Removing the Delrin Screw from H16 Lower Rudder Casting
By Gary Willcox
I have done 4 castings now using a wood boring bit. It works great and I haven't had any problems damaging threads. Use a 7/16" or 1/2" wood bit the ones with the leading center tip. That tip keeps the bit centered in the delrin screw hole. You will then have a thin shell of delrin still in the threads. The old delrin is so brittle that you can chip it out with a screw driver.
For complete details, see OTW archives at:
home.earthlink.net/~mattson/hobie/archives/v1-i8/feature2.htm
Gary Willcox
P.S. Matt Miller of Hobie suggests that delrin fumes from torching is very toxic. If trying that method, do it outside!