# Alkyd primer



## M Winther

I have sized hardboard (fiberboard) panels with white alkyd primer (Beckers Nondrop) bought at the hardware store. The result is a perfect surface for oil painting. The traditional way is to size with rabbit skin glue or fish glue and then add a layer of oil gesso. Alternatively one can use acrylic gesso. However, since both glue and acrylic gesso are water based, the panels will inevitably become warped. This doesn't happen when using alkyd primer. 

Moreover, alkyd primer can be used on any material because it is a super-adhesive. Nor does it cause rotting in the underlying fabric, so one doesn't need an underlying layer of rabbit skin glue. It can be used on any kind of weave, too. It can even be used on a plastic surface, at least if you sandpaper it slightly. So oil painters can now paint on virtually anything (plaster, wood, concrete--anything!), just like acrylic painters. Beckers Nondrop is thixotropic and has a buttery consistency. Thus, it should be suitable for oil painting, too. Alkyd primer is less flexible than acrylics but more flexible than traditional oil primer. It is very strong and non-absorbent. 

So forget about acrylic gesso as well as traditional gesso. The problem with acrylic gesso is that it does not form a chemical bond with the oil paint. This means that alkyd primer is decidedly more archival, because oil paint forms a chemical bond with alkyds. In order to add "tooth" to the alkyd, so that it becomes a gesso proper, you could add calcium bentonite, or any other traditional additive. A good idea is to add a layer of alkyd primer to the ready-made panels that you buy at artists' shops. Thus, you get a better coating to paint on, because the oil paints adheres perfectly. Since the alkyd adheres strongly to the acrylic layer, there is no risk of delamination. 

In fact, Gamblin has an alkyd oil paint ground (Gamblin Ground) to which has been added barium sulfate, to provide tooth. They also give the advice that pre-primed acrylic canvases should be coated with Gamblin Ground. Since oil painters still use whites containing zinc oxide, it is recommendable to use an alkyd ground, because zinc oxide adheres badly to the acrylic layer, due to the formation of saponins. This could give rise to delamination in the future. 

So if you buy raw canvas, you only need to add two layers of alkyd primer, which can be added directly onto the canvas. This provides a much better ground than oil painters have had recourse to in earlier times. The water-based glues, since they absorb humidity, have proved to be damaging to the paintings because they keep expanding and contracting in keeping with the humidity in the air. That's why many think that acrylic primer is better. But this isn't good for other reasons. So we will see that alkyd primer will gain adherents. 

Mats Winther


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## M Winther

I should add that Gamblin recommends that one should wait 5 days before painting with oils on alkyd ground. I don't know why. After all, alkyd dries much faster than oils. It is dry-to-the-touch in a few hours. 

Mats


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## WFMartin

Alkyd primer is basically an oil-based paint, albeit an _*alkyd oil. *_If one applies that stuff to a raw canvas, you can plan on having that seep through the canvas, with stains appearing on the backside of the canvas, and eventual deterioration of the canvas. Perhaps not in days, or weeks, but years.

In short, oil paint rots canvas. Alkyd primer is an oil paint. One must first apply _*some *_sort of size to the raw canvas to protect it from the ravages of oil paint (oil primer), before applying alkyd primer.


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## M Winther

WFMartin said:


> Alkyd primer is basically an oil-based paint, albeit an _*alkyd oil. *_If one applies that stuff to a raw canvas, you can plan on having that seep through the canvas, with stains appearing on the backside of the canvas, and eventual deterioration of the canvas. Perhaps not in days, or weeks, but years.
> 
> In short, oil paint rots canvas. Alkyd primer is an oil paint. One must first apply _*some *_sort of size to the raw canvas to protect it from the ravages of oil paint (oil primer), before applying alkyd primer.


I'm not entirely certain, of course, because this is really advanced chemistry. However, Gamblin says that their alkyd primer is designed to be applied _directly_ onto a panel without sizing, although they recommend sizing before applying it on raw canvas. Sizing was earlier customary before applying oil ground on panel, but this isn't necessary with alkyd ground. This makes me think that sizing is unnecessary when applying alkyd ground to canvas, as well. It has to do with the fact that the linoleic acids in the alkyd resin have been _neutralized_ and do not attack the substrate.

This is further vindicated by what Beckers says about their Nondrop alkyd primer. They say that it is designed to be painted on any surface directly, including weave. Since it has high viscosity, it doesn't seep through the weave. This is also true of Gamblin alkyd ground, because it is a rather high viscosity formula with much pigment. They say that one needs only apply two layers, rather than three or four, which is customary with the very diluted acrylic gessos.

I think Beckers is right, because they have great expertise, having made paints since 1865, and artist grade oil paints since 1908. Conservators say that sizing with rabbit skin glue has drawbacks because it re-absorbs atmospheric moisture, which has deleterious effects on paintings. Arguably, then, it is better to prime canvases directly with alkyd ground.

However, this is a very interesting issue, and I would be glad to get more information. If alkyd primer is ideal to paint directly on both panel and canvas, then it's very important news. Many conservators remain suspicious about acrylic and vinyl as oil painting grounds.

Mats Winther


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## luzz

It says on the tin not to apply neat, what are you supposed to mix it with do you know? Thanks


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## M Winther

What tin? I don't know what "apply neat" means. Alkyd could be diluted with any solvent, preferably non-odour.


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## sl60

Glues such as rabbit skin--aside from needless harm caused to rabbits--are not advised because they are prone to cracking.


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