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Happyblueberry
10-23-2011, 02:42 PM
Hi all,

I did a search and saw many threads on gesso. But I couldn't find an answer.
My problem is that if I coat ready to use stretched canvas with gesso (specially made for using with acrylic paints), it will peel off if my paint is watery and even if I spray canvas lightly with water.
Is that normal or I bought a really bad brand of Gesso? The brand is Omer Deserres, I think it's not known in US. It's cheaper than Liquitex or Golden, but the guy at the store reassured me that it's good :) Also, when I came back to him with a question about gesso peeling, he said that "that shouldn't happen".
So, am I stupid and doing something wrong or gesso is not meant for over diluted paints?

OkeeKat
10-23-2011, 02:48 PM
I have had no problem with using inexpensive gesso!
I also use thinned acrylic paint with only water and have no problems with it peeling off, I often spray the canvas on the back with water to tighten it more on the bars.. and my surface as I work to blend.

Lightly sand the store bought canvas' before gesso then
coat the canvas well including the sides and then lightly sand
inbetween coats... each coat paint in different directions. helps get in the grain better.

Happyblueberry
10-23-2011, 03:04 PM
Thank you OkeeKat. Maybe my problem was that I didn't coat the sides.

idylbrush
10-23-2011, 03:38 PM
Without seeing what is going on it almost sounds as though the ready to use canvas was gessoed with an oil based gesso rather than an acrylic based gesso. Acrylic over oil is very unstable and may be the culprit here. I would suggest checking the label on the canvas to see if it is primed for oil painting or primed for universal painting (acrylic, oil, etc).

Just my thoughts.

Charlie's Mum
10-23-2011, 04:40 PM
My thoughts were the same as Howard's.

I've had no trouble using a cheap gesso - I just find it thinner, less covering power, than the Liquitex gesso I also have.
I think your problem has to lie between the bought canvas and its gesso, and yur own application - the two don't seem to want to marry! :)

DonEc
10-24-2011, 04:01 PM
Did you clean the canvas before applying the gesso? If the canvas was stored where air currents could coat the canvas with light oily dust then I doubt the gesso would stick well.

Einion
10-24-2011, 04:33 PM
The two likely culprits here are your 'gesso' and the canvas, although it could be a little of both together.

Never heard of Omer Deserres before but that doesn't mean anything, the quality could be just fine. But it would be a good idea to test the primer separately to see if it has good adhesion to something else, in which case you can rule that out as being the cause of the problem here.

The other possible issue is the surface of the existing priming, one of the additives to the primer might have come to the surface. Since these don't dry they can form a slippery, non-adhesive layer between the factory-applied primer and anything you apply on top. It's for this reason that many people now routinely give the surface of preprimed canvas a quick wipe down with water before using.



Another thing to mention, primer and paint takes a lot longer to fully cure than it does to dry to the touch. Although with our type of paints a single coat can appear to dry in just minutes, it is still not truly dry for a lot longer than this.

The curing progresses can take a couple of days to complete and the bond and the strength of the film are increasing the whole time.

You can actually sometimes find a difference in the strength of bond after more than two days, so you might want to try a small test on the edges of one of your canvases to see if the bond gets better merely by waiting for an extra two and then three days.

Einion

Happyblueberry
10-25-2011, 03:40 PM
Thank you all
No I don't clean canvas, they sold warped in plastic. I buy Winsor&Newton brand and the label states that they ideal for use with oil and acrylic.

I don't think that I ever let it dry for two or more days. As soon as it's was dry to the touch, I started painting.
Now, I put gesso over one unsuccessful acrylic painting. It's already drying for a few days. I am going to experiment with it.