Stuck Set Screw Shaft Seal

[sharkdiver84]

I have a Dripless Shaft Seal that was leaking, so intended to recompress the spring and put new set screws in. There was only one screw in each hole. When taking out the last one, it became tight right before i could get it out, and I stupidly tried to power through it.

Now it is completely stuck, and can't go in or out. What are my options here. I've considered drilling it out. That would damage the upper part of the screw hole, but if i leave enough threads on the part close to the shaft, I might be able to get one screw in. But I don't like that idea.

I'm considering just putting in the one screw, and then putting a hose clamp or shaft collar on to keep the rotor in place. Is a shaft collar or hose clamp sufficient to keep the rotor from moving?

I guess the only other option is to change the whole seal. But I don't really feel comfortable with that, and my boat has to leave this harbor in a few days.

Are therw any other methods of keeping the rotor and spring compressed without using the set screws?

[sailingharry]

You might havr better luck than you suspect in drilling out the screw. Over the years, I have drilled out many frozen screws and been able to reuse the threads. The trick is to start off undersized, and then go up one drill size at a time. You are almost guaranteed to be slightly off-center, and you will reach a point where you have mostly taken off one edge of the screw and it will become loose. The threads left behind will be plenty good to engage a new set screw. This approach is helped with the fact that since you don't have to go all the way in, the primary screw will probably still have perfect threads.

[sharkdiver84]

Ok I might try that, and then use a shaft collar to double secure it or in case I can't get it back in. Only thing is I don't think I'll be able to get a drill bit to work on stainless without a lot of pressure, and that is likely to keep breaking bits. I suck at drilling stainless and usually consider it impossible!

[JPA Cate]

sharkdiver84: use oil to lubricate the drill bit and float off the leftover bits of s/s. Also, be fairly gentle with those very small diameter bits. 1/16" and under are very breakable.

Ann

[capt jgw]

Try a left handed drill bit. A lot of times after drilling in a ways and heating the screw the bit grabs ahold and backs the screw right out. A machinist turned me on to these, he used them all the time. Any decent hardware store should have them, Harbor Freight does too.

[jamhass]

Had an identical issue. Bit of heat, penetrating oil and a LOT of patience did the trick. Best to try to avoid drilling, IMHO.

[sharkdiver84]

I tried drilling but kept breaking bits. Got it bored out carefully with my tungsten carbine Dremel burrs. Got better results than I expected. I was able to remove the material without badly damaging the threads. Then I screwed a bolt into it to repair threads. It went smoothly. Better results than I had hoped for. I think both screws will actually bite, not just the bottom one. Then I'm adding a shaft collar just to be sure.