• Painting and Silk Screening PVC
Surface Preparation: As with painting any material, surface preparation is important. For best results it must be dry, clean, and degreased. Cleaning with isopropyl alcohol is one recommended method. Always sand down scratched surfaces using fine sandpaper or fanning the scratch with a heat gun. This will reduce scratch show through.
Printing: PVC provides an excellent surface for printing, utilizing a wide range of inks. When using Silk Screen Methods, colorful, full crisp coverage can be achieved using most printing inks that are normally used for rigid PVC products. Always use PVC screen inks and thinners of the same brand or manufacturers. Never mix different brands or manufacturers of PVC screen inks or thinners. Incompatibility of the various inks and thinners may cause surface cracking and reduce the life span of the sign. Note- Water based inks are not recommended.
Recommended Silkscreen Inks for PVC:
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4400 Series vinyl inks (www.nazdar.com)
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3M 4900 Series inks (www.3m.com)
Painting: PVC provides an excellent surface for paint adhesion. Primers are generally not required unless you wish to use a top-coat that is not recommended for PVC. Any method to apply paint, brush-roller- spray gun or dipping may be used. Vinyl, acrylic lacquers, acrylic enamels, two-component polyurethanes, and other types of paints suitable for PVC are suitable for PVC. *Note-Oil based enamels are not recommended unless an appropriate primer is applied first.
Recommended paints For PVC:
Primers- Only required as a base coat before using solvent based lettering enamels such as 1Shot, Chromatic, etc.
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(www.superfrog.com) Frog Juice
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(www.ronanpaints.com) Prime Lock DTM, Metro Vinyl Primer, Vinyl Cote Flat
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(www.signpaint.com) 74-777SP
Sign Paints: The following sign paints may be used without the aid of a primer.
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(www.ronanpaints.com) Aquacote Bulletin Enamels
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(www.signpaint.com) Matthews Acrylic Polyurethane
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(www.superfrog.com) Frog Juice
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(www.denversignsupply.com) Deka Sign Enamels
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(www.spraylat.com) Acrylic Lacquer
Top Coats- When extra protection is required for harsh environments, the following top coats may be used.
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(www.ronanpaints.com) Vinyl Cote Gloss,Vinyl Cote UV Absorber
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(www.superfrog.com) Superfrog's Sunscreen Clear
*Suitable Inks and Paints are not limited to the above recommendations. Always test for adhesion properties before selecting an ink or paint.
• Achieving Proper Adhesion When Painting PVC Sign Blanks
Always check for proper adhesion properties when selecting an untested ink or paint. The cross hatch tape test should be run after the paint has dried for a minimum of 24 hours. Longer for some paints and inks.
To Run The Test:
A. Using a replaceable blade knife, make eleven parallel cuts 1/16"apart and
make eleven cuts 90 deg. to and crossing the parallel cuts. This will form a
hatch pattern. The purpose of the "cuts" is to break the film plane of the paint.
B. Pressing firmly, apply a 1/2" wide strip of Scotch Tape across the scored area.
C. Immediately, in one rapid motion, remove the tape at a 180 degree angle.
D. Proper adhesion has been obtained if painted surface does not lift off with the tape.
• Improving the UV Fade Resistance of A Sign Blank
As we all know, everything that is exposed to sunlight will fade over time. The color white, whether it is paint or PVC, is much more resistant to fading than darker colors. A Xenon exp. 300 MJ test conducted on different colors of Celtec , Trovicel, and Sintra PVC showed no noticeable color change to the color white. This test replicated 12 months in the Florida sun.
If the sign blank is used as a substrate for vinyl, painted, or silk-screened graphics, then the fade resistance of the sign is really determined by those materials.
If the sign blank is intended to be an extra long-lasting sign in a harsh outdoor environment then it can easily be coated with a UV resistant clear coat, such as T.J.Ronans (www.ronanpaints.com) Vinyl Cote UV Absorber. This will provide an exceptionally long lasting sign in all environments.
• Installing PVC Sign Blanks
PVC sign blanks can be installed in any of the traditional ways.
1. Predrill holes and maintain a minimum distance of 1" from the edge of the sign.
2. Fastening of PVC can be accomplished using all types of screws or nails. Use of elongated or oversized holes allows the material to expand or contract. Screws utilizing oversized washers or grommets give excellent results. For optimum results, screws should be tightened and then retracted slightly. Expansion and contraction are not an issue for interior signs and signs under 12".
3. Use of sign brackets and hangers are perfectly acceptable.
