Research Bulletin 2000-1   (Updated)Refinishing Procedures:
A Guide to Manufacturer's Technical Information


Sherwin-Williams, Clearcoat Blending

Blending Ultra 7000® Clearcoats

Note:
Refer to vehicle manufacturer's warranty recommendations regarding clearcoat blending.

Surface Preparation

1. Adjacent panels or blend areas should be cleaned with soap and water, followed by the appropriate Sherwin-Williams surface cleaner.

2. Using a gray nylon scuff pad and USP-90 Liquid Scuffing Gel scuff sand well beyond the area where the clearcoat blend will end. Rinse thoroughly with clean water.

3. Re-clean the entire area with the appropriate Sherwin-Williams surface cleaner.

4. Mask the adjacent panel(s) with masking paper. Only expose the repair area.

Blend Application

Method #1 (Recommended for All Ultra 7000Clearcoats)

1. Apply the first coat of clearcoat beyond the basecoat blend area. Allow the first coat to become hand slick before applying additional coats.

2. Apply the second coat of clear extending beyond the first coat to taper the edge. Immediately over-reduce the ready-to-spray clearcoat from 100-200% with US-3 solvent. This ratio is 1 part RTS clear to 1-2 parts US-3.

3. Use this over-reduced mixture as a blending solvent, melting in the blend edge with light coats at lower air pressure to minimize overspray. This final blend edge must be within the area scuffed with a gray scuff pad and USP-90.

4. After the clearcoat has thoroughly cured, lightly polish with a foam pad and UMG-30 to remove overspray, fine scratches or enhance the gloss.

Method #2 (Optional Blending Method for CC-632, CC-633, CC-637, CC-639, CC-645 and CC-850)

1. Apply the first coat of clearcoat beyond the basecoat blend area. Allow the first coat to become hand slick before applying additional coats.

2. Apply the second coat of clear extending beyond the first coat to taper the edge. Immediately dump the remaining clearcoat out of the gun and pour a small amount of US-3 into the gun. It is not necessary to clean the gun prior to adding the US-3.

3. Lower the air pressure to 25 psi on a conventional gun and using a restricted fluid flow (either by partial triggering the gun or turning in the fluid control knob) lightly mist the dry clearcoat edge. Do not over-wet the area. Several light coats are better than one heavy coat.

4. After the clearcoat has thoroughly cured, lightly polish with a foam pad and UMG-30 to remove overspray, fine scratches or enhance the gloss.

CC-350 Quantum High Solids Urethane Clearcoat
CC-632 Ultra 7000 2K Kut-In® Clear
CC-633 Ultra 7000 High Solids, Air Dry Clearcoat
CC-635 Ultra 7000 High Solids, Air Dry Clearcoat
CC-637 Ultra 7000 Maximum Performance Clearcoat
CC-639 Ultra 7000 Super Glamour Clearcoat
CC-850 Ultra 7000 High Solids Booth Clearcoat

To blend the clearcoat edge prepare the area well beyond the intended blend area using a gray nylon scuff-pad and USP-90 Liquid Scuffing Agent. Extend the first coat of clear beyond the basecoated repair. After allowing the first coat of clear to flash to handslick extend the second coat of clear beyond the edge of the first coat. Over-reduce the clear with 1-2 parts of US-3 and melt the remaining clearcoat edge. After a thorough cure, lightly polish the blend area for the best appearance.

Note:
The final blend line must be within the area prepared with the gray scuff-pad.

CC-645HS High Solids Universal Urethane Clearcoat

To blend the clearcoat edge prepare the area well beyond the intended blend area using a gray nylon scuff-pad and USP-90 Liquid Scuffing Agent. Extend the first coat of clear beyond the basecoated repair. After allowing the first coat of clear to flash to handslick extend the second coat of clear beyond the edge of the first coat. To blend the clearcoat edge, use US-3 medium reducer using 25 psi at the gun or 8-10 psi for HVLP. After a thorough cure, lightly polish the blend area for the best appearance.

Note:
The final blend line must be within the area prepared with the gray scuff-pad.

 


©2004, Sherwin-Williams Automotive Finishes
Reproduced with the permission of Sherwin-Williams Automotive Finishes.