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Two earlier forays into test-grinding the inside of the hull indicated that the job was going to be tougher than anticipated.  All along, I knew that grinding out the interior was not going to be particularly fun, but certain portions proved to be worse than I had thought.

I performed my first trial run on the inside of the hull several weeks prior.  Armed with my big 7" angle grinder and soft-pak sanding pad that I used on the bottom, I attacked the starboard quarter with some 40 grit Stikit discs.   These did an acceptable job removing most of the paint, grime, and rough edges left over from tabbing, spilled resin, and generally sloppy glasswork.  Soon, though I reached the remains of the aftermost bulkhead.  Earlier, I had sawn this out of the way as close as possible to the hull with a Sawz-all, but there remained 1-2" of the plywood bulkhead, plus 1/4"+ of fiberglass tabbing thickness on each side--all amazingly well adhered.  The soft-pak and 40 grit didn't begin to touch this, which didn't surprise me.  Undaunted, I pointed my computer browser to the McMaster-Carr website and ordered some heavy duty grinding discs for my 7" hard pad on the grinder, choosing a box of 36 grit and a box of amazing 16 grit.

When I next had a chance to try working on the boat again, I installed one of the 16 grit discs on the grinder, reached for my trusty full facepiece respirator and hearing protection, and climbed aboard.  Almost immediately, I was sadly disappointed.  The 16 grit and hard backing could barely make any headway against the bulkheads!  I had been sort of counting on this being the answer, and for a time I was a little stumped.

I decided to try a cutting disc on my small angle grinder.  I purchased several thin discs that looked like they'd cut easily through fiberglass, and installed one on the tool.  It did work quite well, and buzzed through the tabbing rather easily.  However, the discs wore out quickly, requiring frequent replacement.  But at least it worked.  By cutting through the tabbing in this way, I could remove the plywood and often some or all of the tabbing that had been secured to the plywood.  In most cases, the tabbing portion that was bonded to the hull was too well adhered to attempt to remove.  This meant that there was a 3/4" gap between two sections of tabbing that I would have to fill later if I wanted a smooth interior surface (I do).  The depth of the depression--shown in this photo as the dark strip in the center--is about 2/4" - 3/8" or so.  There was more of the blue adhesive gunk behind portions of the bulkhead, which I will chisel out before I do any further filling work here.

Once the plywood was removed, and most of the tabbing, the big grinder with 16 grit disc worked relatively well at smoothing things down, though the rough contours and relatively high speed of the grinder tended to rip and tear the discs prematurely if I wasn't careful.  After removing the bulk material in this manner, I switched back to the soft-pak pad and 40 grit, and performed a final smoothing. (It's kind of amusing when 40 grit seems like a smooth paper!)

The heat buildup on the pad was enough to cause the discs' adhesive to melt, and the discs would often begin to spin off, frequently causing rips in the sandpaper.  With care, though, this process worked pretty well, and removed the outer layers of paint, grime, and rough edges.  Working in this manner, I cleaned up the after third of the boat on both sides, creating mountains of dust in the process.  With this done, I cleaned up the mess and rinsed out the inside of the boat, since there was so much dust that it was difficult to see what had and what had not been sanded.

There's much more interior sanding, grinding, and prep work to come, but at least I made some progress in that general direction.  In preparation, I ordered 20 cutting discs for my small grinder, and 30 more 40 grit Stikit discs for the large grinder.  The softpak pad for the large grinder is pretty torn up, and I'll need to get a replacement for that as well.

With a new arsenal of cutoff discs (20) for my small grinder, it was time to get back to work.  I was a driven man as I attempted to complete the nastiest  portions of the grinding work before the boat was moved to the inside of the new boat barn, about six weeks hence.

The cutoff discs worked really well cutting through the tabbing.  Were the tabbing more typical (i.e. thinner), the discs would be the est.  As it was, however, with tabbing ranging between 1/2" to an astonishing 7/16" thick, the discs wear out extremely quickly; the edge gets worn away as the disc cuts, and soon the outer cutting edge is worn back to the metal backing disc on the grinder, which is needed to support the thin, fragile discs.

Ultimately, the combination of several cutoff discs' full service life and persuasion with hammer and chisel freed the worst of the plywood remnants from the settees and bulkheads.  The general process I used involved cutting through the tabbing with the cutoff disc, and then breaking free any tabbing I could with the hammer and chisel.  This also helped to release the plywood remains inside the tabbing after which, in most cases, the pieces could easily be freed.  This typically left a small ridge that could later be ground away.

