building darkroom sink - need advice on materials

gandolfi · Feb 6, 2008

we're making a new darkroom at mu school, and we want to make a large darkroom sink.

I was then asked: what is the best choise: Stainless steel, or aluminium?

would aluminium react to spilt chemicals or is it good enough a material to make that kind of a sink? (aluminium is only half as expensive as stainless steel - hence the question)

please let me know, if you know.

thanks

Kevin Caulfield · Feb 6, 2008

I understand that aluminium will react with some chemicals, which is why it cannot be used for print processing trays, etc.

Neanderman · Feb 6, 2008

gandolfi said:
I was then asked: what is the best choise: Stainless steel, or aluminium?

#316 Stainless is pretty much the industry standard for photo processing equipment. I'm not sure about aluminum, but one alternative is marine plywood coated with fiberglass.

Ed

bdial · Feb 6, 2008

Aluminum is pretty reactive, I don't think it would be a good choice.
Here's PE's take on Aluminum for trays... (there was a url link here which no longer exists)

vdonovan · Feb 6, 2008

I built a large sink from plywood and fiberglass. It was easy, cheap, and has lasted forever.

Edwardv · Feb 6, 2008

I would go stainless steel if the school is paying for it and make it a deep sink, like 8 inches deep. If not, use plywood that is 3/4 inch.

Good luck.

gandolfi · Feb 6, 2008

thanks all for the quick replies. I thought aluminium was a bad choise, but the cost in mind, I had to ask..

maybe plywood would be the answer (if I only knew what that is....)

thanks!

richard ide · Feb 6, 2008

I think that when you price type 316 stainless, you may want to build one of plywood, fiberglass and epoxy resin. Will last forever. Aluminum might last a week or two; nevermind contamination.

Kevin Caulfield · Feb 6, 2008

gandolfi said:
thanks all for the quick replies. I thought aluminium was a bad choise, but the cost in mind, I had to ask..

maybe plywood would be the answer (if I only knew what that is....)

thanks!

Plywood is very thin layers of wood glued together. When you look at the edge profile you can see the separate layers. You can get three-ply, four-ply, etc. It's usually cheap, but fairly strong because of the layering.

Soeren · Feb 7, 2008

gandolfi said:
thanks all for the quick replies. I thought aluminium was a bad choise, but the cost in mind, I had to ask..

maybe plywood would be the answer (if I only knew what that is....)

thanks!

plywood=krydsfiner
Så vidt jeg ved findes der en "Marine" kvalitet der skulle være vandfast.
Mvh

BobNewYork · Feb 7, 2008

Soeren: I was just about to say that

Bob

Soeren · Feb 7, 2008

BobNewYork said:
Soeren: I was just about to say that

Bob

Are you sure?
Its a bit difficult to translate english to danish if writing english only :confused:
Isn't there a "marine quality grade" Plywood?
Kind regards

GeorgesGiralt · Feb 7, 2008

I second the plywood idea. I've used at my camera club sinks made of plywood which were 40+ years old and still nice and perfect. I've used plywood to make my sinks. I coated them with epoxy resin (used in boats) and they are perfectly fine !
You may have a look at PVC plastic it comes in sheet and can be solded/glued to make sturdy tanks. I've seen a comercial darkroom using a sink custom made of PVC and perfect for it's use. But buying PVC is buying oil.So it will not be cheap. On the other hand, it will last forever.
On the other hand, if using plywood, you will have to find the carpenter able and willing to make it...

noseoil · Feb 7, 2008

Emil, if you make it with plywood, use a type made for exterior use, 20mm would be about right. The glue will be better for a darkroom. I'm not sure about the european market place and availability, but in the u.s. there is a liner material made, which is made for new truck beds. It is a sprayed in material available in various colors. It is tough, water proof and will stick to almost anything, made like a hard rubber coating. This will coat the inside and work to keep water and chemicals out of the wood. tim

http://www.rhinolinings.com/

gandolfi · Feb 7, 2008

noseoil said:
Emil, if you make it with plywood, use a type made for exterior use, 20mm would be about right. The glue will be better for a darkroom. I'm not sure about the european market place and availability, but in the u.s. there is a liner material made, which is made for new truck beds. It is a sprayed in material available in various colors. It is tough, water proof and will stick to almost anything, made like a hard rubber coating. This will coat the inside and work to keep water and chemicals out of the wood. tim

http://www.rhinolinings.com/

plywood sounds like a good idea.
not with fiber glass or PVC I think, as it will proberly be more expensive than stainless steel (remember; we are in Denmark, and there are huge taxes on plastic like things (inviroment issues))

but the material you mention here is worth exploring.. (I don't know whether it can be bought here, but I'll look into it.)

thanks all

Mark_S · Feb 7, 2008

More comments on plywood -
I have two darkrooms, one has a commercial plastic sink which I am not thrilled with (not as sturdy as I would like), the other has plywood covered in fiberglass, which I like.

