Refurbishing Sailboat Safety Lines

Intro: Refurbishing Sailboat Safety Lines

Welcome to another kick-ass Instructable from yours truly, Disc Dog!

Y'all know I'm a sailor and own a sailboat, and y'all know I am all about fixing a repairing stuff rather than throwing it away. What better place to practice my trade than on the sailboat! While I have done a lot of DIY projects on the boat, few have been as practical as this one.

Like most sailboats, my boat has white, nylon coated safety lines that run from the cockpit to the bow pulpit. And, after about 10 years of continuous exposure to the sun the white nylon has cracks all up and down the lines. And while the cable underneath is stainless steel, a couple of ocean waves over the bow and you are quick to discover that [when subjected to salt water] even stainless steel will show a superficial coat of rust. Compounded with rust with the cracks in the white plastic coating the rust stains will start making your lines looking like something off the Black Pearl [in Pirates of the Caribbean]. And while the safety lines are an eye-sore, they are still perfectly serviceable.

I've tried a variety of cleaners and rust removers to improve their appearance but nothing seemed to work.

At this point many boat owners would simply opt to replace them. On my boat alone that would cost $245 for the 1/4" lines and $120 for the 3/16" lines; totaling $365. That doesn't include the swag fittings on the ends...so add another $250. And while I am not cheap when it comes to sailboat safety, I'm also not stupid.

So I came up with an outstanding, perfectly functioning repair that looks fantastic.

STEP 1: Clean and Prep

Remove the lines from the boat, lay them out and clean them with water and a mild detergent (just to remove any salt on them). Let them thoroughly dry. If you want to remove any surface rust from the swag fittings, now is the time to do so.

For each safety line grab enough heat-shrink tube to make one continuous cover. If you can, do not cut the heat-shrink tube to length at this step. As it turned out, one box was just enough for each of my safety lines with a few feet leftover for the short, removable lines [like between the stanchions for getting in and out of the cockpit] so I left my heat-shrink tubes uncut until I covered each main line, then I used the leftover tubes to finish the shorter safety lines.

Now, here's the tricky part:

Most sailboat safety lines have one threaded end and one with an eye attached. You will need to start feeding the end of the safety line with the threaded end into one the end of the tubing by hand. Since you bought it by the roll, chances are that the heat-shrink tubing will be flat and will only go on so far. Try to push the safety line into the tubing as far as you can by hand. Chances are you won't get too far, so go to the next step.

STEP 2: Getting the Safety Line Covered Completely

As shown in the 2 photos, lay the heat-shrink tube out completely, pinch open the other end of the heat-shrink tube and attach it to the outlet tube of the air compressor using a few wraps of electrical tape. Set the PSI to at least 40 PSI, turn on the air compressor and inflate the heat-shrink tube. It probably won't inflate enough for you to keep pushing the safety line into the tube with minimal effort, so you may have to hold the heat-shrink tube [at the end you are feeding the safety line into] with just enough grip to keep a good air seal between the heat-shrink tube and the safety line [to keep it inflated] and soft enough to allow you to push the safety line into the inflated heat-shrink tube.

I had this trick down by the time I finished the first safety line.

IMPORTANT: When you have just about covered the entire safety line, and you are about 4" from the swag end-fitting [that's being pushed into the heat-shrink tube] you will need to cut the taped end off the air compressor. Measure and cut the heat-shrink tube off at the end leaving about 1"- 2" of coverage on each swag fitting at both ends when you are done pushing it on. You can now push the reminder of the safety line in the tube by hand. If properly cut to length all of the white nylon coating will be sealed off from the elements after you shrink the tube in place (next step).

If you don't have a long enough shrink tube to cover the safety line in one piece, don't worry about it at this time. I'll cover that problem in the next step.

STEP 3: Shrinking the Tube in Place

Now that you have the shrink tube covering the safety line it's time to shrink it down.

If you have to use two pieces of shrink tube to cover one safety line, shrink the longest piece on first starting from the swag piece that your first shrink tube ended up at (usually the eye fitting as shown in the picture). Shrink the entire tube down to minimum diameter, and then shrink the additional tube on to the end of that safety line with about an inch or two overlap on the first tube shrunken down.

As the picture shows, start the shrinking process at the last end of the safety line to get covered [having pushed the entire safety line through the shrink tube]. You'll notice I have attached the shrink-tube fitting to the end of my heat gun. This attachment works like magic.

As you hold the heat gun in place slowly draw the assembly through the heat at such a speed that the tube just starts to shrink as it approaches the attachment and is completely shrunk as it exits the attachment. If the tube is not shrinking down completely then draw the assembly through the heat slower. Make sure that all sides of the safety line are being covered properly with a completely shrunken tube.

Over time (and with a little experimenting) I found it best to sit down, spread my legs apart, hold the heat gun between my legs (with my right arm resting over my right leg) and then use my left hand to draw the assembly through the heat gun attachment over my left leg. It's not a fast process, so however you decide to shrink the tube down, make sure you're comfortable and into your setup for the long haul. It took me at least 4 hours to cover my safety lines; so be prepared to take your time.

STEP 4: Results

As you can see, the 'before and after' makes a world of difference. The boat is still in the yard so I will wait until put her back in the water before I put the safety lines back on. I did want to see the effects of weather on the shrink tube so I installed one of the finished safety lines across the stanchions along the back of the cockpit, and as you can see after 6 months it still looks I just put the shrink tube on it.

Be sure to comment if you have any questions or concerns.

Comments

[yojimbostark]

Those cables are NOT stainless steel! If they are showing rust, then they are becoming weak and will fail you. Wire rope, also called "steel cable" or "aircraft cable" is not made of stainless steel, because the "stainless" alloys are too brittle to be flexible. Please don't trust your life to rusty lines.

