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.

Supplies

For equipment: You will need a heat gun, preferably the type that works best on heat shrink electrical tubing. You'll notice that mine has an end attachment just for heat-shrink tubing; $20

You will need a bicycle-type electric portable air compressor. Pictured is the one I purchased a while back. It's not the most expensive nor the cheapest. If you don't have one expect to spend about $40 for a good one.

For consumables: One or more continuous roles of UV resistant, industrial grade heat shrink tubing for each diameter of safety line that you are going to cover ($10/roll). This stuff comes in all sorts of colors, and since a lot of the canvas on my boat is light grey, I chose the same color for the shrink tubing. As you chose your heat shrink tubing, pay attention to the starting, un-shrunk diameter and the shrink rate. I bought an inner diameter only slightly larger than the safety line with a 2:1 shrink rate. I used 4 rolls (2 each 10m [33'] for the 1/4" lines and 2 each 10m [33'] for the 3/16" lines); $40

A few inches of electrical tape ($1 a roll)

Total spent on consumables: $41

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.