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Old 05-14-2017, 03:02 PM
jawnn jawnn is offline
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Question Flexible Gesso formula??

I want to make flexible gesso for my somewhat flexible oil painting. I need to roll the canvas for mailing.

A dozen years ago I got some chalk (Calcium carbonate?) and finally mixed acrylic into it to make gesso. But it was not flexible. And the other-day I found a video that told how it should have been used with oil.

So is there a way to make it more flexible? Like thin it out with acrylic medium and add some thing else? I buy most of my additives and pigments from Kremmer pigments.

A formula including some chalk would be great. But should be Mostly titanium dioxide pigment? What else can I use for filler? Aluminum hydroxide? marble dust?
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Old 05-14-2017, 05:40 PM
Trond Trond is offline
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Re: Flexible Gesso formula??

If I needed flexible gesso, I'd simply use acrylic "gesso". Traditional gesso is brittle, and adding oil will hardly change that. People did use traditional gesso on canvas back in the day, but I don't think rolling it up was recommended. It was a way of making canvas as stiff as a board.
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Old 05-14-2017, 07:36 PM
jawnn jawnn is offline
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Unhappy Re: Flexible Gesso formula??

maybe I should just buy a gallon and thinken it up with a little some thing....recon I will have to experiment.

tempera is bad, I discovered that mold will grow on it.
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Old 05-14-2017, 08:36 PM
jawnn jawnn is offline
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Question Re: Flexible Gesso formula??

so what make it flexible?

the acrylic medium probibly. but aluminum hydroxide will make more sticky, but I don't know if that will mix with water base....
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Old 05-14-2017, 09:42 PM
Trond Trond is offline
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Re: Flexible Gesso formula??

No, seriously, I think you are overthinking this. Traditional gesso is brittle, but modern acrylic gesso is more flexible. You don't need to mix anything unless you really want to. Just look for a good brand of acrylic gesso. People use it as a ground for oil paints all the time.
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Old 05-15-2017, 02:10 AM
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Seaside Artist Seaside Artist is offline
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Re: Flexible Gesso formula??

The old masters rolled many of their canvas for easier shipping of large pieces to their wealthy clients. Many artist today do the same. My canvas have an acrylic gesso made by Golden...premixed. I frequently have shipped rolled painted canvas because it is less expensive. I leave the recipe up to the specialist who produce this product and I have never had a failure. I have a few rolled canvas that are more than 20 years old and still no cracking. Keep in mind that the painting has to be fully dried...6 months, but better 1 year after completing.

Some novice artist I have known decided to ship when their work was touch dried and ended up with a total loss. Other friends who ship to Europe from the US use only the rolled up method with pre-primed acrylic gesso canvas...not stiff, cracked or other issues when received from their clients.
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Old 05-15-2017, 05:09 AM
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Gigalot Gigalot is offline
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Re: Flexible Gesso formula??

Avoid Chalk. I don't know who was the first advertised chalk and marble dust for primers on WC, but this material can cause trouble. Chalk is basic (alkaline) material. In contact with oil paint it can cause unwanted reaction and can make paint brittle. Chalk particles can react with moisture and form soluble Calcium Hydrocarbonate cause hydrolyze of oil and forms soap and moisture on the surface of "tooth" into gesso.
That can reduce adhesive properties. High amount of chalk into oil primer can cause significant brittleness of it. High amount of Chalk into Acrylic gesso can cause poor adhesive, moisture sensitivity and brittleness of Acrylic primer.
In industry, oil paint is not recommended to apply on lime, fresco, concrete or carbonate content surfaces because industrial chemists well know how poor paint layer it will form. But Artist's always like to do Calcium Carbonate into any primer or into paints!

For better flexibility you can try Acrylic paint instead of Acrylic gesso. Most of Acrylic primers are quite brittle products.

From the American products, many artists use Golden GAC100, probably the only flexible primer from whole their line!

Last edited by Gigalot : 05-15-2017 at 05:42 AM.
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Old 05-15-2017, 06:42 PM
jawnn jawnn is offline
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Question Re: Flexible Gesso formula??

so maybe I should use only titanium dioxide with acrylic medium?





Quote:
Originally Posted by Gigalot
Avoid Chalk. I don't know who was the first advertised chalk and marble dust for primers on WC, but this material can cause trouble. Chalk is basic (alkaline) material. In contact with oil paint it can cause unwanted reaction and can make paint brittle. Chalk particles can react with moisture and form soluble Calcium Hydrocarbonate cause hydrolyze of oil and forms soap and moisture on the surface of "tooth" into gesso.
That can reduce adhesive properties. High amount of chalk into oil primer can cause significant brittleness of it. High amount of Chalk into Acrylic gesso can cause poor adhesive, moisture sensitivity and brittleness of Acrylic primer.
In industry, oil paint is not recommended to apply on lime, fresco, concrete or carbonate content surfaces because industrial chemists well know how poor paint layer it will form. But Artist's always like to do Calcium Carbonate into any primer or into paints!

For better flexibility you can try Acrylic paint instead of Acrylic gesso. Most of Acrylic primers are quite brittle products.

From the American products, many artists use Golden GAC100, probably the only flexible primer from whole their line!
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Old 05-16-2017, 01:27 AM
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Re: Flexible Gesso formula??

