UV damage and webbing jackstays

[NPMR]

The webbing jackstays on our boat are 12 years old.

They look and feel fine but have not been used in a MOB situation or stressed.

Question. How long are they likely to be good for? UV and abrasion resilient according to the manufacturer.

 

[RunAgroundHard]

For continuous use, exposure nylon and polyester web based lifting sling strength can deteriorate by 60% and 30% respectively. In my industry they are inspected every 6 months in the U.K., or annually, depending on the regulations in country of operation. If you remove when not in use, or use in countries with more cloud cover, then they last longer.

In my opinion at 12 years old, based typical summer use, I would replace. I think 5 years is a feasible life for Scottish cloudy weather and typical usage, removed when not on boat.

 

[RunAgroundHard]

According to this article, linked below, which is a subscription service, testing by a manufacturer (Hathaway, Reiser & Raymond) after 1 season, in the USA, IASF compliant Dacron jackstays had lost 25% of their strength and failed the IASF load test limit below 2040 kg.

Jacklines: Materials, Fabrication and Installation

 

[greeny]

If they've been outside for 12 years then I would say its time to replace them. You will only find out for sure by testing them with a suitable weight/load.

 

[zoidberg]

Apart from the reference above, no-one really knows. And just about everyone assumes that the safe life of 'their' jacklines and tethers is far, far longer than all indications from industry..... so such kit doesn't get replaced when it probably should.

'They look and feel fine'.

Essentially, you're gambling your life - and that of others who you invite on board your boat who reasonably assume your boat and kit is safe - on your hunch, no, your biased preference. But at least you're asking yourself the question....

 

[Daydream believer]

Some years ago I bought a long reel of webbing from a tack shop & made my own jackstays. A year later my wife was on deck just off Ostend, suitably clipped on, setting fenders. The jackstay fell to the deck as it was rotten.
When berthed we were discussing this with some dutch people on the next boat. It was suggested that I tested a length of the unused webbing. To do this I stretched it across the 2 genoa winches & winched on one winch.
The Dutch chap was sitting dead opposite on his cockpit coming with his knees apart.
The webbing snapped & went like a whip. It caught him straight in the nether regions with an almighty whack.
He yelled out in pain & gave me one hell of a verbal. Poor bloke was in real pain for a while
My wife went below so no one could see her expression
Now we use orange marlow braid on braid, which is easily identified from other cordage.

 

[Snowgoose-1]

In the days of hank on jibs, after you got the jib in the bag and chucked through the fore hatch, the next job was to coil the jib sheets and jackstays which also went through the fore hatch until next time. .Lasted forever.

All done on autopilot. We seemed to have so much more time in those days.

 

[ithet]

The last webbing jackstays I fitted had a label to record the fitting date, and stated that they were rated for (if I remember correctly) 720 days exposure only.

 

[dancrane]

At 12 years old, if their UV resistance has been put to any kind of test at all, I bet they're useful as chocolate teapots.

Go to 7 minutes 50 seconds in the clip below, for one season's UV effect. Although the whole channel is worth watching/subscribing to.

 

[PetiteFleur]

My previous boat had jackstays rigged when I bought it and didn't check/inspect then before I used then. I checked at layup time, and I managed to rip the stitched ends apart easily with not a lot of force - the stitching had completely uv degraded. I scrapped them and made new ones for the following season with correct thread and overlap twice as long and remove them after every trip and stored below.

 

[BobnLesley]

When we were sailing in the Med and Caribbean we were switching them out every 2 - 3 years

 

[thinwater]

Rock climbers have died because of trusting slings that had been left in place for 5 years or more. I've pulled 5000-pound slings off with my bare hands.

The general wisdom of 3-5 years in the UK is fair to lenient. 1-2 years in sunny places.

If you want truly durable jacklines, you do not use webbing. Webbing is nice, but only for a few years. After 12 years, even in the UK, cut them in sections so no one uses them. They are probably only 25% strength.

 

[Graham376]

Stick fingers in the end loops and try to pull them apart. Chances are the stitching may well be rotten, long before the webbing.

 

[Neeves]

Unless you test them to destruction you will never know. Unless you can document their exposure to UV you will not know. I assume, I don't know, that exposure to sunshine in Sydney will degrade jackstays more quickly than exposure to sunlight in Edinburgh.

However if you test to destruction you have lost your jackstays anyway - so don't waste your money testing - just buy new ones.

Companies like Marlow should have an accurate idea of applicable lifespan of their webbing and they probably have a good idea of the lifespan of professionally applied UV resistant thread. Rather than guess - ask them. They have a technical department - they will know - they will be cautious with their answer - they don't know how you will use their answers - so treat them carefully.

