The supplies and tools you need will vary depending on the type of fire hose you use. The fire hose I have is double layered. It is difficult to work with double layered fire hose, so I simply separate the layers and make two rock slings from one length of fire hose. The inside layer is rubber with white canvas covering. The outer layer is red canvas.

Step 1: Supplies and Tools

Here is what I use:

50 ft. double layered fire hose
sheet metal snips for cutting
corded drill with metal/wood drill bit
propane torch
vice with sledge hammer head
clamp
measuring tape
markers
screw driver or scrench
socket wrench
ratchet wrench
40 nuts (for two rock slings)
40 bolts (for two rock slings)
80 washers (for two rock slings)

The size of the bolts, nuts, and washers will depend on the tools you are using and type of fire hose. The drill bit I used (5/8") allowed for a 5/16" bolt. You may want to drill a hole into a scrap piece of fire hose and take it to the hardware store to see which bolts will fit best.

I used regular nuts. However, I would highly recommend stop nuts. They cannot be hand tightened, which may be frustrating when assembling. However, stop nuts are way less likely to loosen and will eliminate the need to retighten them after every hitch.

Some other feedback I have received about these rock slings is that the screws are too long and stick out too much. Sometimes they stab people when carrying rocks on the sling. Shorter screws might work as long as there are stop nuts on them.

Step 2: Measure and Cut

I cut three 65" and four 68" pieces of fire hose. You can adjust these measurements if you want your rock sling to be bigger or smaller. The final dimensions of the sling when cut to these lengths is 52" by 57".

Step 3: Separate the Layers

If you have double layered fire hose, I highly recommend separating the layers. It will be much easier to work with each layer separately. The best way I found to do this is to clamp one layer. (I would recommend a bench vise. I do not have a bench vise, so I used a clamp and a metal door.) Pull the unclamped layer from the other end. I clamped the outer (red) layer and pulled on the inner (white) layer.

Step 4: Measure and Cut... Again

I added 2" to all my measurements when I cut the fire hose the first time. I like to have a couple extra inches just in case I make a mistake or the canvas layer starts to unravel. Cut any extra length from the pieces of fire hose now.

Step 5: Burn the Ends

Using a propane torch, I burn the ends of each piece of fire hose. It cleans up the frayed edge and will prevent the canvas from unraveling.

Step 6: Measure and Mark

Measure and mark holes for the bolts. The placement for the bolt holes may vary depending on the size of your rock sling. I would love to give exact measurements, but it's going to largely depend on the type of fire hose you're using and the size you want for your rock sling. Even when working with the same fire hose I tweaked these measurements every time. Make sure a rock bar can fit through the ends loops you create and that there is equal spacing between each piece.

Step 7: Drill the Holes

I use the drill for the rubber layer of the fire hose. I do not have a mounted vise, but I would highly recommend one. The key to drilling through the fire hose and not simply indenting and bending it is to have the edges of the fire hose supported. I used a sledgehammer head, but as long you as you are drilling over a flat surface with a hole for the drill to go in it should work. Once you've drilled through the fire hose, clean up the bits of rubber and fabric.

Step 8: Heat and Punch

I use the heat and punch method for the canvas layer of the hose. When drilling through the canvas without the rubber attached, the bit gets caught in the thread. Using the propane torch, heat a flat head screw driver you don't care about (I actually used a broken scrench). It may take up to 30 seconds to heat it the first time. Once the screw driver is hot enough, you should be able to punch it right through the fabric. I hope this is obvious, but wear gloves. The screw driver will get very hot. Also, you may want to wear a mask. The burning fire hose smells like cancer. In fact, if you can find a way to drill holes in the canvas fire hose without burning it, I would highly recommend doing so.

Step 9: Assembly

Assemble the rock sling. The direction that you fold and assemble the different pieces is somewhat changeable. I would highly recommend looking at an already assembled rock sling for direction on how to assemble. It will be much clearer than a typed explanation with lots of confusing measurements. I add a washer to each side of the fire hose and simply hand tighten all the nuts and bolts while assembling. That way if you make a mistake, it'll be much easier and faster to disassemble and put back together.

Step 10: Assembly Part 2

Assemble the rock sling. The direction that you fold and assemble the different pieces is somewhat changeable. I would highly recommend looking at an already assembled rock sling for direction on how to assemble. It will be much clearer than a typed explanation with lots of confusing measurements. I add a washer to each side of the fire hose and simply hand tighten all the nuts and bolts while assembling. That way if you make a mistake, it'll be much easier and faster to disassemble and put back together.

Step 11: Assembly Part 3

Assemble the rock sling. The direction that you fold and assemble the different pieces is somewhat changeable. I would highly recommend looking at an already assembled rock sling for direction on how to assemble. It will be much clearer than a typed explanation with lots of confusing measurements. I add a washer to each side of the fire hose and simply hand tighten all the nuts and bolts while assembling. That way if you make a mistake, it'll be much easier and faster to disassemble and put back together.