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idylbrush
03-31-2007, 12:44 PM
Those looking for the extended drying times. This may be of some use. I have not tried it, don't endorse it and can't even begin to understand why it works.

Proceed with great caution. Cause I don't know any better.

http://www.neadeenmasters.com/Global%20Blending.htm

Thomas Greaves
03-31-2007, 02:02 PM
my only comment is this.....if these are the kind of drying times you require...why not just use oils?

aggiestreasures
03-31-2007, 02:43 PM
Hello All: I am new to this forum but not new to the use of retarder or extender. I taught tole painting for many years and these items have been on the market longer then that. They work great if you need your paint to stay blendable such uses would be in skies, water reflections, blending colors for realizm in fruit etc. The trick is using only what you need. You don't have to mix with paint. You can use retarder or extender in place of water on your brush it onto the sky before adding color (similar to using liquid white or miracle white in oils except the extender does not change the color) Hope this is helpful. Love this site by the way.

dreamz
03-31-2007, 04:23 PM
Awesome find Howard but I LIKE the fast drying time of acrylics (usually)

idylbrush
03-31-2007, 06:28 PM
Aggie, thanks for the input.

Thomas, some folks have an allergic reaction to the volatile mediums in oil, people like me. I get around oil paints and I stop breathing. For me acrylics are a much better option.

Doc, I like the fast drying time myself. At times they don't dry fast enough.

So each to their own gout.

timelady
03-31-2007, 06:33 PM
Something I have used and it's quite amazing, though like you Howard I don't know how it works, is Daley Rowney's acrylic screenprinting medium. I bought it by mistake once, could never find ANY information on what's in it, and never looked for it again. But man it keeps the paint open for a loooong time! (by the way, bought it thinking bucket=gesso. Boy was I surprised!)

I still have a 1 litre bucket of the stuff. :rolleyes: (I don't like open time.)

Thomas: choice of medium isn't just about working time. Acrylic has (or I should say, can have) a different finished look - some of us specifically want that look. It also has different toxicity/health implications as Howard mentioned. It also has an incredibly wide range of styles of application from thick impasto to watercolour effects. It doesn't have issues with supports such as rotting of unprimed surfaces, and doesn't have inherent longevity issues related to application 'rules' such as fat over lean. (PS, I love oils, just showing acrylics and oils aren't directly comparable. Just two different mediums.)

Tina.

quebectouch
04-16-2007, 03:55 PM
Those looking for the extended drying times. This may be of some use. I have not tried it, don't endorse it and can't even begin to understand why it works.

Proceed with great caution. Cause I don't know any better.

http://www.neadeenmasters.com/Global%20Blending.htm

I already tried this technic during experimentation, I didn't knew someone else tried.

I tried it with anti-freeze, not those with ethylen Glycol, but propylen Glycol, which is basically what a good deal of the retarders contain.

Those wanting to use such a method must consider few things. Blending weakness of acrylic vs oil is not only due to open time, but also to acrylic polymer itself and the way it isolate pigments individually and make mixture more difficult, not to say the fact that oil has a higher pigment load.

Also, using retarders that much heavily affect the adherence of the painting, the paint does not act like acrylic anymore but becomes a new media. First because open time is not only dependent of water containt but also acrylic polymer which while water evaporate it modifies in a chemical process which is ireversible. When you use such a method used on that site, the polymer itself is affected, you slow down the chemical reaction but do not halt it, and adding the retarder like this you obtain an uncompleted chemical reaction + retarder, which will basically never completly dry unless you use a hair dryer. To protect it, don't think of using a vernish applied with a brush since you could scrap the painting itself. The only way is to use a vernish in spray form. I don't know if the finished painting will have a very long life spam though.

In short, this technic gives you not acrylic, but a pseudo acrylic, definitly a new media, which is far from having the same adherence, while it does extend effectivally the blending time, it does not in any way increase the quality of blending vs when normal acrylic is wet. I did not try adding pigments to see if adding propylen glycol actually increase the pigment load capacity, an interesting experiment, also adding something in it to increase the adherence(fructose?). I will be trying to do this with acrylic experimentation, but definitly the weakness of blending with acrylic polymer I should find a solution with, probably if propylen glycol increase the loading capacity of pigments, it could fix the problem significantly.

autolisp
04-20-2007, 04:29 AM
I have been trying all sorts of things to get an extended 'open time' for my acrylics. I'm willing to give this idea a go. One question. Is 'retarder' the same as 'extender'?

Is the 'Global Extender' a specific brand/chemical only available through this company? Or is it, as I understand, the readily available form of retarder?

I will be using the 'Golden' retarder.

Thanks for this topic.

Is there an alternative name for 'propylene Glycol'? I can get 'Ethylene Glycol' as a chemical (not antifreeze) would this work?

autolisp

autolisp
04-20-2007, 08:23 AM
Ok.

I just located 'Propylene Glycol' on eBay (U.K).

250ml 7.00 (inc p+p)

Also 1 litre 13.99 (inc p+p)

Hope this is of use to someone. Its cheaper than the branded products (but only if it works). I have just purchased a copy of 'Acrylic revolution' by Nancy Reyner. She states that acrylic paints contain a percentage of 'Anti-freeze'!

I am in the midst of trying the global blending using the 'Golden' retarder. After 2 hours in a sunny room my trial tub of paint has developed a 'skin'! I have stirred it a couple of times as per instructions on www site.

Any suggestions (printable only please)

autolisp

autolisp
04-21-2007, 04:22 AM
For those interested in this post.

Its now approximately 24 hours since I started the experiment with the acrylic paint + retarder.

