Fed up with being cold and damp at the start and end of each sailing season and with a fair bit of winter work to do on the swing mooring, I decided to finish and fit the charcoal heater I’d originally been making for Macavity to Idris. A piece of heavy section steel box left over from a job putting security gates on a clients driveway gave me the idea originally. “Oh…” I thought as I was about to throw the left over end of industrial strength gatepost into a skip, “…that looks like it would be just about the ideal size to make a compact, upright pipe stove for my old boat.” and so it was.

 

Square box section heater. Free materials, just required a bit of thought and a welder.

Square box section heater. Free materials, just required a bit of thought and a welder.

You can see from the photo above that it’s a very simple thing indeed. I essentially divided the length of box into five segments. The fire grate is merely four steel bars tack welded into some holes drilled across the width of the box at one fifth of the overall height up from the bottom. The bottom fifth thus becomes the ash pan with a hinged plate on the bottom.. Above this I’ve left just over a fifth more height as solid firebox. I then cut out a square panel from the front the height of another fifth using thin discs in a 4 inch angle grinder. I made it as tidy as I could because it then had to be used as the fire door on a top hinge. (I tacked on a rough frame using some scrap pieces of flat steel to cover the air gaps.) The top two fifths of the tube are left as smoke hood/ heat transfer space before the top was capped off using another piece of heavy scrap plate with a pipe collar welded to it as a chimney connector. I had a pair of steel pipe brackets out of a skip kicking about which when welded to the sides of the box provided a good strong bulkhead mount with minimal heat transfer.

Test run outside the workshop proved a success but more chimney height was required to get adequate draw.

Test run outside the workshop proved a success but more chimney height was needed to get adequate draw.

 

A two section chimney would be required then. One section to go through the deck with another piece to be fitted when in use.

A two section chimney would be required then. One section to go through the deck with another piece to be fitted above deck when in use.

I have to say, this thing has worked far better than I thought possible. Having originally tried it with small sticks and boiler coal, I’ve now got a good stash of commercial lumpwood charcoal to use which is far superior. The coal wouldn’t really burn hot enough and didn’t get the required up draught going to keep itself alight. The charcoal burns very clean and hot and produces virtually no ash. I fitted it in the old heads cubicle on Idris on a weekend where I was planning to sleep on board. It was a typical miserable, cold, wet Winter weekend but with the little stove going it was beautifully cosy in the cabin. I had a real job motivating myself to do anything other than sit on the sofa berth drinking tea and reading whilst the wind rattled pellets of January rain across the windows.

Before anyone asks, yes I did simultaneously install a good battery operated carbon monoxide alarm just in case. I’ve no concerns though as with the extra three feet of chimney above the deck, it draws better than Picasso.

Quietly doing its thing, heating and drying my little living space on a mere handful of charcoal...smells great too.

Quietly doing its thing, heating and drying my little living space on a mere handful of charcoal…smells great too.

The chimney itself is made of two different materials. Inside the cabin I used a section of flexible car exhaust pipe (bought from a local motor factors) which proved to be a very good fit around the stainless milking palour tubing I’d used for the top section. The deck already had a large hole cut through it for one of the three brittle, leaky old vents that had been fitted previously, so I removed the offender and fitted my home made stainless pump cover cowel in its place.

Section of an old stainless steel milk pump provides a good through deck chimney mount.

Section of an old stainless steel industrial milk pump provides a good through deck chimney mount. Extra 3 foot of tube fits onto the stub when in use.