The square cut end was not comfortable while pushing it with the palm of my hand, so I put a silicone rubber knob on it.
It has a narrower blade than my other trowel, which is good in some situations. For this kind of trowel, the blade width depends on the diameter of the pipe, and this is about the maximum diameter my hand wants to deal with in the handle part.
The pipe is 1 1/2 inch diameter pipe, and the blade is about 2 inches wide. Total length, 10 1/2 inches.
Step 1: Forging the Blade
Step 2: The Rubber Knob
First, I drilled four holes a little tight, for two nails to give something for the silicone to lock onto. Using direct extrusion, and a palette knife, I worked it around the nails. To keep the mass of rubber light, I then mixed some with Styrofoam granules filed from a block of Styrofoam with a rasp, and sculpted the knob. A final layer of pure silicone smoothed with the palette knife completed the knob.
The knob feels soft and comfortable.
Trowels cut through dirt and roots easier if they are sharp. The original angle cut of the pipe resulted in a sharp edge, which didn't need much touching up.