Selecting the Right Optical Polishing Pitch

Selecting the correct opitcal polishing pitch is very important to the success of your telescope mirror. The correct pitch will conform to your mirror allowing you to accomplish a precision optical polish. Selecting the wrong pitch, however, can slow down the polishing process or even defigure your mirror. So what is optical pitch? Optical pitch is a very viscous substance that can be made from many differnent substances. Gugolz is made from a natural wood resin whereas Acculap is made synthetically. Although it looks and feels like a hard solid, pitch will flow slowly, or more quickly when heated or under pressure. To polish your mirror you will need to make a pitch lap tool (usually a plaster or glass base with pitch poured on top). We will be adding more how-to pages on this process in the future. With this tool and a polish such as cerium oxide or red rouge you will rub the pitch lap tool and your mirror against each other causing the pitch to change shape and match the curve of your mirror.

We offer two types of optical pitch: Acculap and Gugolz. Selecting the correct pitch comes down to two facters: personal preference and your working space. While some minor differences may be noticed between them when polishing you will certainly be successful with either type. For most of our customers it comes down to the fact that some prefer the piney scent from the Gugolz. Whereas others find that smell to be malodorous and prefer the minimal ordor from Acculap.

The major concern when selecting the correct pitch is the tempurature of your work space. Each grade of pitch is designed to be used within a certain ambient temperature range. We call this the "working temperature." See the charts below to help select the correct pitch based on the temperature you will be working in.