Judging by the workbenches of my father and grandfather, I believe that many do-it-yourselfers like to hang on to their tools as long as possible. Following in their footsteps, I still have the first pair of diagonal cutters and needlenose pliers that I ever bought, way back when the budget was nil. They were good enough for occasional use, but had no spring loading. At present, however, I need these frequently. I make and sell an invention that I must produce weekly and it involves repetitive cutting motions. Rather than replace them I decided to add my own spring mechanism with things I already had in the workshop. The steps are simple enough to follow in a few minutes.

Supplies

The tool itself is shown, as it is part of the project.

You will also need:

1 or 2 zip ties

A piece of shrink tube that can accomodate two layers of zip tie - length determined by next step.

2 pieces of wider shrink tube that will accomodate one handle of the tool and two layers of zip tie - again, length determined in next step.

There are a couple of approaches to acquiring the shrink tubing. You can buy it pre-cut or in longer rolls that allow you to pick your length. If you choose to order from a supplier like Amazon you can get either, and often there are large assortments of pre-cut sizes sold together. However, the length of the pre-cut sizes may be shorter than the length of the custom spring we are building. If you use these you will need to use several pieces, shrink one at a time in place, then overlap the next piece and shrink, and so on. Still achievable, but takes a bit more planning and work. If you buy the shrink tube at a big box home improvement store you may have fewer options in terms of length, size and color, but hey, this project is pretty flexible. (See what I did there?)

Scissors to cut the shrink tube.

Heat source such as heat gun or solder iron to shrink the tubing.

Step 1: Measure Your Zip Tie

FIrst, wedge the zip tie into position between the handles of the tool to find the length and position needed. This does not need to be precise to the millimeter, just make sure that you have plently of zip tie running along each handle. Do not start the arc between handles too far up, or you cause a kink at the apex and lose the spring effect. Use this measure to determine the length of zip tie needed. Cut the zip tie with the tool you are enhancing, and think about how much easier this will be from now on.

Step 2: Create the Spring

I found that one zip tie was not strong enough to open the tool jaws, so I cut two matching lengths, then bound them together with an appropriate cut of shrink tube. You can cut the shrink tube to cover most of the zip tie length. I found it deisrable to have this shrink tube extend under the larger tubing that will connect this spring to the handle.

Once you have this cut, stack the two pieces of zip tie together, and insert them into the shrink tube.

If you have never worked with shrink tube before you will find that it a heat gun from a craft store works very well from a short distance. Choose a size just large enough to fit over your item, then aim the heat gun at it from all directions, applying heat evenly. The shrinking will be visible. Stop when you have a tight fit with even shrinking at all points of the tubing. You can also apply a portion of a soldering iron not near the tip, but make smooth steady passes over the material. Don't linger long enough anywhere to do damage. I do not recommend using an open flame for all kinds of reasons, mostly legal. ; )

Step 3: Attach the Spring

Once the spring has been created, place it into the handles of the tool and slip the larger pieces of shrink tube over the handles and the ends of the spring. Make sure that the spring does not shift up toward the jaws of the tool in the process. You are still concerned about kinking the zip tie at this point. Once you have the desired placement, apply heat to finalize the arrangement, observing the tips in the previous step.

Step 4: Test Out Your Work

Enjoy your finished product. Remember that because the materials are inexpensive and easy to manipulate, you can quickly repeat the process for another try if you want to modify the results.

I hope this Instructable makes life easier for someone. Thank you for reading it.