Holes Drilled

Late last week I drilled 6 holes to accommodate the new solar panels, which for me was a very big deal that had been worrying me for a while.

Hole template on rickety platform

Each side of the cockpit frame has three straps running athwhartships upon which a solar panel rests.  Each strap has a hole at each end through which a bolt passes through to the panel frame, giving a total of 6 bolts per panel.

The new panels are narrower and slightly longer than the old ones, meaning that the distance between the holes on each strap would have to be reduced slightly.  The task that I dreaded was drilling through the thick and very hard stainless steel material which for me has as always been a challenge at the best of times, and more difficult now because I would be working aloft.

To minimize the drilling I decided to use three of the existing holes for each panel, thus there was the choice was between fixing the panels near the center line of the boat or spreading them out and leaving a bigger gap at the center.  I decided that the result would look better with the panels spread out.  That meant that I would use the existing holes on the outboard edges of the straps and drill new holes on the inboard side.

New holes on right side (inboard) side of straps

New hole at left

The first problem was to find a fast and fool proof method of marking the distance between the new holes.  In the garage I found an aluminium strip of suitable size and at the boat cut it to span the panels.  I then drilled a hole at one end of the strip, fitted it to the panel using a bolt, then with a pencil carefully traced out the other hole on the aluminium strip.  Drilling aluminium is easy and I was able to drill the hole to within 2 mm of the required span.   I now had a template and used the same procedure to trace out the hole locations on the cockpit frame.

Then Stephen and I visited a tool shop where I got good advice on the drilling technique (very slow speed, no lubrication) and the best drill brand.  I suggested a second, smaller bit for a pilot hole and the salesman agreed.  I would need to center punch the material to avoid my drill bit dancing around so I also purchased a new punch.

On the day when I had everything ready Stephen arrived at the boat with a heavy wooden block.  His job was to use the block as backing while I center punched.  This was necessary to avoid bending the straps or, worse, breaking the welds that held them to the frame.  In order to raise myself to working level I set up a rickety system using the boat's boarding ladder with a small foldout ladder on top.

Once the hole centers were puched and I had partially drilled the first hole to make sure that the punches were deep enough I thanked Stephen for his help and proceeded to work on my own.

After 3 hours of patient work spread over two days I managed to drill the holes without breaking either of the bits.

Fitting the panels should be easy.  Each panel has 3 pre-drilled holes on each side.   I'll bolt one of the center holes of the panel to the center inboard hole on the cockpit frame and when the panel is orientated correctly I'll drill the other 5 holes on the panel through the holes on the stainless steel strapping.

There is no substitute for good planning.