Using silicone and ash to increase insulation?

[alanb1976]

Perhaps you are right. Maybe I'm trying to achieve too much for the design of the BBQ (at least too much without spending a fair bit of money).

[essexsmoker]

There comes a time when actually you don't save money and still end up with a substandard unit.

I'd call it a day, sell it for whatever you can get and start again with the right tools.

A UDS is a great start if money is tight.