trying to cold form brass, need some help

Gerald J.

To use a forming die you need 8 times the metal thickness for die clearance. If your dies are to close mated, it will cause the metal to rip and tear as it forms.

I would would make the float in 3pcs. The main body I would break the 1" sides then open to form the 1/2 round, then hand form the 90º's, then lap and solder. I would then add the end pieces and solder.

What your doing is preforming the sharp 90º bends so after rolling the 1/2 round, the 90º corners will return to 90º very easy by hand forming.

To make the end pieces, cut your patteren about 1/8" larger then use a piece of steel round stock as a dolly and hammer form a 90º inside lip. This lip will attach to the main float body for easy soldering.

When dolling this inside lip up, only dolly up about 10º at a time then repeat until 90º. This keeps the lip metal from stretching and folding.

To solder a closed vessle you need to leave a small air vent, solder all joints, let cool, then solder the air vent hole.

IF you don't leave a air vent then the heat from the soldering process will cause the inside chamber to fill with pressure and you will never get the joints to solder.

Your brass shim stock is also tempered. To anneal, heat to a null red then quench in water. This will make the shim stock form alot easier.

T_Bone

Ok your building a "C" shaped float.

If your hand building the float then I would still make it in 3pcs. Bend a 1/8" lap joint seam, then a 1" 90º, then roll the inside "C", then bend a 1" 90º, then roll the outside "C", then lap and tack solder.

Build the end caps with a 1/8" inside lip with the dolly/hammer. Tack solder the end pieces.

If your trying to production build the float then you need to build the "C" in 2pcs with a inside die and a outside die with having the lap seam in the center of the "C" edge.

You would also need a "off-setting" die. This die looks like a "Z" when viewed from the end. This allows the center seams to lap over and fit tight and adds a "stiff" edge for the halv's to fit to each other.

For this type of form to shape from a die, you need a different type of brass stock. You need a annealed brass stock. Shimm stock brass has a small amount of chromium??? nickle??? that adds a springing effect to the metal.

I lost all my bookmarks to a worm last month so I don't have a website for you. Do a google search and one of the brass metal mfg has a website explaning the different kinds of brass and the suggested use for the brass metal series. I'm thinking you need a 300series brass.

T_Bone

And I think you will need more die clearance than normal and the dies will need mirror polished to allow for the least amount of drag on the die.

T_Bone