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Gesso

I gessoed a small maple wood panel some weeks ago, and I took it out last night to look at it in prep to start painting again, I very gentley rubbed my finger on the panel and the gesso came off in small particles of gel like dust, is this normal?
i am tempted to rub off totally and reapply, I can not sand as it has an underdrawing on the panel.

never seen this before 

any help gladly absorbed,...
al 

Comments

  • Did you prime the panel first? It could have been so absorbent it sucked in all the liquid contact and left the acrylic paint underbound on the surface.
    BOB73cadia
  • @Richard_P ; - that is what i am thinking the panel was like a sponge and drawn all the liquid from the gesso leaving the white compound.
    I will try again and reapply, oh the "under-painting" is a posrerized image laser printed on the wood panel, but more of that to come with my WIP thread (another experiment) once I get started - thanks


  • BOB73BOB73 -
    edited November 27
    Not knowing where the panel came from I can only surmise that @Richard_P is correct but there's a possibility that either the gesso was a bad lot or the panel had been treated with a preservative oil like teak oil.  Also, maple is a very open grain wood and it's common to use a wood filler to provide a smooth surface.
  • PaulBPaulB mod
    Oil paint penetrates porous gesso.  If there is no primer or size between the panel and the gesso, the oil paint will reach the wood, which can rot and delaminate.  The same is true for canvas, which oil paint can also rot and delaminate.

    Primer is not porous, and provides a seal.  You can skip a primer if the substrate is non-porous or inert. Your concern then becomes one of bonding and texture.  Weak bonding means delamination.
  • PaulBPaulB mod
    Richard_P said:
    It could have been so absorbent it sucked in all the liquid contact and left the acrylic paint underbound on the surface.
    ... leaving what is essentially a pastel.
    alsart
  • @PaulB ; i will not apply any oil paint until I know the panel is able to hold the paint, @BOB73 has a good point, and I have asked the factory if they applied a finish that I was unaware of - I am trying something brand new here, so its all suck it and see,...thanks
    PaulB
  • I got an update from the factory, the wood panels (maple) are sealed and then a "dye process" (top secret) i used to layout my image on the wood panel - the gesso may have reacted with the "process"
    So I will  1) try to clear this gesso off and reapply
    2) try to apply oil direct on another panel, as the wood panel is already sealed,...
    More to come in my WIP  thread, but wanted to follow up with this info
    SummerBOB73
  • I'm following this thread and am very glad to hear you have possibly solved the problem.
  • dencaldencal -
    edited November 28
    alsart

    Gesso (Italian pronunciation: [ˈdʒɛsso]; "chalk", from the Latingypsum, from Greek: γύψος) is a white paint mixture consisting of a binder mixed with chalkgypsumpigment, or any combination of these.
    This quote from Wikipedia indicates that gesso is designed as an absorbent layer, an open, porous and receptive surface to bind with the oil paint.

    The binder, traditionally rabbit skin glue, in the modern form an acrylamide binder. In each instance gesso is formulated differently with more or less binder. 

    Another sought after attribute in gesso is ease of sanding to produce a smooth surface, probably a leftover from the fresco tradition. 

    In in short I think you have observed normal behaviour of gesso, but other formulations may behave as you expect.

    Try coating a panel with gesso, but not subjected to your secret dye process. Check if the dry surface has the same friability.

    Perhaps a clear gesso will be a better option.

    Denis

    Summer
  • All these years I thought friability had to do with the quality of catfish and chicken tenders. Just kidding the term is used a lot in association with asbestos and has to do with how easily it flakes or crumbles. I guess it could also mean how easy it is to sand.
  • Just wild guess on my part here, but I wonder if wiping down your panel with isopropyl alcohol 99% before applying anything else, would this help?
  • dencaldencal -
    edited November 28
    Forgiveness

    I’m sure the alcohol will degrade the effectiveness of the binder and liberate more calcium carbonate.
    Or do you mean the raw panel surface?


    Denis
    Forgiveness
  • edited November 28
    Denis, yes I am referring to applying to the raw panel surface. Thank you!
  • @dencal ; - I did use clear gesso my guests leave the island today so I am keen to try to get this resolved and paint will test how it preforms
    Oh the " secret dye process" is the factory who makes the panels, they would not elaborate, more to follow over the coming weeks
    thanks everyone

    Al

  • Are the panels advertised and sold for the purpose of oil painting?
  • @BOB73 ; - no they are for photographs, i have corrupted the panels with my evil plans,,and wizardry ha ha 
  • alsart said:
    @BOB73 ; - no they are for photographs, i have corrupted the panels with my evil plans,,and wizardry ha ha 
    Errr... Are you sure this is a good idea? :p
    BOB73
  • @Richard_P ; - probably not, but he who dares,...ha ha
  • This is after I brushed of the panel, the white are the flakes - I actually think that the gesso has taken, and it was residual flakes  - anyway, I hope to start on the first step tonight (black) and will post in the WIP thread  - consider this one closed - thanks

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