Cracks
Hi
just a topic to discuss. Ive got recently some horns to process. This is what ive noticed.
Horn 1 - Bob and Horn 2- Alice
Bob abd Alice had the same shap at the beggining (not the best raw product, twisted, curly, etc...) as portrayed in the 1st picture.
I took Bob and cut it without following the growth direction. I had previosuly flattened it with warm water at 75C for half an hour. I left it to dry for 20 days plus less and to flatten inasmuch as possible in a workbench with press at around 100#/cm2. When I put it there , the temp in the room with the bench was minus some C. Today I discovered that a lot of cracks tiny ones, had appeared from side to side following the thickness axis. Like a microscopy of a hair with broken ends, if you understand...
The picture of Bob before processing is the second one.
I took Alice, and did the same, but following the direction of axial growth, third picture, but for flattening, i preferred to put in a press at room temperature, surrounded by heat guns at 50 C plus less (no close contact). NO CRACKS.
The first one to me is a classic of pressurized thermal shock - PTS. Though I cannot be sure because of the different growth directions of the plates.
just a topic to discuss. Ive got recently some horns to process. This is what ive noticed.
Horn 1 - Bob and Horn 2- Alice
Bob abd Alice had the same shap at the beggining (not the best raw product, twisted, curly, etc...) as portrayed in the 1st picture.
I took Bob and cut it without following the growth direction. I had previosuly flattened it with warm water at 75C for half an hour. I left it to dry for 20 days plus less and to flatten inasmuch as possible in a workbench with press at around 100#/cm2. When I put it there , the temp in the room with the bench was minus some C. Today I discovered that a lot of cracks tiny ones, had appeared from side to side following the thickness axis. Like a microscopy of a hair with broken ends, if you understand...
The picture of Bob before processing is the second one.
I took Alice, and did the same, but following the direction of axial growth, third picture, but for flattening, i preferred to put in a press at room temperature, surrounded by heat guns at 50 C plus less (no close contact). NO CRACKS.
The first one to me is a classic of pressurized thermal shock - PTS. Though I cannot be sure because of the different growth directions of the plates.