I have read the various threads about creating your own polymer exposure unit but can’t find anything very clear and definitive about type of bulbs. My unit is 24” and I read unfiltered/UV/black/etc. with no consensus. Are the variables too hard to control that it just becomes all trial and error? Can anyone recommend a bulb type and vendor that would be a good start? Thanks, Neil
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It’s my understanding that polymer (which is not that different from screenprinting materials) exposes 330-440 Nanometers is the light wavelength.
You want light bulbs with an instant start ballast that generate good amounts of light within that wavelength.
Try looking at AWT GPI’s website for parts and lamps; again, though they’re for screenprinting, they could potentially work a lot better than your garden variety home depot backlights.
Another thing- results are only as good as emulsion on the film you’re using and tightness of contact between the emulsion and the polymer.
What are you using to make a negative-plate sandwich?
The best systems seem to use Kreen/vacuum based contact- some people use a heavy piece of glass/furniture foam but this can be a bit uneven- and lastly there’s the old gator-clips-plywood-glass method some people like. I have found the latter two to be inferior to the former in personal experience.
Thanks. I am not using any kind of vacuum system - just a sandwich of polymer/negative/glass and I could improve upon that after I find the right bulbs. More on that soon. THanksThanks once again to all. Neil
Call Anderson & Vreeland Inc. (you can Google them). Among other things, they sell letterpress photopolymer plate material and they make plate processors for letterpress plates. I didn’t see bulbs on their website, but I would be surprised if they didn’t sell them. If not, they will know which ones to use for letterpress plate exposure, and they will know where you can get them. (They will know because some of their processors use them).
When you call them, tell them you need bulbs for exposing hard photoploymer letterpress plates, and be sure you know what make and type of plate material you are using, because they will probably ask.
You can try and call them, but I will warn you- the reason I did not already suggest/list anderson and vreeland’s phone number as an option is that they are not a very helpful company to ‘little guys’.
If you already own one of their all-in-one processors (like I do), they are a moderately helpful company as long as you are trying to buy parts from them or have a technical question about the machine. Gene Lockhart over there at A&V is very knowledgable about the machines and parts, and he knows what they do, including exposure- but that is within their system.
There are other experts there on polymer, but you’re talking about calling someplace for free advice on what to buy from someone else! How would it be good business for them to advise you? I think that’s foolish, both for you to ask and for them to answer kind of, if you look at what kind of company they are. They’re just too big to deal with small printers and hobby people so they tend to get off the phone quick unless you’re buying something.
Also- They won’t sell you the lamp bulbs to their machines without a serial number for the machine you have, not that they would be of use without the exact ballast and configuration you would need to run them with. And I doubt that would be information you could glean from them. Any other bulbs they are going to recommend will be very similar if not the same as the bulbs I am suggesting you look into/contact AWT-GPI about above- high output UVB spectrum bulbs with the right frequency and the ballasts to match.
Hi Neil -
I’ve had decent success with a home-made polymer unit, just grow lights from Home Depot, and a glass/kreen/neg/polymer/backing with alligator clips setup. My exposure is about 3 hours, which I understand I could drastically reduce with black lights.
All my prints on my site are printed with these home-made polymer plates, so I must be doing something right. Check inkpopstudio.com, click on “inkpop shop” and it will take you right to the works I’ve been printing. I use KF152 on a home-depot base (laminated ply and MDF), print on a foot-treadle 8x12 C&P Old Style (circa 1905)
For custom jobs I send out for professionally made plates, but my own cards and posters can be designed to work within the time and technical limitations of the home-made plates.
If you ever do figure out which bulbs are appropriate, one of the best places to get this stuff is Atlanta Light Bulbs.
All very good and helpful as usual. Thanks, Neil