Sprayed canvas cracking

[JaneAshton]

After two years of putting up with roller-related disasters(streaking, foaming and dust collecting to name a few) when applying varnish to canvas, I thought Id found the solution to the problem when i read about Wagner HVLP sprayers. Two pictures now have split after being stretched after applying the varnish with the sprayer. The varnish just seems to be sitting on top of the canvas, rather than being absorbed and is brittle rather than making the canvas stretchable. Im using Eternacryl matte but have just ordered some GlamourII matte in the hope that it's the varnish that's the problem. When spraying im putting 3+ lightish coverings on. Has anyone had similar problems and been able to overcome them? Its make or break as this is just costing me so much to rectify problems all the time. Id be really grateful for any advice.

[dgberg]

A little more information would be helpful. What are you calling a split and more importantly where are they? We cover with Glamor II and still get small checking or splits through the ink on the backside edges of the stretcher frame. We have isolated the small checks through the ink to over stretching the canvas with our gallery stretcher machine. I think they suggest about 20psi and we have been cranking it up to 30 because of issues with canvas going slack in several months. Its a fine line . We are still using 30 + or - because loose canvas is tough to fix when its several states away. We are living with the small cracks through the ink on the backside and have a box of 30 different colored sharpies to touch this up when it happens.
As a final note and I can tell you from experience. No varnish will prevent checking or small cracks in the ink. It will help reduce them but their are way too many variables that will completely eliminate them.

[JaneAshton]

The splits vary from each canvas but are mainly on the fronts, the back bits i dont really care about as theyre not on show. And when i say split i mean its a clean line, the worst being 4inches long, showing the white stringy bits of the canvas. Ive had cracking before when folding the corners and like you have touched them up and usually this was down to me not using enough varnish. I hand stretch too so its not like im using excessive force as im not the strongest person. The only good thing about rolling varnish on seems to be that the varnish took to the canvas better and made it pliable, almost elastic. Also, when am stapling the back cracks appear in the varnish like it was glass.

The Glamour II has arrived so im hoping the problem here has been the varnish. Fingers and toes crossed! Thanks for taking your time out to reply to me, its good to know am not alone here. I wish id found this site 2 years ago.

[Ernst Dinkla]

When you spray make sure that the varnish is dissolved enough to penetrate the coating with the first layer. It's nice to have an HVLP sprayer and little varnish is lost but too thick the emulsion and there will not be enough bond beteen the canavas an the layers on top. The water based dispersions have the advantage that they remain flexible over a longer period, the structural bonding of the polymer takes longer than with solvent based varnishes. Nevertheless mount within 6 hours or so after the last layer is sprayed. I usually apply two gloss layers and a very thin satin layer.


met vriendelijke groeten, Ernst Dinkla

Dinkla Gallery Canvas Wrap Actions for Photoshop
http://www.pigment-print.com/dinklacanvaswraps/index.html

[JaneAshton]

Just an update to confirm that it was the varnish that was the problem. Glamour II matte has worked a treat and the canvases I have just completed are fine. Hooray!