Technical Manual NASON SELECTPRIME™ 421 ... - Auto Paint Plus

Technical Manual
NASON ® SELECTPRIME 421-20 TM (GRAY)
2K ISO-FREE SPEED PRIMER
Nason ® SelectPrime 421-20 is a productive 2K Iso-Free Primer (Gray) that is designed to deliver
high build and exceptionally free sanding film without shrinkage or sand scratch swelling. Nason ®
SelectPrime 421-20 is designed for those shops seeking a productive 2K primer with steady
speed to sand that provides increased production capability during the repair process. 421-20 is
designed to maximize DOI (Distinctness of Image) when used under any Nason ® topcoat color.
MIXING:
4-1
Mix:
4 parts Nason ® SelectPrime 421-20
1 part Nason ® SelectPrime 483-53 or 483-83
(Slow) Activator
Example:
To 1 gallon 421-20 Primer-Surfacer add 1
quart 483-53 Activator.
TINTABILITY:
Not recommended.
POT LIFE:
1 Hour at 70°F / 50% Relative Humidity
SUBSTRATES:
Properly treated bare steel, galvanized steel and
aluminum; properly prepared painted surfaces.
Treat bare metal areas with Nason ® 491-17 Etch
Primer, or 491-16 Ful-Poxy Epoxy primer.
SUBSTRATE PREPARATION:
� Clean surface thoroughly with mild detergent
and water.
� For substrates other than plastic or fiberglass,
wipe surface with Nason 441-05 Wax and
Grease remover, 481-75 Aerosol Cleaner,
or locally permitted cleaner.
� Sand and featheredge according to the
following minimum grit recommendations:
Steel: P180 grit
Aluminum: P320 grit, then pretreat
Galvanized: P320 grit, then pretreat
E-coat: P320 grit
Cured paint: P320 grit
OEM featheredge: P180 grit followed by P240
grit
Body filler: P180 grit
2K putty: P180-P240 grit
SMC/fiberglass: P180-P240 grit
� Notes: Aluminum, galvanized, and steel must
be pretreated with Nason 491-17 Etch
Primer or 491-16 Ful-Poxy Epoxy Primer
or other Nason ® Etch Primer or Epoxy Primer.
Tips for Success:
� When using coarse grit paper, step your way
up through P80/P180/P240 grit prior to
priming to remove coarse scratches and avoid
sand scratch swelling in OEM finishes.
� Finish sensitive substrates in P320 grit.
� Sand beyond the area to be primed with P320
grit or finer to ensure good adhesion at the
thin edge of the primer.
TOPCOATS:
All Nason ® Topcoats
SPRAY VISCOSITY:
30”-35” #2 Zahn
SPRAY PRESSURE:
Conventional: 30-40 PSI
HVLP: 8-10 PSI @ gun cap.
Rev. 08/09 Copyright © 2009. E.I du Pont de Nemours and Company. All Rights Reserved.
A Member of DuPont Performance Coatings ® and TM are registered trademarks/trademarks of E.I du Pont de Nemours and Company.

TYPICAL GUN SET-UPS:
Conventional
Siphon Feed: 1.8 mm – 2.0 mm
Gravity Feed: 1.8 mm – 2.0 mm
HVLP
Siphon Feed: 1.8 mm – 2.0 mm
Gravity Feed: 1.8 mm – 2.0 mm
APPLICATION:
Apply 3 medium wet coats. Allow 5-10 min. flash
between coats.
Tips for Success: Do not ignore flash times
between coats; this prevents solvent entrapment
that can cause pinholes, popping and shrinkage if
flash is abused.
DRYING TIME: TO SAND
2.5 hours at 70°F when activated with 483-83 TM
1 hour at 70°F when activated with 483-53 TM
Lower temperatures may require longer flash
times.
SANDING:
Sand wet or dry with #400 or finer paper. Clean
sanding debris with Nason ® 441-05 Silicone and
Wax Remover or locally permitted cleaner.
SEALERS:
No sealer is required but may be sealed with
Nason ® SelectSeal 422-50 or any Nason ®
Sealer.
CLEANING OF PAINT EQUIPMENT:
Use Nason ® 481-16 TM , Nason ® 481-21 TM Low
VOC Gun & Equipment Cleaning Solvent, or
any other DuPont equipment cleaner as
permitted by local regulations.
IMPORTANT NOTES:
� Sanding is required for adhesion of topcoat to
primer and optimal appearance.
� 421-20 can be used under any Nason ®
topcoat system.
Technical Manual
PHYSICAL PROPERTIES:
VOC LE: 4.8 lbs/gal maximum, ready to spray
Theoretical Coverage: 585 Sq. Ft. @ 1 mil
Weight Solids: 56.2%
Volume Solids: 36.5%
Recommended Dry Film Thickness: 4-5 mils in 3
coats
Flash Point: See MSDS
VOC REGULATED AREAS:
These directions refer to the use of products which
may be restricted or require special mixing
instructions in VOC regulated areas. Follow mixing
and usage recommendations in the VOC Compliant
Products Chart for your area.
SAFETY AND HANDLING:
For industrial use only by professional, trained
painters. Not for sale to or use by the general public.
Before using, read and follow all label and MSDS
precautions. If mixed with other components, mixture
will have hazards of all components.
Ready to use paint materials containing isocyanates
can cause irritation of the respiratory organs and
hypersensitive reactions. Asthma sufferers, those with
allergies and anyone with a history of respiratory
complaints must not be asked to work with products
containing isocyanates.
Do not sand, flame cut, braze or weld dry coating
without a NIOSH approved air purifying respirator with
particulate filters or appropriate ventilation, and
gloves.
Please visit: www.nason.dupont.com to view or print
an additional copy of this technical “Product Data
Sheet.”
Rev. 08/09 Copyright © 2009. E.I du Pont de Nemours and Company. All Rights Reserved.
A Member of DuPont Performance Coatings ® and TM are registered trademarks/trademarks of E.I du Pont de Nemours and Company.