how are preformed hoses made?

Me, too.

I guess the hose is vulcanized enough to cure a thin layer of the outside, bent in a form, then vulcanized completely.

--Winston

I've molded rubber parts from cut-up windshield washer tubing with heat and pressure. I put a piece of 60/40 solder on the mold and heated it until the solder melted, then squeezed the mold in the vise and let it cool.

jsw

They used to be made by extruding.The outside die plate could be moved off centre which meant a thicker wall on one side of the tube. The other side being thinner extruded at a faster speed and therefore caused the hose to bend.A simple plc programm to control the die along with a face knife and off you went. That technology is over twenty years old so they may have moved on.

That is intriguing!

Your mold was on the outside of the tubing? How did you avoid kinking? Multiple stranded wires stuffed in the I.D.?

--Winston the Curious

They were print head hammer pads for a Teletype ASR33, little buttons that snap over a steel mushroom on the hammer. The ink solvent slowly turns them to mush.

The mold cavity consisted of a flat-ended cylinder for the OD and striking face, and a negative of the recess on the piston.

The head slid freely in and out of the cylinder so I could completely disassemble it to remove the molded pad.

jsw

Here is a real one:

The rubber didn't last as long as factory ones, partly because I re-inked old ribbons with stamp pad ink, but since I could pop them out as needed, it didn't have to.

jsw

OIC. Thanks!

--Winston

Thanks for the picture. Interesting!

--Winston