ASK THE LABS
Q&A
by Karlen McLean, ABOC, NCLC

WATER WORLD

Q: How often should the water in my edger be changed, and why should I change it at all?

A: Water should be changed daily. When edging an unfinished lens, almost half the material is removed and carried away to a receptacle. While most edgers have filters attached to the drain, particulates can be recycled. These particles can potentially redeposit on the lens surface.

Also, water can have high mineral content, which can be corrosive to machines and pumps. Daily change-out can eliminate corrosion and lessen the incidence of particulates gaining access to the edging process.

Another reason for changing water every day is temperature variation. Filling the tank in the morning with 58- to 60-degree water is optimal. If you run a pump continuously throughout the day, a 15- to 35-degree increase in temperature can occur. When leap pads get warm, they become pliable and susceptible to torque, potentially causing spoilage. A lens with a 1.5 center thickness or less also reacts negatively to heat.

—Dan Gauthier, vice president production, Precision Optical Co., East Hartford, Conn.

AVOIDING CLOGS

Q: How can I avoid clogging the edger pump and how do I fix a clog?

A: This is an easy fix. First and least expensive is to maintain the quality of the water in the edger reservoir. It should be changed at least twice a week to maintain a clean environment for the pump as well as the edger.

Second, at a nominal cost, you could purchase a filtering system that will keep up the quality of the water for a longer period of time. These systems are available from many companies.

You will have to change your filter cartridge from time to time, but it's much easier and less messy than changing the edger bucket.

Once the pump is clogged, you'll have to disassemble the impeller side of the pump, clean it thoroughly, and reassemble it.

This usually requires removal of a few screws, then flushing the parts with clean water to remove all the debris, then reassembly.

— Joseph Seibert, director of operations, Three Rivers Optical, Pittsburgh

Calibration Concerns

Q: How often is it advisable for me to calibrate my edger? Is there such a thing as quick calibration? How much time should I set aside for the task?

A: We recommend that ECPs calibrate their edgers weekly or at least every 1,000 cuts. You can also calibrate as the situation warrants. If we notice that the axis is off, we recalibrate. Calibration frequency can also depend on individual machine needs and the types of materials processed. Calibration length and involvement depends on the machine. The longest calibration takes around 45 minutes. When you think about blowing a $200 pair of lenses, you realize the need for timely, consistent calibration.

— Chris Parker, president, Optiks Unlimited, Inc., Orlando, Fla.

If you have a question you'd like to have answered in Ask the Labs, send it to Karlen McLean. E-mail: mcleank@lwwvisioncare.com. Fax: 215-643-1705. An archive of past Ask the Labs columns can be found on the Eyecare Business Website at www.eyecarebusiness.com.