Thursday, September 4, 2008

32, Production starts.

It was to going to take me a month or so before I went into full production, there was a fair bit of fine tuning to be done and minor modifications to be made. Screens to contain the water spray also needed to be provided. A pair of old industrial PVC door flaps were perfect for the 2 sides and for the back section I fashioned an annex from doubled, woven poly plastic sheeting.
The saw was exceeding all my expectations and was cutting beautifully. By mid June I had started to accumulate a stockpile of stone blocks, ready for use. The courses, although random, are spaced in increments of 25mm so the blocks are cut the same, less 10mm for mortar. I store the blocks according to height, with the smallest, (90mm), to the left increasing to the largest, (290mm), to the right. Smaller 40 and 65mm pieces are kept in slab form separately to be cut to size as required.
The first stage of construction that I wanted to resume work on was the bay windows, for these I needed a number of large quoin blocks with a chisel dressed margin, 32mm x 32mm at 45degrees. The saw has the capacity to tilt to this angle in both directions but I opted for a simpler method, this would dispense with the need to reposition either the stone or saw or both.

I aligned a number of blocks along the length of the trolley and set the blade to a height of 267mm from its surface. The wall thickness around the bays is 265mm, this gave me an allowance of 2mm for the hand chiselling. A series of cuts was then made, moving the blade across about 5mm for each pass, until I had a flat 32mm horizontal surface. This face complete, I then made further multiple passes, each time moving the blade about 3mm horizontal and 3mm vertically down until the angled surface also reached 32mm.

The same block, as seen on the trolley nearest to the camera in the previous picture, with the angled face roughly pitched.

The main face now also roughly pitched.

The corner margin chiselled and the block is ready for final trimming. It seemed to be a pity to chisel off the sawn surface but it looked too artificial.

For the quoin blocks that were to project from the main wall, I used the same method of sawing to remove the excess from the inside face. To reduce the amount of slurry produced I stepped the blade to do alternate cuts, leaving about 6mm thick fingers of waste that I could snap off before performing the final cuts. I left a raised margin adjacent to the pitched face that could again be hand chiselled.

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