Durall Boat Bottom Paint

 
Return to Articles

Speed: You can’t win sailboat races without it!

People with new sailboats don’t need to think much about boat bottoms because new boats have fair bottoms so all you need to do is keep them clean. Over time. however, your bottom will start experiencing increasing drag meaning your sails will need to produce more power to reach hull speed. Increased drag will slow you in lulls or turns and you require more power to recover back to your hull speed after the lull or turn has been completed. Class racing is all about going the right way at the right time. If your boat's drag is greater than your competition's, you will need greater sail power or much better tactics.

The easiest way to make your boat faster and more efficient is by fairing its bottom. The Royal Navy was aware of this and invested millions in seething their wooden ships with copper bottoms. The Brits found that marine parasites did not like copper and they did not adhere to these copper bottoms. Bottom condition is critical. The bottom of your boat should be smooth and the paint needs to stay on with good adhesion. Older bottom paints in many cases have built up, because the older paints (like Interlux Bottom kote, or Petit Uniepoxy) let cuprous oxide leach through, leaving the paint resin behind. Excessive paint build up on the bottom can lead to chipping which ultimately causes drag. Flaking and/or peeling paint make the bottom less smooth which increases drag and diminishes the anti-fouling properties of the coating.

To solve this problem re-coat the bottom with a smooth and hard anti-fouling bottom paint. The largest molecule known is used for products like Teflon. Teflon has a drag coefficient smoother than ice. Anti-fouling products that use fluorourethane can add anti-adhesive qualities to hard, smooth urethane bottoms. An even better solution is a copper Teflon bottom which gives you the advantages of anti–adhesion plus copper which is a proven repellant of marine organisms.

If you are now convinced that a smooth bottom is a must to remain competitive, lets talk about preparation and coating a boat bottom. Almost no one can do a great job of painting anything with a single try and a single coat. Imperfections seem to surface in even the most conventional of applications. Plan on two coats if you desire a smooth, hard competitive finish. Most of the quality coatings can last multiple seasons but do you really want to chance losing because you save a few hours and the cost of some crew lunches by skipping bottom paint for a season?

Bottom painting is not a science. You start to smooth your bottom by sanding the surface. This will remove any lingering growths or organisms and result in leveling off the high spots which will reduce much or your drag. However, as you sand you will see spots that remain shiny. Those are low spots which also create drag. Fill these spots in by using an easy to shape soft epoxy glaze to smooth and level your bottom and then seal it with your bottom paint which produces a hard watertight seal. Performing these tasks every year, on your bottom, keel, rudder and other surfaces that slice through the water will result in a better, smoother, and faster surface. You can remove spidering cracks, gouges from flotsam, skiffs from bottom mud and sand as well. Those critical leading edges that take all the punishment and start the smooth laminate type flow over your hull should be the smoothest parts of your boat.

In conclusion, here are some tricks for a smooth bottom finish. Your first coat is the thickest and can fill small irregularities. Any drips or runs need to be sanded smooth again. The first coat alerts you to low spots. Use your glazing compound to fill those in. Plan on two applications just like the bottom paint. The first fills it in and the second application, the loving application, makes it fast. Now lets talk about the last coat which is the speed coat. The thinner it is the less surface variation it can create and the less drag. So using the smoothest roller or finest spray will produce the best speed for you. Thin your bottom paint as much as you can. Thin coats are smooth and smooth coats are desirable for speed. If not satisfied with the coat, sand off the high spots and coat again. You have already invested in the difficult part which is the cleaning and sanding process. If you re-coat as soon as the previous coat is no longer tacky, then no sanding is needed for good adhesion. If you are coating the next day, you may want to put some micro scratches for adhesion by sanding it quickly and gently.

With bottom painting at the top of your list this year, you will be fast and have less drag, resulting in reaching top speed with quicker acceleration and pointing better!

For more information, contact Harvey Chichester at info@boat-bottom-paint.com or phone 612-226-5200 (24/7).

Smooth Sailing, Inc.  |  102 North Street  |  Hudson WI 54016
Email:
info@boat-bottom-paint.com   |  www.boat-bottom-paint.com
Telephone: 612-226-5200