darkroom sink dilemma: plastics or steel?

[gab1]

I'm building a darkroom sink and originally wanted to build it out of

a plastic. I've gotten quotes for a pre-made custom welded plastic

sink for almost $3,000. Can I find a plastics supplier that will do

the job for less?

 

Also, many plastics suppliers I've spoken to have told me I cannot

glue the water and chemical resistant plastics together and that it

must be welded. However, PVC can be glued? Does anyone have

recommendations for the type of plastic I should use or can use

without welding?

 

And is a plastic sink better than steel for any reason, or vice versa?

 

thanks a lot,

gab

[eric friedemann]

Gab, Delta makes numerous configurations of plastic darkroom sinks that are sold through B&H and Adorama:

 

 

http://www.hirtech.com/HomeDarkroomSinks.htm

 

 

It would be wayyyyyy cheaper, even with shipping, to get one- or even two- Delta sinks than to have a sink custom-made for you. I had a Delta sink in my darkroom for years without any problems.

[william_john_smith]

Since the 1970's I have been using wood for my sinks. The one in my studio is 15 years old.

The great thing about wood is that you can make the sink any shape you want. I use boat

paint to seal the wood, the same paint that goes on the underwater part of the hull of a boat.

I figured that if the paint can keep out salt water it certainly can work for city water. In 30

years I have never had a leak. Another way is to use fiberglass on wood, works but not as

eloquent as work/paint. If you are handy with hand tools you should be able to build a 2x6'

size sink for around $150.<div></div>

[michael erlich]

I considered building a sink out of wood sealed with marine paint, but I opted for an eight-foot Delta plastic sink and metal stand. It has worked well for 7 years, but I did have to add supports underneath because it tends to sag from the weight of my Jobo CPP-2 and/or loaded 16x20 trays.

 

The stand comes with an under-sink shelf that comes in handy for storing trays and chemical bottles.

[richard_cochran]

Here's another vote for wood covered by marine epoxy paint. It's inexpensive, durable, easy to build in any desired size/shape, and easy to maintain.

[bill_pearce1]

In many areas, there are frequently used sinks available from pro labs, industrial photo departments, etc. If you don't mind stains, they can be as cheap as free.

 

I don't know where you're from, but in many parts of the US, there are also the ubiquitous green fiberglass sinks. They are quite good, and come in many forms.

 

Bill Pearce

[terence_spross1]

Until I moved I had a sink I made in a wood frame covered in plexiglas and edge sealed with silicon calk, the same kind used to seal fish tanks. No problems there. This held my trays. At the other end of the dark room, where there was no plumbing I fitted a large PVC laundry basket for miscellaneous work, I cut an oval hole in the formica work surface that just fit it. It was held in by gravity and still had its carrying handles, at the end of the session I would just pick it up and carry it to a ordinary laundry basin outside the darkroom to dump it. It fit my needs and I wish I had that set up now. I used that setup for 7 years and seemed to be fine for B&W conventonal and litho; and color C22, C41, E4 and E6, even did open tray development of E6 sheet film.

(I took photos of everything else -apparently I never took a photo of my own darkroom!)

 

Does anybody know any reason why I shouldn't have used the silicone sealant or why Gab couldn't use it? Mostly my sealant was exposed to tray or tank spashover and washwater.

[william_john_smith]

Just paint over it, that what I have been doing and never had a problem.

[colin jackson]

My previous sink was modified from a medical clinic stainless steel sink and my current

one is wood painted with epoxy. The metal sink was noisy when anything was dropped on

it, had slight "wows" in it causing puddling and convected heat so quickly that it had to be

insulated with foam to make it suitable when used as a temperature bath.

 

The wood is easy to make to exact required dimension, inherently better insulated and

quieter. I do have to refinish the wood yearly which takes an hour or two. All considered

the wood wins.

