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Old 09-26-2008, 05:07 AM
Pantau Pantau is offline
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Ideal ground for Golden Open Acrylics

Hello everyone,

I'm about to start painting with Golden Open Acrylics. Now I have a question. I allways paint on masonite. On the website from Golden they describe the following ground as the optimal system for preparing wood supports for use with OPEN Acrylics, Gel, and Medium:

<LI class=normtext>Apply 2 coats of an alkyd-based primer, such as KILZ®, or a white pigmented shellac primer like B.I.N.® Let fully dry. <LI class=normtext>Apply one coat of GAC 100. Let dry. <LI class=normtext>Apply 2 or more coats of GOLDEN Gesso, or 1 coat Gesso followed by 1 or more coats of GOLDEN Sandable Hard Gesso.
I must say that I'm surprised by this description, because I've allways learned that it is not wise to work with waterbased paint on top of oilbased paint. For as far as I know an alkyd-based primer contains oil (or am I wrong here?). I remember reading somewhere that alkyd itself can not dry. So, to make alkyd dry it is modified with oil. This means that when you use the ground as described by Golden, you will be putting a waterbased gesso (is GAC 100 also waterbased?) on top of a ground that contains oil.

What do you think? Am I wrong about things here? I don't know the alkyd-based primer from the brand KILZ. Maybe this a special primer? If so, does anyone know a similar primer that is for sale in The Netherlands?

Sincerely,

Charles
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Old 09-26-2008, 06:13 AM
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Einion Einion is offline
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Quote:
Originally Posted by Pantau
I must say that I'm surprised by this description, because I've allways learned that it is not wise to work with waterbased paint on top of oilbased paint.
There are a lot of things like this that aren't as simple as we've heard.

Once cured oil paints aren't strictly oil any longer - during 'drying' the oils form polymers, effectively turning into a type of plastic.

Quote:
Originally Posted by Pantau
For as far as I know an alkyd-based primer contains oil (or am I wrong here?).
Alkyd paints are generally oil-modified alkyd resins, but not all I think.

Quote:
Originally Posted by Pantau
I remember reading somewhere that alkyd itself can not dry.
Don't think that can be right but it's not really relevant as anything we buy does dry and was formulated so that it would, however that's achieved

Quote:
Originally Posted by Pantau
What do you think? Am I wrong about things here? I don't know the alkyd-based primer from the brand KILZ. Maybe this a special primer? If so, does anyone know a similar primer that is for sale in The Netherlands?
Nope, sorry.

Personally I'm not 100% that the method they're suggesting is the best route here, you might like to try a couple of thinned coats of polyurethane varnish followed by priming as normal.

Einion
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Old 09-26-2008, 07:01 PM
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JamieWG JamieWG is offline
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Re: Ideal ground for Golden Open Acrylics

Quote:
Originally Posted by Pantau
Hello everyone,

I'm about to start painting with Golden Open Acrylics. Now I have a question. I allways paint on masonite. On the website from Golden they describe the following ground as the optimal system for preparing wood supports for use with OPEN Acrylics, Gel, and Medium:

<LI class=normtext>Apply 2 coats of an alkyd-based primer, such as KILZ®, or a white pigmented shellac primer like B.I.N.® Let fully dry. <LI class=normtext>Apply one coat of GAC 100. Let dry. <LI class=normtext>Apply 2 or more coats of GOLDEN Gesso, or 1 coat Gesso followed by 1 or more coats of GOLDEN Sandable Hard Gesso.
I must say that I'm surprised by this description, because I've allways learned that it is not wise to work with waterbased paint on top of oilbased paint. For as far as I know an alkyd-based primer contains oil (or am I wrong here?). I remember reading somewhere that alkyd itself can not dry. So, to make alkyd dry it is modified with oil. This means that when you use the ground as described by Golden, you will be putting a waterbased gesso (is GAC 100 also waterbased?) on top of a ground that contains oil.

