MK 5 and MK 10 Piston Stem O-ring Tool
I just received my new toys from Herman and I am impressed to say the least. Herman’s Custom Scuba Tools MK 10 and MK 5 piston stem o-ring tools makes installing the piston stem o-ring an easy task. If you've ever attempted to install the piston stem o-ring, you know it can be a chore unless you have a specially designed tool to do so.
At first glance the Custom Scuba Tools device looks very similar to the other tool available.
They also operate based on the same concept; however there are some important differences. The older design when used without mounting it to a tank or held by some other method is very awkward.
Thanks to the design of the Custom Scuba Tools lower guide, it can be used on a flat surface such as a work bench or table.
The o-ring insertion rod of the currently available device is a single diameter and will pass through the regulator body and o-ring. A close inspection of the CST insertion rod reveals a couple of improvement Herman incorporated into his ingenious design. The insertion rod is machined in a fashion so that only the end of the dowel will fit into the o-ring groove. This prevents the rod from pushing the o-ring past the groove into the high pressure chamber. The same end of the rod has a slot which guides the o-ring into place. A 360 degree twist of the rod seats the seal in the groove.
My very first attempt at installing a new o-ring was successful and took 10 seconds flat. Compare that with having to first mount the regulator body in a vice or on a tank valve and it is easy to see why this design is superior.
The Custom Scuba Tools o-ring insertion tool is competitively priced and much easier to use than the tool currently available. Note that the MK 5 and MK 10 tools are separate tools, so if you need both mention it to Herman.
Look for Custom Scuba Tools on eBay, at http://vintagedoublehose.com/index.php? ... d=15502679 or PM Herman.
Another well made tool from Herman-thanks.