Home Forums Explore Subjects Plein Air Best way to seal MDF panels

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  • #987942
    acadianartist
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        I know this topic would apply to lots of art forums, but since plein air painters seem to use more home-made panels than anyone else, I thought I’d check in with you folks on this one.

        After a considerable amount of trial and error, I’ve decided to continue making my own panels despite the effort and time involved. I can’t get Ampersand Gessoboard locally and having it shipped in is too pricey. Making my own panels allows me to screw one up once in a while and not feel guilty about the wasted money! I also like being able to tone my panels, getting them cut whatever size I like and having control over the finished texture.

        Since many of you are doing the same thing, I’d like to get some ideas about sealing the MDF. I’ve done it using polyurethane on front, back and edges with a brush, but it’s painstaking and time-consuming, plus the stuff is not cheap! It really soaks into the untempered MDF board I buy so I use a lot of it. After that, I prime with tinted Gesso with a bit of pumice mixed in. Not much, just enough to get a bit of grab.

        Any other options than using polyurethane to seal the board? I find this part of the process the biggest pain in the you-know-what so I’d welcome suggestions. While you’re at it, why not go ahead and share your method and recipe!

        [FONT=Palatino Linotype]Chantal (C & C always welcome)
        http://www.flickr.com/photos/102840288@N03/

        #1119218
        Anonymous

            I started with MDF as well but stopped using it as it was a little heavy for what it is and it was more expensive than what I wanted to spend.

            The answer??…..Go to a lumber yard and ask for door skin, either birch or mahogany (homedepot or revy don’t carry it). I got mine at Windsor Plywood but your local lumbar yard should carry it as well. It comes in 3×7′ and 4×8′ sheets and usually the place can cut it to size if you ask. The best thing is that door skin is 1/8″ plywood. Very light and strong.

            After it is cut to size you can seal it with shellac on both sides. Shellac only takes a couple hours to dry. Once dry you can coat one side with gesso (I usually give it three coats) and your ready to go.

            I got about 50 panels out of a 4×8′ sheet, ranging from 6×8 to 9×12″, that cost me $12 CDN. How great is that. That comes to $0.24 cents a panel. Add in the cost of shellac and gesso and in the end a panel will cost you $1.

            You just need to invest your time.

            Hope this helps.

            Mike

            #1119217
            MichaelR
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                Any other options than using polyurethane to seal the board? I find this part of the process the biggest pain in the you-know-what so I’d welcome suggestions. While you’re at it, why not go ahead and share your method and recipe!

                I use Unibond which is basically a PVA sealer.Same as wood glue only thinner, it soaks in , dries bone hard and stops warping if you seal both sides, then gesso which you can add colour to if it is acrylic and you want all the boards toned the same.

                We had a natter about this afew weeks ago, you might have missed it?

                https://www.wetcanvas.com/forums/showthread.php?t=561422

                Michael Richardson
                Constructive and informed criticism is requested. I am here to learn and will not be offended:)
                "Oil paint needs only to be thinned by the vigour of its application" Walter Sickert
                Michael Richardson's oils and watercolours and Michael's Blog and painting holidays

                #1119238
                acadianartist
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                    Thanks Mike, I’ll look into this door skin you’re talking about… I’ve seen really thin birch panels, I can see how that would work in a 1/8″ thick sheet. It might not absorb moisture as much as MDF, which will swell right up if it gets wet. I have a gallon can of Shellac primer/sealer left over from a painting job, might as well use it up!

                    And thanks Micheal, I did see your post and I believe I commented on it. I found it interesting that you use Unibond. That post, and others like it, got me thinking about what other people were using. Always looking for the cheapest, most effective solution! Though I’m not particularly worried about achieving archival quality, selling a few pieces lately has made me more conscious of the importance of preparing the surface. I used to paint straight onto the MDF board, no primer, nothing! But I wasn’t selling paintings then.

                    [FONT=Palatino Linotype]Chantal (C & C always welcome)
                    http://www.flickr.com/photos/102840288@N03/

                    #1119203
                    JamieWG
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                        I’m sealing my current batch of panels with the KILZ latex sealer, rather than the shellac. In the past I’ve always used GAC100. I’m doing two coats with KILZ, then I’ll add 3-5 coats of gesso over that. I like tile board because it’s masonite with one side already melamine-sealed, providing a clean look on the back and saving me tons of work!

                        Mike, thank you for the tip on the door skin. I love the masonite panels, but you’re right that they weigh a ton!

                        Jamie

                        Hudson Valley Painter[/url]
                        Hudson Valley Sketches -- Reviews/Lightfastness Tests/Art Materials
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                        One year from now, you'll wish you had started today.

