Valve Seal for Coleman Powermate Air Hammer 024-0075CT

Valve seal for Coleman Powermate air hammer 024-0075CT

This is the stupid space-gun design with the red plastic trigger (see photo), not the prior common design with a pivoting trigger. This file may be able to be adjusted to fit other tools (drills, impacts, other brands). The valve seal in these tools is made of some clear/white elastomer overmolded around a star lock washer as a reinforcing member. The presence of air oil will rot the overmolded plastic, leaving behind a chunky, waxy scum and an apparently random lock washer. Like most cheap air tools, replacement parts don't exist. Scrape/pick all that crap out and make your own replacement.

To be printed in relatively soft TPU, directly on a smooth(ish) build plate. The lower (-z) surface of this model is the sealing face, so it needs to be relatively smooth and compliant. I used a relatively stiff TPU, installed it with some silicone grease, and it works okay. I would have liked to have used a softer TPU, but I don't have any. Even if you find the sealing isn't perfect, it'll be better than an air hammer thats stuck on full blast.

I think that the original seal would have been a simple flat washer shape. The use of the overmolded lock washer is likely an attempt to make a seal which is both soft at small scale (to improve sealing), and rigid enough at large scale to prevent the washer from collapsing and being shoved through the large underlying bore by air pressure. With that in mind, I made the seal in a flanged shape instead of a flat washer. This helps with seal retention, and should give a little more latitude in the choice of durometer and print density.