Newbie LF questions

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Hello:

I just found this group and hope my questions haven't been asked 400 times already, because I know it can get old answering the same question that was asked a week earlier.

1) Any idea how to make homemade BTZS tubes? It seems simple, but I'm sure someone else has worked the bugs out already.

2) I'm planning experiments with a 18 x 23 bellows for pinhole work for starters, maybe a lens someday, too, with as large a sheet of film as I can find - I've spoken with local newspaper, and while they haven't told me what brand they use, they mentioned Kodak Rapid Access developer. Is this a commonly available product, and if anyone has experience using 'newspaper' or graphic arts film, any comments on film performance and alternate developer?

Thanks

Murray

-- Murray Leshner (murray@uptowngallery.org), November 17, 2001

Answers

I can help with the tubes, since I've made a set.

First, I'll assume that you're using 4x5.

Head to your local hardware store, and pick up some 1 1/2" Inside Diameter (ID) *black* ABS pipe. This is your standard sewer pipe. Don't get PVC, since it's not light-tight.

For 4x5 negatives, the tubes need to be just a bit shorter than 5" - this way, you can grab the negative a bit easier. Each tube will need a length of 1 1/5" ID pipe, an end cap, and a male coupler. Each cap will need an end cap, a female coupler, and a fairly short length of the same ABS pipe. My caps can hold about 80ml of fluid - the fluid level goes up to just below the threads on the female coupler. Any higher, and the fluid can wick out when you assemble the two parts.

I also place a rubber ring on the male coupler - this helps keep the entire unit sealed.

I would recommend cutting the ABS pipe with a chop saw if you have access to one, as the cuts will be perfectly straight. No worries if you don't have one - just use a hack saw and take your time. Make sure you remove all the burrs. Also, make sure the ABS pipe is smooth on the inside. Use coarse steel wool, or emery cloth, and work through to as fine an abrasive as you can fine. Make it as smooth as you can - we don't want any scratches on the back of the negative!

To assemble the tubes and caps, first use fitting cleaner/solvent - this stuff is pretty potent, so do it outside where you've got lots of fresh air, else you'll lose a few brain cells. The ABS cement is the same.

I ran a ring of cement around the inside of the coupler, shove in the pipe, giving it about a 1/4 turn as you insert it. Make sure you get it seated the first time, since with this stuff, there is no second chance.

One thing you want to keep in mind is that you want the assembled tube to be balanced when in the water batch. My tubes, when asembled, are about 7 15/16" to 8" long, and they seem to balance quite nicely. Did I figure this out? Naw, pure luck.

Also, I can't stress how important it is to get the rubber ring - it will seal the unit, and it'll also prevent you from tightening them too much - when you tighten the cap, you create friction, which of course will cause the plastic to expand ever so slightly. As soon as you stop tightening, the parts cool, and they *lock* together. And do I mean lock! I've had them so tight that I had to use a monkey wrench and a vice to get them apart. Using the rubber ring pretty much prevents this, since it also acts as a spacer.

If you're not using 4x5, just measure the diameter of your negative when you curl it along the long edge. Pick the pipe with the I.D. which is just greater than your measurement.

You probably already know how to use the tubes, but in case you don't:

http://www.darkroom- innovations.com/BTZS_Film_Tubes/FIlm_Tube_Instructions/film_tube_instr uctions.html

I made four tubes, and am planning on making more. No more scratched negatives, and perfectly even development every time. Buy 'em or make 'em. They're worth it!

Good luck!

-- Ken Miller (andawyr@hotmail.com), November 17, 2001.


It took me years to learn this simple trick. To cut plastic pipe square, wrap a piece of paper (with a straight edge) tightly around the pipe so it lines up. Draw a line on the pipe with a pencil against the edge of the paper. Cut on the line.

-- Conrad Hoffman (choffman@rpa.net), November 19, 2001.

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