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Painting on Dibond

Dibond is a trade name for a type of painted aluminum composite panel made by Alcan Composites. There are other brands and types of Aluminum Composite Panels that may have a bare aluminum side or different types of coatings, which may require different surface preparation.

Dibond panels are made with two lightweight sheets of .012″ aluminum with a solid thermoplastic core. Both sides of the aluminum are coated with a polyester paint. The advantages of this type of panel are:

  • Dimensional stability
  • Very lightweight
  • Relatively inexpensive
  • Available in large sizes
  • Long term durability

The current information from the Fabrication Manual from Alcan/3A Composites says that the best direct adhesion occurs after lightly scuff-sanding the painted polyester surface followed by wiping with isopropyl alcohol, and then application of properly selected paints. They also caution not to sand through the coating to the aluminum surface. Acrylics are mentioned among the list of “suitable paints”, and this suggests that many of our Acrylic Mediums, Gels, Gessoes and other waterborne acrylic products should have similar adhesion. With some higher viscosity products, however, an effect called “hold out” is a possibility, and variations in a formula could alter adhesion, so we always encourage testing. It is very important not to touch the cleaned surface with your fingers as this can leave oils that will interfere with adhesion. They also recommend always testing the paint system you are using for adhesion and suggest a cross hatch adhesion test, which is something we also often recommend. The following are adapted from both their guidelines and the testing we do:

  • Apply the paint or ground and let dry for a minimum of 24 hrs. As both sides of the Dibond panel are the same, you can use the backside for testing if desired, leaving the front untouched for now.
  • Over a 2” square area, using a razor blade or X-Acto knife, cut a series of parallel lines 1/8” apart. Then cut another series perpendicular to these, to form a crosshatch pattern.
  • Make sure to only cut through the paint and not through the Polyester coating.
  • Apply a piece of strong masking tape to the center and burnish.
  • Peel the tape straight back at a 180 degree angle in one rapid movement.
  • For best adhesion, no paint squares should come up.
  • If any parts of the squares do come up, the test can be repeated after 3 days, 1 week, and even 2 weeks. It is not unusual for some coatings to improve in adhesion over time, depending on application and environmental conditions.

If there is need for increased adhesion, or for an exterior application, we recommend applying a suitable commercial primer to the prepared surface. These are often called “bonding primers” and are made for hard, non-porous surfaces. Two that are widely recommended are included below in our testing. While Alcan does not mention oil paints as one of the “suitable paints” for use directly on Dibond, once you have a suitable primer applied, then oil paints or an oil ground can be used.

Here is a link to the Fabrication Manual for 3A Composites’ graphics display products:

http://graphicdishttp://graphicdisplayusa.com/downloads/Dibond%20Fabrication%20Manual_May%202011.pdf

We selected four products to test for adhesion to the sanded Dibond surface:

  1. Sherwin Williams DTM Bonding Primer
  2. XIM’s UMA ( Urethane Modified Acrylic ) Bonder Primer ( white )
  3. Golden Artist Colors Gesso ( White )
  4. Golden Artist Colors Heavy Body Acrylic – Pyrrole Red
Adhesion test Products

Adhesion test Products

We determined that the DTM Bonding Primer and the UMA Bonder Primer would be the best two commercially available primers since both specify use on polyester coatings and other hard to coat surfaces, and we have seen successful applications with these products in the past. This does not mean that other similar primers could not work as well. PLEASE NOTE: While all the products we tested can be used for interior applications, we DO NOT recommend our Gesso for exterior use.

As a first step, we lightly sanded the polyester painted surface on a piece of Dibond using 150 grit (Fine) sandpaper making sure not to sand through to the aluminum, and then degreased it with isopropyl alcohol, wiping enough to remove all of the fine white powder from the surface.

