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Permalink Reply by Rick Newman on July 24, 2012 at 11:24am

Karen there are almost as many opinions about paint and finishing a driftboat as there rapids in the Grand Canyon, perhaps more. It the classic conundrum, how nice do I want it and how much time money and effort do I want to spend. The best finishes are commercially applied, usually by an automotive paint shop. They do all the work, they apply all the finishes, they do all the sanding, use the highest quality materials, buff out the finish and your boat will look like a million bucks. You won't pay that much but you will pay a pretty penny. You will also have a durable, high quality finish. Ukalady built her own driftboat for the Grand Canyon and chose this path. Do a search for her, you can see pictures of her boat and even send her a private message to ask her questions. I haven't seen any posts from her in a while so she may be busy boating, she worls as a guide.

The second option is what I would call the talented woodworker finish. This is my definition formed from years of amateur painting of houses, interior woodwork and such. The quality of the finish starts with the quality of the work done to smooth and prepare the surface for paint. The greater the attention to detail, the filling of minor holes, the fairing or smoothing of surfaces will build the foundation for the rest of the job. Using a torture board, an 18" to 24" long automotive type body sander that uses adhesive backed sandpaper. They can be found at automotive refinishing paint shop. The length of the board allows the reduction of high spots and reduces the chances of creating divots or low spots. After an initial sanding and application of primer a light coat of a different colored primer can be sprayed on. Now use the torture board to see where you have high spots and low spots. after sanding the high spots will be the original primer color and the low spots will still have the second primer color. Now you fill the low spots, repeat the procedure until you are comfortable with the surface. In a darkened environment a bright light can be shined across the boats surface. Put your head down to where you can see the surface. Any imperfections will be seen. The more you do this the better the finished product. This is part of what the experienced body shop guys do and have spent years [racticing their craft. They also have air powered tools to speed up the process. The end results can be the same. You either take the time, do the work or pay the pros if you want a top rate job.

Once the talented woodworker has prepared the surface he then applies the paint. I prefer to use a HVLP spray gun. In other words a high volume low pressure spray gun. I got mine from Woodcraft for about $40. I already had an air compressor that would power it. I have been spray painting for decades but only rcently with spray guns. I have also spray painted my house with primer and paint. My house is about 1000 square feet and it takes me about two to three hours to completely spray it. To paint it with a brush takes me two or three days.

So I had already learned the appropriate techniques do basic spray painting I added this to the skills I needed to know to use a clear finish that I applied to my boats parts. With practice you learn what distance from the part being painted, the speed to move the spray gun and what the surface should look like if the paint is going on right. My first spray job with the HVLP gun was a learning experience, so the first few hours was mostly learning, I had to resand the parts and redo the painting. However once I learned the procedure I was able to quickly spray the additional coats and they turned out great. This computer doesn't have the pictures I took, but if you look at my page here on Wooden Boat People you can see some of my construction pictures.

Multiple coast of finish especially clear give depth to the finish and provide more durability. Sanding between coats insures proper adhesion of additional coats and removes imperfections, runs, drips, orange peel ,etc. If you choose you can get out your buffer and some 3M finishing compounds and bring the final clear coats to a wonderfully glossy finish. This level of finishing takes the largest amount of time, costs less but does require patience and lots of effort. I am not as talented as many woodworkers and I work slowly, my paint job will never be as good as the talented woodworkers and finishers. I am using a water based urethane finish from Woodcraft. It applies easily, dries quickly isn't too expensive and is UV resistant. It doesn't have a strong smell and can be recoated within a few hours. There are many other choices, enamels, acrylics, polyurethanes, etc. I'm sure others will add their ideas. I want a high quality coating that will be easy to repair, looks good and wasn't too expensive, I think I paid about $65 a gallon. I want a five foot finish! I am using a stain with my clear coat to make a cherry wood colored boat to cover up some wood imperfections. I will then spray several more coats of clear to add depth to the finish. Other very talented and experienced finishers will only do what is called a roll and tip technique. You roll on a coat of paint over a small area and then use a brush to "tip" the finish and smooth out imperfections. This too can provide a good surface. It is often chosen by experienced varnishers when the do the "Bright Work" on expensive wood boats. However I think that with some practice and the right paints a patient person can do a reasonable job.

