I agree with Rob,
There are no stupid questions, only stupid answers sometimes.
I do not understand why David want to stop this conversation. If he does not like it, he can skip it or delete it on his mailbox.
Jean-Paul
N1JPL
> On Jan 17, 2017, at 11:37 AM, Rob roomberg@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
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> I was asking a chemistry question here on HOMEBREW_PCBs because we have a number of VERY toxic
> processess that we use to etch PCBs and we often had chemists drop in and give us directions and safety advice.
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> I use the off the shelf hardware store muriactic acid for etching.
> I believe it is 30% hydrochloric acid mixed with 70% water
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> and
> I use the off the shelf drug store hydrogen peroxide which is 3% peroxide and 97% water.
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> So when I mix 100 millileters of peroxide with 50 millileters of muriactic acid I end up with a lot of water
> and a pretty safe chmical that has successfully etch 50 PCBs for me so far without any toxic incident.
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> I would never have learned that here if it were not for the chemists.
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> Thank you chemists.
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> On 01/17/2017 05:20 AM, 'David C. Partridge' david.partridge@... [Homebrew_PCBs] wrote:
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>> Can we stop this off-topic discussion please
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>> Posted by: "David C. Partridge" <david.partridge@...>
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