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MITRA Forum Question Details

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  • Cat Spray on Gessoed BoardsApproveRejectUn-ApproveSubscribeUn-Unsubscribe
    Question asked 2017-08-17 22:02:15 ... Most recent comment 2017-08-18 23:23:30
    Grounds / Priming Other

    ​This may win the prize for the weirdest question... I have five maple panels that I sized and then later gessoed and left out on my porch to air dry. It's possible that a cat (or squirrel?) may have sprinkled them with their "marking fluid" while they were drying. (I've heard that cats are attracted to the smell of amonia.) There are a dozen or more shiny specs on each of the boards, which were laid end-to-end. And the peculiar and unpleasant odor is only slightly diminishing after a week and a half. I had thought maybe there was a reaction between the sizing and the gesso, but I think that would have resolved by now. So...if the panels have been sprayed, do you think it's a reasonable approach to clean them with vinegar and water 1:2? That's one of the home remedies that is suggested for spray on interior walls. I can wipe the specs off with straight water, but the odor seems to remain. I'm concerned about adhesion problems when I proceed with oil paint, or de-laminating further down the line. Alternatively, I could put another coat of gesso (water-based) on the boards, or an imprimatura of oil paint...? Any suggestions would be greatly appreciated!  :-(

Answers and Comments

  • ApproveRejectUn-ApproveUser Comment

    ​Have you confirmed the presence of cat urine with UV light?

    2017-08-18 07:47:02
  • ApproveRejectUn-ApproveUser Comment

    I have read that one can do that, but no I haven't...I'm just guessing the possibility due to the strange amonia smell (unlike the regular water-based gesso smell on the back side, which is Golden's Gesso) and the shiny specks on the surface. The front side (that smells persistently) is a  different brand of water-based gesso, which the manufacturor says does NOT smell, and hasn't smelled in my past experience with it. (It's a new jar, and the jar itself and two test panels made at the same time--but without sizing--do not smell.) This is the first time I've used a gesso over a size, but again, the back side does not smell and was done the same way. It's a cat urine-like odor, but I can't think what else the smell could be caused by.

    2017-08-18 11:58:03
  • ApproveRejectUn-ApproveUser Comment

    ​I've just checked my deck where those boards were lying to dry, and there are shiny specks everywhere that's under a pine tree and not under the eaves, so maybe it's not cat spray. That leaves me scratching my head: high-quality non-smelly gesso from a new jar...gesso over size that's supposed to be ok...proper drying times between...non-smelling (different brand) gesso on the back...decent brushes...180 grit sandpaper...nothing smells but the front sides of these panels that have this particular brand of gesso over a size layer. What could it be?? I'm about to chuck them all, as it's too strong of a smell for my tiny work space. I suppose I have nothing to lose at this point by putting another layer of the same gesso on the smelly side...   :-(

    2017-08-18 12:56:23
  • EditDeleteModerator Answer

    Ammonia is commonly used in acrylic dispersion artists' paints, mediums and primers to maintain proper pH. Once in a while, (rarely) a mistake in formulation can result in a noticeable ammonia smell. If you have any leftover primer, I would try to duplicate the sequence of application. I doubt there would have been a reaction between different brands of acrylic that would cause a persistent odor but if you can duplicate the smell, it might give a clue.

    I would be interested to hear from one of the qualified Moderators as to whether an enzyme neutralizer would be safe to apply in this case, even if it's not yet determined that urine is the source of the issue.

    Matthew Kinsey, Utrecht Art Supplies
    2017-08-18 20:30:25
  • EditDeleteModerator Answer

    Given the uncertainty here, I am not sure that I could make any sensible recommendations at the moment.

    Matthew, I have not tested the effects of enzyme neutralizers on artworks.

    Honestly, unless this turns out to be a case of normal residual odors derived from quality materials, I would probably just start with afresh with new substrates etc., rather than risk the longevity of works that may turn out to be important to the OP.

    Brian Baade
    2017-08-18 22:43:30
  • ApproveRejectUn-ApproveUser Comment

    ​Thank you for these thoughts, Matthew and Brian. Hopefully, the amonia (or whatever the source is in this quality gesso with built-in sealer) smell will lessen in time and won't be an issue. Meanwhile, I am considering my other options for a substrate. Best wishes to you both, Susan

    2017-08-18 23:23:30

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