Primer came off from Dibond?

GTOGTO -
edited June 18 in Studio & Supplies
I was prepping Dibond after I coated it with primer and the primer came off.?!!
I had lightly roughed up the Dibond with steel wool. Wiped it down and coated the Dibond using Rustoleum 2X gray primer.  I let it dry for four days.  I mixed up a thin combination of Holbein oil ground (white) with burnt umber.  When I brushed it on the gray primer got  gooey and mixed with the paint.  

Comments

  •  :o  :o:o:o

     Quite the red flag for that combo. Thanks for the heads up.
  • Very odd! I wonder if a solvent in the oil ground has dissolved the primer? Have you used these two products before in this combination? Any issues when using the oil ground over normal acrylic?
  • @Richard_P I’ve used these before.  I am now wondering if the oderless turp that I used had varnish in it.  I had a jar that I used to clean gamvar off a brush.  That may have been the cause but I don’t know for sure.  
    I am wondering if anyone bothers with oil ground on an ACM panel?  Maybe I can just use a mid tone Uber auto primer?  Will oil paint adhere well directly on auto primer?
  • GTO

    The gooey mess suggests a chemical incompatibility b/w the primer and ground.
    Suggest switching to a water based primer such as Dulux Precision Maximum Strength Adhesion Primer.

    Denis
  • I know Rustoleum primer and ingredients - it's a fairly robust primer so can't imagine why the ground itself would have this effect. I used it for a couple of paintings as primer and ground successfully. Does the holbein ground require thinning with turps?
    You can test on a spare piece of something if you can be bothered. Rustoleum primer then try: a) pure turps; b) undiluted ground; c) ground diluted with the turps you used; d) ground diluted with new turps.
    The chemists at rustoleum said their Zinsser cover stain (as primer & ground) was better than their rustoleum primer. I just did a test alongside gamblin ground. Zinsser cover stain (as primer & ground), Gamblin PVA & Ground. I got slightly better results with Gamblin products, but in terms of prep time the spray was way, way quicker and simpler, less waiting time, hard to get wrong.
  • @GTO, it sounds like there was something in the Holbein oil ground that reacted with the Rustoleum. If you have used these together before without a problem then, assuming the Rustoleum was the same,  there must have been the inadvertent addition of something to the oil ground. You mentioned varnish as a possibility. That may be it. To avoid the possibility of this happening in future it might be easier to  just use acrylic primer?
  • Thanks @dencal when I search the store, you know …Amazon… I don’t see Dulux primer.  I do see zinsser  and kilz products.  Are they the same type of thing as Dulux?
    Do you apply a mid tone on your panel after that dries?  What do you use for a mid tone?

    @Abstraction you must have an engineering backrest or testing background.  I’ve got some test pieces I may try.  Do you use a mid tone on top of your primer?  If so what do you use?

    Thanks @tassieguy it probably was the varnish tainted turps.   Do you use a mid tone on top your acrylic primer?  What do you use? 
  • GTO

    Look for a water based metal primer. There are dozens on the market. Low odour easy clean up.
    Ask the retailer to tint to a mid grey or a rust red. I use mine frequently and decant to a home made brush/screw top container.

    Using readily available materials I knocked together a cheap, recycle version of the "Paint Saint".
    Standard peanut paste jar ($0), combined with a cheap sample pot brush ($1) hot glue sealed to a hole cut in the lid. A cut down wood tongue depressor is hot glued to the jar wall to adjust brush loading.

    Now filled with my favorite iron oxide gesso and stands ready for use as needed.



    Denis

  • edited June 19
    @GTO, on top of the white acrylic primer, I paint a mid-to-dark tone in acrylic which I try to make close to the colour of a shadow tone that occurs widely throughout the picture. Then on top of this toned layer I begin in oils. 
  • @dencal that’s a very cool idea.  You are quite the inventor. 
    Thanks @tassieguy.  I’m going to see about sanding lightly, wipe with isopropyl alcohol and roll two coats of zinsser. And the a very light sand of maybe 220 or 320 grit.  I will have to see about acrylic or oil for the mid tone.  I think I am going to skip the Holbein oil ground going forward though.  
  • I did some quick searching on google and found some unsourced info on priming aluminum. Have no idea if these are true or not.

     I read that aluminum surfaces can reoxidize quickly so it’s important to sand surfaces well before priming. The photo showed a sheet being sanded with an electric sander. Vigorously.

    Another search said for aluminum it is not ok to use a primer designed for various metal - use a primer specifically designed for use on aluminum. It said to use an etching primer only and to wear a proper respirator as the fumes are highly toxic. It also said to use alcohol or other degreaser before priming.

    These days I have a robust, and well founded, distrust of experts - especially those who are trying to sell me something or may have other vested interests. This includes experts involved in the art conservation business, research paper writers, and those who vet them.
  • dencaldencal -
    edited June 19
    Suez

    Of course, do what you think best suits your purpose.

    Yes lightly sand ACM to give it tooth and wipe off with alcohol just before applying a water based, no odour metal primer. (Non Etching, the etching agent is an acid).