Quote:
Originally Posted by jawnn
so maybe I should use only titanium dioxide with acrylic medium?
No, you can also use Talc, Silica, Kaolin. Glass powder. Rembrandt used purest silica in his gesso. You can see many quartz particles on micro photography of cross-section in his paintings. He got this silica probably from porcelain factory because it has highest possible purity.
But for high flexibility you can use less filler and more polymer dispersion. You can try 3-4 layers of Calcium Carbonate acrylic primer (Calcium Carbonate is a very cheap) + one final layer of more expensive Calcium-free acrylic primer to seal alkaline substrate.

Last edited by Gigalot : 05-16-2017 at 01:38 AM.
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Old 05-16-2017, 06:18 AM
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lithophotos lithophotos is offline
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Re: Flexible Gesso formula??

Classens sell their oil primed linen in rolls - its the best!
"For an ‘oil canvas’, zinc white is used as the primer, bound with linseed oil. The paint is applied on to the glued linen by passing 2 ‘knives’ (1&2)
After that, we sand the canvas and apply a coating layer based on titanium white. Again passing the 2 ‘knives’ and this time also rolled (3) to achieve the typical Claessens oil-primed canvas." (sic.)
"
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Old 05-16-2017, 06:38 PM
jawnn jawnn is offline
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Re: Flexible Gesso formula??

I am really into doing as much of the work my self as I can. It saves money 'n the long run.

Here is a formula from Kremer pigments


200 g 58500 Marble Dust, extra white
400 g 58700 Blanc Fixe
150 ml 76000 Plextol® D 498
10 g 63610 Cellulose Glue K 1000, thick
100 g 27000 Kremer Color Paste - Titanium White
700 ml Water
Sieve, fine
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Old 07-22-2017, 01:57 PM
jawnn jawnn is offline
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Lightbulb Re: Flexible Gesso formula??

I found information about making gesso from PVA adhesive (¼ by weight 1part) and calcium carbonate powder (½ by weight 2parts) and water (¼ by weight 1 part) but then they also put acrylic paint into the mix for color, (another half weight? 2parts)

And this information for people that want to know some of the technical aspects:

Styrene acrylic is a modified acrylic polymer to increase weathering resistance of the polymer. Polyvinyl acetate (PVA) is an early emulsion polymer being used in trade coatings.

Pure acrylics means only monomers based on esters of the acrylic acid (for example butylacrylate, ethylhexylacrylate etc.) are used. It can be a copolymersiation of different kinds of these esters.
Styrene acrylics means a copolymerisation between styrene and different esters of the acrylic acid.

Polyvinyl acetate (PVA)- based emulsions means it can be a copolymerisation between vinylacetate and acrylate or vinylacetate and ethylene or also a terpolymerisation of vinylacetate, ethylene and vinylchloride etc. In each case one monomere is vinylacetate.

Vinyl acetate polymers (encompassing polyvinyl acetate [PVA] and ethylene vinyl acetate [EVA]), acrylics and styrene-butadiene (SB) latex. Smaller volume types include emulsions based on polyvinyl chloride, latex nitrile and acrylonitrile copolymers. PVAs are among the least expensive materials available, while acrylics generally are the most costly, with SB latex typically falling in between.
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Old 07-22-2017, 02:05 PM
jawnn jawnn is offline
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Question Re: Flexible Gesso formula??

You think the oil paint will have problems over cacium carbonate, mixed with polyvinynal acitate? tell me more?


Quote:
Originally Posted by Gigalot
You can try 3-4 layers of Calcium Carbonate acrylic primer (Calcium Carbonate is a very cheap) + one final layer of more expensive Calcium-free acrylic primer to seal alkaline substrate.
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Old 07-22-2017, 03:16 PM
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Re: Flexible Gesso formula??

Quote:
Originally Posted by jawnn
You think the oil paint will have problems over cacium carbonate, mixed with polyvinynal acitate? tell me more?
I never used PVA for gesso, I think it is not flexible to use on canvas support.
Oil/alkyd housepaint paint has manufacturer's recommendation do not use directly on concrete, lime or fresco surfaces because these paints "can't adhere well on such alkaline surfaces. They recommended to apply acrylic primer, let it dry and then use oil/alkyd paint on top of it. Personally I never try to ignore their recommendation to get direct evidence how can oil paint peeling from fresco or lime. I just trusted them due to a laziness to try to crack a "myth" or to make a step on rake and to get personal bump on the head!
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Old 07-22-2017, 03:16 PM
contumacious contumacious is offline
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Re: Flexible Gesso formula??

I have tried quite a few different formulas for making my own grounds for oils and encaustics using PVA and Acrylic Mediums plus Calcium Carbonate and some Titanium White pigment. Without question I would go with an acrylic rather than PVA or oil, if I wanted the most flexible ground I could make. Acrylic films from my own testing are significantly more durable both in flexing, abrasion and tearing than anything I made with PVA. I made some test strips of PVA and Acrylic dried on glass then removed with a razor blade. The PVA would tear far more easily than the acrylics. The more they dried the worse the PVA became. The acrylic either stayed the same or got stronger as it dried more. One of these days I am going to do the same tests with commercially produced oil and alkyd grounds for comparison. I am betting the acrylic will win in the bending / tearing tests and the alkyd will come in 2nd place, followed by oil then the PVA.

If I wanted to use an oil ground rather than acrylic for whatever reason, I would go with an alkyd formula. I will never use PVA for a ground, only for the first, thin sealing layer on canvas, birch panels or hardboard. I go straight to acrylic gesso on ACM panels or will prime it first with XIM. On the hardboard or wood that has knots in it, I put at least two coats of PVA first to reduce the chance of SID.

Last edited by contumacious : 07-22-2017 at 03:24 PM.

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