View Full Version : Paint for darkroom sink

27-Oct-2016, 15:19
Update on my darkroom sink: Topic was part of a thread I started earlier this year. Sink and base were constructed from 3/4" exterior plywood. Inside of sink was painted with 6 coats of Rust-oleum Restore 4X Deck Coat paint over Rust-oleum's proprietary primer. Paint is so thick that no need to caulk corners. After months and months of constant use I can 100% recommend this paint. Sink still looks like it did after I applied the last coat of Rust-oleum Restore 4X Deck Coat paint. The buildup of the 6 coats of the paint produced a very mildly flexible surface... several times my glass graduated cylinders have accidentally tipped over but never have they broke. I like to create Chemigrams using a vast array of sometimes caustic chemicals.... none of them has stained the gray paint to my surprise. Silver Nitrite (Salt prints) has stained my hands several times but has had no effect on the paint.

27-Oct-2016, 18:39
Some of the modern low VOC outdoor paints can hold up well to standard processing chems... I have some finished 10 or so years ago, and still look great, just rinse well after use, and don't abrade the finish...

Steve K

27-Oct-2016, 19:38
I would love to see some pics of the sink! I am finishing up a new sink build and will be ready to paint very soon. I had been looking at the West Systems and S-W Tile Clad epoxies but its always nice to have options, especially cheaper ones. I am also curious about your coverage, how much does 1 gallon cover?

Drew Wiley
28-Oct-2016, 09:02
The West or Smith penetrating epoxy systems would definitely be superior to paint, but also distinctly unhealthier to apply. Alas, my next sink project involves a
slab of green granite, so there goes some more of my long-awaited darkroom time down the drain!

28-Oct-2016, 11:12
The West or Smith penetrating epoxy system

I wholeheartedly agree, this stuff can stand up to a brutal salt-water ocean environment.

28-Oct-2016, 11:38
Use boat paint. Not bottom but top paint. This is what i used about 4 years ago and still like new.

28-Oct-2016, 11:54
I would love to see some pics of the sink! I am finishing up a new sink build and will be ready to paint very soon. I had been looking at the West Systems and S-W Tile Clad epoxies but its always nice to have options, especially cheaper ones. I am also curious about your coverage, how much does 1 gallon cover?

Couldn't get back any farther so 2 images

28-Oct-2016, 11:56
Thanks for the tip! I'm planning to repaint my sink, now I know what I'll use.

28-Oct-2016, 15:10
Very nice greg! Thanks for the pics. I think I might get some of this and give it a go.

28-Oct-2016, 19:22
Instead of paint why not use the rubber shower pan liner? Comes in varying widths and in rolls you can have cut to length at a Home Depot of similar. Just lay it in the sink, screw in the drain and you have a complete water tight sink without all the painting. My Uncle has built a few (he did mine) and uses the stiff sheets of Owens Corning Foamular under the rubber membrane and it absorbs noise as well as providing a cushion in case something is dropped on it. Watched him make mine and it was done in a few hours and ready for use.

29-Sep-2017, 14:53
Follow up on my darkroom about one year later...

Deck paint on the plywood darkroom sink has been holding up amazingly well. Honestly, in my experience, it is equal to epoxy resin paint without all the ventilation necessities while it is drying. I have been using various alternative processes and some caustic liquids on it. Very little staining but a 5 minute new top coat of the deck paint took care of that.

Foam on front rim of sink. Bought 2 of the foam tubes that kids use to play with in a pool. Cut a slit down the tube and pressed it onto the front of my sink. (See attached image) So, So... much more comfortable too rest my forearms on rather than the edge of the 3/4" plywood.

Light that I turn on first from being in the dark is a ceiling mounted Kodak rectangular safe light with a low wattage bulbs in it and no glass filter. The hanging on/off cord has a pull tab at the bottom which I painted with fluorescent paint. Now so easy to find it in the dark.

LED light panel replaced an older fluorescent light box. Its always on LED when it is plugged very bright and most distracting in total darkness... Simple solution: piece of black Duct tape over it. Same solution for the couple od power strips I have in the darkroom.

