Print Washer


Introduction: Print Washer

A low-cost, DIY darkroom print washer, with automatic fill & empty syphon action.

Step 1: The Whole Thing All at Once

If you can cut plastic, you can make this budget print washer, with automatic (syphonic) fill and empty action, from basic household items and plumbing supplies.

The blue storage box holds forty litres, because it was made for my 12 x 16 inch prints, but you could change that to suit your needs.

The holes in the spray bar are the same size as those in your bathroom shower head.

The syphon tube pipe is one inch (25mm) in diameter. The spray bar is half an inch (12mm) in diameter. Dimensions are not critical, as long as it empties faster than it fills up.

The hose on the bath tap feeds the spray bar pipe, which is plugged at one end to force the water through the tiny holes along its length. Rotate the spray bar pipe in its clips to get the aim right. The tank fills. The loaded prints are kept apart by the plastic fingers from an old print drying rack. The heavy chemicals leach out of the prints, then sink to the bottom of the water. The syphon tube, about one inch (25mm) above the tank floor, fills as the water level in the tank rises. Eventually it overflows into the attached airtight drain hose. The bottom end of this hose must be below the bottom of the tank (my bath is curved, which makes a gap underneath; you could use blocks). The syphon cycle starts by itself, gravity fed. The tank empties, the syphon action is broken as the air gets in, then the whole thing starts again.

It's in the bath because 40 litres of water is heavy. Any leaks or accidents won't flood your floor (keep the bath drain clear).



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    What is the fitting at the top of the syphon/drain? It looks like a bath too waste & overflow but I've never seen one under 1 1/2"?

    1 reply


    All plastic components from the plumbing supplier are UK standard fittings with either 15mm or 22mm diameter. The overflow was 22mm and is a design fitted to toilet cisterns.

    Best wishes,


    Sorry what you use in you washer for distance the print? thank you

    1 reply

    It was a plastic rack, made for air drying resin coated prints, manufactured by Paterson. Anything waterproof will do, as long as the spaces between allow water to circulate freely and the material is heavy enough to sink.


    Cool. I just got the supplies for developing my own photos.. so I'll probably try this soon.. Does anyone want to collaborate on a How to for developing film? I haven't tried it yet, but as I said, I've got the supplies...

    3 replies

    Oh. I'd love to see something like that. I'm in the same position of acquiring darkroom equipment but never having done it before I'm a little anxious about my first trial. I'll keep an eye out for that instructable.

    Not sure what "collaborate" means, being a newbie here, but may I suggest getting a free (or out of date) roll of film, then practicing loading it into your developing tank & film spiral in the light, with your eyes wide open? Then try it blindfolded. Once you get the hang of how film takes on a life of it's own, you'll be more confident when doing it for real.

    That's a start. Once you have the hang of loading the developing tank spool, you'll be off for the chemicals required. I don't know that the ones I used in 70's are still out there, but Microdol-X cut 1:3 was a favorite for black and white. 12 minutes @ 68F for Plus-X? That's what I remember, might have been 8 (long time ago). That, stop bath, and fixer is it for B/W. Color is more intensive..

    I took care of it for you. In the edit menu, there's a "remove" link under pictures that let's you remove them from a step.

    Please could you tell me what URL to e-mail to people, so that they can just look at an Instructable? One or two reported the need to login when I copied and pasted the contents of my brower's address bar for them (under my login). Thanks, B.

    That's very helpful of you, thank you.

    O awesome! Thanks, I've just started getting into developing my own prints, and this will definitely help cut down costs. Thanks

    1 reply

    Good. Just walk around any pro photo store. Look at the fancy equipment costing a fortune, see how it works, then make something that does a similar job wherever you can. That way you can put your money into a good enlarger lens, which none of us can make, instead of a print dryer, which handy people can.