How much fraying around thimbles acceptable?

[daveg_72]

Hi All!

Let me start by saying that I love this forum! I have been researching Macs for the past couple of years and within the past month have found myself the proud owner of a 1991 Macgregor 26S. This forum has been an invaluable resource for me and I hope that some day I can give back.

Our first trip in the boat was nice, but ended by getting caught out in a thunderstorm and having to anchor in a small cove of our local lake, Greers Ferry Lake in Arkansas. In the cove with us were a belt of trees that lined the water's edge due to the water level being so high. I had a hard time getting an anchor to set and the wind and waves pushed us back into these trees. My mast did a fair amount of banging around in the tree branches and my hull took a few scrapes. At one point, I stayed down below with my six-year-old and just hoped for the best.

By nightfall, the storms has receded and we were able to set a more proper anchor further away from the trees. My son prepared a lovely dinner of beef jerky and cheetos, which we enjoyed by the cabin light and fm radio. By midnight, after checking the anchor ever 30 minutes, I was finally able to get some rest. After surveying the damage the next morning, I noticed that everything was still intact, but the rigging was a little loose. I attributed most of this to the frontstay turnbuckle being almost full extended. However, after returning home, I noticed some fraying in the thimbles of my shrouds. I don't recall what it looked like before, so I'm not sure if I can attribute this to the storm.

The picture is of the lower starboard shroud and it is probably the worst. I would imagine that the braid should be a little tighter, but maybe I'm being paranoid. Can I get a second opinion on whether or not the cable around this thimble looks normal? Thanks so much!

[Hamin' X]

I am far from a rigging expert, but it seems to me that the thimble spreads the load out over one, or more twists. I would say that as long as there are no broken strands, you should be fine, unless offshore, or racing use is anticipated. At least I would not worry about it if it were my boat. More opinions to come, I'm sure.

~Rich

[Catigale]

Ill concur with Rich on this one. The lowers are tensioned less on these boats, so I doubt the 'unwinding' is an issue. I would take pictures on both sides and see if the unwinding 'progresses' - if it does, replace of course.

Fresh water use you wont have to worry about corrosion failure. The majority of failures of Mac rigging come from being too loose, not too tight.

[Crikey]

OK, I'm looking at more than one broken strand here!

[dennisneal]

daveg,

I too think I see at least one broken strand.

The rigging on your boat may be about 20 years old, if it has never been replaced. Some "experts" recommend replacement every 10-12 years.

Here's a link to a recent article in Practical Sailor Magazine:

http://www.practical-sailor.com/issues/ ... 876-1.html

I think the photo caption is important:

"A broken wire strand offers a clear warning that wire replacement is due. Failure at a deck-level swaged terminal is one of the most common failure points."


Dennis

[Divecoz]

Click on the photo in the original post... then click the + and I believe you will not see any broken strands.. I believe you will see a sloppy attempt at installing a thimble.. One Strand towards the bottom has a "nick" in it but not IMHO enough to be of concern..

[daveg_72]

Thanks for the responses! I spoke with the PO last night and he confirmed that in his ten years with her the rigging had not been replaced. I, too, have heard the 10-12 year replacement suggestion and I think I'm going to go ahead replace the four shrouds and get a new turnbuckle for the frontstay, as the old one seems to be binding. If anything, it will make me sleep better at night. I checked the prices at BWY and I can think of dumber things that I've done with $200. I appreciate everyone looking at it and opining!

David

[seahouse]

The spread open thimbles indicate that side thrusts have been applied to this area, probably during rigging and de-rigging. Looks like it happened often.

To illustrate, if an upward (and to the left) force were applied to the fitting in the lower picture, I think you can envision that exactly this could happen if it didn't happen to slip to the end of the eye.

While there are no broken strands visible, this side loading can stretch the swaging open and weaken the connection.

You can prolong the life of your new stays by avoiding this as much as practicable. But it's not always possible to watch every fitting every time, but if resistance is felt some gentle caution is appropriate.

If I find this on a swage fitting, I bend the thimble ends back into place because it stabilizes the cable as it exits the swaging, contributing to the overall strength of the joint.

I think you have made a wise decision!

- Brian.

[Capt Capsize]

Good choice, $200 is great investment. Take from one who has dis-masted, twice, on a Hobie 16, once under heavy winds. The parting cable sounded like a 22cal gunshot. It was no fun and you could get seriously killed. I was very lucky.

By the way, my the failed shroud, looked better than your photos. I am now very fond of double Nico-pressed thimbles One to hold the thimble and another an inch back for strain relief and insurance.

[rtrinkle]

I agree, I think you are making a good decision to replace. The shrouds will only be as strong as its weakest point. Better safe than sorry when it comes to personal safety.

[Divecoz]

Seahouse: I was glad to see some else does this.. I have always done it because? It just seemed to be begging attention.. However? I wasnt sure if what I was doing, was considered correct install.. I use a pair of Plumbers channel-locks/smooth jaws to accomplish this..

If I find this on a swage fitting, I bend the thimble ends back into place because it stabilizes the cable as it exits the swaging, contributing to the overall strength of the joint.

I think you have made a wise decision!

- Brian.

[seahouse]

Hey Dive!

The bent thimble is an artifact of abuse. The only disadvantage I can think of to closing up the thimble is that you have covered up that artifact, and made the joint appear to be in better condition to someone who doesn't know it was done.

I think it would be bad for a boat yard to do this only if they didn't record it or let the owner know it was done.

But I think it is a good DIY maintenance practise if the shroud is not being replaced (and you're not doing it repeatedly to the same fitting).

-Brian.

[Catigale]

I missed the thimble bending on my first take. My guess is someone rigged the boat with the thimble caught on the edge, and when they swung the mast up, the chainplate put that dent into the thimble. I've learned to get my mast and check all the thimbles on the lowers and uppers before I tension anything.

[Divecoz]

Over my many years running a lot of big jobs, we repaired , altered and built a lot of our own rigging / lifting apparatus..We used either a hand pump Greenlee or an Electric over Hydraulic pump to Crimp / swag our fittings. I was always adamant about bending over those "Tails" on thimbles.. Just an area for snag potential in my mind.. I got gigged Once by an OSHA inspector for covering my swags and bitter ends with Shrink-Tube.. he was concerned we wouldn't see the braid fraying.. I pulled out my Buck Knife and trimmed it back about a 1/4 " onto the swag to show we had no fraying and he was happy and we cleaned them all up ... No Fines $$$$$$ I was concerned about injuries from bitter end , snags and our stuff got Used and Abused !!!!! A LOT more than the shrouds on a boat..Over time I found Clear Shrink Tube and we used it exclusively from that point on..

Hey Dive!

The bent thimble is an artifact of abuse. The only disadvantage I can think of to closing up the thimble is that you have covered up that artifact, and made the joint appear to be in better condition to someone who doesn't know it was done.

I think it would be bad for a boat yard to do this only if they didn't record it or let the owner know it was done.

But I think it is a good DIY maintenance practise if the shroud is not being replaced (and you're not doing it repeatedly to the same fitting).

-Brian.