View Full Version : Tips for mixing PVA/gel mediums for glassless framing

10-10-2012, 01:08 AM
Hi, I just recently got my hands on the Preval Sprayer (FINALLY!!:clap:) and I've been trying to mix Elmer's Acid Free White Glue and Golden Soft Gel Gloss to spray on not just pastels, but on other works to form an isolation barrier for other mediums before varnishing. However everytime I mix them, the spray unit sputters after the initial burst, and it appears to be clogged, and even after turning the unit upside down and releasing air to clear the nozzle, it still won't spray the contents of the bottle.

I've really diluted my solutions (10ml white glue to 150ml water) and for the soft gel solution I kept pouring away and topping up with water to dilute it further. Still, each time the spray doesn't work. Can anyone help me here?

10-10-2012, 07:11 PM
First let me say that I have absolutely no knowledge about your formula. It might be perfectly OK to use. But the use of Elmer's White Glue made me raise my eyebrows and lead me to ask the following:

Even diluted, is it transparent enough? And since it is a glue - even diluted - will it be tacky enough to not clog up your sprayer? Again, I have no idea of the answers.

The only isolation layer information that I have personally seen described is on the Golden website for use with acrylic paintings.

As per their instructions, the Golden Soft Gel Gloss is used for brush application. For a spray application they recommend GAC-550 plus Transparent Airbrush Extender.

Here's the paragraph from their website:

For brush application, the appropriate isolating medium can be made by diluting Golden Soft Gel Gloss with water (2 parts by volume Soft Gel Gloss to 1 part water). If a spray application is desired, a 2:1 mixture of Golden GAC-500 to Transparent Airbrush Extender can be applied with an airbrush, touch-up spray unit or commercial spray equipment. The absorbency of the surface will dictate the number of isolation layers required. For relatively non-absorbent surfaces, as is the case with a uniform paint layer, one coat brush applied or two coats spray applied are recommended. For more absorbent surfaces, which tend to be very matte, it is recommended to apply sufficient isolation coats to achieve a satin sheen on the surface. This may require two or more brush applied coats or three or more spray applications.
Again, your formula may be perfectly fine. I really have no idea!

Of course, the general consensus about glassless framing by using some sort of varnish coating is that it doesn't really work that well and alters the look of the pastel. But I'm sure we are all curious to see your results!


10-11-2012, 12:57 AM
Thanks for your reply! I tried white glue because it works well as an isolation barrier, but I'm not too sure if the it may behave in a strange manner like you mentioned.

I prefer to spray as much as possible because brushes will definitely alter the piece due to the strokes. I think I will try using the GAC additive again. Thanks!

10-11-2012, 10:21 AM
I think you'll find that the use of any liquid over pastel causes the colors to sink, sprayed or otherwise applied. Please do your experiments on test pieces, not on finished paintings!


10-11-2012, 12:43 PM
Yes! Thanks for the reminder.
I've only been trying them out on test pieces. And frankly speaking, I'm trying to get it working right such that I can spray on jus about any piece of artwork. (Pastels, watercolour, block prints etc) Especially those that are water-sensitive, and will get altered by brushing on of any barrier or varnish.

10-25-2012, 04:19 PM
Just a little update. I actually looked around local art stores, and bought Liquitex Airbrush medium, and Liquitex Gloss Medium Varnish. I mixed them 1:1 and the spray was pretty smooth. Number of coats required depends on absorbancy of surface and medium used. I suppose Golden Airbrush medium with other acrylic polymers should work as well too. Ideally, I think it would be great to use acrylic mediums of a fluid consistency. That way, you can be sure that there won't be tiny lumps of unmixed acrylic gels which would clog up the sprayer. After completely sealing with spray, brush over with a varnish of your choice and you're done!

Honestly I have yet to test out this method on pastels, but I believe it should work, but it might take quite a couple of coats to seal the pastels.