A Start

Today there was some physical progress on the pool solar water heater.  I’ve been hiding from the sun inside the workshop cutting holes in the top and bottom of the aluminium cans which will form my solar heat collectors.

It has been a trial and error process as I attempted to identify a method that didn’t damage the cans.  Initially I used a can opener to remove the top.

I quickly realised this wasn’t a good idea as the can had lost much of its structural strength and was easily damaged.  I needed to retain both the top and bottom ring of the can.  This also made me realise I should only grip the can by the top or bottom ring.

My successful method was to first remove the tear tab by flexing it backwards and forwards until it broke away from the top of the can.

This ensured I had a flat top surface.  The can was then turned upside down and a pilot hole drilled in the centre of the base.

It doesn’t really matter if the hole isn’t dead centre as the final hole will be much larger than the copper pipe that will pass through the can. The next step was to use a large (25mm) spade bit in the drill to cut a larger hole.

Grip around the top of the base with one hand and drill the hole with the other.  This is probably the easiest part of the process provided you apply minimal downwards pressure.

Next cut a rough hole in the top using a pair of tin snips.

Remember to wear gloves when doing all of this

The walls of the cans are very thin.  However if they get dented it’s possible to remove the dent either by lightly squeezing either side of the dent with your finer and thumb or by using your index finger from the inside after you have cut the hole in the top.

I’ve probably processed enough cans for three rows.  Only 15 rows to go…… I’d better start seriously drinking!