Lower & Longer - Repeated (Iron Smelt #92)

October 29, 2022

The usual Samhain iron smelt was a repeat of the June experiment, again using lower air volumes inside a standard 'Norse Short Shaft' bloomery iron furnace. This all in an attempt to investigate the effects of the levels of air delivery possible from our proposed Viking Age smelting sized bellows. 

In the past, a number of experiments have used variations on the type of twin chamber bellows known from (admittedly limited) historic illustrations. One feature of this type is that it will deliver a pulsing air blast, with variations in both volume and delivered pressure over individual strokes occurring roughly one per second (and between operators). 

For this smelt, air was delivered via the standard electric blower, at a volume determined by measurements made during # 90 (October 2021) - approximately 500 litres per minute. The same furnace as was used in June, with some minor repairs, used the same ore type (DD1), following the same sequence of additions. 

Furnace set up for #92 - at start of wood splint pre-heat

 

The reason it was decided to repeat the June experiment was that the results of that test were not was expected, with yield at 28 %

The full report : Lower & Longer - Repeated (Iron Smelt #92)