[chuck_pere]

Maybe you can look at putting a plastic liner over the wood base. The home stores sell 4x8 plastic wall panels for under $20. Just glue it to the plywood and seal the seams. I think a lot depends on if you plan to use the sink as a waterbath. If you're only using it to hold trays and wash things it doesn't need to be as well done as something that's holding water. I read someplace that a persom just used exterior house paint. Also the looking used first is good advice. You can probably pickup a good sink for less then the cost of wood and paint.

[profhlynnjones]

Hi Gab,

 

I happen to be expert in this area. If you choose to use stainless steel for photography, it must be either AISI 316 or AISI 316L. Every thing else will rust! Stainless steel is resistant partly because it develops a coating which is resistant. This is called passivation. Normally AISI 316 is delivered passivated. If the surface is scrtched, sanded, or abraded it must be re-passivated. This is the dangerous part, that area needs to bathed with 10% nitric acid and then after a few minutes, flushed with water. Years ago there used to be passivating stainless steel polish, however I haven't seen these products for years.

 

Welded plastic is very expensive and somtimes the welds break. My suggestion is to build the sink from plywood being carefull that the construction is good and sturdy. Use water putty to curve the seams so that there are no hard corners. Paint the outside with any good quality exterior latex paint. After sanding the inside and edges to smoothness and recessing the sink hole so that it will fit the drain, paint the entire inside with epoxy boat hull paint (I suggest white). I also suggest two coats after lightly sanding the first coat. DON'T use any other kind of paint for the inside, it won't work. Epoxy is darned expensive in the area of $50.00 per gal. Don't forget to add and mix the the hardening agent in the paint. After this, place the sink drain into position using traditional plummers puttty and tighten it so as not to leak. I have used this technique successfully for many years for sinks and to make sheet film tanks.

 

This epoxy material is outrageously strong and adds tremendously to the strength and sturdiness.

 

The only failures I have ever seen have been when some cheapskate decided to use some othr kind of "water proof" paint like urethane and latex on the inside.

 

Lynn

[tom_holum]

Instructions for the sepia and selenium print toners that I use specifically warn against using these products in steel trays. Since I'm an obediant child I can't say what dire consequences would ensue if you contravened these warnings, but I think they provide yet another reason for avoiding steel sinks in favor of plastic or wood.

[kelly_flanigan1]

A source for a quart batch of Epoxy paint and hardener is a Rust-oleum Tub and tile refinshing kit. These are about 19 bucks at walmart, usally hidden in the spray paint area ; paint for appliances. <BR><BR>The kit covers 70 to 110 square feet with two coats; ie about 2 to 3 coats on a standard bathtub. You can mix up small batches if you want for small jobs. The ratio is 4 to 1 base to hardener. I use small plastic caps off of coke bottles etc as disposable measures for dinky jobs. You should do the painting in a ventilated area, the vapors are abit bad for you.<BR><BR> After searching for epoxy paints in smaller sizes in vain , I stumbled upon these kits by accident when buying some appliance spray paint, and have used them on a washing machine inside drum, a gargage sink, and a homemade old wooden darkroom washer for about 4 years.<BR><BR>Decent waterproof epoxy paints are expensive, figure 60 to 140 per gallon. The lower cost stuff is often just for floors. These 1 quart refinishing kits are are not designed for constant long term water immersion, but seem to work well for the sinks I have used it on. For a sewer or chemical plant there are very expensive epoxy mixes that run several hundred per gallon. <BR><BR>Our process camera darkroom 4 tanks and mixing sink are custom made out of 316 stainless when Nixon was president. We bought the stainless sheet in a big city, strapped it to a top of VW bug "car top carrier" , and had a local sheet metal outfit do the fab. The tanks and sink cost 1/2 the going price to build, and will be around for centuries.

[kelly_flanigan1]

My fathers Kodak darkroom kit had paper trays that were wax coated, like a paper milk carton. The depression era darkroom books had you making wooden trays, sealing them with ball jar wax or candle wax.