Kono V (and possibly VI)

The kono grill is just about finished - I've left it for ages to cure, drilled a couple of vent holes in the side and given it a griddle (old oven shelf).

I still have to fathom out how to incorporate handles (although I may simply not bother) and want to put some kind of sealant or glaze on the cement wash on the exterior.

I'll leave flashing it up with some charcoal and curing the fire cement on the interior till the weather improves, leaving it inside in the meantime, just to ensure every bit of moisture has evaporated, The last thing I want is for it to crack on first use through there being any remaining water within the matrix.

OK, it looks like something my Neanderthal ancestors may have cobbled together from river mud, but it was a learning experience.

Looking closer at the really nice, Japanese ones on eBay, they appear to be made from relatively thin firebrick blocks, like the ones below, cemented together and held in place by a skeleton cage. 

If this one doesn't succeed then I'll have a go at constructing one on that basis. Given its Lego brick construction (see the image below), there would be far less risk of it cracking and the perfect rectangles of the firebricks would also lend themselves better to an aluminium retaining cage. Weight would be far less too. I'd probably require a larger one for the base, as it would need to be a single slab.

4 x vermiculite firebricks measuring 4.5" x 9" x 1", can be bought for under £7 on eBay, which seems a bargain. To make something the same size as the perlcrete one I'd need 12 for the sides, plus a large 18" x 9" slab for the base. Total cost, around £48.90, which would work out cheaper than the one I made (although I had bought enough cement and perlite for Trump's Mexican wall).

To avoid the thing falling apart, I'd need to stagger the joins in the same manner as brickwork, requiring some slicing of the smaller blocks. With a cage that holds to entire structure together, it's doubtful whether they'd actually need cement bonding. I'd make the retaining cage of the aluminium angle I bought for the one I made, but couldn't use due to the rounded corners. 

Yes - the more I contemplate this, the more I think it has to be done. Rather than buying the exact number of firebricks, it might be wise to buy 25% more than I need to cater for breakages in construction.

Stop Press: blocks ordered - £54.90 with 4 extra side blocks. I already have the aluminium angle and brazing rods. Watch this space...