in the trip lever - that's the bend that eventually breaks off. In a pinch, I've just trimmed and rebent the broken end (you need very fine pliers to do this). Other than that, the only thing you have to watch for is (as tnell points out) a worn sheave, and to avoid that use a rope that fits well.

But Oxens were a game-changer for me - I would never have developed the technique or confidence to solo trapeze without them. I'm an evangelist.



Edited by jonathan162 on Feb 08, 2021 - 05:22 PM.

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Southern Alberta and all over the damn place.
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1981 SuperCat 20 "Roberts' Rockets"
1983 SuperCat 19
TriFoiler #23 "Unfair Advantage"
Mystere 17
Unicorn A-Class (probably made by Trowbridge) that I couldn't resist rescuing at auction.
H18 & Zygal (classic) Tornado - stolen and destroyed - very unpleasant story.
Invitation and Mistral and Sunflower and windsurfers w/ Harken hydrofoils and god knows what else...
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