To assure the highest quality and long lasting results, every detail in preparation and painting must be followed. This excerpt from a paint workshop (given by C&N at a trade show) demonstrates the attention to detail that is given to every yacht.
1. If in doubt – do a paint compatibility test. (Check with the paint manufacturer for testing methods.) If the old paint surface that you are overcoating with a new expensive 2 part polyurethane paint turns out to be a one part enamel, you may end up having to strip it all back down and do it all again.
2. Before sanding, Clean the surface with Comet cleanser in a bucket of water and a Scotch Brite pad. Sanding the paint surface without first cleaning can:
a. clog sandpaper much faster
b. force contaminants into the substrate, affecting adhesion and overall quality.
3. When working with compressed air tools, the use of clean, dry regulated air- is a must. Moisture in the air line cuts the life of the air tools and contaminates the working surface, and paint being sprayed, undermining the overall quality of the job.
SOLUTION: Compressors 10 hp and smaller should have a quality in-line air pressure regulator and water trap. Compressors over 10 hp should have an in-line dryer system and regulator. Also, the closer the in-line regulator/water trap is to the working surface, (and further away from the compressor) the less condensation and pressure drop occurs.
4. Use a guide coat – A light coat of contrasting color lacquer (spray cans work fine)
a. dark guide coat for light colored surfaces
b. light guide coat for dark colored surfaces.
A. guide coat acts as a sanding guide and shows where the nicks and scratches are. (Note: Use only lacquer paint for guide coating surfaces to be sanded the same day.
5. Mixing fillers – don’t mix large batches. There is less waste mixing small batches and less chance of trying to use the last of a big batch of filler while it is “kicking off”. Mixing the filler thoroughly insures consistent curing and eliminates soft spots.
NOTE: The use of glazing putty for filling pinholes and hairline scratches is proper. Never substitute the use of one part glazing putty for heavier filling where a polyester filler or 2 part epoxy filler should be used.
6. Use air tools to take down body filler areas close, then finish the body work with a hand block. This way you do the job right the first time, and avoid having to re-skim an area that was oversanded with an air tool.
7. After final sanding, follow these procedures (NO SHORT CUTS)
a. blow sanding dust off the surface with an air line and a clean, dry rag. (Be sure to blow out all cracks, crevices, doorjambs, and adjacent surfaces–not just the flat prepped surfaces.)
b. Wipe down the prepped and ready surface with alcohol, Prepsol, AwlPrep or a similar brand prep solvent and a clean, damp rag, but allow sufficient drying time before the final blow off and tack ragging.
c. Tack off the surface with a fresh tack rag designed for the type of paint being used. (some tack rags are much thicker than others) Open the tack rag completely and use a light touch. Never use a dirty rag, headband, or shirt in place of a tack rag, as body oils or other contaminants will foul the clean surface and cause ’fish eye.” Now you are ready to paint!
When brush painting (or varnishing) larger areas, use a roller to apply the paint, and a brush to “tip off” the paint. Don’t try to brush the brush marks out of the paint surface. (The faster you apply the paint and move on, the more time the paint has to flow.) Example: You are painting the house side of a 60’ yacht. You have a nine inch roller, (with the correct roller cover for the paint being used) roller tray and four inch brush. Apply two roller widths of paint vertically on the house side and then “Tip off” the paint vertically with the brush. (If you get too far ahead with the roller, the paint will begin to set-up by the time you try to “tip off’ with the brush.) Then apply two more roller widths of paint and repeat the “tipping and rolling’ procedure.
8. Always adjust the spray gun and shoot a test pattern on the adjacent masking paper prior to spray painting. This allows you to fine tune the spray pattern before it’s too late.
9. If something serious does go wrong (runs, fish eye, heavy dust, masking paper blows into paint) consider wiping the paint off with reducer-soaked rags before it sets up. Whenever possible, use the same reducer to wipe down with as used in the paint. If this is practical, (especially if you are still part way through the first coat and the painted surface isn’t too big), it allows you to proceed with repainting the same day, after correcting the problem, and saves the labor of re-sanding the whole job.
*(Excerpts from Workshop WK10 at IBEX 1995 Trade Show, C& N Yacht Refinishing, Inc. is not responsible for any results of using procedures listed above).