Here are some ideas I have.
1. The surface finish (texture) on the reels is different enough for the bubbles to cling to its surface. I suspect a smooth surface is better than a textured one, so don't use an abrasive.
2. Have you tried developing one roll in a two-roll tank with an empty reel above the one loaded with film? It really is best for agitation as the air space above the loaded reel permits the development by-products to disperse equally thoughtout the solution. Ensure that the lower reel is fully covered with liquid plus some.
3. You might try boiling your water before mixing the developer. A good 20 minutes is supposed to precipitate any dissolved solids, but it also removes air that is dissolved in the water. Let it cool before to the correct temperature before mixing the developer. You can try this without mixing the developer (i.e., just boiled water) to see if you get air bubbles.
4. Maybe adding some alcohol to the developer could reduce the surface tension of the developer enough to break the bubbles. Ethanol is probably best, but isopropyl alcohol will probably be fine. Make the alcohol about 5 to 10% of the solution (as a guess).
1. The surface finish (texture) on the reels is different enough for the bubbles to cling to its surface. I suspect a smooth surface is better than a textured one, so don't use an abrasive.
2. Have you tried developing one roll in a two-roll tank with an empty reel above the one loaded with film? It really is best for agitation as the air space above the loaded reel permits the development by-products to disperse equally thoughtout the solution. Ensure that the lower reel is fully covered with liquid plus some.
3. You might try boiling your water before mixing the developer. A good 20 minutes is supposed to precipitate any dissolved solids, but it also removes air that is dissolved in the water. Let it cool before to the correct temperature before mixing the developer. You can try this without mixing the developer (i.e., just boiled water) to see if you get air bubbles.
4. Maybe adding some alcohol to the developer could reduce the surface tension of the developer enough to break the bubbles. Ethanol is probably best, but isopropyl alcohol will probably be fine. Make the alcohol about 5 to 10% of the solution (as a guess).

