Don't Use PVC Pipe for Developing Tubes

Here's on I've learned the hard way. I was intent on building a

tube-type developer system for my LF work. The recommended material

is Black ABS pipe. Well, the local hardware stores no longer carry

black ABS so I decided to use white PVC instead. I thought the

thicker schedule 40 pipe would work. WRONG. After several sheets

coming out fogged, I used tray development and things came out

fine. Holding a piece of PVC up to the light, it became obvious.

The stuff is still transparent, even with a wall thickness of about

1/8 inch. Hope this saves someone else from making the same

mistake. Use black ABS pipe as recommended.

I guess that BLACK PVC would be fine too. It's the colour (absorbs all the light or lets some light through as in the case of white PVC tube) that matters and not the PVC, right?

 

Cheers

I'm not so sure Rick. I'm inclined to believe its partly due to the physical structure of the material. White color reflects, black absorbs.

Since you've made the thing, could you cover it with some kind of material like black tape or a couple of thickness of duct tape (as much as you can spare in the event of an anthrax attack, of course) to make it light tight?

I hate to nitpick but white PVC is trans<i>lucent</i>, not transparent. If you spray paint your tubes black, they'll work just fine. Roughen the suface of the PVC first and use several light coats of paint.

Well, you can use white PVC if you develop in the dark. Somebody actually recommended that method several years ago in one of the photo magazines. Some where I missed the point.

 

Many home depot stores and hardware stores do not carry black ABS plastic. If there is a store in your area that specializes in mobile home supplies you might check there as ABS plastic is often used in the plumbing of mobile homes.

 

Another material that will work is gray plastic electrical conduit, available at large electrical supply stores.

 

Sandy King

Like Gene & the Stones said...paint it black. That's what we're were told at a seminar several years ago. The tubes the instructor used were originally an aqua green color. He used a flat black outdoor paint for plastic that seemed very durable. He also had a corrigated insert in some of the tubes. He installed it to see if it made any difference...didn't seem to.

another concern for me could be contamination .

What is the absorption grade of PVC ?

I am not saying that the fogging wasn't caused by the light

seeping through , but if the PVC has a pourous surface it could

lead to chemical contamination .

David, I thought about wrapping with duct tape. The other minor problem with these is their mass makes for more resistance to rolling in the water bath. Schedule 40 pipe is the only the only wall thickness commonly available. By the time you glue caps and couplers on the basic tubes, they start to get a bit ungainly. I'm afraid the addition of tape would add to the rolling resitance. And, leaving the light off defeats the benefit of the tube as was mentioned.

 

Gene's right, translucent is the word I was searching for. As far as painting goes, I'm a little worried that the paint might leech through the PVC and interfere chemically. I don't think the PVC is causing any chemical interence by itself but have no way of proving that scientifically. The negative fogging is much less in the area where the coupling is glued onto the tube. Much less light transmission since the wall thickness is doubled, but still enough to be bothersome.

 

As another proof, I just took an ABS black plastic chemical sample container and put it next to a 60W bulb. No light transmission and its only maybe 1/16" thick. Too bad its not quite long enough to hold a 4x5 sheet, plus it has a rib around the inside which would interfere with loading/unloading.

 

I'm not giving up on this yet. There's got to be a source of ABS pipe in the greater scheme of things.

You need grey PVC type 2. This is the same material the handle on the Seal drymount press is made of.

Yeah, that or the electrical conduit recommended by Sandy may be a solution. Thanks!

Alex, the best source for ABS tubing is a recreational vehicle supply outlet, or a place that outfits pleasure boats. Inch and a quarter ABS tubing is regularily used in those types of vehicles for drain piping in galley and lavoratory sinks. It's not cheap. A few years ago, I tried using six inch sections of ABS tubing for developing 4X5 sheet film. The tubes were cut to the proper length, and the rough edges were carefully sanded off. Then, a sheet of film was loosely rolled up and inserted into the tube, emulsion side toward the center. Four, or five tubes could be rolled in an 8X10 tray of chemicals, in the dark. I probably could have used PVC, but the instructions in the magazine article stipulated inch and a quarter ABS. It worked. The films developed evenly. However, the method left an area of irregularity where the film base pressed against the inside surface of the tube. It did not show up on the prints. The technique just didn't seem to be worth the effort. I went back to using tray development. If you are determined to use tube development, the BTZS tube kit that the The View Camera Store sells, is well worth the investment.

Alex, whynot make it easy on yourself and just find an old unicolor outfit for $15-30 bucks? Its just a thought. I fiddled around with some old Western drums and then Dev-tecs without much luck. My "poor man's Jobo" works just fine! -------Cheers!

I bought black ABS tubing material and caps at a local Loew's store.

I sure would not buy the BTZS tubes: check my details on tube construction:

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<a href="http://home.att.net/~shipale/index.html">phil sweeney's website</a>

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Regarding translucency vs opacity, if you make pinhole cameras out of household objects you find out pretty quick what blocks light and what doesn't! I have my Intro Photo classes do this and much as I warn them that the container has to be light-tight, a few students bring in oatmeal boxes with white translucent tops (hopeless) or other inadequate cameras. Alex, if you paint your tubes, the paint had better cover completely -- we find that even a few tiny chips will let in light and fog our film or paper.

 

Check out Eric Renner's "Red Pepper Natural Safelight Pinhole Camera," though -- if the material is red translucent, like the pepper, it doesn't have to be painted since B&W photo paper isn't sensitive to red. (Not sure if it would work with film.) I thought this would also work with a pumpkin -- like an amber safelight --- but it didn't. However, a basketball, already black on the inside, makes a superb camera. Can you process your film in a basketball? ;)

 

In Renner's Pinhole Photography book, page 125, there's a picture of a long camera made of black 3" plastic pipe in which film was used successfully.

 

Cheers,

Sandy

From what I can remember my used Dev-tec cost me someting

like $25 with 2 tubes, motor, and 5 solution containers that sit in

the bath. Why bother with pvc?

Thanks for all the suggestions and sympathy. I made the switch to PVC out of frustration from not finding any ABS, not realizing it was translucent. Just wanted to pass this on to prevent someone else from making the same mistake. If anyone's interested in doing this, see Philip Sweeny's website. Until I find some ABS, I'll stick with tray development, which is turning out not to be as hard as I thought it might be. Thanks!