Kono VII - The Finale (well, almost)

 Not having much to do yesterday, I made a start on the firebrick Kono.

I first applied the fire rope glue to the surfaces to be joined and then stapled across the joins. .

It appeared to hold together reasonably well. I then started cutting the 2" aluminium angle to create the base of the cage.

The problem was that I didn't have a mitre saw and was using my electric sabre saw, which is meant more for cutting oil drums up. Angles were very squonk and didn't meet at all well. Note to self - look out for a mitre saw at Lidl.

The brazing was a total failure, as the brazing rods were far too thin to adequately fill in the gaps. 

I decided instead to drill holes into the firebrick panel ends and use screws to hold the joints together. It worked.

Flushed with success, I then screwed the handles into the firebrick end boards and was quite pleased with the result - till I picked it up - the handles promptly fell off. Luckily there was no damage to the box as it dropped (I told Hay it was a drop test) but, whereas screws are OK for holding the box together, the material is just too fragile to screw the handles into it, especially just a single, 1" thickness.

I was struck with a bolt of an idea for the retaining cage - pop rivets. I have thousands - and a pop rivet gun. I even have a pneumatic one, if required, for heavy duty stuff. Don't know why I didn't think of it earlier.

Given I wasn't using mitre joints, there was going to be a bit of a gap here and there with overlaps, but it worked to my advantage in terms of inserting the pop rivets. Even managed to pop rivet the handles on to the aluminium angle around the top of the ends and the slight air gap between the cage and firebrick means the handles should remain relatively cool.

Eventually ran out of the 2" angle (because of the faffing with the mitre joints, although I did manage to recycle most of it) and used the 1/2" stuff, of which there was plenty, for the last two struts of the cage along the two long surfaces on top.

Dodging the screws with the pop rivets was a bit of a pain and I only hit one, but managed to recover the situation.

For added heat protection I decided to add a double thickness of fire brick over the bottom and at the ends. It required a thin sliver of firebrick to completely fill the 2nd layer on the bottom and I then applied some fire cement to the join..

All that's now required to complete the project is the air damper, which has yet to arrive from 'Merica.

I'm rather proud of it. Just need to put it through its paces now, tot up the cost and then start taking orders...