Gas exit port cap preparation

Take one of the 3 pipe caps and drill a 3/8 hole in the center of the cap. The hole is the hydrogen gas exit port, and the cap will be the top of the electrolyzer. Center a 1 /16 pipe coupler inside the cap (see bottom photo at right), and use a fine tip marking pen to outline the coupler s outer circumference inside the PVC cap. This circle is a gluing guide for attaching the coupler to the cap. 

In the same cap, drill another /4 hole between the inner wall of the pipe cap and the circle outline you drew in pencil. This hole is the oxygen gas exit port. 

Be careful drilling holes for exit barbs in these thin walled pipe caps. If you drill them a tad too large or at a slight angle, the barb will be floppy when seated on the cap. The fit should be as tight as possible. 

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