January 2006

Tour of the Whitechapel Bell Foundry

We are awaiting the climate to improve before progressing on the onsite refurbishment of the foundry. In the intervening time we visited the Whitechapel Bell foundry who have been going since at least 1570 (possibly as early as 1420), 8 years prior to the recreation date of 1578 set for 2006. This visit has lead to some interesting new knowledge about loam making and mould pouring techniques.

List of master founders at the Whitechapel bell foundry At the foundry is a list of all the founders associated with the Whitechapel dating back to 1420. As Kentwell is to be set in 1579 and My name is Robert I'll be 'borrowing' Robert Mot's name for the duration. A fair selection of his work is still being rung today and he did also make other items including mortars that I've been able to trace.
Drawing of Bell mould In the showroom / museum they have a nice, sectional drawing showing the method of bell making for larger bells. Due to the quantity of bronze required for this I wouldn't expect to be going this far although we may consider making the mould for a laugh. To warrant this method of production the finial bell would normally weigh in at in excess of 10Kg. That may not sound much but playing with 10Kg of bronze at 1200'c is rather dangerous. Final cast church bell
Recipe for the mixing of loam Of interest is their recipe for loam, the clay type substance used to make moulds. It involves using 6 buckets of old loam which raises the question, how do you get old loam to start with! This is a chicken and egg type problem as most foundry's have had their loam around so long nobody knows how it got started.
Master bells on a shelf
Here we see a collection of the hand bells they make. Well... sort of. try playing a tune on these ones and you'd be able to play as well as I can, take my word for it, it would sound terrible. Every one of these bells you see here is out of tune. They are the masters.
When a bell is cast from a master the resulting bell is a little smaller due to shrinkage. It then needs to be cleaned up on a lathe which makes it smaller still. These reductions in size change the note so the masters are made bigger so the final item is in tune despite the masters being off tune.

Work bay This is where the real work starts and something like the foundry at Kentwell should be. This is a selection of lesser used masters, tools for making the bells and stacks of molding boxes. We will be using wooden boxes as metal ones weren't in use at the time. Sand casting was in it's infancy during the Tudor period so metal cope's and drag's are not known of The design and operation is the same with wooden ones however construction is easier. The only real difference is how long the boxes last. Wooden ones often get burnt by accident and / or fall apart through use.
Cope filled with sand in a bell mould Open but completed sand mould for a bell Drag filled with sand in a bell mould
Cope Cope and Drag Drag

This is a sand mould made for a handbell just before being closed and how we will be doing the majority of our casting at Kentwell. The cope on the left fits over the drag on the right leaving a void into which the bronze is poured resulting in a bell shape in bronze.
Directly out of the mould the bell would be out of tune and look a little rough, not what is wanted when playing in the Albert hall. So....

16 17

...the bell is put onto a lathe for cleaning up and final tuning.


Kentwell foundry rebuild continuation

Nozzle former for the bellows to furnace connection Back to repairing the Kentwell foundry and some stuff we can prepare in the comfort of our own Garage. I use the word comfort purely as a relative term you understand.

The air from the bellows needs to get to the fire pit and the original 'ducts' were showing serious signs of their age. The end of these ducts is at the hottest part of the furnace and take a battering from the crucible, charcoal, and general poking in the fire.

To remake the ducts I turned up a piece of wood to a taper. The thin end will be the furnace end and the wider end goes via a sliding metal sleeve, onto the bellows.

initial making of the nozzles This is then covered in fire clay. A mix of clay, burnt clay and sand. This mix makes it very resistant to heat which it defiantly needs to be.

This is air dried for a day or so then baked in an oven at 100'c for a few hours. The process is repeated 3 times in our case and is finally put in a fire for a while to finish off the drying / baking process.
The baking would normally be done over an open fire but the oven was there and the wife thought I was being nice doing some cooking (She wasn't please when she found out it wasn't dinner though).

Completed nozzles This is about all we can do directly for the foundry at Kentwell without going there. In the mean time preparations are underway to do more bell casting and loam practicing ready for the main event. Plans are also afoot for another visit to Long Melford to finish off putting it all back together again.