                        #1119219
                        Nilesh
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                            These products might be worth a look,

                            http://www.zinsser.com/subcat.asp?CategoryID=1

                            The water-base products seem easier to work with and more benign.

                            Like oil-base primers, Cover-Stain Water-Base is a great sealer for all types of wood – new wood, weathered wood, plywood and T1-11. The advanced formula water-base primer offers easy flow and leveling, so it can be brushed, rolled or sprayed — without the special respirators, solvent clean-up, or hazardous disposal associated with oil-base products.
                            Cover-Stain Water-Base is ideal for use on all interior and exterior surfaces including drywall, painted wood, cured plaster, concrete, stucco, aluminum, vinyl, steel, galvanized metal or PVC.

                            This one also looks good: http://www.zinsser.com/product_detail.asp?ProductID=11
                            [/COLOR]

                            #1119237
                            bnguffey
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                                Acrylic latex enamel semi-gloss indoor housepaint. Every hardware store has a “mistake” section they’ll sell at least half off regular price. I buy just about any color in the mid-value range. I prefer gray, blue or tan though. My local store will even add more color at no cost if I need it.

                                #1119239
                                acadianartist
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                                    Thanks Bill and Nilesh. I like the primer-sealer idea, because a big can is cheaper than the little cans of polyurethane and because you can get a water-based version. I’ve used house paint to tone panels before Bill, and yeah, the mistake section is great!!! I always check there. I’ve even used it on my walls ;) However, as a primer-sealer directly applied to wood, I’m not sure it would be enough. I’ve seen wood stains leak through paint enough times to have me worried… it could, however, replace the gesso and would have the advantage of already having some tint to it…

                                    The bottom line is that I really just want something that will last a few decades so that a buyer doesn’t come back p.o.-ed… beyond that, I’m not too worried. But people seem somewhat reluctant, at least around here, to buy paintings on masonite so I figured by prepping the support well, I might calm some of their fears. I had a request for a large painting (basically a commission I guess, but she’s letting me pick the subject) and the buyer is supplying the canvas because she wants wrapped canvas, not board. Yet so many great artists painted on masonite and worse!!!

                                    [FONT=Palatino Linotype]Chantal (C & C always welcome)
                                    http://www.flickr.com/photos/102840288@N03/

                                    #1119254
                                    hoakley
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                                        Chantal,

                                        If you are concerned to ensure that a purchaser does not return with a complaint, then I recommend that you use the recommended (i.e. Gottsegen et al.) sizing of diluted GAC100. This is widely documented as addressing the problem of colour bleed (or SID, as Golden term it), and is of archival quality. It is also easy and quick to apply, and will support either oil primer or acrylic ground on top.

                                        Howard.

                                        [FONT=Garamond]There is no place for prejudice, insult, or taboo in open discussion; instead use evidence, objectivity, and reason.

                                        #1119220
                                        Nilesh
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                                            Chantal,

                                            If you are concerned to ensure that a purchaser does not return with a complaint, then I recommend that you use the recommended (i.e. Gottsegen et al.) sizing of diluted GAC100. This is widely documented as addressing the problem of colour bleed (or SID, as Golden term it), and is of archival quality. It is also easy and quick to apply, and will support either oil primer or acrylic ground on top.

                                            Howard.

                                            In conversation with the Golden tech dept., KILZ primer-sealers (or similar products) were recommended as an initial coat. They seemed to be saying that these products were an even better solution to the SID problem than GAC 100, and they recommended using them.

                                            Some local paint stores prefer the Zinsser primer-sealers over KILZ.

                                            Although some of the oil-base KILZ and oil-base Zinsser products seem to give the very highest level of stain-migration and SID protection — and I once leaned toward them for this reason — some of the other (water-base) products are also very good, and probably more than good enough.

                                            We are not dealing with extreme stains or knots or creosotes or tannins here, usually. The various sorts of plywoods mentioned, as well as the masonites (esp. the pre-coated masonites, panel boards, or tile boards), do not have *severe* problems with stain migration. I just don’t think it is severe enough to warrant going with the oil-base primer-sealers rather than the best of the water-base primer-sealers. These are almost certainly more than adequate, and I would much rather work with the water-base products.

                                            GAC 100 is probably fine as well; I’m not sure whether the SID protection is as good, and I don’t know how it compares in longevity (or archivalness); but it seems to me that the best of the water-base Zinsser primer-sealers are quality products with long lifespans.

                                            It would be interesting, though, to find out for certain what the life expectancy would be for the applications in question. Maybe Zinsser could answer this. They probably have an email or phone number for customer service and inquiries — it seems very much a part of their job to provide answers to questions like this from prospective buyers.

