Tuesday 26 July 2011

This week's work

The horse and shoe

On Monday this week Ray and Richard made more progress on the grain feed, completing the woodwork of the hopper, including the slide shutter, and the shoe. Richard and Bob then made some steel brackets to support the hopper from a hoist while its best position was determined. Once we had sprayed these and fitted them, we offered the hopper up to the horse and left it in what we judge to be the best position.

Richard fits brackets to the hopper

We also discussed whether all the wooden parts that contact flour actually need to be coated with shellac as advised by the SPAB booklet, or whether there is some modern alternative. This needs further investigation.

Bob guides the hopper into position

Tuesday 19 July 2011

Weekly restoration work

Today Ray made further progress with the stone furniture. The horse is complete and the grain hopper is being constructed.

There is a snag here - the chamfer angle for the ends of the boards for an inverted pyramid is difficult to estimate. By trial and error we arrived at an angle of 36.5 degrees (the outer angle of the hopper being 60 degrees). I did manage to find a mathematical solution on the web (http://www.slyman.org ... PyramidAngleCalculator) which gives an answer of 35.3 degrees, but I guess we will go with what works.

Meanwhile, Bob and Richard were looking at the tentering for no 2 stones. This depends on a bracket fixed with a long bolt through the hurst frame, which is rather insubstantial at this point, due to woodworm and mortises from former use of the timbers. At present the tentering beam is supported by a car scissor jack. The bracket leans forward at a few degrees, but seems otherwise quite sound at the moment.
We decided to make a tapered washer out of 2 old iron wedges to compensate for the lean in the bracket, and keep an eye on the set-up for any deterioration.

Wednesday 6 July 2011

Visit to Lode Mill, Anglesey Abbey

Today we visited Lode Mill, part of the National Trust's Anglesey Abbey estate. This is another big, multi-storey mill, again mainly built of wood but with a large, iron 4 o'clock breastshot wheel.

The mill wheel

The stone floor

Once again we found the person in charge, in this case Chris Stimson, was generous with his time and knowledge and showed us round the mill and millwheel, including parts not normally open to the public.

He agreed with the thought that it was illogical to mill flour NOT for consumption. We would, however, have to sort out the lifting of delivered grain to the upper floor.

There was a suggestion that if you mill on four days or fewer in any five week period, there may be exemptions from some of the food hygiene regulations - but this may conflict with tea room use, of course.

Lode Mill also offers a hand quern and the opportunity to handle grain and flour - in general both mills had excellent educational facilities and interpretation.

Un-greased wooden cogs
Chris stated that you should NOT grease wooden cogs, as they pick up dust and debris to form an abrasive mixture that wears the wood too rapidly. maybe a better option for us would be to smooth the surface of the stone nuts.

Lining of grain boxes can be achieved with sheet aluminium as a Houghton, or metal gauze as at Lode. Other containers are mainly plastic Really Useful Boxes, one with a hole cut for the flour chute - on a table, not at floor level.

There are some issues around cleaning up after every milling, stone speed and tentering all of which we need to resolve - the input of a miller was stated to be essential, so Nic Jones' input needs to be obtained.

Tuesday 5 July 2011

Visit to Houghton Mill near Huntingdon

Today we (Bob and Glenis) visited the National Trust's watermill at Houghton. We were made extremely welcome by Phil O'Donohue and Steve (sorry, can't remember his surname), who spent two full hours showing us round and discussing some of the issues around milling.

Houghton Mill is a rather bigger affair than Acorn Bank, being on 5 floors and powered by a "4 o'clock breastshot" wheel about 15 feet in diameter and 16 feet wide. They produce flour in one operating session each Sunday afternoon, which is sold at the mill and makes a valuable addition to the economics of the property.

The main lesson was that if we are milling flour, we ought to sell it, otherwise the public will (rightly) ask why we are bothering. They suggested that we should get the local authority food hygiene people involved as soon as possible. Their flour is also used in their tearoom scones, and it was suggested we should consider doing the same.

They also have a hand and a rotary quern to show the concept of milling - I think we should have at least one of these.

The design of our tun needs some extra consideration, as the uprights will form pockets in which flour can become trapped. This photo shows the Houghton solution of fixing internal boards across the angles.

They always un-tenter the stones after each milling session, as the flour can pack down into a dense, cement-like substance if left under pressure.