What do you think? Am I wrong about things here? I don't know the alkyd-based primer from the brand KILZ. Maybe this a special primer? If so, does anyone know a similar primer that is for sale in The Netherlands?

Sincerely,

Charles

Hmmm....I don't see that on the site. I see two coats of GAC100, then gesso. That's what I've always done. Did you look here?
http://goldenpaints.com/technicaldata/prepsupp.php

Jamie
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Old 09-26-2008, 07:06 PM
Mark Golden Mark Golden is offline
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Re: Ideal ground for Golden Open Acrylics

The advice on the Golden Website has been developed over a great deal of work and research, developing a resource for best practices. Since the first studies of Support Induced Discoloration in 1990, (a severe yellowing of cotton, linen, wood and masonite supports) we have tried to develop better priming systems to block the water miscible components in these substrates from coming through to the painting. In most cases an artist may not perceive this yellowing unless working fairly thickly with acrylic paints, and mostly with fairly transparent mediums or glazes. The OPEN Acrylic stays wet on the substrate much longer then traditional acrylics therefore allowing more of the discoloring materials to be pulled to the surface. With linen or cotton, you can wash the canvas and dramatically reduce the yellowing. With wood or masonite, you don't have the same choice. For best results, therefore, we recommend a sealing system. You will see the difference in just the color of the gesso with the sealed and unsealed versions.

It would be wonderful if we had a waterborne acrylic that could seal on all surfaces, but we don't. The GAC 100 will work will on most surfaces, but to really stop the tannins and other materials coming through unprepared masonite or wood, the best is a pigmented shellac. The pigmented sealer tends to offer significant tooth for adequate adhesion of the GAC 100 and subsequent layers of paint. Additionally, modern acrylics were developed to have fairly good adhesion to pigmented alkyds as well. Hope this is helpful. Mark
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Old 09-27-2008, 03:57 PM
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Re: Ideal ground for Golden Open Acrylics

If you're open to having someone else prep the surface for you, I've been very happy with Ampersand's line of "board" products, especially their Gessobord. Of course, this might cost more than doing it yourself, but it's a lot easier ;-) Tech info on their sealing process is available at:

http://www.ampersandart.com/tips/archivalinfo.html

They recommend GAC-100 to seal the support if you start with their "Hardbord" product, but if you go with one of the other sealed & coated products (e.g., "Gessobord") you wouldn't need to do that (although GAC-100 does reduce the absorption of water into the gessobord, which I've found kind of helpful when painting with Golden Opens).
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Old 09-27-2008, 05:31 PM
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JamieWG JamieWG is offline
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Re: Ideal ground for Golden Open Acrylics

Mark, thank you so much for your input. I'm going to test the supports I've prepared with the 2-3 coats of GAC100 followed by several primer coats, and see if any discoloration migrates up through some OPEN medium sitting on the surface. I'd really like to avoid the shellac if I can. I'm about to prepare a batch of large panels, so if I absolutely have to do that extra step, I'd rather find out about it now than later!

Andrew, I love the Ampersand Gessoboard too, but it becomes very expensive once you move up to the larger sizes.

Jamie
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Old 09-27-2008, 09:43 PM
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George Servais George Servais is offline
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Re: Ideal ground for Golden Open Acrylics

If at all possible please, for the sake of your health and safety stay as far away from the oil and alcohol based commercial primers like KILZ or BIN. I used them as a commercial stain sealer years ago. That is there primary use. The name KILZ is appropriate for the product. The list of warnings is lengthy and these primers can and do cause blood disorders, nerve problems, lung problems and the list goes on. The primary attraction of acrylics is to not have deal with the smells and toxicity issues associated with other mediums. Please use a good quality gesso like Grumbacher acrylic gesso. I have used it with great success when painting on Masonite. Simply seal it with an acrylic sealer first if you have any bleed-through issues.
I used KILZ during the winter and the ventilation was not as good as it should have been. I woke up a day later in the hospital restrained and sick. It took 3 months to fully recover.
Both KILZ and BIN have extremely strong odors which linger for a long time.
I favor pre primed Gessoed hardboard. Available on line. The extra expense is worth it. Dick Blik has them. I know you are in NZ but a good on line search may get you what you need. Golden should know better.
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Last edited by George Servais : 09-27-2008 at 09:47 PM. Reason: typos
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Old 09-29-2008, 06:46 AM
Pantau Pantau is offline
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Re: Ideal ground for Golden Open Acrylics

Thank you all very much for your responces. They are all very usefull.

