skin of the can out flat on your bench. Place the Altoids lid rim-down on this aluminum sheet. Scribe around the lid onto the sheet (Figure L), then cut along the lines with tinsnips to create a leaf of aluminum. Gradually trim down the edges of the leaf until you can just tuck it into the lid of the tin without it wrinkling. Once you’ve fitted the leaf, pop it out again, taking care not to crease or tear it. Cut or file away any “needles” or other sharp features on the leaf. K
6. SEAL THE BOILER.
Lay out dollops of J-B Weld epoxy and hardener on a disposable surface.
Sand both sides of the aluminum leaf about
6" in from the edges, all the way around, to
take off paint and the oxide layer that clings
to the aluminum (Figure M). Quickly, before
oxides can re-form, mix the J-B Weld together
with a stick and apply it to the inside of the
lid. Lay the aluminum sheet inside the lid.
Smear the J-B Weld over the flat flanges
you folded into the tin bottom, paying special
attention to the gaps in the corners (Figure N).
Press the bottom and the lid together, sandwiching the aluminum between them. Apply
J-B Weld all the way around the gap between
the lid and bottom, and smear some into the
hinge holes in the side of the lid.
If the aluminum leaf looks sunken or
gapped around the edges, blow into the
copper tubes to push it up — if you have to
do this, you’ll push out some of the wet J-B
Weld, so look for fresh air gaps. Using a clean,
disposable rag, wipe any excess J-B Weld off
the surface of the aluminum (Figure O). Allow
the J-B Weld to cure overnight.
and up. If it’s too tight, loosen it a little by
pressing firmly on its center with your thumb.
7. PRESSURE-TEST THE BOILER.
Immerse the boiler (Figure P), put both tubes
into your mouth, and blow. If you see bubbles,
you have a leak. Patch it with more J-B Weld.
When the J-B Weld is dry, test the diaphragm
again: put both tubes in your mouth and suck
and blow — the diaphragm should pop down
8. FIT THE MOTOR
TO YOUR BOAT.
For a boat, you can use anything small and
light that floats and doesn’t catch fire. For
simplicity I used a 16oz ham can (Figure Q),
but you can make as awesome a boat as you
like. You can also fit a rudder to the stern.
Measure the outside distance between the
2 tubes where they bend, subtract 1", and
drill 2 holes to this measurement in the bottom of the boat, equidistant from the center.
Your punch will help get these holes started.
Depending on the shape of your boat, fitting
74 Make: makezine.com/28