    Denis
  • @dencal, I hope you are right - for every painter choosing that path.
  • It also depends if the ACM panel you are using is bare aluminium, or has a coating like polyester on them.
  • @Suez @dencal @Richard_P the panel has a polyester coating.  I’ve never used an etching primer before.  I wiped it down with alcohol before painting.  The humidity was high when I painted.  Maybe that contributed to it.
  • Glad to know the panels are polyester coated. 

    Didn’t know polyester needs to be sanded. How thick is the coating? How would you know if you sanded it off in places reexposing the aluminum? I have microscopes which could reveal that. Do you?



  • I think that most oil painters do not have the background to understand the chemistry of metal-size-ground layering. I don’t. So, I have educated myself as much as I can. The indeterminate areas for me are: 1. how long it takes for aluminum to oxidize in the presence of the air. Some metal chemists (NOT artists, conservators, or art material manufacturers) state that it is instant, and in an inside area, will be self-limiting within seconds – “passivation”. Meaning that it won’t progress without humidity and acidic compounds in the air. 2. If this aluminum oxide layer will disrupt the oil paint or size over it later on.

    Since I don’t know, I make some efforts to prepare for the worst case, but will not bother with acid etching, etc. For me, finding an authoritative source is important, so I tend to go the same few places and not get too deep in internet discussions about topics I don’t have the background to follow. I suspect, but don’t know, that aluminum, even if the plastic covering is broken and the aluminum is exposed to the air, will not continue to develop an aluminum oxide layer which will cause the oil paint layer to crack or fall off. I suspect it is stable.

    Here is the best resource I have found on prepping ACM for oil paint.

    Microsoft Word - MITRA_Rigid_Supports.doc (udel.edu)


    Abstraction
  • Thanks @Desertsky I’ve bookmarked that page.  They list DTM Bonding Primer by sherwin Williams as an example of a compatible primer.  I ended up using Zinsser BondZ.  I sanded the polyester with 320 grit and wiped with isopropyl alcohol before applying.  
  • dencal said:
    Look for a water based metal primer. There are dozens on the market. Low odour easy clean up.
    Why water-based? Just for odour? The spray is significantly quicker, easier, no cleaning required, if you have an outdoor option.
  • Abstraction
    * low odour - even with a quality respirator mask the spray fumes of Rustoleum were dire.
    * lower environmental impact - petrochemical toxins in spray products and greenhouse gases
    * lower cost per application sq/m - Rustoleum spray required three coats - water based primer one coat.

    My peanut paste container of tinted water based primer (shown above) is quick, easy and no cleanup.

    Denis
    Abstraction
  • @dencal how do you tone your panels?  Oil ? Acrylic?  How thin do you make the paint?  
  • GTO

    Using lightly sanded ACM, I tone with tinted, water based, Dulux Precision Maximum Adhesion metal primer.
    This is a low odour, acrylic product, used as is out of the tin. The consistency is a bit thicker than a flat plastic wall paint.
    I leave this to harden up over a day or two, draw on a rough outline in pastel pencil, or fine point sharpie if I want to revert back to the drawing after scraping off some paint. Sometimes a working fixative.
    Then a value block in using acrylics. After a day or so oil paint is applied with a focus on value and texture.
    Six months later, a spray on varnish.

    Denis
  • @dencal when you block in using acrylics do you use a monochrome color?  Is it gray sepia, ?  Do you use full strength acrylic or more of a wash or thinned down?
  • I am wondering if I can mix some acrylic burnt umber (maybe Liquitex) with some acrylic gesso to get a mid tone that I can use to coat the BondZ covered panel as a prep before I start applying oil paint in the panel? 
  • @GTO, Amazon sells burnt umber acrylic gesso premixed. I don’t know what value it is.
  • GTO
    when you block in using acrylics do you use a monochrome color?  Is it gray sepia, ?  Do you use full strength acrylic or more of a wash or thinned down?
    The block in with acrylics is the full colour range and full strength. It is the same workflow as Michael James Smith except I use ACM and toned metal primer.

    Denis

    https://youtu.be/Awk_nXEo21Q




  • @Suez I see the black gesso but not a burnt umber gesso.  
    Normally I would mix a lead white oil ground with burnt umber to get the same color and value as the color of my pallet.  The back of my glass pallet is painted that mid tone umber color.

    @dencal that’s an interesting workflow.  My workflow is pretty much the same as Mark Carder’s.  I use a toned panel and I complete each section to a high degree before I move on.  After the canvas is covered I tweak whatever needs adjustments.
    dencal
  • @GTO, Sorry - it’s at DickBlick.

    I painted the back of some glass cutting boards with Geneva canvas stain. Even though the glass looked almost clear it turned out a full value off from my canvases. I have two more cutting boards I hope to get right next try.
  • @Suez I see Duck Blick has a variety of gesso primer. The details in the descriptions indicate you can add any colored acrylic paint to tint a white gesso.  I think I will go that route for now.  Thanks . -Gerry
  • @GTO, Artefex has a lot of good info on their site about preparing panels for mounting or painting. They are a sister company of Natural Pigments. They offer a great range of options for various mediums. Very tempting. 

    I just watched a YouTube video interviewing one of Artflefex cofounders. Well worth watching! It’s called “Artfefex AMC artist’s panels” on RublevColors YouTube.
    GTO
  • * typos, darn phone, Artefex.
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