Chapter 7 - The Flat Hook as a Gasket Clamp
Several places in the organ, flat hooks instead of screws were used to close gasketed joints. This novel arrangemet is an interesting trick, new to me. Since it might be useful to someone, I am including the details. The picture shows one instance, on the primary valve box, where the supply nipple which will go in one corner, was in the way of one of the chest screws, and a hook was used instead.
I wondered how these could be effective in properly clamping a gasket, in place of the usual screw. The secret is to modify the hook so that it provides a wedging action when closed. Flat brass hooks, normally have a uniform inside radius, from the attachment hole to the inside of the hook. The tip of the hook can be bent slightly outwards with a pliers, about 1/16". Then the working radius of the hook decreases as the hook is more fully engaged with the other screw.
After the hook is modified and installed as shown, smack the place indicated by the arrow with a screwdriver and hammer. The wedging action will draw the gasket up tight, just like a screw. If a joint with such a hook has a new gasket, it probably won't fit up right, because the dimensions are slightly different, or the old screws have loostened. Plug the old holes and start over at a new place. New 1" flat brass hooks can be found in some old fashioned hardware stores, or from McMaster-Carr; item 1775A13 on page 2656.