Refilling the Carboy

Refilling the carboy is an important safety step in the process. Instead of filling each bottle separatly with the nitric acid and hydrofluoric acid solution, this step allows the solution to be made all at once, therefore reducing the amount of exposure time the technician needs to spend using hydrofluoric acid and nitric acid.

Procedure

Note: Hydrofluoric acid is very dangerous. If a small amount is splashed on the skin, rinse it off, then rub in calcium gluconate, which is stored on the wall to the left of the hydrofluoric acid jug. For large amounts, also call 911. Refer to the safety page for more information.

1. This should be done at the end of every day. The carboy, when full, contains enough solution to fill a number of bottles equal to the maximum capacity of the rollers. After the carboy is refilled, it must sit for at least a few hours before the acid is used.
2. Take note of the volume of acid remaining in the carboy.
3. Add hydrofluoric acid and nitric acid to make a five percent acid solution by volume -- that is, just add enough HF and nitric to make up 5% of the missing volume.
4. Fill the carboy to the line with pure water.