c. Workboat finish, Many users are perfectly comfortable with what is known as a workboat finish. The sanding requirement are less, probably no torute board work, just a mechanical sander and some sanding blocks. Basically this style of finish requires the surface to be prepared just enough to get rid of major imperfections and to rough up the finish enough for the next finish to adhere to. A variety of paints can be used to achieve a workboat finish, oil based porch paints, enamels, some even use latex house paints. The normal workboat is designed to be used hard and the finish is primarily to protect the wood underneath. Looks are not the primary concern.

So to conclude this wordy post, I will say that there are many ways to go. I have only shall we say, "touched the surface"! There are tons of resources on paints, paint products and such. The difficulty is deciding what will work with your budget, time and amount of effort you wish to expend. The finished results you desire will also point you in an appropriate direction. Let us know more about your desires, I know that others have different methods and opinions. Good luck!

Rick Newman

Primer will depend upon what type of paint you are using, what the finish

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Permalink Reply by Eric Loudenslager on July 24, 2012 at 9:04pm

You have at least six choices:

Latex house paint - poor

Alkyd (oil based) house paint - OK, but not great

Alkyd Marine Paint from Kirby in Mass...see internet and Jamestown Distributors - fine choice, not high gloss.

Alkyd/Urethane single part blend Marine - Epifanes, Interlux, Pettit - fine choice, high gloss, can be buffed per RN's reply

2-Part Urethane Marine from Epifanes, Interlux, Pettit - hard, glossy, expensive, requires positive pressure air mask when spraying.  Can be applied roll and tip.

System 3 Waterborn LPU (linear poly urethane) - hard, moderately expensive, waterborn so no nasty or expensive solvents for clean-up, and reduced number of brushes to throw away.  Can be applied with spray, brush, or roll and tip.  Challenging to apply in warm weather.

Paint can be applied with brushes, roll and tip, and spray.  Given your experience, unless you can find access to a reasonable HVLP sprayer, roll and tip is probably the  best way to go.  You use a foam nap roller (I use the yellow 1/8 nap) to apply the paint, and then brush out the bubbles from the roller (tipping) with a brush.  Many of the paint companies tell you to use expensive fine natural bristle brushes.  However, these require solvent to clean.  So, when using an oil based paint or marine enamel I use foam brushes and throw them away after a single use.

I painted my dory with Interlux Toplac (a single part polyurethane) and that paint is no longer available.  Consequently, in anticipation of needed to repaint in a couple years I have been testing paints.

My assessment is that oil based house (porch) paints are much softer than the marine alkyd paint or alkyd urethane blends.  I would use any of the marine enamels before house paint.  But a quart will cost you nearly $40, compared with $25 for ben moore porch enamel.

I have no experience with 2 part marine polyurethanes.  They are expensive.

I have tested System 3 WR-LPU and am quite satisfied with the product.  It is not easy to apply, especially in hot weather and low humidity.  System 3 sells 4 oz samples for $5 so you can take it for a test drive if you wish.  It is not cheap - $59/quart, but there is no solvent for thinning (just use water), and you can clean out your brushes and rollers and reuse them.  So on a cost basis I believe it is competitive with the single part marine alkyd/urethane blends.  It does not have a strong odor, you can apply it with roll and tip or brush without wearing a mask.  

I find the fumes from single part marine alkyds strong enough to require a 3M organic vapor mask.

See the instructional videos at Jamestown Distributors for application guidance on roll and tip, and comparisons of pettit, interlux, and epifanes paints.

The scheme you outline in your message - primer, topcoat, clearcoat - is the sequence used in applying polyurethane LPUs...aka car paints.  This can be done with boats, but is not required.

Good luck

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