I have a question about tapping existing holes on the mast
to a larger thread size. I have three blocks on eyestraps that are attached to the mast
by #10-24 half-inch machine screws.
Ultimately I didn't like the setup, so I have decided to replace the blocks with a different type, that require #12-24 half-inch machine screws instead. Luckily the center to center distances to the existing screw holes are exactly the same as needed for the new blocks. I want to reuse the holes in the mast if possible, and simply tap to the next larger size.
I have never tapped anything in my life, so I am a bit nervous about doing this. First, can a good tap be made into an existing threaded hole, that is so close in size? If not, I guess I will have to tap new holes, and use epoxy
putty to fill the old ones.
Assuming it can be done, any advise to a novice
on the steps to properly make the tap (or re-tap)? I will do it by hand, and be careful to stay perpendicular with the mast. I assume I should use tapping oil
, correct? It is an aluminum
mast, and fairly thick -- I estimate somewhere between 1/8 and 3/16 thick.
What spec of tap should I use? I have SAE tapset, but I haven't researched the exact tap specification needed to mate with a #12-24 screw. Also, I assume a right-hand tap is needed for righty tighty, correct? Any particular metallurgy for the tapset, or tap configuration for tapping into aluminum