Turns out the thinner seems to the problem. I did a pour without the thinner and in a space without any thinner fumes from past pours and upon drying the plate is clear of speckles. Thank you all for your input and attention. M
Forum: General Discussion

Thanks Joboo and Robert. I don't wipe the plates before varnishing but I do hit them with compressed air. It is hard to tell if I am altering the collodion itself with the varnish or if it is dust. As I said earlier, I am less inclined to think it dust due to the way it looks the same across the plate. Also, I am pouring the soluvar, not spraying, but of course archival quality is a conce
Forum: General Discussion

Thanks Andy. Unfortunately it happens with newly mixed varnish in new pour bottles as much as when I pour re-used filtered varnish. And I do isolate the drying rack in an enclosed space dedicated to drying plates. Weird part about it is that the speckles do not vary much in terms of size and frequency, as I expect dust would.
Forum: General Discussion

Dear Forum: I make 8x10 ambrotypes out in the field. I use Coffer's Old Workhorse, a Ferrous/glacial/grain alc developer, and fix with Sodium Thio. I varnish with Soluvar Glossy Varnish mixed with Paint Thinner (1:1). This has been great to use for ease of mixing, and I have gotten good results generally, until recently. I do not heat the plate, just pour, blot excess and leave in dish r
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Thanks JOBOO for the info and advice. M
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as promised - a diptych from yesterday. And no luck yet finding whiting - not at Sherwin Williams or the best hardware store around here. I will keep looking... Brunswick Canoe Portage, from the Androscoggin River series, 26 Oct 2011
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I forgot one thing. Joboo, you mentioned diatomaceous earth, which intrigues me - to understand you better - do you wash with soap and water before or after the DE treatment, or both before and after? Thanks, Mike
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You guys are great. Thanks. Just got back from shooting and all seemed to go well, despite (or maybe because of?) the cold. I will post a few tomorrow once they dry and I can scan them. I will look for the whiting - there is a Sherwin Williams down the street and a few hardware stores to scour. Interesting to hear that the bath could be overly silver. Though I mix faithfully to a 9% solu
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Thanks so much for the posts, Joboo, Ray and Robert. I should have been clearer about time IN bath instead of BEFORE. I pour and wait about 15-30 sec for collodion to set, and then sensitize in the bath for 3.75 minutes. It could be the rottenstone - I agree - but what is strange is that the bath is initially clear when I inspect it upon return from shooting, but the next morning it has the
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Thanks for the suggestion and link. I just ordered some.
Forum: General Discussion

Dear Forum: I am newly admitted to the forum, very thankful it is here. I have been reading it for a while, and appreciate being let in to participate. I have been shooting 8x10 ambrotypes outside with dark box since May. I use the Quick Clear collodion mixed with Cad Bro and Ammon Iodide as Mark O.'s formula for positives suggests. I also use his formula for developer, and fix with SodThi
Forum: General Discussion