Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

--- On Fri, 3/15/13, Roland Harriston <rolohar@...> wrote:

From: Roland Harriston <rolohar@...>
Subject: Re: [Homebrew_PCBs] calcium carbonate, HF acid...
To: Homebrew_PCBs@yahoogroups.com
Date: Friday, March 15, 2013, 9:29 PM
















 









wow!



You dudes play around with some very nasty stuff just to etch a printed

circuit!



Or, maybe this thread is just a sort of "pissing contest" to show off that

the participants have had Chem 101 at a community college.



Pardon my cynicism, but I just don't get the drift.



Keep it simple..........keep it safe.



Roland F. Harriston, P.D.

∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗

This all started because someone wanted to etch glass.  HF was just one of the nasties I got to play with.  What I did was etched quartz tubes in HF, put red phosphorous and Zinc in them and sealed them under vacuum.  We then put the tube in a furnace with a heating profile over days  and hoped it didn't explode while reacting.   Others got to play with Silane, phosphene and a lot of other Hydride gasses. I got to design the safety system.   I got to routinely fix high voltage regulators such as a 30 KW electron gun with a 15 kVDC 1 A tube shunt regulated power supply and an X-ray set with a 100 kV at 0.1 A DC power supply and a 1 KW RF power supply.  No one else did, but me.  We still thought the table saw in the shop was the most dangerous piece of equipment followed by the 5 HP engine lathe.  One little piece of equipment would use 70 A 208 V 3-phase power.  Ouch! Yep, Be safe or don't try this at home.























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