There is a bit more work to be done before the two major parts of the boiler can be brought together for the next significant silver soldering operation. The two 5/8″ diameter holes for the front feed bushes and for the one or two safety valve bushes need to be marked out, drilled and reamed. The most important reference is to make sure the centre line down the top of the boiler is maintained from which to mark out these additional holes. Dealing with the front feed bushes first; ideally the boiler shell should be set up squarely on a flat surface and with a height gauge or scribing gauge and steel rule, the horizontal lines for these bushes can be made near the front of the barrel. Those with a proper marking out table are well placed but with the appropriate sanction, even a kitchen worktop (suitably protected) is sufficient for this task. Here I actually measured from the central reference line, a quarter of the outside circumference in each direction round the barrel using a very flexible steel rule I have had since my training days. Also, marking out and drilling the holes for the safety valve bushes (or the single hole for the Drummond whistle valve) will be straightforward. Centre, drill, ream and de-burr these holes and then the more onerous task can be tackled.
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