12. Care and Maintenance
The ΔStop is built to last a long time in a darkroom environment, but darkrooms are hard on equipment. A few minutes of care now and then will keep the unit working well and looking right for decades. This section covers routine care, occasional maintenance, and long-term storage.
Routine Cleaning
The faceplate and enclosure can be wiped down with a soft, lint-free cloth. For normal dust and handling marks, a dry cloth is sufficient. For fingerprints or light smudges, a cloth lightly dampened with water works well. Wring the cloth out thoroughly before wiping, and follow with a dry cloth to remove any residual moisture.
Avoid household cleaning sprays, solvents, glass cleaners, and alcohol-based wipes. Many of these can damage the laser-cut faceplate's finish or the printed labels over time. Water and patience will handle almost any darkroom grime the ΔStop encounters.
The dials can be wiped down with the same cloth. Don't use compressed air to blow dust away from the dials or buttons; it can drive particles deeper into the control shafts rather than removing them.
Handling Chemistry Splashes
Darkroom chemistry is the most common cause of damage to darkroom electronics, and a splash of developer, stop bath, or fixer should be addressed promptly.
If chemistry splashes onto the faceplate or enclosure, wipe it off immediately with a damp cloth, followed by a dry cloth. Do not let chemistry sit on the unit; even short exposure to fixer can pit aluminum and discolor printed labels.
If chemistry gets into a control (a dial shaft, a button, or an outlet), disconnect power immediately. Do not operate the unit until you are certain the affected control has dried fully. In most cases, a day or two on a dry shelf at room temperature is sufficient. If the unit behaves erratically after drying, contact support before continuing to use it.
Keep a small cloth within reach at the enlarger bench for exactly this purpose. The best way to handle a splash is to catch it in the first few seconds.
Protecting the Unit Between Sessions
Between printing sessions, it is best to unplug ΔStop and the relay unit entirely. Many printers prefer to disconnect the power supply from the wall when the darkroom is not in use, both for electrical safety and to extend the life of the external adapter.
If your darkroom is humid between sessions (common in basement or bathroom darkrooms), consider a light cloth cover for the unit when it's not in use. A clean cotton cloth or a fitted dust cover keeps moisture, dust, and chemistry vapor off the faceplate. Do not use plastic covers, which can trap moisture against the unit and cause condensation.
Keep the rear connections clear of dust and debris. A quick wipe around the power input, the outlets, and the footswitch jack once or twice a year is sufficient.
Periodic Checks
Once or twice a year, take a few minutes to check the unit's condition:
Inspect the power supply cable along its full length for any signs of fraying, cracking, or damage at the connectors. Damaged cables should be replaced, not repaired.
Inspect the enlarger cord where it connects to the normally-off outlet. Darkroom cords often sit in the same position for years and can develop stress at the connector.
Confirm the dials still turn smoothly through their full range. Grit or chemistry residue in a control shaft will cause resistance or roughness that's worth addressing before it becomes a real problem.
Confirm the Start/Stop button responds consistently and returns to its rest position after each press.
Confirm the outlets still grip plugs firmly. Outlet contacts loosen with repeated insertion and removal over many years. If an outlet no longer holds a plug securely, contact support.
Long-Term Storage
If you need to store the ΔStop for an extended period (months to years, perhaps during a move or darkroom renovation), a few practices will keep it ready to use when you return.
Disconnect the unit from all power and remove all cables. Coil the cables loosely and store them with the unit.
Wipe the unit down with a dry cloth to remove any accumulated dust or residue.
Pack the ΔStop in its original packaging if possible. The original box and interior protection are designed for safe transport and storage, and they will protect the unit better than most improvised alternatives. If the original packaging is not available, wrap the unit in a clean cotton cloth and pack it in a rigid box with soft fill on all sides.
Store in a dry, temperate location. Avoid attics, garages, and unheated basements where temperature and humidity swing widely. A closet in a climate-controlled living space is ideal.
When you return the unit to service, let it reach room temperature in the darkroom environment for at least an hour before connecting power. This allows any temperature-induced condensation to evaporate before the unit is energized.
What Not to Do
A short list of things that will shorten the life of the unit or void the warranty:
Do not open the enclosure. There are no user-serviceable parts inside, and opening the enclosure voids the warranty.
Do not immerse the unit in any liquid or run it under a faucet to "clean" it. Damp cloths only.
Do not use solvents, alcohol, acetone, or aggressive cleaners on the faceplate or enclosure.
Do not operate the unit with a damaged power supply, a damaged cable, or a cracked enclosure. Contact support for a replacement or repair before continuing use.
Do not substitute third-party power supplies, even ones with matching voltage markings.
Do not exceed the rated load on the switched outlets.
With reasonable care, the ΔStop should outlast several enlargers and many thousands of prints. It's designed as a long-term tool, and treated as one, it will reward you accordingly.