5x7" tanks are cheap and plentiful. You can get older style hard rubber ones on eBay or look for a used set of stainless tanks (try finding them locally on sources like Craigslist, because they can be heavy to ship, particularly if they come with a water jacket), or buy new ones with floating lids--
If you get older hard rubber tanks, buy more than you think you need. Some have hidden cracks, which can be sealed, but since they're easy enough to find, you might as well use the leaky ones as dry tanks for storing hangers and holding them temporarily while you load before moving them to the developer.
Bromide drag around the edges of the frame is usually caused by insufficient agitation.
I process sheet film using open trays, daylight Nikor sheet film tanks, and with open tanks and hangers, and when I have a lot of film to process, tanks and hangers are the most efficient method.
I wish that I could endorse the idea of buying the stainless Arkay tanks through B&H, but when I finally broke down and purchased a set of 1-gallon 8x10 tanks, they took almost a month to deliver and the quality is rather poor (functional, but one of them is angled at the bottom to the point that it will barely stand upright).
On September 1st, I broke down and yielded to the temptation of buying an Arkay print washer; after five weeks, it took almost another week to get the fact that the washer hadn't been shipped, built, or even scheduled yet. They did, however, cancel it for me promptly.
Making acrylic tanks is almost certainly the best solution nowadays, since the most common used tanks seem to be ones that will take 4x5 but not 5x7 hangers (don't ask me how I know this...). The only difficulties are likely to be that imperfect seams will create traps for residual chemicals (having dedicated tanks for developer and fix pretty much solves this) and the low thermal conductivity of acrylic means that adjusting temperature quickly by setting the tank into warmer or colder water is problematic. But the same technology that lets you make the tank will also serve to build a water jacket, assuming that you have the luxury of enough time and a supply of tempered water.
One thing to think about is to make the tanks sized for 8x10. That way when you do try 8x10 you won't have to build or find new tanks. They make hangers that take 2 5x7 sheets and fit 8x10 tanks. They used to be very cheap but I haven't looked in a while. Used tanks also used to be cheap but maybe that's also changed. If you use the 2 up hangers you can go with 8x10 tanks which should be easier to find. You can also look at the various plastic products in the food storage section of large stores or plastic file folder boxes.
What he said...;)
Originally Posted by David A. Goldfarb
I processed a sheet of 4x5 in a 4-reel stainless tank the other day in a water bath @ 101deg F.
I'd imagine that if you wanted to, you could do it for b/w as well. I don't have access to 4x5 tanks for developing at school for color. B/W only, and thats in trays.
worked for me, I just made sure to give it random movement, side to side and rolling back and forth, rotating ends every 30 sec or so.