                                            #1119250
                                            halthepainter
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                                                Perhaps I’ve been doing something wrong. I cut my masonite to size and give it three heavy coats of acrylic gesso on both sides and edges. I’ve been doing this for twenty years and have had no problems. Unfortunately, I still have a few of those twenty year old paintings hanging around and I can seen no problem with them (other than the poor quality of my painting skills).

                                                I would apply the gesso with a cheap bristle hardware store 2 inch brush. After about two coats of gesso, I would apply the next layer with all horizontal strokes. After drying, I would add the next layer with all vertical strokes. If another layer were required, I would do another horizontal layer. This gave me a pseudo canvas texture for my acrylic paintings.
                                                This surface could get a little slick when painting with my acrylics.

                                                I much prefer the feel of canvas, so for a number of years now, I’ve been glueing canvas to my gessoed panels. I love this surface. It is firm and the canvas still pulls the paint off my brush. I use preprimed canvas, and if painting in acrylic, I’ll give this surface an additional layer of toned toned gesso. If I going to use it for soft pastels, I’ll add a couple of more layers of gesso to diminish the canvas texture and a final layer of gesso with pumice in it.

                                                I found using pastel on gessoed and pumiced masonite, the hard surface broke entirely too many pastels. The pumiced canvas has a great feel and much less breakage.

                                                I’ve also used watercolor paper on masonite, wet paper glued down with acrylic medium, otherwise with the same preparation, for use with my pastels. However there is a tendency for warpage with the paper but not to the point the masonite was unusable.

                                                In summary: I’ve only just used 3 or more coats of acrylic gesso for my masonite panels.

                                                [FONT=Fixedsys]

                                                #1119255
                                                hoakley
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                                                    There is nothing necessarily wrong in doing anything – it is your choice. However, if you are going to exchange your work in return for money from a customer, they are likely to expect that you have exercised due diligence in ensuring that your work does not discolour, delaminate, degrade, or decompose at least during their lifetime.

                                                    If you follow fairly authoritative published procedures – in particular those of Mark Gottsegen in his The Painter’s Handbook – then you can rely on those as being best practice. If you instead rely on phone conversations with those whose job is to sell building supplies, or industrial paints that only need to last a decade or two, or even very (apparently) knowledgeable friends, then your customer may not believe that you exercised due care.

                                                    GAC100 has quite an established reputation and literature, and is sold specifically for the purpose of sizing supports like these, and for preventing SID. It is an art material intended to last well past my or your lifetime, and is extensively used by professional artists and conservators. Its component cost within a painting is a tiny fraction of the cost of the paints. Sure, it is a boring ‘safe’ option, but most paying customers prefer that you do not gamble with their investment.

                                                    Howard.

                                                    [FONT=Garamond]There is no place for prejudice, insult, or taboo in open discussion; instead use evidence, objectivity, and reason.

                                                    #1119240
                                                    acadianartist
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                                                        Hal, I would recommend you seal your masonite before priming it with Gesso, just to ensure no problems creep into your paintings years down the road. I’ve also got old paintings sitting around done on just about every surface imaginable that have held up fine, but have also seen other artists paintings done directly on plywood in the 60s deteriorate badly in the last few years – paintings that were purchased by a university to adorn their hallways and presumably as an investment.

                                                        One of my big concerns with masonite is that it absorbs moisture like crazy which can warp it or worse, cause it to swell up. Sealing the front, back and edges prepares the surface and support for the Gesso (yes, it’s a royal pain, but as Howard says, if someone is paying for my paintings, they have a right to expect that I protected the surface as well as if I’d bought archival quality Ampersand Gessoboard, for example). This prevents warping, discolouration due to chemicals in the masonite and hopefully some degree of moisture damage (have you ever left a masonite panel on the floor of a moist basement? I have and it’s not pretty). I do think I’ll try the birch door skin product out as it seems a little less processed to me than masonite which can contain any number of chemicals and other undesirable additives.

                                                        Howard and Nilesh, thanks for your differing points of view! They have been most helpful to myself and to others doing the same thing I’m sure. This has been a very interesting discussion.

                                                        [FONT=Palatino Linotype]Chantal (C & C always welcome)
                                                        http://www.flickr.com/photos/102840288@N03/

                                                        #1119212
                                                        yazelm
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                                                            I have always wondered about the archival qualities of the adhesives used in the manufacture of masonite. I have never seen an article devoted to its longterm durability.

                                                            #1119251
                                                            halthepainter
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                                                                I have always wondered about the archival qualities of the adhesives used in the manufacture of masonite. I have never seen an article devoted to its longterm durability.

                                                                Being 70 years old, I have all these tid bits of information floating around in my head and I couldn’t begin to cite a source for almost any of them.

                                                                Somewhere I read that early art works painted on masonite shortly after it’s invention are doing just fine, with no discoloration or detoriation.

                                                                [FONT=Fixedsys]

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