Thursday, July 09, 2015

Tancho the chemist, a story from the wayback machine.

Growing up kids use to have hobbies. Now I think their hobby is texting or surfing the Internet etc.

My  hobby was radio and electronics, building radios out of old parts, putting together Heathkits or Eico test equipment, taking old TV's apart saving the parts in order to build other stuff like power supplies to power my Ham radio transmitters.
I was also a Ham radio operator, wasting countless hours talking to other people all over the world. We didn't have Internet so it was unique and exciting when you were able to discern that the other guy you were talking to was from Iowa or Japan, Alaska or Spain. It was pretty normal to talk to people on the west coast, countless hours of chit chat talking about how you built the radio you were talking on, or the antenna design that you had tweaked in order to get more signal out.

They were exciting days then.

I was like 9 or 10 , and that lasted until probably my second  year of high school.

As part of building radios, technology had advanced to the point of being able to put components on to circuit boards.

It was a miracle to be able to mount all the parts for a radio onto a 6 X 8 phenolic board that had copper zig zags running on one side. Those small lines replaced individual wires.  Now, you get thousands of components into one minuscule chip the size of a M&M that basically replaced all the components of that 6X8 board.

Gadzooks, how things have progressed!

In order to make those boards you had to buy some chemicals. And that's what got me to thinking of really how things have most definitely changed.

I remember taking the Muni bus downtown one day to purchase some supplies in order etch those boards.
One of the chemicals was Nitric Acid.

The company that I found that carried it was located South of Market in the commercial area,it was the Braun-Knecht-Heimann Company. BKH was a supplier of all kinds of stuff, chemicals, tools for laboratories, scales, lab glass, anything that anyone wanting to make out of rocks or chemicals would always wind up at that company.  I am sure that was before chemistry got so popular for entertainment purposes from home amateur chemical experimenters, trying to enlighten their mind.

That company was established during the gold mining boom of the 1850's and finally closed up or disappeared in or after the 70's.

It's funny that I remembered the name of that company, I can also visualize the front of their old building, the pale yellow stucco and the lobby reception area where I was asked to wait until a white lab coat gent brought out my small wooden crate that housed the bottle of Nitric acid in a straw bed.

I don't remember how much it cost, but I would guess it was probably about 5 or 6 dollars at the time, perhaps less.

Once I got home, I called a couple of my ham radio buddies who lived in the area who most of  were also about my age.   We all wanted to see how it would eat up metal. So we took one of the phonelic boards and loaded some resit tape on the side which would cover the copper, not allowing the acid to penetrate where the resit tape was placed. Anywhere other that didn't have either the tape or special paint would then be dissolved ending up with the board with thin traces of the remaining copper which would then act as the wires, connecting the components that we would place into the board in predetermined locations, then soldering the parts to the remaining copper.
So, we made the test board which was about 4 inches square and I fetched a small Pyrex dish from my mother's kitchen which we would use as the vessel.
Since this was experimental we had no idea how strong the solution would have to be.
Little did we know, that we had to dilute it. We carefully poured about a cup of the acid onto the glass dish. A few wisps of smoke came up as the clear liquid hit some dirt or dust that was in the glass dish.
Then one of my friends gently put in the copper board into the dish.....

As the board when it, it started to smoke and bubble and give off a lot of steam, we rebounded from that area and waited for a few minutes only to find the board devoid of any trace of copper.
The places that were covered with resit were gone. All the copper on the board disappeared.

WOW one of my friends said as we all agreed that we needed to read up on the process and that it was a little more complex than we though it was.
It probably would have been advantages if we had asked someone from high school chem class or even the teacher about how to handle that.  But, hey, we were brave, and we liked to experiment with lots of stuff....
We kind of put that printed circuit board project on hold for awhile . A few weeks later one of the guys brought over a bottle of Ferric Chloride, which was sold at the local radios stores specifically for that application, which we used on the next board, with considerably better results.

Interesting that there were no warning labels on any of the stuff then, other than a skull and crossbones on the wooden box that nestled the acid in it. I never really ever found a use for that acid other than to play with it, pouring it on stuff, and when I finally moved from that house at around 18 or 19, and not wanting my mother to deal with it, I remember taking the bottle and pouring into a hole I dug in the back yard. ( watching the dirt fizz and bubble, releasing acrid steam in the process)

A lot of those acids were blacklisted by some decree in the 80's and are basically no longer available over the counter so to speak, because they are used for making recreational drugs or bombs. Can you imagine nowadays seeming a kid on a bus with a box containing acid advertised with a large scull and crossbones?
How many of you had those great Gilbert Chemistry Sets?  Remember all those neat jars of stuff?
BAD. real BAD, you can't find anything like that anymore.  I remember  making stuff that could in quantities  blow the roof off the house. They had  potentially deadly stuff. Like potassium permanganate, which, besides being poisonous, has been known to make things catch on fire.  Or ammonium nitrate, the same chemical that the U.S. wants to regulate now because it's used in homemade bombs and stuff.
Now anything even looking like that would send you and your family  to the hoosegow.

And that's my story of my Chemistry experiences way before taking Chemistry class in High School.... where we would heat up pennies and dimes on the Bunsen burners and toss them out the window in the school yard for the freshmen to pick up..... but that's another story for another day.

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