Cord Grip on heating element weatherproof box

hennesse

When assembling my heating elements, I could not get the cord grips to fully tighten down on the weatherproof boxes. While the NPT threads will prevent any water ingress, the little space between the cord grip's hex nut and the box annoyed me.

The silicone O-rings used on the balls valves came in a package of 50 so I had 46 extra. I tried one, and it fit nicely on the cord grip. It fills up that little space and gives a nice finished look.

Now I only have 44 extra...

Dave

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Thanks for that tip! I will be drilling my kettles soon and mounting the element boxes, so handy to know! Did you use the cord grips from mcmaster?

hennesse · Posted: Wed Apr 06, 2011 4:47 pm Post subject:

Yes, I used the McMaster cord grips.

I'd be interested to know if others had the same gap. The waterproof boxes are not what you'd call precision machining, so results may vary.

One warning though, the cord grips are aluminum, and once you lock the threads, it galls the aluminum. After removing the first one, I had to clean up the threads before putting on the o-ring. For the second one, I didn't trial fit - I just put on the o-ring and screwed it in.

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Burglar · Joined: 11 Feb 2011 Posts: 56 Location: Detroit

A wrap of teflon tape will lubricate the threads and prevent galling.

kaikoasurf · Joined: 15 Dec 2010 Posts: 96

Just ordered my Hole Punch and my parts from McMaster today! Thanks for the tip with the O-rings and I planned on using teflon tape and liquid teflon just to be anal. Also, What size pilot hole did you use for the 1-1/4 Hole-Punch? Or did you use the Step drill bit? I would really like to save 50 bucks and not buy this Smile

hennesse · Posted: Fri Apr 08, 2011 2:33 pm Post subject:

The directions included with the punch tell you to drill a 1/2" pilot hole. The pilot hole needs to be bigger than the punch's shaft so that the "disc" you are punching out doesn't bind on the shaft and hurt the threads. The disc gets bent during punching, so the pilot hole closes-up.

If you've only got a 3/8" drill, you'll need to use the step bit. You could buy a 1/2 drill bit with a reduced shank, but you're going to need the step drill bit for the 22mm holes in the control panel anyway.

I've got a DeWalt hammer drill with a 1/2" chuck (120v). While I've only used the hammer function on concrete a half-dozen times, it's a great heavy duty drill that has served me well for many years. While my 3/8" cordless gets used most of the time, the hammer drill is great for larger bits or heavier jobs. And just like an electric brewery never runs out of propane in the middle of a brew, a corded drill never runs out of battery in the middle of a job.

Burglar · Joined: 11 Feb 2011 Posts: 56 Location: Detroit

FWIW, I bought a two pack of step bits at Harbor Freight on sale for $15. They were good enough to do my brew pot and entire panel with no issues, even using our cordless drill.

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois