Re: Seeking: (1) orange LED safelight, (2) wire coating rod
From: martinm <martinm@gawab.com> Subject: Re: Seeking: (1) orange LED safelight, (2) wire coating rod Date: Thu, 10 Apr 2008 11:21:21 +0200 > In which case you'd have to cut the weak green line present > in all the red LEDs I've seen. > You can easily check that out with a diffraction grating, a > CD or a DVD. Do you know if orange LEDs of 625nm peak have that line? Well, maybe I'll check whether orange LEDs can fog a high speed negative emulsion without dye sensitization. > That will largely depend on their length and diameter. By > the way, DELRIN might be another candidate (I meanwhile saw > that you can get a large selection of threaded plastic rods > in the US, thanks). I'll look into them... > I am not sure about their wettability though. Fluoropoylmers > most likely might be more difficult in that respect. That may vary. But that may be ok with a combination of good surfactants. Since coating rod wouldn't make bubbles, I could use some effective anionic surfactant and blend in a small amount of a fluorosurfactant, or a branched secondary alcohol ethoxylates, at least. (I usually use non-branched ones whenever their performance is adequate, as they are biodegradable.) > On the other hand I've used some liquid mold release > products made of fluoropolymers (similar to Teflon) to treat > a simple metal threaded rod. Is that a coating tool? Can you elaborate? > But I don't know to what extent those rods are "inert" with > respect to a silver halide emulsion. If the coating is PTFE or something, that's good. HDPE, PVC, ABS, etc., are also good. What I'd worry is iron, zinc, copper, etc. -- Ryuji Suzuki "People seldom do what they believe in. They do what is convenient, then repent." (Bob Dylan, Brownsville Girl, 1986)
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