Posthole Digger Importance of fishtail

   / Importance of fishtail #1  

orezok

Elite Member
Joined
Jan 30, 2004
Messages
3,230
Location
Mojave Desert, CA
Tractor
Kubota B7800
I'm in the process of planting 30 trees to create a windbreak. Eight of the trees fall in a soil zone of very dense clay interspersed with quartz monzonite which is an alumino-silicate. Translated into English, it's a very hard and abrasive material that will not drain. It is similar to caliche but orange in color..

I wanted to bore through the layer if possible with my phd. Originally I had standard dirt teeth on the auger. After partially completing one hole the standard teeth were completely ground off. I switched to hardface teeth and they did not fare much better. I finally got carbide teeth and they seem to hold up against the abrasiveness.

I did not go to a carbide fishtail (point) and while it does not seem to be wearing much, I am still unable to bore through this hard layer. My question is that how important is the fishtail in boring holes other than keeping the auger centered? I didn't want to spend another $100 if I didn't have to.

I do not have down force but I have 230# of weight on the auger head.
 
Last edited:
   / Importance of fishtail #2  
You best go to a 2" rock bit, and drop in a stick of dynamite or black powder charge. ;)
 
 

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