I have found that I have had to use a lot more retarder than 30%! More like 50%!

However. The paint in the trial is still 'fluid', but slightly thickened, just added about 5% more retarder.

Its bright and sunny here in the UK today. I'm going to leave the paint in a sunny position today without adding any more retarder and see what happens.

I have not tried to paint with it yet, so I cant comment on that aspect.

autolisp

quebectouch
04-22-2007, 02:20 PM
Sorry for the late reply, ethylen glycol is toxic. You should be able to get antifreeze at a store which sell them, then check for the non-toxic ones, they often have at least one, those active content is propylen glycol.

Just a reminder, that the paint you will have will not act as acrylic after this experiment.

autolisp
04-23-2007, 03:52 PM
I have ordered some Propylene Glycol (99%) to try this idea out.

Which might be better than anti-freeze as it won't have any additional chemicals.

Thanks for the update

autolisp

autolisp
04-24-2007, 01:19 PM
Its now 48 hours since I mixed the retarder + acrylic paint and left it to its own devices.

I've just had a look at it and given it a stir. It is still 'fluid'. But. To my mind I think its looks as though it is 'congealed' (something like a 'half-set' jelly).

There must be some difference between the 'extender' shown on 'Global Blending' site and the retarder I am using.

This experiment is going in the bin.

On another point. I got my 'Propylene Glycol' today. It is very thin (fluid) compared to the 'Golden Retarder' I have been using. Another post says about mixing 'Glycerin' with acrylic paint to slow down the drying time. I wonder if the 'commercial' forms of retarder have a percentage of glycerin in them?

Also. I had a 'sniff' of the Golden retarder. I'm certain I could detect a trace of 'Ammonia'. I know it is sold as a water softener (I use it in my darkroom for that purpose). Has anyone any further ideas.

autolisp

quebectouch
04-24-2007, 01:51 PM
Propylene glycol is fluid, in retarders they add something to make it less fluid.

After doing every possible thing to extend acrylic blending time with moderate success, I switched to a better technic not long ago. And I think that every painters with acrylic after being frustrated for a while should serious consider.

Use acrylic for the first few layers with some propylene glycol or other extenders mixed with acrylic based gesso to make it more absorbant, then finish your work with water mixable oil by layers of glazing. The best of the two worlds, you won't be decieved, the finished paint has a particular look. If for now you don't like the open time and are trying without success, don't think too far, I have tried everything, like filling the back of the canvas with sponges. Everything, it still did not satsfy me, and like this was not enough, not only the blending problem was open time of acrylic, even when wet, oil still blend more naturally.

I can garanty you that you won't be decieved with what I am proposing to you.

Its now 48 hours since I mixed the retarder + acrylic paint and left it to its own devices.

I've just had a look at it and given it a stir. It is still 'fluid'. But. To my mind I think its looks as though it is 'congealed' (something like a 'half-set' jelly).

There must be some difference between the 'extender' shown on 'Global Blending' site and the retarder I am using.

This experiment is going in the bin.

On another point. I got my 'Propylene Glycol' today. It is very thin (fluid) compared to the 'Golden Retarder' I have been using. Another post says about mixing 'Glycerin' with acrylic paint to slow down the drying time. I wonder if the 'commercial' forms of retarder have a percentage of glycerin in them?

Also. I had a 'sniff' of the Golden retarder. I'm certain I could detect a trace of 'Ammonia'. I know it is sold as a water softener (I use it in my darkroom for that purpose). Has anyone any further ideas.

autolisp

autolisp
04-24-2007, 03:29 PM
Thanks for the suggestion. Definitely an approach to be seriously considered.

When you say 'Add Propylene Glycol to acrylic Gesso to make it more absorbent'. Do you mean the 'base coat on the ground' and after it has dried?

autolisp

quebectouch
04-24-2007, 06:10 PM
Thanks for the suggestion. Definitely an approach to be seriously considered.

When you say 'Add Propylene Glycol to acrylic Gesso to make it more absorbent'. Do you mean the 'base coat on the ground' and after it has dried?

autolisp

The Gesso is only if you want to finish your work with glazing with oil. I don't know if it is necessary, I just use it as precaution for the adherence of oil. The propylene glycol is of course for the blending time. You could use other retarders of course, but this stuff is really really cheap.

If you want further information, I use Winsor and Newton Artisan water mixable oil colours for the glazing. You will probably get better quality, it is just that the better quality I found does not have a standard colour palette names. And beside the W&N cost about the same thing as my acrylics and is readily available. For cost effective I have found that this glazing on acrylic cost me less than painting my entire work with acrylic, because all the waste with the dried paint on the palette and for the canvas the need of all those multiple layers of wasted acrylic while with oil it stays wet on the canvas and ready to work on it.

This technic I use is not new, centuries before when artists were still continuing to paint with egg tempera and oil paints were invented, the properties of egg tempera(like the very fast drying time, even faster than acrylic) were still needed for the under layers, while they compleated the works with oil glazing. I use egg tempera also, I then had the genious idea of replacing egg tempera with acrylic which has a better blending time(I was using acrylic previously, but alone not in combination of other medias). At first my reason of replacing with acrylic was because I was tired having to prepare the egg tempera paint each time I wanted to paint also egg tempera is not fit for canvas painting. When I realised the final product I was settled that this conbination was by far the best I had ever tried. It uses both mediums strongest sides. As we will never replace with oil, acrylic with those fast drying mediums (the oil become too gummy and lose its positive properties) and we will never replace oil with acrylic of course then, you won't need to try what you are trying if it was to happen. :)