GAC 800

GAC 800

Low Crazing Extender for Pouring Acrylic Colors

PRODUCT DESCRIPTION

GAC 800: Reduces Crazing / Modifies Paint for Pouring / Improves Adhesion to Chalky Surfaces

• Add as an extender to acrylic paint for pours or puddles. Dries to a glossy level finish. Most fluid acrylic mediums will ‘craze’ when applied thickly 1/16” (1.50mm) or thicker. Crazing is the formation of crevices or valleys that run through a pour/puddle caused by uneven shrinkage during the drying process. GAC 800 helps to minimize this problem. (Paint Additions into GAC 800 for Pouring Applications)
• Best when mixed with color as binder dries with a slightly "hazy" quality if used alone
• Dries with good gloss and film flexibility
• Improves adhesion to chalky surfaces
• Suggested wet film thickness 1/8”(3mm) or less

Keys to Successful applications of GAC 800 as a Pouring Medium

1. Always test product mixtures and applications before working on the actual artwork.

2. Properly set up your studio for pours, with a focus on temperature, cleanliness and a level work table.

3. For best results seal your surface with a gloss medium before applying GAC 800 mixtures(Preparing  a Painting Support) 

4. Minimize foam in mixing or allow mixtures to sit so foam can escape (Taming the Foam Monster)

5. .After applying a layer of GAC 800, let dry for a minimum of 24 hours (even longer if the pour is heavy or large) before applying additional products. Ideally wait 3 days before moving. 

6. Thinner  films are less prone to crazing

7. GAC800 dramatically reduces crazing, however, there is still always a risk of crazing. Depending on studio temperature and humidity, allowing a pour to dry under a “tent” (see below) provides the smoothest surface with the least defects.  

Ideal Studio Environmental Set-up

• Application and Drying Temperature is between 65-75° F (18-24°C) with Relative Humidity above 50%
• Studio space, working table and substrate should be clean and free from dust and oily contaminants.
• Avoid areas with forced air (central air ducts, ceiling fans, fans blowing directly onto the painting).
• Work Table needs to be as level as possible. Unleveled surfaces can cause crazing and uneven results.
• Possible tent for curing 

Substrate and Surface

• Textural or absorbent surfaces can affect evenness of film. Flat, sealed surfaces will give smoothest results.
• Most substrates commonly used by artists are acceptable, but there are some known issues unique to each.

1. Canvas – textural and absorbent.  Can result in uneven pours unless sealed.  Stretched canvas can sag towards the center due to the weight of a thick pour. Ideally, use backing board under canvas and seal surface with acrylic medium before pouring (see below).
2. Wood Panels – have increased risk of Support Induced Discoloration (SID).  Hardboard and other wood-based panels are prone to bowing, warping, and raised grain.(Preparing a Painting Support) 
3. Synthetic/Composite Panels- test for application and adhesion- cure time is increased, thick pours may bubble primer layers (Painting on Dibond)

Product Mixing

GAC 800 is compatible with GOLDEN paints and mediums. Additions of 10% color or less are recommended for best results.  Often 1-5% color is sufficient for color development in poured applications.  Higher levels of colors or other mediums, especially thinner (lower viscosity) materials like the High Flow Acrylics, can overwhelm the GAC 800’s resistance to crazing.

Mixtures with other products and brands have not been fully investigated for use with GOLDEN GAC 800.

Ideally, blend color into GAC 800 and allow the mixture to sit closed for 6-24 hours or more before use.  This allows bubbles formed during mixing to release, resulting in a more uniform layer.  Mixtures may be kept in airtight containers for weeks, but realize that there may be pigment settling or other interactions during this time.

Note: dilutions beyond the 2:1 mixture (GAC 800 to Water) will increase the haziness of the dried film as the binder is further extended. If a more dilute mixture is needed, we recommend testing before application to a painting surface. 

While GAC 800 has undergone intensive testing, there is still the chance for unusual interactions with other products and environmental factors.  Therefore, be sure to test for your application whenever introducing a new material or paint prior to use on large areas.  Contact [email protected] or (800) 959-6543 / (607) 847-6154 for assistance.

Drying

Pours should be allowed to dry at least 24 hours before moving or resuming applications. Ideally allow layers to dry for 3 or more days before moving.  

Tenting – air flow and drying cause stress to build up on surface of pour leading to possible crazing.  Using a tent to create an elevated humidity environment allows for these stresses to dissipate as a material dries, creating a surface less prone to defects.  A plastic material such as 3mil plastic sheeting is commonly draped above the surface 6-12” and gently allowed to drape over the edges without touching the pour. Pieces should cure under the tent for 6-12 hours.  Care should be taken to ensure plastic does not contact surface.

Packing and Shipping

Packing materials touching the dry surface of an acrylic painting, including a pour, may cause change/ damage to the painting.  Pack and store without plastic, glassine, or other materials touching the surface. For more information please consult the Materials and Applications Department: [email protected] or (800) 959-6543 / (607) 847-6154.

Adhesion to Chalky Surfaces

GAC 800 has shown the ability to increase adhesion to chalky surfaces such as plaster and weathered paint.  

• If possible pre-wet surface with water  by spraying or brushing
• Mix GAC 800 with 20-40% with water and brush apply to surface, allow to cure
• Once dry if needed apply additional coat  GAC 800 un-thinned to further consolidate surface
• Note: If applying over weathered paint underlying layers may have unknown adhesion properties to the substrate. Consolidating surface chalking will not correct previously existing intercoat adhesion issues.   

Clean-Up

Clean tools with soapy water immediately after use and avoid allowing paint to dry in brushes or other tools.

Technical Details

Disclaimer

The above information is based on research and testing done by Golden Artist Colors, Inc., and is provided as a basis for understanding the potential uses of the products mentioned. Due to the numerous variables in methods, materials and conditions of producing art, Golden Artist Colors, Inc. cannot be sure the product will be right for you. Therefore, we urge product users to test each application to ensure all individual project requirements are met. While we believe the above information is accurate, WE MAKE NO EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, and we shall in no event be liable for any damages (indirect, consequential, or otherwise) that may occur as a result of a product application