Peeling backer off Dibond

Peeling backer off Dibond

We then divided the Dibond panel into 4 sections and applied the coatings using a white bristle brush in one relatively thin layer. The coatings were tested for adhesion using the Cross Hatch Adhesion Test at 24 hour, 3 day and 1 week intervals. We use a standardized adhesion test kit that contains a special type of tape, a burnishing tool and an 8 blade knife to make the cross hatch cut pattern, which creates 49 small squares on the test area. For the maximum adhesion, no pieces of any of the squares should come off. This is always the ideal to aim for. If any squares come off entirely, then one has complete adhesion failure. If small bits come off, retest after several days or a week has passed and see if there is improvement.

Tests for adhesion using the Cross Hatch Adhesion Test at 24 hour, 3 day and 1 week intervals.

Tests for adhesion using the Cross Hatch Adhesion Test at 24 hour, 3 day and 1 week intervals.

Results were good to excellent with all the products, with no squares coming off at any of the time intervals. At 24 hours our Gesso and Heavy Body Acrylic had good adhesion with some minor failure as tiny bits of product were pulled off with the tape, primarily on the subtly thicker ridges produced by the brush. Both of the commercial primers had excellent adhesion after 24 hours. At both 72 hours and one week, the Gesso showed some very minor flecks of paint still lifting, while the Heavy Body paint was now performing quite well.

It is interesting to note that while both of the bonding primers worked equally well, they have very different colors and surfaces. The DTM primer has a pale greenish gray color and is quite toothy, almost like our Acrylic Ground for Pastels, and could easily take pastel and various dry drawing media very well. The UMA primer was much smoother and a pale warm white color. However, it is important to point out that these primers were made to be covered with paint so we cannot assume there would not be changes to their color, as they are not fine art grade products. Also, whenever using commercial products, please remember that they can often change without notice, so testing and reading the company tech sheets is always strongly recommended.

Finally, while a simple light sanding and degreasing with alcohol allowed painting directly on Dibond with our Heavy Body paint, and this should be true for our other acrylic paint lines and products, our test obviously did not cover all the possible materials, applications, and environments you might be working in. So it is always important to test. If for any reason you need increased adhesion, then the bonding primers we tested could be an alternative to look into.

20 Responses to Painting on Dibond

  1. Jill Nathanson February 2, 2016 at 9:46 am #

    HI Scott,
    Thank you for this excellent survey of your findings! I’m thinking that I’ll use the UMA primer and then one or two coats of Golden gesso to assure a white ground that won’t change. Does that sound right/necessary? Thanks.
    Jill Nathanson

  2. Scott Bennett February 2, 2016 at 10:30 am #

    Hi Jill. You are most welcome! Applying a coat or two of our Gesso over the UMA primer sounds like a good idea. The only other thing would involve creating other types of painting grounds over the Gesso, if your painting method might require a surface with more or less absorbency.

  3. Andrew Werth February 2, 2016 at 1:53 pm #

    Thanks for this much needed “official” article about Dibond! Because I sometimes like to keep the reflective, brushed aluminum showing through, I have used a “primer” composed of Matte Medium and GAC-200 (“Improves Adhesion to Non-Porous Surfaces”) with good results. I have found that if I let this dry for at least 48 hours the adhesion is excellent.

    Additional Tip (from experience): Make sure the aluminum composite panel is the kind with the polyester coating (not raw aluminum!) and don’t sand all the way through it (as mentioned above).

  4. Roy Kinzer February 2, 2016 at 4:48 pm #

    Great article by Scott!

    All my acrylic paintings in the past 4-5 years have been on Aluminum Composite Panels preparing the surface this way.

    2 years ago I started working with watercolors and treating the aluminum with Absorbent Ground after the gesso and industrial primer (I’ve been using Sherwin Williams – Extreme Bond Primer a relatively new product) and then doing QoR Watercolors on that. I spray 2 coats of Archival Varnish to protect the watercolors and free them from the need to be under glass. Really great results.

    Roy Kinzer

  5. Scott Bennett February 3, 2016 at 12:34 pm #

    Thanks for your kind comments about my article, Jill, Andrew and Roy!

