Larry, I have been getting my presensitized PCB material from the company Circuit Specialists I believe they are located in Arizona, there material is fresh and is delivered in about one week. Their website is ....
http://www.circuitspecialists.com/Usually I get the 4.6" x 6.6" size double sided boards
http://www.circuitspecialists.com/gd114.html and then trim them down to 3.3"'4.6" to match the size that eagle software allows. Are you offereing boards like that?
I use the UV exposure process and it seems to be working for me alright here is a you tube video of... Making PCB for the FTDI Vinculum 2 Chip
http://youtu.be/qK6DKbzm024If you interested in my youtube videos please subscribe. If you are going to make up a bunch of double sided positive photoresist boards I would give some a try. Let me know. Tom
From: Larry Battraw <
lbattraw@...>
>To: homebrew_pcbs <Homebrew_PCBs@yahoogroups.com>
>Sent: Tuesday, October 11, 2011 1:32 AM
>Subject: [Homebrew_PCBs] The case for crowd-sourced PCB materials
>
>
>
>Hi All,
>
>I've been lurking on this list for some time and seen a lot of different
>takes on making PCBs, whether it's toner-transfer, direct-print via
>last/inkjet, or UV-exposed resist (And a few stranger ideas). One thing I
>have noticed is that it is sometimes difficult or impossible to obtain the
>raw materials for our projects. In some cases (Dry film resists) it either
>takes forever (2 weeks to over a 3 months!) to get some from Hong Kong or
>the Czech Republic (via eBay), or you have to buy a lot at one time (Think'n
>Tinker 100-foot rolls for example, at $150+ w/mandatory express shipping).
>There are exceptions, but finding them and having any idea of how "fresh"
>the film is (Which is important to get reasonable results) is problematic.
>A couple years ago a company called Genesis MT sold a great product by the
>name of AQ-3000 water-based photoresist. It worked very well, was very
>reasonable for the amount you got for the price, and was available via
>eBay. Recently I found they had been acquired by another "professional
>services"-type company that requires large, company purchases of anything
>(i.e. ask for a quote, and no way to buy electronically). It is now
>impossible to get any of this great resist, the only water-based photoresist
>around. I don't consider the VOC-based resists as viable for use due to
>health concerns.
>
>What I propose is that we as a group of hobbyists provide our own materials,
>where some of us will volunteer to be a source for a particular material, in
>this case photo-imaging materials. I know there has been a lot of
>experimentation with direct/transfer tech but for repeatable, high-quality
>boards you really can't beat photoresist-based boards. I'm sure some people
>will differ with me but I've read too much about problems with board
>coatings, pre/post-heating, different inks (Sometimes very expensive), and
>the challenges modifying inkjet printers to be very interested, especially
>after I ruined a perfectly good printer trying it myself :-)
>
>Naturally I am volunteering for the dry film photoresist, since I have
>already placed an order which should be here in a couple days. I'd like to
>do the same for the Genesis AQ3000, although I have to find out the minimum
>order quantity (Apparently they make up a fresh batch for each order) and
>available payment methods. I'd like to think that we can use enough of the
>purchased products to have them avoid going bad (Shelf life for AQ3000 is 6
>months, similar for dry-film). I would suggest charging actual cost plus a
>small surcharge to cover gas and time spent (Maybe $3.00 per order?). I
>want to make it possible for us to use high-quality products without a lot
>of delay or uncertainty/experimentation in regards to product quality. The
>cost would include cost of postage plus mailing materials (Padded envelope
>or plastic bottle+box for AQ3000). If it's popular enough, I could offer
>additional things like drill bits, PCB blanks, etc.
>
>I am certainly not adverse to having someone else take all the "business"
>from me, as the whole point of this exercise is to provide the materials at
>near-cost, quickly. However, since nobody else has suggested this (That I
>can remember) I figured I could at least start the process. I have to add
>some disclaimers here: I reserve the right to ship within 2-3 business days
>of a prepaid order, and if there are unusual restrictions on shipping items
>there (i.e. countries that have export regulations for the USA) I also will
>not even try to ship an order. Likewise, if I find out after the order has
>been placed it's going to be a lot of hassle to ship to I reserve the right
>to refuse/refund orders. Ditto for people who piss me off, sorry, I just
>won't work with people who can't be polite. If there are unusual
>circumstances like having a package refused and returned I also will charge
>a fee based on the time spent plus shipping/materials (Assuming the PCB
>materials can be re-used and are not damaged). And finally, I reserve the
>right to halt the service at any time, refunding any outstanding orders.
>
>This whole idea is an experiment in supply and demand and so I apologize for
>all the disclaimers. I don't want to be sued or even given a bad reputation
>because I had a package returned from Elbonia after being opened and
>damaged, and the person is upset.
>
>I apologize for the length of this email, but I'd like to gauge the interest
>levels (And potential orders) from people in the group and elsewhere.
>Please email me if you're interested, and what you would like to see
>offered. I would probably accept PayPal (Yes, they aren't wonderful but
>they're big and fairly reliable) for payment. Materials could either be
>ordered direct from me or I could post auctions on eBay, but I'm more
>interested in serving the community we have here rather than the entire
>world. I have a day job and this is just a way to benefit a group of
>like-minded people, so it can't be too much of a hassle or I will need to
>either put a stop to it or raise prices. It may be necessary to go the eBay
>route just to avoid having materials expire but I'd like to avoid it. Let
>me know!
>
>Kind regards-
>Larry Battraw
>
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