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View Full Version : Any advice on bag mags?



John Kasaian
6-Aug-2007, 15:55
I'd like to try to use my bag mags on a 5x7 but I have no idea how. They look like they need rebuilding but again I have no idea how (or what kind of leather to use.) I'm really clueless here. They appear to me to work sort of like graphmatics, but then again I'm not really sure how they work either---or how to load and use them. Are there any on-line resources available, especially directions, manuals, etc...? Or are there any books covering the topic? Do you know of any camera repairmen that can rebuild bag mags?
Until I can find some info, I am aimlessly blithering away with bag mags in Fresno:o

David A. Goldfarb
6-Aug-2007, 16:09
I have a couple for my 5x7" Press Graflex--one old wooden one for plates (with film inserts) and a newer metal one for film.

They load from the back door, which is a convenience, because you can easily remove the exposed sheets, if you don't shoot them all, without disturbing the whole stack, as you would with a Grafmatic. The septums should be oriented so that the numbers read correctly through the red window.

Once you've loaded the back you shoot just like with a regular filmholder--remove the darkslide with the shutter closed, and you're ready.

To advance the film, pull the rod on the bottom of the bag mag in the direction of the bag. This will bring the exposed septum most of the way into the bag, and then ease it the rest of the way by feeling for the septum through the bag and pulling it out, and angle it toward the back of the stack. Then you can push it through a slot at the back. The slot guarantees that you won't accidentally push the septum into the middle of the stack, and you can confirm by reading the number of the septum through the red window.

Now you're ready to take the next shot.

When you get good at it, it's like having a 1fp15s or so motor drive.

If you have a really old wooden one, it might be worth fully disassembling it, cleaning any corrosion of the brass parts and lubricating it with paraffin wax, and regluing the light trap comb if needed.

You can cut down a modern darkslide to fit if the old one is worn (don't try to insert it until you've compared the size to the slide you have. If it's too wide, it can tear things up inside).

I've just patched the leather bags as needed with leather patches and Pliobond. If it's really bad, you can have a new one made by a leather worker or make one out of nylon or an old changing bag.

Glenn Thoreson
6-Aug-2007, 20:19
I use them in 3X4 and 4X5 sizes. Make sure all your septums are flat and undamaged. Damaged or bent septums can cause you all kinds of grief. Be careful with them. They are easily damaged. Carefully check the bag for light leaks and patch as necessary. Mink oil rubbed on the outside of the bag will keep it soft and flexible. Replacing a bag is not as easy as it may look. I made a new one for one of my 3X4s and it an experience I don't care to repeat. My prize mag is a 18 shot 3X4.

John Kasaian
6-Aug-2007, 20:47
Thanks! I'll give it a try. Mine slide onto the back of a Keystone F8 and would allow me to use sheet film instead of 7" wide rolls.

Bill_1856
7-Aug-2007, 00:24
Be careful! That supple leather from 50 years ago has become friable, so go slow and don't force anything.

douglas antonio
7-Aug-2007, 04:31
hi john,

possibly this thread will help you to understand the bag mags better?
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00Ibmj

hope it helps?

douglas

douglas antonio
7-Aug-2007, 04:32
just saw this is a hell of an old thread.
quite sure you got things settled by now or just got rid of the mags? ;-)

jnanian
7-Aug-2007, 05:18
john

if your bag is brittle and leaky ..
find a ritzy leather repair shop and ask
them if they are able to do a light proof stitch.

there are a handful of tiny screws that hold a metal strip
that holds down the bag. if you remove the screws you can carefully
remove the bag and have it duplicated. i had a leather shop replace the bag
on one of mine, and it works like new. you can also lubricate the metal pull/rod
with a little brasso ( or at least some 95 year olde graflex fanatic told me that ) ..

good luck!

john

David A. Goldfarb
7-Aug-2007, 05:22
Brasso is an abrasive cleaner--good for cleaning the brass parts that have become oxidized, but not a lubricant.

jnanian
7-Aug-2007, 07:11
Brasso is an abrasive cleaner--good for cleaning the brass parts that have become oxidized, but not a lubricant.

hi david:

that is what i told the old guy, and he just laughed at me and said
the reason why the rods get sticky and don't pull smooth
is because they get gummed up with "stuff" ... once clean + shiny
they will work like new.

guess i should also say: YMMV


john

David A. Goldfarb
7-Aug-2007, 07:57
Maybe he meant that he just cleaned the rod with Brasso, not that he left it on there as a lubricant. Brass is self-lubricating to some extent.

jnanian
7-Aug-2007, 09:25
Maybe he meant that he just cleaned the rod with Brasso, not that he left it on there as a lubricant. Brass is self-lubricating to some extent.


YES!

sorry it came across the other way :(