Going through old files, I found a 1989 article I wrote for a long-defunct darkroom magazine on building a PVC darkroom sink. (Predates homepage article by 13 years.) There are enough differences in details between the two approaches that I thought it might be of interest here. I have posted a PDF below.
Major takeaways:
⦁ First, safety. Unless one intends to assemble a sink outdoors, a respirator with appropriate solvent cartridges is essential, even in well ventilated indoor spaces.
⦁ It's a stronger design to think of a sink not as a big broad "U", but rather as a big broad "H" – with short legs. Whether plastic or wood, this has a lot of options for reinforcing the attachment of sides to the bottom.
⦁ It's useful to outline your darkroom on graph paper with cut-outs of the sink or sinks all to scale. Can prevent major problems later on. In my case I wanted a sink large enough to accommodate six 20 x 24 trays for black and white. It was clear that one sink that large could never be moved out of the space, or handled by one man. So I decided on two roughly equal sinks. Since I worked left to right, developer(s) to rinse/holding, the design would have the right hand sink a little higher and draining into the left-hand. Used a small sheet of PVC to make a splash/drip shield to hang between sinks. Would I do this again - having one sink drain into another? Possibly not. It was a neat idea, and it worked fine, but made design, precision required, and installation much more complicated. I'd still go with two identical sinks for that space, touching at the ends but plumbed separately.
⦁ Cementing long seams using the cement can's built-in mop was futile. PVC cement has two contradictory behaviors: it will start to dry at one end of the seam before one gets to the other end. At the same time, since it is hygroscopic, any significant moisture in the air will start to bead up all over the cement. Solid weld is impossible. The solution, after applying PVC primer, was to use a big veterinary syringe to lay down an ample wavy line of cement and then slide pieces back and forth to distribute it until everything began to grab, followed by multiple C-clamps. (Most plastic syringes are nylon or other which are not attacked by PVC cement.)
⦁ I used extruded PVC 'L's to cement sides and bottom together – .75 x .75 x .080 on the inside; 1.5 x 1.5 x 3/16 below. The small ones from Gehr Plastics were a perfect 90° outside, but the big ones from the local supply house were not. One side had to be run through the tablesaw to square it up. Whatever shapes you use, it's well worth making sure that they're square before ordering.
⦁ Speaking of table saws: I worked a trade to cut all the pieces with one of my bigger clients, a cabinet shop who had really big Delta industrial table saws. I imagine cutting 4 x 8 sheets on a small tablesaw or with hand saws is possible, but…
⦁ "Dump troughs": these were not a needless complication. Extremely handy in getting rid of one tray's contents without slopping it into the main sink or contaminating adjacent trays. Would definitely build those in again, but YMMV.
⦁ And yes, there are several places where I was trying to look 'clever' with my verbiage. Cringe-worthy. No need to point them out!
sink article.pdf,,
,
For members who are seriously contemplating a new sink build in the near future, I still have several pristine copies of this issue. PM me.
Finally - I had to sell these many years ago when I moved from Bellingham, WA to Colorado. If anyone in western Washington has seen or acquired these, I'd love to know. Hopefully still used in a darkroom, though I suppose they might be used for gutting fish or potting ferns....
Reply With Quote
Bookmarks