Plastic Project box w/metallic paint.

Nov 17, 2021 Last reply: 4 years ago 13 Replies

I am finishing up a electric project and I need a small project box to house some components that will pass frequency. So I am really looking for a metal box, but If I can't find metal box that will fit my purpose, can use a plastic box and spray it with metallic paint and get the frequency trapping properties that I would expect to have with a metal enclosure ?



Thanks


How big? They make metal junction boxes all the way from a handy box to something you could get inside of. Talk to a guy at an electrical counter. (if you can't find something at Home Depot). You may need a knockout (chassis) punch on some.

Maybe line it with aluminum foil?

IDK if metallic paint will be any kind of conductor. I guess it depends on what happens when it cures. If metal particles are actually continuously in contact with each other, it would work. But it's possible they are spaced out, mostly not touching each other. Or the paint could surround each particle and insulate it from the one right on top of it. If you have some and a ohm meter, you can find out. Actually I was planning on doing a small project here with a spray can, I'll test it out when I do.

I was able to find this stuff, but I am starting to wonder if the effort is work the outcome. was hopping to find this in a spray-can ?!

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Here is a cheaper option:

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expect to have with a metal enclosure ?

I have built some small projects in recycled boxes that were for selecting multi computer devices. Going to flea markets I often find them for a dollar or two. Maybe some of the Good will type stores will have them.

expect to have with a metal enclosure ?

They do make electrically conductive paint but it isn't cheap. It would be better to find a plastic box with the metal in the resin. We used to have them in a couple of machines for RF shielding but they went back to metal.

expect to have with a metal enclosure ?

You can buy a little sprayer that uses a baby food size jar for the cup and a separate spray attachment can that screws on (one time use). They usually have them at an auto paint store if you can't find one anywhere else. I have used them for touch up work where I didn't feel like dragging out my butterfly gun and cleaning it after.

metal project boxes are still available - Hammond is one manufacturer.

- available in die-cast, extruded aluminum, and bent sheet steel or aluminum. Digi Key carries them, as well as Allied and you sometimessee them on FleaBay. They also make plastoc enclosures.

Yes you can get the boxes new, but have you looked at the price of them ?

I have bought some plastic boxes off ebay from China. Good boxes at a decent price.

I have taken to recycling some of the older computer printer and such switch boxes I can find for a dollar or two. Sometimes take some of the aluminum flashing you can get at the HOme Depot or Lowes and use a few pop rivits to make a new front or back with out any extra holes showing.

For cutting out large holes that are square or rectangles I have found that the viborating tool from Harbor freight does a good to get close and then use a file. If plastic the Dremal tool works well for the odd shaped holes.

There are thousands of used knockout punch kits on ebay if you need to punch some holes in the box. One basic set would go from 1/2" to 1 1/4"

I've even made boxes - just like we used to make the chassis for radio projects when I was a kid. A "finger break" (no, not the painfull type!!!) makes the job eazier but I've done it with a vixe and a few chunks of plywood.

You COULD use metallic tape - the real "duct" tape either inside or outside the plastic box to make the farraday cage - -

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