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On Thu, Feb 2, 2017 at 7:26 PM, Rob roomberg@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
I was told by a 70 year old chemistry teacher that I should avoid using ACETONE because ACETONE is definitely a bad ass carcinogen.
any ideas here?
I always wear nitril gloves and run a low speed fan over the work for air flow when I do kitchen etching.
On 02/02/2017 11:59 AM, Harvey Altstadter hrconsult@... [Homebrew_PCBs] wrote:
I did a search on toner density spray, to see what it is. From several sites that I found, unsurprisingly, that it appears to be a combination of solvents like toluene and acetone. Further research brought me to this thread:
After reading it, it reminds me of two other activities that have been discussed on this forum. The first is the "setting" of the toner on Mark Lerman's direct laser print to the board, where he suspends the board over acetone to let the fumes reflow the toner, and the second is the cold toner transfer process that was discussed a while back. This also used acetone with denatured alcohol.
The thread describes various way to reflow the toner, but in the end, they are variations of getting a small amount of solvent onto the surface, and letting it reflow the toner before evaporating. This thread brings us full circle to our other activities, that show that acetone, and possibly, some other solvents have the capability to improve the toner coverage in several different approaches to making PCBs.
Other items of interest in the thread have to do with testing printers and scanners for resolution. Some nice, detailed instructions.
Harvey
On 2/2/2017 2:58 AM, Kamen Lilov kamenl@... [Homebrew_PCBs] wrote:
Here is my setup:∗ LaserJet 2100 - bought this refurb for about $80, including refilled cartridge∗ LaserJer has ethernet module (otherwise it's LPT only, difficult to drive in this day and age)∗ Drafting paper∗ Set the density to 5 (default is 3, tried to do this via the new Universal Printer driver and failed, then did it by sending the specific escape codes via lpr to the network port where I have attached it)
I used to print two copies on the drafting paper and align and glue them perfectly. Worked well. Then I read about and bought a toner density spray. It's technically designed for transparencies, but works very well with the drafting printouts too.
I now only use only one copy. Blackness is perfect, going down to 12 mil traces every time and under than (e.g. for 0.65mm smd parts) with some care.
The critical part of my process now is getting a uniform thick coating (I use Positiv 20 on bare stock). Exposure and black opacity is no longer causing any troubles.