The Ampersand board products sound interesting. Especially the description about masonite is usefull. As far as I knew/know 'Hardboard' is the untempered version and 'Masonite' the tempered version.

This is the informationpage I read about an underground for Golden Open:
http://goldenpaints.com/technicaldata/open.php

I'm still not convinced that it is wise to use an alkyd-based primer as an underground for acrylic gesso and paint. A pigmented schellac might work oke, although schellac has it's own negative characteristics that one should be aware of.

So, for now I think I'll prepare my masonitepanels like this: 1. I'll apply 2 or 3 layers of GAC 100 (I ordered it, waiting for it to arive). 2. than 3 layers of Golden Gesso. 3. 1 layer of Golden fluid matte medium.

Ordering pre-primed panels might be a possibility,although I never use standard dimensions. So I'll have to do some searching where I can order non-standard-dimension-panels that are pre-primed they way I want it and how long it takes for them to be deliverd.

Cheers,

Charles
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Old 09-29-2008, 08:37 AM
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Re: Ideal ground for Golden Open Acrylics

Charles, Mark and George,

According to my tests, Mark is right as usual. Tests on my panels show serious support induced disoloration---not only with OPEN medium, but with other acrylic traditional mediums as well (though not as pronounced). Linseed oil and Liquin show no signs of color change, so it appears that the sealing and priming I did is safe for oils. This is a bummer. I'm going to have to change my preparation methods for acrylics. Maybe it's still warm enough outside for me to apply the B-I-N coats outdoors. I checked their website and it appears that my local Home Depot carries it. If that's not going to work out, I guess I'll be covering my panels with linen and canvas.

I'm going to retest my own panels on the chance that this one board escaped a sealer coat. I'm also going to test the Ampersand Gessoboard that I use so often.

I'll post results with images. It's not hard to see what happened; the color change is dramatic.

Jamie
P.S. Charles, thank you for posting the link.
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Last edited by JamieWG : 09-29-2008 at 08:42 AM.
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Old 09-29-2008, 09:01 AM
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Re: Ideal ground for Golden Open Acrylics

I'm adding the image of my first test panel. I'm still going to retest my own surface and some others, and will post all of them to a separate "SID" thread.

The applications of mediums on this panel are a lot thicker than what I use when I paint, but you'll notice that even the thin application of OPEN medium shows staining. In tests to come, I'll apply the materials in a manner more in keeping with what I do when I paint.



Jamie
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Last edited by JamieWG : 09-29-2008 at 09:03 AM.
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Old 09-29-2008, 09:17 AM
Pantau Pantau is offline
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Re: Ideal ground for Golden Open Acrylics

Jamie, thank you very much for sharing the information from your tests!

Some interesting results. I didn't expect that the SID-issues would be that visible.

I'll try some tests as well with some different materials. As soon as I have results I'll post them. Hope that the GAC 100 I ordered will arrive soon.

Charles.
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Old 09-29-2008, 09:37 AM
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tobiano tobiano is offline
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Re: Ideal ground for Golden Open Acrylics

Jamie, how long did it take for the yellowing to show? I prepare my own panels and will need to check if mine will do the same. I do use 3 coats of minwax polycylic, then 4 coats of acrylic gesso. So far I haven’t noticed any yellowing of the color, but this is all fairly recent, don’t know about long term. Thanks for posting your test results.
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Old 09-29-2008, 10:09 AM
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Re: Ideal ground for Golden Open Acrylics

Quote:
Originally Posted by tobiano
Jamie, how long did it take for the yellowing to show? I prepare my own panels and will need to check if mine will do the same. I do use 3 coats of minwax polycylic, then 4 coats of acrylic gesso. So far I haven’t noticed any yellowing of the color, but this is all fairly recent, don’t know about long term. Thanks for posting your test results.