I would definitely use a marine grade ply. Another thing to consider - there is a local school which has a plywood darkroom sink which was taken to a place that does spray-on pickup truck bed liners - the material is somewhat rubbery, and gives good 'grip', as well as being close to indestructable. I don't know what sort of waterproofing was put under the bedliner material - fiberglass?, epoxy paint? but this particular sink has been in use in a school setting, being used 12+ hours per day for at least 15 years now and still seems very sturdy.

Ole · Feb 7, 2008

Plywood (krydsfiner) and what's called "våtromsmembran" in Norwegian should do the trick.

That's the stuff you paint on the floor and walls of a new bathroom before putting in tiles or similar - it's designed to make a waterproof seal. Since you're not covering it up (e.g. with tiles or wallpaper), I would use several layers - and make sure you caulk the joins well beforehand!

pesphoto · Feb 7, 2008

This might be helpful. It has pretty detailed instructions for a sink and other parts of building a darkroom.
http://www.darkroomsource.net/sink.shtml

Soeren · Feb 7, 2008

How about concrete? I saw a "how to" on that some where once
Kind regards

removed account4 · Feb 7, 2008

the paint ole suggests is good stuff.
i wish i knew about that when i repaired/rebuilt my wood sink ..
i just used fiberglass resin ( 2 part mix ) and fiberglass cloth to
seal the edges ... hard as nails, and lasts a long time ... but
ole's paint sounds much easier

john

CBG · Feb 7, 2008

Whether or not it happens to be taxed in Denmark, I think most of the best surfaces are oil or energy intensive, and maybe the responsible thing is to build your sink well, and get many happy years out of it by using materials good enough to not need early replacement.

That said, my vote is for these three - either polyester resin on fiberglass over plywood, or epoxy on fiberglass over plywood if you make it yourself, or if you have it made for you, stainless. Polyester isn't very popular since it stinks vey badly during application and cure, and isn't as rugged as epoxy. But it is more than rugged enough regardless and applied carefully does a wonderful job. I've used polyester before and had very happy results. Epoxy always gets the best rating for do it yourself application and final quality.

With either polyester or epoxy, your mechanical strength comes from the plywood, and the resins just create a durable, watertight, and washable surface.

I had a friend 30 +/- years ago who made a sink from plywood and polyurethane varnish. No fiberglass cloth. Just sealed the surface with varnish. He did commercial B/W photofinishing with that set up and expressed satisfaction with it. I can't remember if he told me how he sealed the joints at the edges. It always seemed to be a chancy way to build a sink to me, but he was happy.

Best,

C

aznative · Feb 13, 2008

Darkroom Sink

I built mine using 3/4" AC plywood, caulked all seams and applied 3 coats of Rustoleum Garage Floor 2-part Epoxy (gray color and did not use the chips). It looks good and has held up well. You can buy the stuff at Home Depot or Lowe's. It is a lot cheaper than going with a commercial S.S. sink and you can build it how you want. If your school has a wood shop class this would be an easy project. Here is the link posted in the Darkroom Portrait Thread showing my sink. Good Luck.

(there was a url link here which no longer exists)

jeroldharter · Feb 15, 2008

I have never built a darkroom sink. I have an 8-foot ABS plastic sink which is OK but a large custom sink would be great.

In regard to Stainless Steel, you might get a quote from a restaurant supply business. In the US they do the bulk of custom stainless steel countertops and sinks. We have alot of that in our kitchen and it was all custom work by a restaurant supply company in Minnesota.

For plywood, that would be cheaper and more of a do it yourself job. Fiberglass is probably easy if you know what you are doing. But the darkroom sink that will last your lifetime is probably not the best place to learn. Others have suggested various paints that would work as waterproof coatings. I have never heard anyone do this, but you might check out painting the plywood with the liquid rubber material that is used for RV roofs. Look like you can by it in cans in small quantities.

Whichever way you go, consider designing it with duckboards which I think help the functionality.

Troy Hamon · Feb 23, 2008

I used an old wooden door and scrap linoleum to make a pretty nice sink that will probably outlive me. Darkroom portrait thread shows it in case you are interested.

matti · Feb 24, 2008

I will build my new darkroom sink of plywood and epoxy. I will use birch plywood, since the surface is smooth. Fir plywood is really hard to get fair. I will use "filets" as described at westsystem.com. That is thickened epoxy with silica. I will also paint all plywood with epoxy at least two times, with a good scotch brite wash between.

Ole, won't your stuff scratch easily? Or react to chemicals? Epoxy won't mind some straight rodinal.

/matti

building darkroom sink - need advice on materials

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