On 4/8/2004 7:43 AM jjs spake thus:

In article laddc.52524$Ig.40384@pd7tw2no, "SofaKing"
wrote:

My local photo place wants $9 a pop for those 1 gal. chemical jugs! I feel
it's a little much for 25 cents worth of plastic. Are they magic or
something. Couldn't I use rinsed out antifreeze jugs or windshield washer
jugs? Do they have to be opaque? Thx.

If you don't mind semi-transparent plastic, then 1-gallon bottles with
caps can be had new for between $1 to $3 each. Check out
http://www.usplastic.com. Try searching on "industrial jugs". Their
delivery service is very fast.

But what we could really use here is some true expert input from a
plastics engineer. Plastic technology is a mystery. Some plastics let
oxygen flow through, some let hydrocarbons pass, some are dark looking but
are not really opaque to light. What's best for chemicals?

Perhaps you missed my post on this very question in another thread
("Rodinal"). Here's the gist of it:

From his page on plastic bottles ["he" being someone named "Ryuji"]
(http://silvergrain.org/Photo-Tech/plastic.html):

Why manufacturers and chemists recommend glass bottles for storing
photographic chemicals has a lot to do with idiot-proof factors. With a
little attention, inexpensive and convenient plastic bottles can be used
for most photographic chemical storage without compromising their shelf
life.

Plastic materials and chemical properties

material gas permeability acid resistance max usable temp
---------------------------------------------------------------
PET (PETE) very good reasonable 60°C
HDPE poor good 120°C
PVC very good reasonable 70°C
LDPE very poor good 80°C
PVdc (Saran wrap) excellent reasonable 65°C


PET (polyethylene terephthalate) is used as a clear (colorless or tinted)
bottle material in bottled water products. It has very small permeability
to oxygen and nitrogen.

Use PET for developers. Use PET or HDPE for most other chemicals. If you
store acetic acid stop bath in concentrated form, use HDPE. If PVC coated
cap is available, use it by all means.

My bottles of D-76, Microphen, and various other experimental formula are
still alive and as vigorous in filled and tightly capped 500ml PET bottles
after two years!

And as someone else pointed out, the best is still glass (assuming a good
tight seal of some non-permeable material).


--
.... but never have I encountered a guy who could not be bothered
to make his own case on his own show.

- Eric Alterman on his appearance on Dennis Miller's bomb of a show
on CNBC (3/17/04)