On Sun, 05 Oct 2003 15:34:26 -0000, Dave Mucha <
dave_mucha@...>
wrote:
>> OK, how about this: does anyone in California know of a masking
> product I
>> can get here for chemical etching? I have the Chicken Shak (oops -
> Radio
>> Shak) kit, but I am using sheet brass and have had no luck with the
>> transferring of toner from a laser print-out. Unfortunately, I
> can't find a
>> California-friendly product to coat the brass to make a developed
> mask from
>> an overhead printout.
>> Thanks
>> Bert
>
> Sounds like you are looking for a beter toner transfer method ?
>
> From my experiances, a totally clean surface is a must as it a decent
> medium for the toner.
>
> really shinny magazine pages are clay based and seemed to work will for
> some of my feeble attempts.
>
> Dave
>
>
>
>
Why don't you spray on photoresist and expose it just like a pcb?
I too didn't manage to get a good toner transfer.
The photoprocess sounds more complicated than it really is.
You print your mask design to a ohp transparency (as dense as possible).
Then you apply either liquid photoresist or dry film on the brass.
liquid resist is sold in ready-made spray cans, just apply like spray
paint.
(in a no-sunlight room, avoid dust).
After drying you expose the whole thing (fix ohp film with tape or similar
to workpiece).
you can use sunlight here, different kinds of light bulbs also.
(time depends on light source).
to get your mask you have to develop the whole thing, there are lots of
developers, your
chicken shak has it. developing only means putting the thing in the
soultion and waiting until
all exposed parts are gone.
I don't know which brand photoresist is sold in your region, but worst case
it is available
mail order. all you need it the spray can of resist, any developer, and
some ohp transparencys (get a good brand).
i managed to get the photoprocess right(useable) with the second try when i
started.
it sound difficult but the results are guaranted.
this resist should withstand most etchants - what do you use?
st