The settees had been secured with heavy tabbing at the top edge, but also with sloppy tabbing beneath, which had obviously been installed once the plywood was in place by the workers reaching up beneath the settees, in the tight, angled, space, and applying the resin-soaked tabbing.  The pieces were uneven and messy, but fortunately, once the plywood was removed, they proved to be easy to pry off with a chisel by inserting the point into the gap at the upper side and hammering the chisel into the space.

In this manner, I prepared the second third of the boat (from the aftermost bulkhead up to the remaining full bulkhead just aft of the vee berth) for paint removal and grinding.  Because this section of the hull was largely visible from the interior of the boat (back when it had an interior), the hull was painted with a number of layers of thick paint.  Much of this was flaking off, but surprisingly, some of it was well adhered and proved to be somewhat resistant to removal.

I began the initial sanding with my 7" grinder, hard pad, and 16" grit discs.  This is an effective combination to remove bulk stock remaining from the old tabbing installations, and I also used it to scuff the painted areas, which removed all the loose and flaking paint as well as a good portion of the various paint layers.  I ground the starboard side as far forward as the main bulkhead, which is still installed nearly intact.

After much effort, I finally got the remains of the vee berth removed.  Talk about overbuilding--these simple plywood platforms (which I had cut back as far as the 1/4" thick fiberglass tabbing several months earlier) were solidly secured and showed no inclination for easy removal.  With the cutoff discs and my small grinder, I cut through the remaining tabbing and then, with great effort, managed to--slowly--pry the plywood and lower tabbing away from the hull, breaking the secondary bonds free with continued pressure from a 1" chisel and a flat bar that I alternatively hammered into the growing gap, working from the bow aft.  It's interesting in these Tritons.  The cockpit sole was so weakly constructed that it flexed underfoot, but the settees and vee berth were secured with enough fiberglass to sink a battleship.  

With that, virtually all of the wooden interior structure was gone.  All that remained was the forwardmost (chainlocker) bulkhead web, which I intended to leave in place, and the main bulkhead a bit farther aft, which I cut back just outside the fiberglass tabbing to open things up.  I left this in place to keep the hull stiff enough in that area for moving the boat one more time; it will eventually be removed entirely.

Next, I geared up for some serious grinding.  My goal was to grind the entire remaining areas of the hull (port salon, vee berth, chain locker) with the heavy-duty 16 grit paper to remove the worst of the remaining paint, rough fiberglass, and to begin the smoothing process.  Several discs, and hours, later, the job was complete, and I spend a goodly amount of time cleaning up the mountains of dust and paint chips from the hull before washing everything down with a hose to remove residual dust.  With each grinding, I moved closer to my ultimate goal of completing all the unbuilding and demolition work, and being prepared for new construction!

After many weeks (OK, months...) hiatus from actual progress on the Daysailor itself, I finally completed the removal of the final bits of remaining interior structure:  a small portion of the main bulkhead, blocking around the old head through hull location, and the port chainplate knee.

Using the same tools and techniques as during earlier portions of this unbuilding process, I cut away the tabbing and chiseled out the bulkheads, then ground the remaining tabbing edges down as flush as possible with my big grinder and 16 grit discs.  Then, I sanded the forward part of the hull and the newly-ground bulkhead areas with 40 grit discs mounted on a new 8" soft-pak pad for the grinder, removing the remaining paint and smoothing the rough interior surface of the hull.  This finally wrapped up the preparation of the interior of the hull for future building steps.

This process, as before, created large amounts of abrasive, shop-clogging dust.  However, the process was nearly a pleasure this time, as I was trying out a new shop accessory:  a supplied air respirator system.  The system consists of a small compressor, which supplies air to a full face mask through a length of air hose, and provides fresh, cool air to the user.  Despite the hose, the mask was comfortable to wear, and the air supply was clean and easy to breathe.

 Click here for a brief sidebar about the supplied air system details.

The wooden cross beam that I had installed just prior to cutting off the deck was getting in the way, and, with the boat now in her final project location, the beam was unnecessary.  In fact, I noticed that the beam was actually pulling the hull  slightly inwards in that location, creating a minor unfairness when the sighting the sheer down the length.  So I removed it, freeing up the bare hull for new construction.

The sole remaining original structural member (other than the stem and transom knees, which also remain in place) was the small chain locker bulkhead.  Earlier, I had decided to leave this in place, but to cut it back more closely to the hull.  I marked out 4" all the way around and removed the excess with a jigsaw.

This day brought to a close the unbuilding and preparation of the hull for the new construction.  Earlier, I had decided to create a loose goal of one year's anniversary from the delivery of the boat to my yard (which occurred on December 23, 2002), so it was doubly satisfying to complete the unbuilding and demolition work--and nice to be done with the messiest part of the project.