[yojimbostark]

Sweetie, don't believe in magic. Rusty lines mean death. Look at the photos in this post. The rusty cables are made from the same "stainless" alloy as a new line. Peeling plastic off of rusty lines and shrinking new plastic onto them is a practice that will accelerate their failure. People will die. We should not be calling our alloy cables "stainless", because that will give people false confidence in them. A steel alloy that is immune to rust will never be flexible or ductile enough to make wire ropes. You cannot REPAIR a rusty cable. Recycle it and replace it with a new, flexible, stretchy line that will last a good little while (until it doesn't.) Never imagine that it is "stainless", no matter what the advertisements in the magazines might tell you.

[Disc Dog]

Seriously dude...know what you are taking about before you chime in with a comment like this.

[peterandclaudette]

One poster has mentioned that stainless steel requires oxygen to remain stainless. That might seem counterintuitive or just plain wrong to the layman. However, the protective chromium oxide layer forms on the stainless steel surface when chromium reacts with oxygen. This happens instantly, with formation speeds measured in nanoseconds and film thicknesses in microns.

So why is this important? It means that stainless steel’s most prominent stainless property is corrosion resistance, which results from its ability to form and regenerate a chromium oxide layer in the presence of oxygen. However, stainless steel does not provide corrosion resistance below the oxide layer. As a result, once corrosion initiates, it progresses rapidly.

How long the wire would take to weaken so that it would break under emergency weight bearing of a human - that's a really good question. I've no idea. Maybe better safe than sorry.

[BobDohBuilder]

As a sailboat owner with lifelines that are in slightly better condition than yours, I'd be concerned that you are just covering up cables that are deteriorated close to the point of failing. The final covering looks great, but could break when someone comes to use these for their purpose.

[BobDohBuilder]

Hi Disc Dog - agree with your comments for the most part. My 25' sailboat is used mainly solo with the occasional passenger, and I've always told my companions that the lines are there for a bit of balance but should not be relied upon for fully body weight (I've had a stanchion fail before the lifelines did). Even though the lines may not get submerged in salt water, if your boat is kept in salt water, there is always salt in the air with any breeze. I've seen some people suggest to replace the cables with dyneema line but that is subject to UV breakdown. Also, if someone is clipping in with a safety harness, they'd be attaching (hopefully) to jacklines and not the safety lines. I'm sure that there are a lot of engineers on this site, myself being one as well.

[Mad4400]

Stainless steel contains chromium, which gives it the resistance to rusting. It will still rust however, this only affects the outer few layers of atoms, as its chromium content shields deeper layers from oxidation.

If a bit of surface rust was going to adversely affect the integrity of the stainless steel cable, I'd be questioning why it was chosen as a suitable material for the purpose in the first place.

[Disc Dog]

Hi Bob. As a degreed engineer, and a practicing material scientist I am very confident saying that the safety lines on my boat [that I chosen to cover instead of replace] are very comfortably within any margin of safety that may be required for my sailing situation. That being said, I think that the decision to replace your safety lines is strictly a personal choice.

Here are my thoughts: If I was continually operating the boat in heavy seas, and in situations with the real likelihood that one or crew members may be topside in foul weather (predicating the necessity to clip on to the safety lines) I would probably replace the safety lines at the first sign of rust, especially if the rust was very heavy at the swaged-on fittings. But that's not me or my boat.

However, despite that fact that all of the lines on the boat are marine-grade stainless steel, they will all show surface rust when exposed to salt water. The usual recourse is to just rinse it off and polish it away. Unfortunately the white nylon exacerbates the visual effect of rusty lines making them look to be more corroded than they are. To which, if my lines had been exposed to nothing but salt water over most of their life (that's A LOT of 'green water over the deck'!), with little chance to give them a fresh-water rinse (as I have always done), and remained in a 'rusted' condition every year, I too would have them replaced them after a few seasons.

[lbull2287]

I agree with Bob doh, the rust coming thru the original plastic is an indicator of a potential problem (although, it it not a potential problem, it is a problem). Your lines now look great and I applaud your solution, at a minimum, you need to inspect and srcub the rust off the lines (that, however, is not a recommendedprocess). Good luck.

[Ilex1]

Some warning: stainless steel (inox) needs oxygen to be... stainless steel!

If there is no oxygen it will corode and eventually will brake!

Covering can be dangerous! You covered it...

Better undo all the cables from plastic covers!

I am a sailor myself, I know what I'm talking about...

[Ilex1]

If you look at the rusty spots you had before covering you understand it's just marketing...

Looking good is too important to some.

I would be very carefull covering the terminals where flexing is more limited.

Ofcourse you may do whatever you want and this is not a discussion forum.

Greetz

[Disc Dog]

But wait... if a lack of oxygen is fatal to stainless steel cables, why on the heck are they covered with a white plastic in the first place?!

To quote a famous line: That don't make no sense!

[Pewit35]

instead (or in addition to) of using the compressor, would it help to reduce friction by squirting dry silicon spray or diluted washing up liquid on the wire as you push the shrink wrap on?

[Disc Dog]

I considered that idea, however you would need to figure out a way to force the lubricant down the [collapsed] shrink wrap. When I say that the shrink wrap tube is flat [coming off the spool], I mean it is really flat! If you forgo the a compressor, I would recommend that you can try that idea but I would use a liquid lubricant (like WD40) or some other liquid lubricant. I don't think the dry lubricant will make it down the shrink wrap tube very well, and I think that leaving a decent liquid lubricant on the lines work work to your advantage.

That being said, I might question if the lubricant degrades the shrink wrap any.

[greyhawk83]

Excellent job, well thought out and presented. Thank you

[leethayer8]

Nicely done!

[Disc Dog]

Thanks!