In the last post I reported that neither acetate or polyester film would load correctly in the Rondinax 60 if the end of the film that enters the film chamber in the tank was partially flattened by keeping it under a heavy book. The films were Rollei Infrared and Ilford FP4. After winding the films back on their spools I tried again. The result: no problem; both loaded perfectly into the tank.
So the failure to load I originally described with fresh Rollei Infrared and others have reported for some other polyester-based films does seem to be related to the longitudinal curliness of the film at the time of processing. How long fresh polyester-based film, cut from flat sheets, needs to be stored on a roll in order to take the curly, rolled form, I do not know. Several weeks or months possibly? What I do know is that the Rollei Infrared film I have had for several years now loads perfectly in the Rondinax 60, unlike when I first received it from the online retailer.
So, the problem of getting film flat for scanning or enlarging using a glassless carrier is reversed for the Rondinax 60 user. We want film with a curled ‘memory’ for processing. That’s not usually a problem but sometimes is.