I would not rely on 'my' stitching - I'd knot - as mentioned repeatedly - stitching fails, first. We used a simple overhand know and then reversed the tail through the knot to make an eye (this knot may have a name, unknown to me). Its not as neat as stitching but the two knots, one at each end are not that unsightly.

When we made our cruises to Tasmania the jackstays were installed. The rest of the time, when we were pottering about (which might include 70nm passages in the Tasman Sea) we would remove the webbing jackstays and use hard points and double ended tethers.

Jackstays are pretty useless unless you religiously and strictly demand use of harnesses and tethers by yourself and crew when going forward in all but light conditions - say when the deck starts to get wet....?

Jonathan

 

[William_H]

In the days of hank on jibs, after you got the jib in the bag and chucked through the fore hatch, the next job was to coil the jib sheets and jackstays which also went through the fore hatch until next time. .Lasted forever.

All done on autopilot. We seemed to have so much more time in those days.

I use hank on jibs out of preference. Best for windward performance. Yes afteer race take off the jib then coil the sheets and put away. No jack stays however. All done while sailing back top swing mooring on main sail. The madness continues tomorrow. ol'will

 

[thinwater]

Unless you test them to destruction you will never know. Unless you can document their exposure to UV you will not know. I assume, I don't know, that exposure to sunshine in Sydney will degrade jackstays more quickly than exposure to sunlight in Edinburgh.

However if you test to destruction you have lost your jackstays anyway - so don't waste your money testing - just buy new ones.

Companies like Marlow should have an accurate idea of applicable lifespan of their webbing and they probably have a good idea of the lifespan of professionally applied UV resistant thread. Rather than guess - ask them. They have a technical department - they will know - they will be cautious with their answer - they don't know how you will use their answers - so treat them carefully.

I would not rely on 'my' stitching - I'd knot - as mentioned repeatedly - stitching fails, first. We used a simple overhand know and then reversed the tail through the knot to make an eye (this knot may have a name, unknown to me). Its not as neat as stitching but the two knots, one at each end are not that unsightly.

When we made our cruises to Tasmania the jackstays were installed. The rest of the time, when we were pottering about (which might include 70nm passages in the Tasman Sea) we would remove the webbing jackstays and use hard points and double ended tethers.

Jackstays are pretty useless unless you religiously and strictly demand use of harnesses and tethers by yourself and crew when going forward in all but light conditions - say when the deck starts to get wet....?

Jonathan

Overhand loop.

The problem with knotted jackstays is that because the knot weakens the webbing, and the webbing is just barely strong enough to meet the standard, knotted jackstays don't meet the standard. Not that matters for most people, and the knot is probably stronger than sunburned stitching.

Something I have never seen studied is how knots fare, compared to stitching, in the sun. In fact, all of the sunburned climbing slings I have seen tested, failed somewhere other than the knot or the stitching, where ever the sun hit them the most. I'm not sure that has a parallel on boats.

---

I'm just following. On my multihulls I have always been able to find a place to run rope (way over strength--8,000-10,000#) such that it was not underfoot. Not always or often practical on monohulls. I do like to leave them rigged, since I singlehand most of the time and it would never make sense to rig them when the weather is changing. Too much going on and probably more hazardous at that point than doing without. I'm also not going to claim I use them religiously or even when I should. But they are ready an the harness/tether is ready. Mostly I used them when something needed repair/adjustment, I was going to use both hands for that, and I wanted to be able to concentrate on that, not holding on and watching for waves.

 

[Neeves]

Overhand loop.

Thank you.

Jonathan

 

[Neeves]

If there are any printers (people who print), specifically textile printers....

On exposure to UV.

Print is subject to UV degradation - so labels can fade at a different rate to 'other' labels or the degradation of a UV cover.

Some labels and some UV strips last better than others.

It should be possible to measure the rate of UV degradation of print and different print chemistries or different textiles.

Items like jack stays could be labelled with an ink whose 'disappearance' could indicate 'end of life' of the jackstay.

When the print has faded the item has reached end of life.

Jonathan

 

[dansaskip]

If you want truly durable jacklines, you do not use webbing.

As he says do not use webbing. Use dyneema instead. Easy to splice and make up your own and much more resistant to UV and it doesn't roll under your feet and a safety clip slides along it more easily. I swopped from webbing years ago.

 

[Roberto]

The webbing jackstays on our boat are 12 years old.

If they are tubular, you might consider using them as sleeves for wire jacklines. Or make ties for sails, dinghy paddles, gaz bottles, etc
FWIW I replace my webbing jacklines every couple of years (and take them off during overwintering), home sewn they cost about 20-30euro (home sewn), half a night in a marina?