Ceiling light leaks addressed. Probably would have never fogged my film, but all way too a bit disconcerting when seeing the multiple light leaks after being 20 minutes in total darkness. Light leaks were coming from being light piped in by the aluminum foil covered duct insulation which was slightly below the hung ceiling in several places. A judicious application of black caulking where the docs entered the darkroom totally got rid of the light leaks..

Exhaust fan above the paper coating area. First I used an internal auxiliary duct fan inside the 6" inch round aluminum duct. It was way too weak. Finally found an Arkay darkroom wall exhaust fan. Thought it was also too weak, but "smoke" tested it and it works just fine. I have fabricated a removable hood above the paper coating area from black Foamcore to help exhaust out the air above the drying Pt/Pl emulsion..

Door to darkroom was anything but light tight where the door hit the frame and underneath the bottom of the door. Painted the door jam and the floor under the door matte black. Also added a draft preventer strip to the bottom of the door... now door is light tight.

Sony radio, CD player, and more has a white LED light that is just way too bright... simple cure to cover it with 2 pieces of red acetate/gel..

I initially used PVC pipes for the plumbing. Replaced them with way more better looking and reliable PEC tubing. PEC is so much easier to install than copper pipes which I had always installed in the past. Also installed on/off valves to the incoming hot and cold water tubing. Valves are very securely mounted on the wall above the sink.

Am very lucky that the temperature inside the darkroom ranges from 68 degrees in the summer to 65 degrees in the winter without having to add an auxiliary heater. Installed a small dehumidifier with a permanent Vinyl drain tube going through the concrete floor. Perk tested it, and couldn't get a gallon of water to back up through the hole for the vinyl tubing. With the dehumidifier's LED humidity % set at 55%, the humidity ranges from 45% to 50% and it only turns on in the summer to early fall.

Bought a small desk fan to use when drying negatives.

Under the sink I built 9 print drying screens that slide in and out. They work fine but with little air circulation over them, prints take a long time to dry. But the good thing is that with the longer drying times (1-2 days), the paper seems to dry flatter.

Will be adding a raised counter/shelf inside one side of the sink to support a presently on-order (JOBO) Stark SST4 Universal FILM & PAPER PROCESSOR on. When I need to use the whole sink's area, will only take me a minute to remove the JOBO and the shelf. Still considering a platform in front of the right side of the sink to house the JOBO on.

Running across the ceiling are 2 IKEA wires about 2 inches below the ceiling tiles. For hanging negatives to dry. With the desk fan running, the negatives take way less than 30 minutes to completely dry.

The temp control I bought from Delta works just fine and I highly recommend it based on using it dozens and dozens of times. My previous temp control unit was a Leedall which I loved but circumstances were that I had to leave it behind with my last darkroom. Ex is now probably enjoying the use of it.

So the things I'd do differently after using the darkroom for the past year:

More shelves for the easy access storage of working chemistry bottles above the sink.

Get paper safes to fit inside the drawers. My drawers are not 100% light tight in spite of painting their insides flat black. Worked in my last darkroom, but not in my present darkroom.

More outlets... and I thought I installed too many permanent ones.

Went with two 20 amp GFI circuits. An overkill in retrospect. Having 15 amp circuits and working with 14 gauge wire would have been so much easier to do. Also their wall locations were theoretical ideal when constructing the darkroom... after using the darkroom for some time, practically they are OK but not ideally placed. Some ceiling outlets might be a very viable option for one to consider.

John Layton
30-Sep-2017, 05:16
Two 20-amp GFI circuits works great for me - with one dedicated to the enlarger bench to minimize voltage fluctuations.

As per the OP's topic...I applied three coats of Rakka marine epoxy (low voc) to my 16 X 3 foot birch plywood sink, having planned to topcoat this with a grey marine paint until I saw how good the epoxy looked over the ply - so I've left as is (will post some pix soon). Has held up great!

The thing about VOC materials is that some of these still contain chemicals that are unhealthy to breathe while curing...so I made sure to install my (backdraft) ventilation system prior to applying the epoxy.

30-Sep-2017, 09:24
I use my Uncle's 11 foot sink. Pink stiff insulation sheet covered with rubber/pvc shower leakproof roll material. Easy to do - I even helped when he moved it. No smells, no leaks and the insulation and rubber make for a quiet padded surface.