Finishing the trampoline frame edges

For the rounded edge on the inside of the trampoline frames, we had to come up with a new method of creating the profile. Although Tom could rout a round-over edge on the topside, he did not have the appropriate tools to mirror this on the underside, since the frames were already attached to the boat.

So, using a hemispherical bit in the laminate trimmer, he removed a concave section of balsa from the edges. This was to accommodate a length of PVC hose (OD 16mm) which would form the new profile.

While Tom was doing this, I threaded some second-hand 10mm rope (left over from our tarp shed days) through the two hose pieces. This would help retain the curved shape in the corners, and provide additional overall strength and rigidity.

Trial fitting below…

Trimming to size…

Piping the glue…

Don’t know what we’d do without these clamps.

Before wrapping the edges in 200mm wide 400gsm double bias tape, Tom straddled 100mm strips of 400gsm double bias tape over the glass trenches we created earlier – “so it’s as strong as the rest”. Regular readers and friends of Bob Oram would be aware that Tom is building a “Swiss watch”. More likely The Deacon’s Masterpiece I think…

Have you heard of the wonderful one-hoss shay,
That was built in such a logical way
It ran a hundred years to a day,
And then, of a sudden, it —
…
went to pieces all at once, —
All at once, and nothing first, —
Just as bubbles do when they burst.