Our new Desoprime CF Chrome Free Wash Primer
was recently launched and has proven to achieve application efficiency improvements over other wash primer
systems while eliminating chrome as the corrosion inhibitor," Cancilla added.
PPG Industries aerospace business has qualified a new chromate-free wash primer
coatings system to SAE International s Aerospace Material Specification 3095 for airline exterior paint.
This DIM system eliminates the need to use any type of metal pretreatment, such as Alodine, Solgel, or Wash primer
technologies; the primer is applied directly to the clean Scotch-Brited substrate and provides the necessary adhesion and corrosion resistance to meet the stringent specification requirements," notes Fusco.
The wash primer
protects the surface and will help the WD primer bond to it.
PPG donated a wash primer
, which was used to prepare the aircraft surface for primer application, as well as primer and topcoat, which recreated the olive drab color and yellow markings of the original "Dinah Might" flown by Maj.
DESOTHANE HS/CA 8800 buffable topcoat in six colors and a DESOTHANE high-solids topcoat in semi-matte silver were applied over P99 wash primer
and chromate-free PAC33CF primer.
In addition, there should be some kind of wash primer
, pretreatment, or conversion coating to enhance wetting and provide a uniform surface for better adhesion.
It eliminates the need to apply a wash primer
, which is often used with urethane adhesives to ensure adequate adhesion of parts.
A Direct to Metal system eliminates the need to use any kind of metal pretreatment such as alodine, solgel or wash primer
Each layer saved means less weight carried and we expect that a recent approval of a 'Direct to Metal' (DTM) system to AMS 3095A means that airline customers can save considerable weight compared to a typical wash primer
scheme," said van der Laan.
Table 1--Sol-Gel Incorporated in Coating Systems Type Sol-Gel Outcome Incorporated Waterborne Water reducible Added in grind Boosted salt spray alkyd direct-to- Boosted blister metal (DTM) enamel resistance Waterborne Acrylic lacquer Added in base Reduced black sealant corrosion Solventborne Vinyl butyral Added in grind Replacement for wash primer
Cr-based corrosion inhibitor Solventborne Medium oil alkyd Added in grind Increased adhesion on primer galvanized steel
Furthermore, it improves adhesion of the paint system on rivets, compared to traditional conversion coatings and wash primer