Wayde Allen (wallen@boulder.nist.gov)
Thu, 21 Oct 1999 15:01:08 -0600 (MDT)
On Wed, 20 Oct 1999, ken wrote:
> It would be easier to add groves to the inside of the PVC pipe.
Let's make certain that we are talking about the same kinds of pipe.
Typically ABS plastic is the most opaque, and is what you will find in the
larger diameters since it is used for sewer plumbing. PVC pipe is used
for water delivery, and often is white or grey and often translucent.
> If you can
> find a good wood working store or someone who is a wood carver they would
> have a gouge with a small radius or a corner chisel that could easily cut
> grooves in the PVC for the same effect (negative bumps for negative
> processing). It might be easier for them to show YOU how to use the tool :-)
That might work, or you could have a machine shop turn a groove for you
with a boring tool. This would probably be more uniform. The thing that
would worry me however, is the possibility of the grooves causing
scratches. I've built a couple tubes out of ABS pipe, and even with the
factory smooth walls I've noticed some slight abrasion on the back of some
test sheets. That is for a dry tube though. I haven't actually tried
developing film in these yet. Adding grooves would likely make for some
sharper ridges to scrape against.
Another thing I wonder about adding bumps, grooves, or whatever to the
tube, is whether the added work is a help or a hindrance. For instance,
would it be possible for the solutions to cleanly remove the antihalation
coating from the back of the film everywhere but where the bumps or groove
ridges touch the film? Wouldn't this make things worse by transfering a
pattern to the film?
- Wayde
(wallen@boulder.nist.gov)
This archive was generated by hypermail 2.0b3 on Fri Nov 05 1999 - 21:26:28