Water drainage on that flat homemade sinks?

[jose angel]

I`m debating between making my own darkroom sink or simply order a big polyethilene one from Nova...

By far I prefer to have that plywood&epoxy homemade flat ones, big and custom made, perfectly flat for big trays, a big archival washer and a Jobo processor, but there is something that takes me back; I hate to have a permanent puddle on it. I`m thinking on aprox. a 8 feet sink (2.5 meters).
If the Nova, it will be a bit smaller than this, probably combined with another stainless sink I already have.

From what I have seen on the web, people have magnificent big wooden sinks, but I cannot see if surface drainage is good enough... they look perfectly flat. Worst of it (to me), it seems like some even use that plastic mats to keep the trays over that "stagnant" water! (I may be wrong... ) I`d like to avoid moisture as much as possible in the darkroom.

Nova ones use ribbed bottoms for better drainage, I expect they work right enough to keep the bottom empty of water, like any kitchen sink. From what I have read, they are quite good.

Of course, I can install a plywood sink at an angle... but it´ll never be flat enough... and the drainhole area will be hard to drain, too... don`t know what to do!

What do you think? If you are a "homemade sink user", your advice&experience will be helpful for me. Thanks a lot.

[Peter Langham]

Bottom is not perfectly flat. I angled mine for drainage. 1/4" per foot if memory serves.

[Brian Ellis]

Put the drain on one end, make the two legs on the other end about a half inch longer than the legs on the drain end.

[C. D. Keth]

Steel and fiberglass sinks can have drainage troubles too. When you're done with a session, rinse the sink out (you do rinse your sink, right?) and squeegee the water toward the drain.

[Peter Lewin]

First, if you are making your own plywood sink, you build a slope into the floor of the sink by attaching the floor higher at one end. I found that I hadn't built in enough slope in mine, so I simply raised the "high end" a little higher by placing a piece of wood (I think a 1x2 or 3) under that end to raise it another inch. So you can either build some extra slope into the legs, or effectively place a shim between the frame and the sink to raise one end in addition to whatever slope is built into the sink itself.

[Bill Burk]

After building my 4x4 frame to hold the stainless-steel sink perfectly level at exactly the right "forearm" height, I realized the folly of my ways too late.

Put a couple squares of 3/4 plywood under the left-hand feet and now all's well.

[Keith Fleming]

The floor of my plywood sink slopes down toward one corner, which has the drain. To provide a level surface for trays, I attached level 1X2's to the long sides side of the sink. These level pieces hold three sets of "duckboards" made of 1X2's, with each set held together by two additional 1X2 pieces. The duckboards rest on the level strips, and that gives me a level surface for my trays. The strips comprising the duckboards are separated by about 3/8 to 1/2 inch, and this allows liquids (spilled or dumped) to flow down to the floor of the sink and down the drain. Having 3 sets of duckboards keeps me from having to remove everything from the sink if something (such as the cap to a storage bottle) falls through the slats.

[jose angel]

Thank you all very much.
Ok, you have convinced me. I have been looking for available materials, and have just draw a first idea of what I think it could be the right design... please correct me if I`m wrong:

The maximum size plywood panel (sink bottom) we have around here is 1200x 2400 millimeters, thickness is 18mm (3/4"). Same for slats (sink walls), bigger than 190x28 (7-1/2"x1-1/8") are hard to find.

I think this is a very basic design, but probably strong enough; the plywood bottom will be glued (white vinylic glue for wood) and screwed to the pine slat sides, maybe one screw every... four inches?. I can add four cupboards for the wall corners.


The drainhole will be placed near the side, with two wedges; the aim is to avoid stagnant water and a front-back slope (I prefer it to be flat), with a right-left 1% slope (the "duckboard" idea is perfect).


The sink will be perfectly flat and squared, the slope or inclination will be given by the leg frames. I think four-five suporting frames (frame legs) will be enough... I`d use them for "shelving" utensils.

My main fear is about strength... it will be heavy! I have seen in the web some sinks with framework to hold the bottom panel, maybe they are much bigger than mine.
Does it look a "reasonable" design? Opinions?

Thanks again.

[ac12]

3/4" plywood bottom, 8ft long, it is going to be heavy.
As you stated, as important as the sink itself is the framing and support.
Use 2x4 (or your equivalent) framing with the 4" dimension vertical.
Front to back supports every 18 to 24 inches.
If you know that you will put a HEAVY print washer into the sink, put extra supports under that part of the sink.
I would put 6 legs; either end and in the middle. The trick will be to cut and install the legs accurately to maintain the slope and support the sink.
Better to over-support than to have the sink sag later.

I would round off the top of the front edge. You will lean on that edge, and a sharp edge will be uncomfortable.
What are you going to use for sealant to coat the wood?

[neil poulsen]

My "The Sink" has ribs that project up from the bottom of the sink to hold the trays. The "ripbs" are flat; the sink is slanted towards the back, and hence towards the drain.

One could do this with plywood sinks by placing lengths of 1x1's cut slanted one end to another to achieve the same purpose.