The Darkroom Sink (Part I)

My plan is to build a proper darkroom sink for all my needs from traditional darkroom prints, Lith process and other alternative processes. The sink should be waterproof, chemical resistant and should last at least 20-30 years of service.

Even though I had already started searching about to see if I could buy a used one.  They do appear once or twice a year on the second hand market. Unfortunately I couldn’t find anything suitable. So hence I decided to have a go and build my own!

This build will explain the parts, links as well, and include instructions along the way for each stage of the darkroom sink construction.

Part two of this article goes into the epoxy and the layout of the sink.

Background Story

The concept of building a serious darkroom sink might seem mad  in this digital day and age. This year I built my darkroom partially for Ikea kitchen units and some kitchen worktop I got at local hardware store. My worktop area is about 3 metres long and 90 cm wide. This served me well for 8×10″ or 18x24cm prints and the occasional large prints. I had all my trays on the workspace, developer, wash, fixer and sometimes toner.

After each darkroom session I needed to clean the worktop down and the tray too. It’s a laborious task of scrubbing for 20-30 minutes. I had also made a divider to separate the wet and dry areas of the workspace. As chemicals tends to splash and go everywhere which you don’t want on your enlarger baseboard or negatives folder. The wet and dry areas in a darkroom needs to be separated well.

At the time I had also ventured into the world of Lith process. Wishing to make much large pieces of artwork. That’s where the sink comes essential. The process requires a large tray and agitating for the duration of 5- 45 minutes depending on the chemicals and papers. That’s where my problems began. Chemical would splash and chemical spots would get onto anything next to the tray. Consider the process is under low visibility – red light usually.

If you can imagine  4 to 6 substantially large trays for a entire workflow. That’s a lot of splashing about! It then becomes resoundingly clear that a long and wide sink is essential.

My design

My design was simple, as I wanted it cut to size locally or online whichever made sense and was within budget. While they are a couple of way to tackle this task from plywood, OSB wood plate, fibre glass and even carbon fibre too. I initially hadn’t decided. I made my design in Tinker CAD as shown below. I finally decided to make mine a bit longer than originally planned as the length of the wooden plate were 2500mm longer. I settled for 2500mm x 800mm with 21mm thickness.

I watched many videos to get inspiration and technical knowledge. It seemed clear that epoxy resin will need to be involved. Many DIY-ers and course boat builders swear by epoxy, for example from West System. The epoxy is needed to seal the joints and the surface of the sink.

Video

Instructions

The plywood panels I managed to get hold off from a local DIY store, are phenolic resin coated, BFU 100 – weather resistant. Because the panels are already strong, thick and well sealed, 2-3 layers of epoxy resin is really only needed. Phenolic resin is also chemically resistant. The German description for these panels are Siebdrucksperrholz Pappel Sieb/Film 1250x2500x21 mm.

Constructing the panels

Darkroom sink panel construction

Part List

• Bottom base panel 2458 x 800 x 21mm
• Two side panels 800 x 200 x 21mm
• Back panel 2500 x 750 x 21mm
• Front panel 2500 x 200 x 21mm
• 3 x lengths of 2000 x 20 x 20mm
• Box of screws 45×4.5

Instructions

1. Using two of the lengths for the front and back panels. Spread a line of contact glue on the length.
2. Align the lengths centred to the panels, one end flush to the edge while the other end raised by 1cm. This is for the water to flow into the sink plughole.
3. Cut the last length to size for the size panels, screw and glue the length on. One length should be flush to the edge while the other raise by 1 cm.

Part II

Part two of this article goes into the epoxy and the layout of the sink.