Shrink Wrap That Circuit

[VA3KOT John]

Call me a cheapskate or miser if you will, but I prefer to build my own radio stuff. And often, I don't have a suitable enclosure for my home made circuit boards. Actually, although a nice slick Hammond box looks great on the radio desk, it isn't always necessary. Sometimes it's enough to simply protect a circuit board from rough handling, or the environment (especially for hams like me who like to operate outdoors).

Some time ago I started experimenting with recycling plastics. I seem to accumulate a lot of plastic containers so I researched online to learn more about the different kinds of plastic materials and what could be done with them. First, the word plastic is an adjective, not a noun. Plastic materials are polymerized (i.e. long chain) molecules that behave in different ways depending on how they are made.

When I moved to Owen Sound I learned one thing really fast - the water tastes absolutely awful! I have a basement full of sophisticated equipment to process the water but the drinking water filters are expensive to replace, so I supplement that with plastic bottled water. Then I discovered that the plastic material used for drinking water bottles shrinks when heated. Great discovery. Now I use it for shrink-wrapping my circuit boards. Cost: zero. Processing time: about thirty seconds! It doesn't result in the neatest encapsulation, but with a bit of practice you can do a decent enough job.

Attached is a picture of one circuit I shrink wrapped just recently. For anybody who is curious; it's an Ezitune - a circuit using a noise bridge for finding the resonant frequency of an HF antenna.
John, VA3KOT    

[Rob_Walker]

Call me a cheapskate or miser if you will, but I prefer to build my own radio stuff. And often, I don't have a suitable enclosure for my home made circuit boards. Actually, although a nice slick Hammond box looks great on the radio desk, it isn't always necessary. Sometimes it's enough to simply protect a circuit board from rough handling, or the environment (especially for hams like me who like to operate outdoors).

Some time ago I started experimenting with recycling plastics. I seem to accumulate a lot of plastic containers so I researched online to learn more about the different kinds of plastic materials and what could be done with them. First, the word plastic is an adjective, not a noun. Plastic materials are polymerized (i.e. long chain) molecules that behave in different ways depending on how they are made.

When I moved to Owen Sound I learned one thing really fast - the water tastes absolutely awful! I have a basement full of sophisticated equipment to process the water but the drinking water filters are expensive to replace, so I supplement that with plastic bottled water. Then I discovered that the plastic material used for drinking water bottles shrinks when heated. Great discovery. Now I use it for shrink-wrapping my circuit boards. Cost: zero. Processing time: about thirty seconds! It doesn't result in the neatest encapsulation, but with a bit of practice you can do a decent enough job.

Attached is a picture of one circuit I shrink wrapped just recently. For anybody who is curious; it's an Ezitune - a circuit using a noise bridge for finding the resonant frequency of an HF antenna.
John, VA3KOT

---

Call me a cheapskate or miser if you will, but I prefer to build my own radio stuff. And often, I don't have a suitable enclosure for my home made circuit boards. Actually, although a nice slick Hammond box looks great on the radio desk, it isn't always necessary. Sometimes it's enough to simply protect a circuit board from rough handling, or the environment (especially for hams like me who like to operate outdoors).

That's a really good idea John

[VE3WI Dave]

Good idea, especially if you tend to spill coffee or other beverage on your workbench :-)

A (slightly) related tip I saw on QRZ.com: "to ward off insects from outside electronics devices: Get a dog/cat flea collar and cut off a small section. Place the section inside the box"

My autotuner is tightly sealed so I don't think I need to try this.  I wonder if the vapor from the dog collar would be corrosive.

73
Dave, VE3WI