Holes in Panels

Radio Record, Volume II, Issue 38, 5 April 1929, Page 30

Holes in Panels

Remedies for Mistakes QCCASIONALLY, owing to an error of judgment, or to some other cause, a hole is bored in a panel which provides too loose a fit for the terminal; and the result is that, no matter how tightly the under-nut of the terminal may be fastened, the terminal itself sooner or later comes loose, and develops a most annoying degree of play. Fortunately, however, such cases can be remedied by the exercise of a little trouble. If the hole in the panel is only very slightly larger than the outer diameter of the terminal shaft, make up a paste of fine ebonite powder and thick gum. Roll the terminal shaft in this, and then insert it immediately into its hole, allowing it to stand for several hours before it is again touched. By this method, the ebonite powder will effectively bind the terminal.

If the panel hole is considerably larger than the diameter of the terminal shaft, another means will have to be employed in order to provide an effective fit for the terminal. This is the method of terminal "pack-ing’-the terminal being packed in its hole by means of some substance which can be poured in the hole in a molten stage, and then allowed to solidify. Substances to Use. PHE two best substances available for this purpose are sulphur and Wood’s metal. Hither of these may be melted, and then carefully poured from a small spoon around the terminal in its hole. They will quickly solidify, and will provide a very fast binding for the terminal. On the whole, Wood’s metal is the better material to use for this purpose, it being rather more indifferent to mechanical shocks than sulphur. Tf the hole in the panel is not excessively greater than the diameter of the terminal shaft the presence of the packing will not show on the upper side of

the panel, for it will be hidden away from sight by the base of the terminal pillar. As for the underside of the panel, if the packing material overflows the hole when it is poured in, and flows over the ebonite surface, it can readily be removed after it has solidified, by the aid of a knife and a little sand-paper.