Unicolor print drum usage

[logan2z]

I picked up a Unicolor print drum and was curious about its correct usage. It has a spout similar to that of the Beseler drums designed for filling while the tank is horizontal, and two ‘feet’ on which the tank stands (when not using a roller base). But I don’t see anything like the ‘trough’ on the inside of the Beseler to hold the poured chemistry before the tank is rotated. There is a small v-shaped channel on the inside of the drum but that doesn’t seem designed to hold the chemistry before the drum is rotated.

So is there anything about the design on the Unicolor drum that prevents the chemistry from coming into contact with the paper before the tank is rotated, or is this feature unique to the Beseler drums?

 

[Chan Tran]

No there is nothing to prevent the chemical from getting contact to the print before you rotate so you should rotate right away after pouring the chemical in. The V shape channel is to hold the paper in place.

 

[logan2z]

No there is nothing to prevent the chemical from getting contact to the print before you rotate so you should rotate right away after pouring the chemical in. The V shape channel is to hold the paper in place.

Thanks, that’s what I suspected. The Beseler drums seem to have the better design in this regard.

 

[xkaes]

The "trick" with most drums is to put the paper in the drum on one side, and make sure the chemicals enter the tube on the other side -- where there isn't any paper. You can always make a mark of some sort on the outside of the drum to indicate where the "up" side is -- where the middle of the paper needs to be. Keep that on top and transfer it to the roller.

 

[Chan Tran]

The "trick" with most drums is to put the paper in the drum on one side, and make sure the chemicals enter the tube on the other side -- where there isn't any paper. You can always make a mark of some sort on the outside of the drum to indicate where the "up" side is -- where the middle of the paper needs to be. Keep that on top and transfer it to the roller.

Oh yeah that's true. The V slots allow you to load the paper so that it would be up.

 

[MattKing]

This is why I like the Cibachrome tubes, with their chemical cups in the removable caps.

 

[logan2z]

This is why I like the Cibachrome tubes, with their chemical cups in the removable caps.

How do those work Matt? Do they need to be filled vertically?

 

[MattKing]

How do those work Matt? Do they need to be filled vertically?

Yes.
then you tip them to the horizontal and start them rotating.
At the end of each processing stage, you turn them vertical again, and they drain out the cap at the other end.
The fill cap has a cup in it that holds the fresh chemical until the tube is turned to the horizontal, at which time the fluid flows over the (rotating) print surface.
The cap at the other end has light tight drain holes.
The cup in the fill end of an 8x10 tube is probably about 2/3 of a cup in volume - i.e. 160 ml or so.

 

[Rick A]

No there is nothing to prevent the chemical from getting contact to the print before you rotate so you should rotate right away after pouring the chemical in. The V shape channel is to hold the paper in place.

The chem trough is opposite the narrow V channel between sheets. When you pour the chems in the liquid sits in the wide area and doesn't touch film or paper until you start rotation. I've been using Unicolor drums for years to develop sheet film.