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Go Back   SailNet Community > General Interest Forums > Gear & Maintenance
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Old 03-17-2007
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Galvanic Corrosion

I'm looking at a corrision probem inside of my stearing pesital. One of the four 1/4" x 20 x 4" ss bolts holding the alimimun housing together doesn't want to budge. I doused it with KOIL penitrating oil about a week ago, but I'm not expecting any progress when I check tomorrow. Applying heat to the area would do more damage than good. I suspect I will be forced to cut the bolt off, (I have room to use a dremel.) drill it out then retap for a larger diameter bolt.

Anybody have another suggestion?
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Old 03-17-2007
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You might consider hitting the bolt with a few shots of PB Blaster (avail at any automotive section) - may work better than "KOIL". A 1/4" bolt may be too small, but if Blaster dosen't work, I would drill a 3/16" hole into the center of the bolt's head, then insert the appropriately sixed bolt extractor into the hole - (left hand threaded bit) and back the bolt out. This way you may not need to retap the bore.
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The easy-out is a good idea. It would be worth a try before retaping
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Old 03-17-2007
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Frozen nuts

Had a bunch of these on my mast. I had 100% success by turning the nut just a little and then turning it back to its original location. This breaks up the corrosion and allows you to turn it a little farther off. I just repeat the turn it off a little more then turn it all the way on until the nut frees up.
Good luck
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Old 03-17-2007
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Have you tried heating the bolt with a torch?? That can often break the bolt free of the corrosion binding it.
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I have tried this back and forth action, so far, no good. The bolt is a standard screw head 4" long. It extends through the upper attachment (about 3/8" thick) then there is a gap until the bolt connects to the lower attachment (again about 3/8" thick) with about 3/8" of the bolt extending thourgh the threaded lower attachment. It seems that most of the twisting power at the head is lost in bolt torsion. I might add, the housing is cast aluminum, so hammering would be a no, no.
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Quote:
Originally Posted by sailingdog
Have you tried heating the bolt with a torch?? That can often break the bolt free of the corrosion binding it.

Saildog, Any amount of heat would scorch the finish on the pesital.
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Rats...

After you get the suckers out...definitely use either TefGel or Lanocote to help prevent the problem from re-occuring next time.
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Old 03-17-2007
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Would the finish stand a kettle of boiling water?
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Old 03-17-2007
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Quote:
Originally Posted by sailingdog
Rats...

After you get the suckers out...definitely use either TefGel or Lanocote to help prevent the problem from re-occuring next time.
Saildog, for sure on the protective coatings.... Mastering these challenges are part of the rewards of our sport... Hell, what I really want to do is go sailing.
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