Wednesday, April 1, 2009
Doryman is what I call myself.
Others call me The Sandman. (Wait! Is that a reference to my story telling ability??)
Don't get me wrong, sanding is not my favorite activity. Not even close.
Face it, now or later - for a good looking wood boat you have to sand. And sand, and sand, and sand. Then paint and sand some more.
I don't have a sophisticated shop. In fact, my shop is mostly mobile and much of my work is done by hand and eye, with a minimum of clamps and jigs. Thus I tend to use hand tools rather than bench tools. And the application of those tools is much like hand carving of any kind. The shape and texture of the object comes clear in the process of shaping it. If you don't like on-the-spot innovation, this is not the method for you!
Free form sanding and shaping requires immense concentration, since the slightest distraction can destroy the work.
The most effective all around tool I've found for a decent finish is a powerful, variable speed random orbital sander with a five inch self adhesive disk mounted on a foam pad. Using abrasive grits from 40-220 I can get a good, weather resistant finish that's attractive and will be a solid foundation for subsequent recoats.
It's time for me to confess. The mirror finish is for others. I'll go for what I call a 90%. Pretty nice, and worth a compliment or two. I'd rather see a slight imperfection than put a lot of putty in a boat. The patches and fillers will someday fall out, and the deception is laid bare. As with all tools, experience is the key. With judicious application of a quality sander and good quality paint, the true beauty of the hand made craft is realized.
A word of caution. The disk sander, random or not, is a potentially dangerous tool. It can take a flier, taking a piece of your hand or your work, or both. A lot of damage has been done to beautiful old boats by careless use of these tools, not to mention the blood loss.
Next is my small grinder with a four inch sanding disk replacing the grinding stone. This is a dangerous tool. With a course grit paper, it can be used to shape wood, much as you would use a block plane. Extreme care must be taken to avoid destroying your work in one quick motion, since any unexpected slight of hand will take away wood, never to be replaced. With caution and several years of concentrated study, I've been able to develop some nice shapes in a free form manner with this tool. It will leave scars and scratches, so enough wood must be left to plane or sand vigorously for a clean finish. And keep your fingers out of the way!
Compressed air sanders are better, all around, than the electric ones shown here. An air driven reciprocal sander is much lighter and more powerful than the one I use, but I've never made the transition to air driven tools.
Indispensable, but not my favorite since it makes me ache all over, is the hand sanding pad. Get used to it. If you want a finish to be admired, you must sand by hand. A lot. I use self adhesive paper on mine and it can be used for everything from shaping to fine sanding. The discarded paper is used later for sanding, with the fingers, into small corners.
The last refuge.
Also pictured is a belt sander. BEWARE! The belt sander is not a boat sanding tool! I used this one on the flat bottom of Huckleberry, to fair out a fiberglass mat finish, which may be the only application of a flat sander in all of boat building. You can sand a hull with a belt sander, but you will have to come back and fair it. If it's all you have, you could use a belt sander (requiring considerable skill and talent) to remove thick paint, but only on a hull made of thick planks! (I'll probably regret saying that...)
I also used the belt sander to shape a couple pair of oars yesterday.
In the background is a sanding block made from a 16 inch 2x4. I've used three sticky back sandpaper disks edge to edge to make a small fairing board. This is another shaping tool. By spreading the sanding edge over more surface area, trim pieces such as the sheer guard can be shaped with long, straight, smooth edges.
I haven't shown respirators or dust masks or ear protection, but I use them. And don't forget protective clothing and dust collectors. Most industrial boat sanding is toxic to all life forms.
It's been Sanding Week here in Doryland.