Looking for a 30x40 drum and processor

[darkroom_rookie]

Allen, did you ever buy one of these concrete forming tubes? Apparently, they're not available in Europe.

 

[Allen Friday]

Yes. I bought a tube and two end caps. They work well for developing very large film and prints. I am currently rolling them on the floor, but I hope to build a mechanical unit using an electric drill to turn the tubes in the next few months.

 

[darkroom_rookie]

Which diameter did you buy?

 

[DREW WILEY]

I've only seen one CPI set for sale used ever, and could kick myself for not buying it. I'm still using my
original unit I bought new, but am starting to wonder if I should stockpile a spare gearmotor or a few spare electrical components just in case. I don't think concrete tubes would work very well for dev use,
though you might be able to impregnate them with liquid expoxy penetrant. ABS irrigation pipe would be
better. The original CPI drums were made of expensive noryl, which is a better insulating plastic per
temp control.

 

[Allen Friday]

I bought the 24" tubes to develop my very large prints. 18" would have done the job, but I went with the next bigger size to make it easier to load.

 

[darkroom_rookie]

@Drew

The largest ABS pipe I was able to find was about 13" in diameter and you have to buy a 40-foot piece at an exorbitant price, whereas leftovers of 9" and 12" PE gas/water pipes are easily found... for free.

@Allen

Could you post some pictures of the tubes and perhaps some details about loading and filling/draining of the chemicals?

 

[2F/2F]

I have some big drums that may work. I will get a chance to dig them out and measure them in a few days once my vacation starts. They belonged to local photographer Richard C. Miller, who was an early adopter of color printing here in L.A. (carbro, and then Ilfochrome).

 

[DREW WILEY]

One very annoying problem is that Fuji is no longer cutting either regular CA paper or Supergloss in 30X40 sheets. You have to purchase it in 32 inch wide rolls, which means you either have to make two cuts
on the material or design a slightly longer drum. Another design problem is that the Jobo-style lids simply
fills and drain too slowly for precise color work: a lot of chemistry has to get through a small hole. The CPI-style lid is far superior in this respect, with the chemical entering and leaving around the entire rim.

 

[darkroom_rookie]

There are several original caps for a 315mm pipe lying around in my darkroom,
so I decided to do this to one of them:

The hole in the middle is fill-only and one on the right drain-only.
Blue denotes half-open or mostly open sections.
Any comments?

 

[darkroom_rookie]

Just got a new 51" scrap piece of D315 pipe for free. This one is made of PVC-U. The inner circumference is just over 36" inches, so with a paper spacer, the largest print stops at 36x50". Now off to perfect the cap design.

 

[darkroom_rookie]

I bought the 24" tubes to develop my very large prints. 18" would have done the job, but I went with the next bigger size to make it easier to load.

Allen, I am very interested in how the printing went with the 24" tube...

 

[PKM-25]

I have a line on a length of grey PVC-U thinwall for air ducting applications, it will be able to handle 33"x43" so it should work well with up to 42" rolls. It is opaque and fairly light too so with it being 10.75 instead of my 3063's 8" diameter, it might even work with my Beseler motor base. Denise mentions not doing a pre-wet for reasons of uneven development but I do it in my 3063 and find it promotes even development....?

I like using the 3063 for 20x24 so much that making the next size up seemed a no brainer.
This should be a fun project...