Take a standard keg
1. Drill centre hole in bottom weld on 28mm drain pipe
2. Weld sheet to the bottom skirt to create a chamber, the drain pipe will pass through this and be welded to it.
3. Weld up the drain holes around perimiter to enclose fully
4. Drill and Weld on 3 internally threadded bosses around skirt
One of thes will be a fill / drain hole and have a threadded plug
Two will be angled slightly to avoid drain pipe in centre and will accept elements.
5. Drill and Weld in a tube sealed at inner end to accept a thermocouple
6. Fit 2 elements from oil filled radiators and fill the chamber with the oil from said radiators.(1 or 1.5kw elements) 2/3kw total
The radiators can be obtained very cheap new and even cheaper used. This should make a boiler that is not prone to scorching.
Any thoughts and suggestions welcome
Aitch