    We do not have any long term testing of GAC 200 and Matte Medium on brushed aluminum, and the important thing here is that this coating will not stop the aluminum from tarnishing over time. There are some coatings that apparently will help with this. Again, we do not have testing with these products to cannot recommend with full assurance. We suspect that Incralac, a coating used on non-ferrous metals like bronze and brass to protect and slow down or block oxidatiion, can also be used on aluminum. They are translucent but may yellow over time.

    Roy,…thanks for the information about your method of doing watercolors on Absorbent Ground on Aluminum!! Very Cool!

    • Scott Bennett February 3, 2016 at 2:30 pm #

      I do want to add that we have seen good adhesion of our Fluid Matte Medium on lightly sanded aluminum and that we suspect adding in some GAC 200 could assist with adhesion. And I want to retract my mention of yellowing with the Incralac as this was only conjecture. Most translucent coatings do have changes over time, so we wanted to make sure that if total clarity was important, this might not be a guarantee. Incralac does contain UV inhibitors which we know can assist with maintaining more clarity in acrylic films over time.

    • Andrew Werth February 4, 2016 at 7:20 am #

      I should clarify that the “brushed aluminum” color I referred to is actually Dibond’s “brushed silver” metallic color and it is still protected by the baked laquered (polyester) coating, so I don’t think there should be an issue with tarnishing. The paint should adhere as well to this as to any of the other colors of coated Dibond panels.

  6. Keith Barnett February 3, 2016 at 2:15 pm #

    Thanks you for the information and testing. This is the first time I have heard of Dibond. I think I will have to try it out.

  7. Dean Anthony February 3, 2016 at 3:20 pm #

    Any experiments with oil paint?

  8. Scott Bennett February 4, 2016 at 1:45 pm #

    Hi Dean,

    You can most certainly use oil paints, and while there will probably be good adhesion directly to lightly sanded aluminum, we would recommend applying one of the primers we tested on the sanded polyester paint, and then the oil ground or gesso or other painting ground of your choice that will be suitable for oil adhesion. If you wanted a translucent ground, we have recommended using our Fluid Matte Medium directly on sanded raw aluminum.

    I do mention oil paints briefly above, in my article. Here is the segment:

    While Alcan does not mention oil paints as one of the “suitable paints” for use directly on Dibond, once you have a suitable primer applied, then oil paints or an oil ground can be used.”

  9. Stephen February 29, 2016 at 9:47 pm #

    Thank you for the article. Appreciate that there might be a more rigid surface than canvas or paper (board) and lighter than masonite that might handle size.

  10. King Farish September 19, 2016 at 4:20 am #

    Just checking to see if I am understanding your opinion , correctly. The commercial primers bonded better , but there are concerns about consistency and content of the material. Would these concerns extend to eventual changes in the painting ? Secondly , it sounded to me like you thought golden heavy body held up better then the acrylic dispersion ground.
    I want to use Golden gesso / acrylic ground and then Golden paints and not work with the commercial primers would it be less strong than starting with the commercial primer ?
    Thanks in advance !

    • Scott Bennett September 19, 2016 at 12:36 pm #

      Hi King! There will always be concerns, and the reality that products may change formulas without notice to the public, and that we have no control over that. This is why we mention it, and why we always recommend testing. We would doubt that these changes would translate into eventual changes in the painting, but this can only be an educated guess.

      There was a very subtle difference in this test between our Heavy Body Acrylic and our Gesso at 72 hours. I would not think this tiny difference would make any significant difference in the adhesion, long term.

      From what I saw in this testing, and this is what I state in my article,….the commercial primers had the best adhesion more quickly, and so we think if you want that increased adhesion, then go with those products, but that the Gesso and HB paint performed very good too. While we can rarely make guarantees, it does not appear that you should have any problems with using our Gesso, following our best recommendations for preparing the surface.

  11. Dan September 19, 2016 at 5:25 am #

    Hi Scott, thank you for this very useful article!
    Do you reckon OMS would make for a good alternative to isopropyl alcohol during the cleaning process of the polyester surface (prior to gessoing)?

