I am in the process of painting the hull and deck or my Triad. I put two coats of primer on and sanded after each coat. Most of the hull was primer white, after the second sanding, but some areas showed the original hull/epoxy color. The primer gets sanded to an almost translucent look.
The primary hull color is Brightside Seattle Grey. It went on smoothly. Two coats covered it. I sanded inbetween coats with 320 grit. You have to wait at least 16 hours before sanding but I find that 36-48 hours is better as the paint takes some time to harden in this cooler weather. Now I am painting the hull side, above the lower rub rail, with a mix of Brightside white and Brightside yellow. I mixed them half and half to get a lighter yellow. I am having trouble getting it to cover. After two coats there are still areas where the hull color faintly shows. The problem is when I sand between coats of the Brightside white/yellow I end up sanding off most of the previous coat in those areas. The problem areas are the corners, where the hull joins the stem and a couple of small spots on the transom.
My question is can the next coat of Brightside white/yellow be applied without sanding the coat I just applied? I am sure that sanding inbetween coats is the most desirerable method but is it and absolute need? Another question is: the paint can label says sand with 320 would 400 meet the sanding need if it is indeed a need?
Terry just scratch it up well with a green scrubby pad. You are sanding too much off.
A green scrub pad like the small ones with the sponge on one side and the green plastic like bristle on the other?
Yes, go over the surface real well and use a tack rag to pick up the dust. What you are looking for is to knock off the dust bumps and provide a mechanical bond for the next coat. If it haas been a while since the last coat you may want to precede the scratch pad with a mild thinner to get any grease or oil from hands or other sources. Paint immediatly after these operations.
The paint guys here at work told me that yellow is one of the hardest colours to get an opaque pigment out of. Most yellows that are opaque have an addition of red or orange to them. I believe this is due to the fact that to get an opaque yellow you have to add some heavy metals.
Mind you, they told me this after I put 5 coats of yellow house paint on my old MiniCup and could still see primer ....
If you're not married to the idea of using Brightside, you may want to consider using one of the "rust" or machinery paints. I've had fairly good luck with the yellow in them.
I have some old tee shirts that your paint guys can have if it'll help any Andrew. They have lots of yellow pigment available if they grind them up.
First off, don't sand primer any smoother then 320 (280 is better), you make it too smooth and the top coats can lift. Now that you've moved onto the top coats, lets just hope your paint likes it smooth. I never use more then 220 on primer, unless the top coat is a weird one, but most paints will easily fill in 220 scratches.
Most of the modern marine enamels and polyurethanes are "runny". This might just be a way of the manufactures getting a few more quarts out of each customer, but it actually because of the "modifiers" used in these new paints. These "additives" make the paint dry faster and most importantly, lay down smooth. Hell, you don't have to do much to get a really nice finish, spread it around with a wire brush and it'll self level, smoothing itself out.
These new paints are good and work great. They dry fast, reduce brush strokes to nothing, have more shine, last longer, tougher, etc. They also have pit falls, much like the drop dead good looking girl you dated in high school that was as useful as a sack of hammers.
In short, you need multiple coats (no kidding) yep, 3 at least, probably 4 or more for good coverage, protection and "film thickness". Film thickness is the key here, particularly if you are wet sanding between coats. You can "color" sand between coats and get a really smooth finish, but you have to remember you're removing half of the previous coat, so you'll have to apply 50% more paint to cover it. In other words if you're sanding between coats to smooth things out, then it will take at least 6 coats to have the film thickness of 4 where you only scuffed the previous layer.
Be very careful with Scotch Brite pads used to scuff paint. They shed little green hairs all over everything, so the surface must be washed and tacked. Most importantly, they can scratch the hell out of a surface, make sure you use the finest pad and not a lot of pressure. A regular grit green pad will easily show scratch marks under a finish coat.
Thanks to all of you. Â I painted parts of the inside with the yellow and white mix and it covered in one coat there. Â The difference was the surfaces were flat and I was able to put the paint on thicker. Â The current application is a vertical surface and the coats I am applying are thin to avoid runs.
The last coat was applied 12 hours ago so there shouldn't be much oil or anything else to worry about. Â I will keep the green pad in mind for possible future application but think the problem is as described. Â I sanded to much off, yellow doesn't cover as well as darker colors and 3 or 4 coats will fix this. Â I'll sand it again after another 4 hours or so. Â The paint can says a minimum of 16 hours between coats. Â I wipe with 333 brushing liquid just before painting, (part of Interlux's instructions).
I am not opposed to a different brand of paint but do like how well Brightside flows out. Â I also like the fact that I own it. Â Perhaps next season or the one after, when I repaint to handle the nicks and scratches, I will try something else.
The original paint scheme was going to be medium blue over grey or vice versa. Â My daughter complained that it was to much of a "boys color" for a boat named the Amanda Marie so I changed the blue for the yellow with reddish pink rubrails and trim. Â I was tempted to paint it yellow over blue but decided it would look to much like the phone book.
Update as of 10/28 - Ok the deed is done. It took 4 coats to finally give the part of the sides I was painting an even, all yellow color. I just made sure that I sanded as lightly as possible and applied thin coats. The upside is the paint looks much nicer then the grey paint on the bottom of the hull. It looks deep, almost like the candy apple paint jobs on cars that was popular in the 60's! The rub rail, between the grey and yellow, will get the watermellon pink after I let the last coat harden for 5 days or so. I wouldn't feel comfortable putting tape on, to mask off the none pink areas, until then. After that I just have to attach the aluminum sacrifice strip to the bottom of the keel and flip the boat to finish painting the topside areas. The holes for the aluminum strip are already drilled and filled with CPES. I will put a bit of epoxy with filler in the over sized holes before pushing in the screws.
In a way it's nice that I won't make a 2009 launch. Now I can take my time and not rush the paint job. I suppose I could float the boat in the small pond, in a park I built the year my daughter was born, but I can't see the wisdom in that. I might change my mind come New Years eve if I have to many shots of Captain Morgans in my cokes, along with a slice of lime of course. Na that would still be a 2010 launch. I may as well wait for spring.