ROLLING MILL TIPS
ROLLING MILL CARE
ALWAYS bolt down your rolling mill to a heavy bench or table top for stability.
When the rolling mill is not in use, it is a good idea to apply a thin coating of oil to the rollers.
Keep from touching the rollers. Oils and acids from your body can damage the rollers leaving behind tiny pits.
DO NOT over exert pressure on the rollers.
Try to use the center of the rollers. This will ensure even pressure on the rollers giving them a longer life.
DO NOT roll ferrous metals such as iron or steel through the mill.
ALWAYS release pressure on rollers after you have completed your job.
PROCEDURE FOR ROLLING
Anneal the piece of sheet or ingot, pickle it, and rinse it with clean water.
Feed the metal into the mill, applying snug (but not overpowering) pressure on rollers.
After rolling the metal through the mill, flip the piece end to end before you roll it through again. You will get a more even roll.
Before passing the metal through the rollers, lower the rollers until you have a snug fit (as in step 2).
If the metal becomes too hard to roll, it must be annealed again. Then roll the piece through the rollers, repeating as necessary until the desired thickness is achieved.
When rolling silver sheet it may be necessary to anneal the sheet after rolling it from 3.0mm to 1.0mm in thickness. For 14kt gold the annealing may be necessary after rolling from 3.0mm to 2.0mm.
PROBLEM - It takes all your strength to turn the handle.
CAUSE - The sheet being rolled is too thick.
SOLUTION - You need to start with a thinner sheet. You can over-stress the mill and damage the mechanism.
PROBLEM - The sheet is being pulled to one side.
CAUSE - The rollers are uneven.
SOLUTION - Be sure that even pressure is being applied to both sides of the mill.
PROBLEM - The edges of the metal is cracking.
CAUSE - The ingot is not uniform in shape or the metal was rolled too much without annealing.
SOLUTION - Remove the part of the metal with the crack (by sawing), anneal, and then hammer out the metal around the missing section until the edges are even. Anneal again and re-roll.
PROBLEM - The surface of the metal is flaking and/or cracking.
CAUSE - When the metal was poured, the ingot mold was cold -or- there may be too much old metal in the ingot -or- the ingot was annealed to much -or- there may be foreign material in the ingot
SOLUTION - Melt the ingot and reform it in the ingot mold. Roll it out again. If the problem persists, it may be necessary to refine the metal before your use it again.
PROBLEM - When wire is rolled out, it is wavy or bent.
CAUSE - There was not enough tension applied to the free end of the wire.
SOLUTION - Hold the free end of the wire tight with one hand.
PROBLEM - When rolling sheet, it comes out distorted, uneven, or wavy
CAUSE - Too much pressure is being exerted by the rollers.
SOLUTION - Remove the sheet, anneal it, plannish the distorted sections, and re-roll. Apply less pressure on the rollers.
PROBLEM - When rolling sheet, it buckles.
CAUSE - Sheet was pushed through rollers after flipping end to end without annealing.
SOLUTION - Remove sheet, anneal and re-roll.