    • Scott Bennett September 19, 2016 at 2:41 pm #

      Hi Dan,

      You are most welcome! Much depends on what you are degreasing and for metals, stronger solvents like acetone or mineral spirits are often recommended, but for this purpose, we think either rubbing alcohol ( typically 70% ) or stronger 99% isopropanol should be fine, and much safer than acetone or even the OMS. It evaporates fast and should remove any small amounts of oils or other surface contaminants.

  12. JB October 15, 2016 at 9:55 pm #

    thanks for this info. What would u advise for adhering raw (acrylic primed) linen (or arches oil paper) to Dibond? Are the commercial products acidic so apply coats of GAC or acrylic gesso before the linen then gloss gel medium to adhere the linen or paper? Then 2thin coats of gesso over the raw linen (does the linen also need a SID GAC layer)? I’m thinking of using fine lightweight linen. Any tips for getting out air bubbles without squeezing out of too much acrylic gel? Thanks

  13. Scott Bennett October 17, 2016 at 2:50 pm #

    Hello JB,

    We generally recommend using our Soft Gels to adhere paper or canvas to panel. The commercial primers should not be acidic and so you can simply prep the Dibond as I recommend and go right to adhering the paper or linen onto that surface. If you are painting with acrylics or oils we do recommend that you size the linen with a coat or two of our Polymer Medium to block oil from getting into the linen, or to block SID from getting into any more translucent acrylic films. You can then apply our Gesso over the Polymer Medium.

    Lightweight linen might be tricky in terms of some of the Gel getting through to the front as you press it down into the wet Gel. It may squish up through the more open weave. A thin, brushed on coat of Soft Gel ( Gloss) on one side of the Linen allowed to dry before gluing down can help. Make sure to secure the linen on a board, stapled all around so it will shrink evenly and not deform when applying the Gel. Just in case make sure you have a sheet of polyethylene plastic under the linen. Then remove when dry. Lay that side down into the wet Gel.

    A printmakers brayer can work well to smooth out the linen and the wet Gel underneath. Here is a link to a video showing a simple method for adhering watercolor paper to panel:

    Adhering Watercolor Paper to Panel: http://www.youtube.com/user/GoldenPaints

  14. Joelle Dietrick January 2, 2017 at 11:04 am #

    Hi Scott, any thoughts on storing Dibond? Headed to a residency and have a stack of the stuff that I’ll paint with acrylics. Then need will need to drive 14 hours home. Temporary then permanent storage plan needed…

    • Scott Bennett January 3, 2017 at 10:47 am #

      Hi Joelle,

      It has less to do with storing the Dibond and much more to do with storing and handling any surface painted with fine art grade acrylics. The main issue has to do with the relative softness of acrylic films and that they will get softer at warmer temperatures ( thermo plastic ) and then potentially stick to other surfaces and also become ferrotyped. The best way to store any acrylic painting is with nothing touching the surface. This is not always possible, but generally accomplished with various kinds of collars around the painting to maintain some space in between the painted surface and any other surface. For panels like Dibond you may need to create some kind of rack system where they are standing upright to reduce pressure, and then use silicone release paper as your slip sheets.

      Here is a good article for you: http://www.justpaint.org/safe-handling-and-transportation-of-acrylic-paintings/

      I hope this is helpful, and best of luck at the residency!

Trackbacks/Pingbacks

  1. Painting on Metal: An Introduction | Just Paint - January 11, 2017

    […] Best practice is to also lightly abrade the surface after degreasing with wet/dry sandpaper. Make sure to avoid sanding through the applied coating. Then wipe off any dust from the grinding process with the alcohol wipe before painting. The supplier or manufacturer of your panel would be able to provide their best advice for their coating system. Dibond® and Alucore® recommend this process for subsequent applications of coatings: 1. Pre-clean with Ethyl- or Isopropyl alcohol (apply to a lint free cloth first and not directly on surface). 2. Follow with a light buff sanding using 360 Wet/Dry sandpaper. 3. Remove dust with cloth moistened with the alcohol. 4. Allow sufficient time to dry. GOLDEN Materials and Application Specialist Scott Bennett, has written an article in JustPaint.org about best practices for painting on DiBond® (See http://www.justpaint.org/painting-on-dibond/) […]

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