Sandstone Heritage Trust - News

HTN 214 - Things are hotting up now with progress on the water wheel - Andy Selfe Reports!

5th June 2007

Hello All,

When I was last at the mill assembling the new planks onto the inside of the wheel, I was prevented from fitting the 7th and 8th plank by a problem in the depth of the groove for the galvanised steel strip in the underside of the 7th plank. So that plank went back to Somerset Timbers, who are supplying the timber, for re-machining. I also suggested that the groove be cut a bit wider, to allow for a bit of misalignment. A wider groove would also allow me to apply the Hydrax carbolineum-based paint more easily into the groove, for further water resistance.

These two planks were waiting for me at the mill when I arrived at the mill on 2nd June 2007. Having learned last time what a messy job it was to apply the Hydrax and then to fit the planks, I brought some latex gloves this time! The planks have a coat of Hydrax, an inexpensive product, applied to the grooves and joint-faces, as well as areas where the plank will be in contact with the metal shrouds of the water wheel rim. In other words, where the surfaces will be inaccessible after assembly. I also apply it to the bores of the bolt holes. I plan next time to use a rifle bore brush for this.

Plank no 7 went on with its new steel strip but there was still a need to ream out the holes on one end for the bolts to line up. Why these holes were misaligned, I'm not sure, but when it came to plank No 8, all four holes lined up, so the problem isn't compounding itself. I then completed painting those two planks and for good measure, gave the rest another coat. I also checked that a spider which had taken up residence at the join of the shrouds last time had moved off, so I painted that join also.

I knew I was going to have a problem holding the planks in position to mark the bolt holes, so this time, I brought some straps along. With these, I held two planks at a time in place, working on the inside, then crawled around to the outside and used an aerosol spray can to mark the holes:
The grain sack was used to keep the wet Hydrax off the new planks, because the next stage is that the planks come off and have their grooves cut for the hoop iron one can see protruding between the planks, and then they get their all-weather tanalith treatment. I'm sure the sawmillers don't want the planks covered with tar in the treatment tank! This treatment will reach into the newly cut grooves as well as the holes drilled for the bolts. We are taking no chances!

I couldn't assemble any more upwards as I haven't stripped further. I want to keep the shape and alignment of the wheel by only stripping, cleaning and painting, with the same Hydrax, a section of three buckets or six planks at a time. So I had to turn my attention to below the previously assembled part.

Every sixth plank is wider than the rest, 175mm instead of 145. I didn't realise that the wide planks which Keith had sent were not finished to this width. Luckily I had that morning treated myself to a new woodsaw, so whilst it wasn't a rip saw, it wasn't too difficult to cut the 40mm thick plank to the required width.

Quite a lot of acrobatics were required getting from one side of the wheel to the other for strapping (inside) and marking (outside) and taking off (inside). Then drilling, then climbing in and refitting the planks, driving the bolts through (inside) and doing the nuts up (outside). Then the next two planks.....
Then there was another wide plank to cut lengthwise, one can see the difference in the colour. The next step was more acrobatics to remove all the nuts on the outside and to remove all the new planks, to send them back to Keith Wetmore at Somerset Timbers for the grooves to be cut and for the 'full-works' treatment.

So on leaving, it looked as though the sum total of a day's work was only two more planks fitted! Not so!

I did have two groups of visitors during the day to show what's going on, but no milling was planned nor done.

In the meantime, we've been discussing the buckets themselves. We had hoped that we could re-use some of them. It doesn't look as though this will be the case. While some look fairly intact, once they are removed, they fall apart where they have been attached to the 'starts' on the shrouds. I had one sheet of 2mm Hot Rolled sheet cut and had 50mm of the edge, which will be against the wood, bent down at 90 degrees. Last week, I took this sheet, along with a sample of an old bucket to Conrad Hicks, Blacksmith, at his works at the old Bijou Theatre in Observatory, Cape Town.
He has a plan to form the parabolic shape one can see is required from the top picture, hot, on one of his electro-pneumatic hammers. This will mean we'll have to have all 48 plates cut and bent, all ready on a day and do the lot! Once shaped, we will mark and drill them, and then send them for hot-dip galvanising. Before fitting, they will also get a coat of.... Hydrax!

If we apply a fresh coat of this to the wheel on a regular basis, we should have a water wheel for a long time into the future!

Otherwise, the autumn colours are coming through strongly:
The buttress on the water wheel corner of the mill is on the left, the photo is taken from where the Lister engine stands.



Below: Looking through the door!