Tobiano, it didn't take long. I checked the panel after a couple of hours and the color had already started. Certainly if you do it and leave it overnight, you'll be able to tell if there have been changes or not.

Jamie
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Old 09-29-2008, 03:32 PM
Pantau Pantau is offline
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Re: Ideal ground for Golden Open Acrylics

In the meantime I received the following response from Golden Technical Support to my questions:

"Alkyd is actually a type of synthetic resin that, while it seems similar to the oils used in traditional oil paints, is actually quite different in chemistry. The confusion often happens because they are both thinned with solvent and many paints described as 'oil-based' for use on houses are actually alkyd-based instead. As for using our products on top, alkyd-based primers are almost always formulated to receive a water-based paint as they are used extensively to prime raw wood prior to application of a water-based house paint. Because of this, you can safely use our products on any alkyd primer that can receive a latex paint.

I do not know which brands are sold in the Netherlands, so it would be difficult for me to recommend anything specific. I would think that any good commercial paint store that sells products for paining houses would have something comparable. And keep in mind that you can also use a pigmented shellac primer, which are also common for use on woodwork when one wants to seal the surface for subsequent coatings."
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Old 10-01-2008, 02:19 PM
Nilesh Nilesh is offline
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Re: Ideal ground for Golden Open Acrylics

Quote:
Originally Posted by Pantau
Hello everyone,

I'm about to start painting with Golden Open Acrylics. Now I have a question. I allways paint on masonite. On the website from Golden they describe the following ground as the optimal system for preparing wood supports for use with OPEN Acrylics, Gel, and Medium:

<LI class=normtext>Apply 2 coats of an alkyd-based primer, such as KILZ®, or a white pigmented shellac primer like B.I.N.® Let fully dry. <LI class=normtext>Apply one coat of GAC 100. Let dry. <LI class=normtext>Apply 2 or more coats of GOLDEN Gesso, or 1 coat Gesso followed by 1 or more coats of GOLDEN Sandable Hard Gesso.
I must say that I'm surprised by this description, because I've allways learned that it is not wise to work with waterbased paint on top of oilbased paint. For as far as I know an alkyd-based primer contains oil (or am I wrong here?). I remember reading somewhere that alkyd itself can not dry. So, to make alkyd dry it is modified with oil. This means that when you use the ground as described by Golden, you will be putting a waterbased gesso (is GAC 100 also waterbased?) on top of a ground that contains oil.

What do you think? Am I wrong about things here? I don't know the alkyd-based primer from the brand KILZ. Maybe this a special primer? If so, does anyone know a similar primer that is for sale in The Netherlands?

Sincerely,

Charles
All the layers and sanding, and the drying and other prep work can take up valuable time that could be spent painting.

There are simpler approaches, in case they might be of interest.

You could paint on Dura-Lar, for example, backed with Masonite or hardboard. This would also eliminate worries about the usual joined-at-the-hip nature of painting directly on hardboard. If something happened to the hardboard backing (warpage, cupping, and other forms of damage sometimes occur), the Dura-Lar could simply be detached or dismounted, and re-supported by a replacement backing.

The Dura-Lar would probably form an excellent barrier against migration of tannins and other materials.

Mark Gottsegen speaks highly of using linen, cotton, or polyester (which has advantages over the others) stretched over a rigid panel backing, rather than stretched over the usual stretcher bars.

This would also allow for replacement of the backing, if it were ever necessary.

***
Plexiglas and similar (acrylic) products bypass many of these problems.

Acrylics are not only excellent for use in painting -- as binders and mediums, gessoes and varnishes, etc. -- they can also serve as excellent supports, with real advantages over the masonites or hardboards.

Last edited by Nilesh : 10-01-2008 at 02:47 PM.

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