Painting Carbon with ALEXSEAL Clear Gloss
Because the material gets soaked into the carbon fibers the application process needs to be adjusted as follows:
- Before applying the clear coat it is necessary to create a smooth and clean surface. Fill all pinholes, voids and other coarse structure (e.g. peel ply) with resin (preferably the resin used to manufacture the CFRP Part or any other suitable, transparent resin). A final sanding with P180-P240 is recommended. The substrate must be clean, dry and free from dust, grease, oil and other contaminations before applying the clear coat.
- Mixing ratio 1st layer of clear
2 parts by volume T0125 ALEXSEAL Topcoat 501 Clear Gloss
1 part by volume C5012 ALEXSEAL Topcoat Converter Brush.
NO Reducer - It is necessary to do the first application by roller to fill the rest of the 1st layer voids better than by spray application. Apply one layer of non-reduced Clear Coat to a wet film thickness (WFT) of 100 - 150 microns (4 - 6 mils). Maximum dry film thickness should not exceed 100μm (4 mils).
- Sand the first layer of clear coat after at least 48 hours (4 days is optimal) of drying with P320-400 to even out the surface. Remove all dust before applying the next layer of clear coat.
- Mixing ratio 2nd layer
1 part by volume T0125 ALEXSEAL Premium Topcoat 501 Clear Gloss
1 part by volume C5051 ALEXSEAL Topcoat Converter Spray
Up to ½ part (17% vol.) R5050 Topcoat Reducer Brush - Apply 2-3 coats to a total wet film thickness (WFT) of 50-75 microns (2-3 mils). Allow 20-60 minutes tack up between the coats. This will achieve a dry film thickness (DFT) of 30-50 microns (1.5-2 mils).
If necessary apply further layers of clear coat (like 2nd layer) until the desired surface finish is achieved. Careful sanding with P320-400 is required between the layers after a period of at least 24 hours (4 days is optimal). - Mix the clear coat with the following mixing ratio:
2 parts by volume T0125 ALEXSEAL Topcoat 501 Clear Gloss
1 part by volume C5012 ALEXSEAL Topcoat Converter Brush
10% R5015 ALEXSEAL Topcoat Reducer Brush - Brush Base layer with 10% reduced clear coat.
- After drying, do a light sanding with P400. Repeat until no pores are visible and the desired surface quality is achieved.
- Sand the first layer of clear coat after at least 48 hours (4 days is optimal) of drying with P320-400 to even out the surface. Remove all dust before applying the next layer of clear coat.
- Mixing ratio for the top layer:
1 part by volume T0125 ALEXSEAL Topcoat 501 Clear Gloss
1 part by volume C5051 ALEXSEAL Topcoat Converter Spray
17% R5015 ALEXSEAL Topcoat Reducer Brush - Brush Top layer with 17% reduced clear coat. If the desired surface finish is not achieved sand with 320 and repeat 2nd step.
- For larger objects and highest requirements 2nd layer can also be applied by spray application.