|Topic Review (Newest First)|
|07-16-2009 03:29 AM|
Yep. My crew is much more tool-savvy than I am and they gave the same advice. We started off going slow and being generous with the oil. I found that the bit seemed to cut better (felt like it was cutting) at the lower speeds. However in spite of all the concern about heat, the bit never heated up... I think the mast might act as an enormous heat sink.
Anyway I think now it's time for a couple of sharp new bits to go at it... I feel like I'm not really making progress anymore.
|07-15-2009 10:30 PM|
|sailingdog||In addition to what FULLKEEL7 said, you want to have the bit turning slowly enough that you can watch the individual flutes rotating... if you can't you're probably turning it too fast.|
|07-15-2009 02:01 PM|
|fullkeel7||Adam, If you are aware of this already, my apologies. In addition to using a sharp or new bit, the key to drilling SS or any hardened steel, is to keep the bit speed to a minimum. Heat is your worst enemy, so trying to drill into steel at the same speed as say aluminum, will only prematurely dull the bit and harden the steel. A little machining oil applied by a helper while drilling helps to cool things down as well.|
|07-15-2009 01:58 PM|
That does help a lot. I have noticed that newer bits drill in pretty quickly... but then my newer bolt blew up and I switched to an older bit which was not significantly sharper than my thumb. I guess I'll grab some new bits and grinding wheels so that I'm not dependent on my friend's angle grinder.
As for the metal bits, I'm thinking of draping a wet bed sheet around the A-frame, which is still in place.
Thanks for your input!
|07-15-2009 01:17 PM|
|donlofland||1)I was using new drills, and it took 5-10' to drill the threaded end of the bolt down to just inside the inside wall of the mast. 2)I used a Saws All (?spelling) to cut the hex head off the bolt between the aluminum spreader bracket and the hex head. I found SS bolts cut fairly easily but are difficult to drill! Then ground it down flush with the outside of the mast and drilled until it fell inside the mast-by some fortuitous quirk of fate, the bolt did not spin as I drilled it. For grinding I used a grinding wheel on my drill...3) the mast was in my back yard, so flying bits of metal were not a problem. 4) the mast was stripped down to nothing but a bare extrusion, and the PVC pipe routine worked, but was very tricky. And they're right about not over-torquing the upper spreader bracket bolt-it's easy to dimple the mast! 5) Hope this helps! Good luck!|
|07-15-2009 03:06 AM|
Happily I've just run into exactly the same problem today. Exactly exactly (same boat even). I've started drilling into available end of the bolt but it's taking a long time and it's a real PITA... we've already broken one titanium drill bit. Hopefully not much more to go before I can turn the mast over and grind off the hex cap on the other side.
Couple of questions for you since you've been through it:
1) About how long did it take you to drill out the threaded end of the bolt? How deep did you go?
2) What setup did you use to grind the hex cap off the cap end of the bolt? I'll probably have access to an angle grinder. I don't think I'll have enough clearance to get between the cap and the tang. I'm considering grinding right through the old cast aluminum bracket to essentially cut off the bolt.
3) When the little bits of burning metal are flying around, how did you prevent them from getting all over your gelcoat (and your neighbors' gelcoat)?
4) Any other gotchas during the bracket replacement after that?
I'd say, "Thanks for having this problem three months ago," but I wouldn't wish this work on anybody. Thanks for solving this problem and posting about it, I guess
p.s. I can confirm that on the C27 the tang bolt hole is wide enough for the bolt, but not for the compression tube. The instructions that come with the spreader bracket retrofit kit from Catalina Direct suggest cutting a notch into a 20-or-so-foot-long PVC pipe and using that to feed the tube into the mast.
|04-08-2009 12:26 AM|
So here's how I did it, thanks to all your input!
I cut off the thread end of the bolt close to the mast, ground it flat, center punched it and then drilled end on into the bolt until that end no longer met the inside wall of the mast, (using a 5/16" bit into a 3/8" bolt). Then I turned the mast over, cut the head off the bolt, and did the same from that side. It fell off into the mast and I fished it out.
|04-05-2009 07:39 PM|
Originally Posted by US27inKS View Post
Originally Posted by Knothead
|04-05-2009 06:09 PM|
|US27inKS||I would guess that the hole on the bolt head side is large enough for the compression tube to slide out. If you drill out the rivets on the bracket you should be able to remove the bracket and bolt together. If this is not the case, I would vote for cutting the bolt head off and enlarging the hole to slide the tube out. Trying to hammer or press the bolt through will likely damage the mast before the bolt comes out.|
|04-05-2009 05:08 PM|
Let it spin and it might develop enough heat to either break the crap off the bolt or the pressure from the wood block will wear the alum out.
Originally Posted by knothead View Post
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