stores have a display of trays
Ban that's a splendid suggestion. It's been eons since I've visited, eg, Home Depot or Lowes
You're probably looking for one with an inside diameter of about 1/4"
Actually it has to be much smaller to protect against the instant surge caused eg, by a timer shutoff. In fact I made one last night from a plastic disk, drilling a hole of 0.021 using a #75 drillbit, the smallest my bench press would accept
The hole size proved about right, but the experiment was a failure because the disc was too thin, transmitting the impulse by distention; so looking round for a thicker plastic disc of appropriate size. Like to use metal but drilling would take forever
Thanks Ban for the suggestion incidentally tho I feel a cap of that sort might also prove too thin
One of these days, I keep telling myself, I've gotta learn to place an image as you've done above