Homebrew PCBs

----- Original Message ----- 
From: "Adam Seychell" <a_seychell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, October 29, 2008 10:09 AM
Subject: Re: [Homebrew_PCBs] Re: MG Negative Dry Film Resist


> leon Heller wrote:
>> ----- Original Message ----- 
>> From: "Michel Baguet" <bagmik@...>
>> To: <Homebrew_PCBs@yahoogroups.com>
>> Sent: Wednesday, October 29, 2008 8:30 AM
>> Subject: Re: [Homebrew_PCBs] Re: MG Negative Dry Film Resist
>> 
>> 
>>> Hi all,
>>>
>>> has anyone already use sodium metasilicate for development ?
>>> I've read that you can leave your PCB in it without any risk of 
>>> over-development and it can last for years.
>> 
>> I have used it, and it has a lot more latitude than NaOH. It's more 
>> expensive, though, and not as easy to find. I prefer NaOH.
>> 
> 
> 1% NaOH and the sodium silicates will strip negative dry film resist.

Both work fine with positive resist, of course.

Leon