A few things to remember:
These were taught to me by my father and other teachers along the way (OK - the last one came from my son). The core thought is that: "With a project of this size, you will make mistakes, have problems, and have to redo things."
When taking on a project of this scope, it is the "Fear of Failure" that prevents many from starting or causes them to pause, all to often permanently.
What is needed, is the realization that things WILL go wrong, and that a logical thought process and perseverance WILL lead you to how to recover from the problems.
There was an excellent article, a number of years ago, in Fine Woodworking on how to recover from mistakes. I have used many of those tricks since.
You have heard the maxim measure twice, cut once. A corollary to it is when making a number of identical parts - make a couple of spares. Always rip a few extra battens, decking strips, or whatever. There is always the piece that will crack, or the cut that is slightly off or simply a miscount of what will be needed. Only rarely do these pieces end up in the scrap heap. The time saved by not having to re-set up the series of cuts or planing and cutting make recovery much easier. The spares also are used for test cuts and fitting trials.
Save your sanding powder (fine sawdust). It makes the basis of color matching epoxy fillers. I have small coffee cans filled with: ash, okoume, mahogany, and walnut. Gather the sawdust from your belt sander and off of the filter of the shop vac or dust collector. Simply clean the filter before changing wood types to get relatively uncontaminated sawdust. Most operations in building of the boat involve a large number of repetitive cuts and / or sanding of a particular wood type. This makes gathering color matched sawdust easy. I run the sawdust through a fine strainer prior to saving it to get rid of stray large particles. Conversely, simply taking floor sweepings and sifting them will not yield nice smooth wood flour, it will simply be too coarse.
Epoxy fillets and filler
One of the joys of using epoxy for the boat is that it fills gaps (joints should be good, but don't have to be perfect). Get in the habit of filleting all joints that will allow it. The filleted corner looks neat and is easier to sand and finish. Later, the smoothly filleted corners will look better and be much easier to clean. The sharp corners seem to attract dirt and mildew.
When gluing and filleting two dissimilar woods, it is usually better to make the fillet to match the lighter colored wood. To color match, mix the epoxy and use 1 part sawdust to 2 parts silica or micro-fibers as a starting point. Pure sawdust filler will be too dark compared to the epoxy coated wood. Remember, the wood darkens when coated and the fillet will not. System 3 micro-balloons also help in matching mahogany and other dark colors.
Late in the game, I started using universal tinting colors to assist in the match. Only tiny amounts are needed, e.g. 1 drop for a 1 pump batch, to match walnut using raw sienna. This gave a better overall match when the joint was sanded than walnut powder and silica.
In the process of fairing the frame, there may be low spots. Add a strip of plywood to the outside of the frame or batten. Plane this off to the correct dimension. It is much easier to shim up a little compared to removing a large area to bring it down to match the dip. Most of the fairing is the creation of flowing curves and side to side symmetry. The fillet will most likely cover the edge and make it invisible
Shift during clamping or alignment errors
The long initial cure time of the epoxy allows for repositioning. If it has partially set before the error is noticed, unclamp, chisel apart and clean off the epoxy goo with MEK, acetone, or alcohol.
If it has completely set up, saw apart along the glue line and re-glue. This happened on the transom, where I did not clean off some extra witness marks and assembled the pieces matching the wrong marks . It did demonstrate how strong the epoxy joint is. I did try, unsuccessfully, to break it apart first.
Notch in the wrong place or too deep
With >200 notches for battens to make, 99% accuracy will yield 2 errors. I was 99% accurate. Make the new notch, and glue in a filler piece, trying for the best color and grain match.
If a notch is too deep, shim with a small wedge. In many cases the depth can be set simply be adjusting with the fastening screw over the batten joint. Fillet the excess.
Not enough glue for a nice fillet
Fix it the next time you glue up. The filleting is done at the end of the glue up and at times there will not be any extra left. Simply fix the fillet gaps at the end of successive glue-ups. Only at the very end, should it be necessary to mix a special batch simply for filleting.
While stapling the first layer of planking on, if the underlying frame or batten is missed, and if a large amount of pressure is used (e.g. while pressing hard to get a joint edge to match up), the plywood will shatter or seemingly explode inwards. This happened twice. Once, the cracked area was able to be battered with epoxy and pushed back into place, and another time, the plank had to be replaced. This is just one of the times, that having spare pieces helps. When the piece exploded , I was covered in epoxy , the batch was hardening, etc. Not exactly the best time to clean up, set up the table saw, bevel the edges, ... - you get the idea.
Fiberglass edge lift
When trimming the edges it is easy to catch the fiberglass and cause a lift or separation. To prevent this:
When this does not succeed or you forget, the lift can be re-glued or removed. To re-glue force glue under the edge and wiggle it t "pump" it in. This works best if using freshly mixed coating hardener and resin above 80 degrees. It will wet out nicely. If the bubble is too large, or it is too cold, simply cut out the area with a razor knife. Make an angled cut outside of the lifted area with the handle pointed out from the center of the bubble. This will help avoid making the lift bigger. cut shallowly to avoid scratching the wood. If it is scratched, the repair edge will be visible. Re coat the area several times to build up thickness. It is not necessary or advisable to add fiberglass to such a small area.
Clean up and fastener removal
Get in the habit of cleaning up drips immediately and following up 6-10 hours later for a second clean-up pass. It is much easier to plane or chisel off the drips and blobs while the epoxy is still partially cured. At the same time, remove your temporary fasteners. Most of my glue ups are done at night and I then get up in the morning and do clean up before going to work. On the weekends, I make a pass at night before going to bed. This also give a chance to sit back and admire your work and start or end the day on a happy note.
Clean off the tools immediately with solvent, including disassembling the planes.
Next: Changes to Make
©2000- 2007 Mark Bronkalla