Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,916   Posts: 1,521,861   Online: 1066
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 32
  1. #11

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    Hi All,
    I will put in my two cents. After seeing Dr. Efners Pysautotype on glass,at A.P.I.S.'07 I became very exited. All of my own work is on glass, Pt/Pd/Au and Gum dichromate. I loved the delicate nature of the physautotype on glass.
    I began with 1% Graphic Rosin, heated as per Howards instructions, in denatured alcohol. Development over Oderless paint thinner. Although I had no troble(i'm leaving out my false starts and screw-ups here), I was never satisfied with the quality of my coating. Until I began adding WATER. Up to 30% water.70% ethyl alcohol. Gose on clear and smooth. Dries white and smooth, and develops cleanly,without over-developing. But use ODERLESS paint thinner. Avoid anything that has Stoddard Solvent.
    Bill

  2. #12
    Akki14's Avatar
    Join Date
    Feb 2007
    Location
    London, UK
    Shooter
    4x5 Format
    Posts
    1,873
    Images
    210
    Quote Originally Posted by wildbillbugman View Post
    But use ODERLESS paint thinner. Avoid anything that has Stoddard Solvent.
    Oh, um, Apparently white spirit, which is what i'm using, is stoddard solvent. What's your odorless paint thinner then? I've never heard of that. Over here the standard is white spirit mostly. It'd help if we used as specific of names as we can as far as chemicals we're using. I think there might be something along the lines of "better than white spirit" paint remover/thinner.
    ~Heather
    oooh shiny!
    http://www.stargazy.org/

  3. #13

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    Heather,
    The brand of odorless paint thinner which I am using is Sunshine brand. The Material Safety Data Sheet (reqired fo just about everything in U.S.) simply states "synthetic hydrocarbon" I would be very surprised if you don't have something similar over there.. In general, things that have strong odors will tend to be more volatile and cause faster development.
    Bill

  4. #14

    Join Date
    Aug 2007
    Location
    melbourne australia
    Shooter
    Medium Format
    Posts
    40
    What gave you the idea to add water ?
    how much longer does the mix take to dry ?

  5. #15

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    Heather,
    My apology! I meant to say Sunnyside Odorless Paint Thinner(not "Sunshine"). I was writing late last night. If you look up the (U.S.)MSDS
    You can probably find something similar in U.K.
    For rosin solvent, lately I have been using retail 70% Rubbing Alcohol.
    I takes about an houer to dry on glass.
    "What made me think of water?" I thought(correctly) that slower drying would cause better levaling of the rosin. I have been developing coatings for glass(industrialy) since 1974.
    Regards,
    Bill

  6. #16
    Akki14's Avatar
    Join Date
    Feb 2007
    Location
    London, UK
    Shooter
    4x5 Format
    Posts
    1,873
    Images
    210
    Oh but aren't you using a completely different alcohol to what Niepce & Daguerre were using then? Rubbing Alcohol is very different from the 95% denatured alcohol that is usually recommended. If you're using 70% rubbing alcohol that's already diluted with water. I might try adding a bit of water to my solution the next time i try. I coated two plates last night one right after the other; one had the opalescent/rainbow-y effect and the other one didn't and was just white & milky. I'm hoping the opalescent one is the one that is going to work. Just letting it expose under the UV tanning box right now.

    See, this process *is* simple but confusingly so because you can have so many variables and still get a result. We're getting so far away from the original concept, it'd be safer to call (some of) this Modern Physautotype, but what Bruce has been up to is more similar to Traditional Physautotype, using lavender oil resin etc.
    ~Heather
    oooh shiny!
    http://www.stargazy.org/

  7. #17

    Join Date
    Aug 2007
    Location
    melbourne australia
    Shooter
    Medium Format
    Posts
    40
    Gee this "modern phsautotype" with rosin is fickle.

    today i got what looked like an fairly even coating on a glass plate.
    nice and frosty, not too much pooling.
    tried a contact print for 1hr, 45 mins in midday cloudy conditions
    amb temp 18'c, uv index about 9.
    I could see a very faint image, so into the d tank with kero

    RATS after only 15 mins the plate had completely cleared, not fair.
    Bill Is kero this Stoddard Solvent ?
    Attached Thumbnails Attached Thumbnails today.jpg  
    Last edited by brucej; 12-10-2007 at 10:02 PM. Click to view previous post history.

  8. #18

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    Hi,
    Bruce- "Stoddard Solvent" is an old timey industrial refference to a particular petrolium distilate. It is realy a mixture of aliphatics and aromatics. It is smelly,with a low vapor pressure. But it is cheep. That is why it is used in cheap,smelly paint thinners.
    Heather- Original denatured alcohol,and the type that Howard uses,is mostly ethanol,with methanol added so that one cannot drink it. (Unless,that is, one aspires to be blinde or dead.)
    I started using rubbing alcohol (70% ethanol/30% water) only after I found that the adition of water to denatured alcohol improved coating chracteristics. Often,denatured alcohol absorbs water from the air, if its been opened and siting around awhile.
    I have also used 70% isopropyl alcohol,with results virtualy identical to ethyl alcohol.
    Cheers,
    Bill

  9. #19
    Akki14's Avatar
    Join Date
    Feb 2007
    Location
    London, UK
    Shooter
    4x5 Format
    Posts
    1,873
    Images
    210
    Bruce, Stoddard Solvent is known as White Spirit here in the UK; it might be called that in Australia too. I agree about the modern physautotype being fickle. I've only just got another (partial) image after a whole week of coating plates every night and doing exposures under my UV light every day and just getting nothing every time.

    Bill, I've not had a problem with using Stoddard Solvent to develop my plates, though. I finally got a tiny bit of an image on a plate today. Maybe it's
    just my method of developing. I use a large tupperware-type box with lid and just a glass ashtray with a little bit of white spirit in it. I use cut-up pieces of cardboard tube (from a used up roll of plastic wrap) around the ashtray to put the glass on it (face down) and then put the lid on the box and leave it for however long I think is necessary. Doesn't stink up the bathroom I work in then and creates a little fume box.

    I always thought rubbing alcohol was isopropanol alcohol but apparently not (after reading wikipedia again). I don't think we can get rubbing alcohol over here, it's usually only isopropanol alcohol which is available if you ask the chemist nicely and tell them you're using it for a valid reason.

    I might try the adding water method, though my plates do take a few minutes to dry anyway.
    ~Heather
    oooh shiny!
    http://www.stargazy.org/

  10. #20

    Join Date
    Aug 2007
    Location
    melbourne australia
    Shooter
    Medium Format
    Posts
    40
    Thanks bill, looks like kero is ok then for rosin, i can buy white spirit here in Oz, we used to use lots of it back in 1980's cleaning banks and wipers in the step by step telephone exchange i used to work in, untill technology replaced it

    Heather i use about 100ml of kero in my d tank, in a flat plastic bowl, the kero is spread out across the bottom of the bowl. covered with aluminium foil, plate sits on 4 bits of pvc, you can test your development process by simply coating a glass plate and let dry (dont worry about getting a perfect coating) and put straight into the d tank, with enough time it should go clear. for me today it took less than 15 mintutes @18'c for the plate to go completely clear (not my desired result)

Page 2 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin