Removing a mid-ship cleat after 25 years (Hunter 40.5)

[Rich Stidger]

I have a 1997 Hunter 40.5 and I have a broken roller on both mid-ship cleats. I have machined new rollers to replace all four in the two cleats. The aluminum cleats are bolted to the aluminum toe-rail with stainless fasteners. I believe that the fasteners are carriage bolts that engage a square opening in the cleat. So I loosened the mounting nuts which was very easy and leaving the nuts on the bottom of the bolt to protect the threads, I tapped the bottom with a 16 ounce hammer. No joy. So I soaked the heads and the bottom threads with PB Blaster for a couple days and periodically tapped the bolts. Still no joy.

I am certain that the problem is aluminum corrosion that has frozen the bolt into the cleat. I tried soaking the bolt and threads with vinegar hoping that the acidic vinegar would help to dissolve the corrosion. Well that didn't work either. Going up to a 2# mallet was non-productive too.

I have read that nitric acid will dissolve aluminum corrosion without damage to the actual aluminum, but I am not convinced this is completely true and if it is, I don't know where I could get any nitric acid.

I can replace the bolts so damage to them is acceptable. I am beginning to conclude that drilling the bolt with increasingly larger bits is the only solution.

Suggestions and comments from all of the experts?

 

[jon hansen]

blaster is fine, however i switched to kroil and have much better results.

love the kroil!

my $0.022, jon

can still take awhile for soaking

 

[Mark Maulden]

Double nut on the bolt tightly and see if you can turn it with appropriate sized wrench..

 

[Rich Stidger]

Double nut on the bolt tightly and see if you can turn it with appropriate sized wrench..

Good suggestion, but since there is no head on the bolt that a wrench could engage, I am pretty sure it has to be a carriage type bolt with a square underside that engages the cleat. Without that type of bolt you would not be able to tighten the nut. So in this case I don't think your suggest would work. But is is a good thought for many situations.

 

[jssailem]

If the bolt is expendable and shaped as you believe, then grinding off the head may let you lift the cleat off the bolt and give you access to the remaining bolt. A Dremel tool may give you the precision you need to grind the bolt head and not destroy the cleat.

 

[jssailem]

There are all sorts of chemical concoctions to try and dislodge a corroded fastener.

I dislike the odor of PB Blaster.

A bigger hammer may also be a consideration. Up from beneath.

 

[dLj]

How much room do you have under those bolts? Do you have room to put like a pry bar and put pressure upwards while tapping the head side? If you have room, I'd take one of those nuts, set it flush with end of the threaded section of the boat and use a long pry bar - like two or three feet - whatever you might have ( as well as room to use) and have one person push up on those bolts with the pry bar. The second person can take a light hammer and tap the head of the bolt. While I realize that's in the opposite direction of the bolt coming out, the vibrations may break loose the corrosion and the upward pressure of the pry bar may begin to push the bolt vertically. You can probably do this alone, but working with two people would be a lot easier...

Those sure do look like carriage bolts to me...

Nitric acid - now that's interesting one - in concentrations above about 80% nitric acid, there will be little problem with Al deterioration, however at around 20% concentration, there will be degradation... It follows a rather unexpected curve. Aluminums are generally resistant to high concentrations of nitric, but not low concentrations of nitric. I'm not sure if this helps you or not. I've no idea if concentrated nitric acid removes the oxide that is holding these in place - my guess would be not really the best way to go... But I don't really know...

dj

 

[Rich Stidger]

How much room do you have under those bolts? Do you have room to put like a pry bar and put pressure upwards while tapping the head side? If you have room, I'd take one of those nuts, set it flush with end of the threaded section of the boat and use a long pry bar - like two or three feet - whatever you might have ( as well as room to use) and have one person push up on those bolts with the pry bar. The second person can take a light hammer and tap the head of the bolt. While I realize that's in the opposite direction of the bolt coming out, the vibrations may break loose the corrosion and the upward pressure of the pry bar may begin to push the bolt vertically. You can probably do this alone, but working with two people would be a lot easier...

Now that is a good thought- I could put both nuts at the bottom end of the bolts, then take a pry bar and put the tip on top of one nut (maybe add a heavy washer to better hold the tip of the pry bar) and the body of the pry bar on the bottom of the other nut. Then lift up, pulling down on one bolt but exerting force upward on the second bolt. Tapping could help on the upward bolt. If that works, then just reverse the effort by putting the tip of the pry bar on the opposite bolt and push up on the other bolt.
A second person would be invaluable.

EDITED TO ADD: Maybe I could use a tie rod end separator ball joint puller- the type that looks like a two-prong fork. With the fork inserted above the washers and levered against the bottom of the other bolt it could be more secure than just the tip of a pry bar. A pipe fitted over the end of the puller could give extra leverage to push upward.

 

[Rich Stidger]

blaster is fine, however i switched to kroil and have much better results.

Jon- I have used both PB Blaster and Kroil and have found no benefit of one over the other. But I can give the Kroil a try. Nothing to lose...

 

[PaulK]

What about applying a little heat? The differing expansion rates might crack the bond.

 

[jon hansen]

my %S have been much better with kroil. my friends report the same.

of course, could be dumb luck.

it is a different formula

like the heat idea too

 

[RoyS]

C Clamp?

 

[Rick D]

Following....same issue. With your attention to detail and serious maintenance, someone will someday be fortunate to get your boat.

 

[sailcapt340]

Roy is on the right track. I went looking at some of my “special” tools I have made for all kinds of various reasons. And the one that stood out was a clamp I heated up, placed in a vise and bent it to make it an offset clamp. By just about an inch or so. It’s around here somewhere or I’d show you a picture.
I used it years ago on a frozen brake bolt on an antique car.
But you get the idea, bend it just enough to sit right next to the bolt head and apply steady even pressure on the threaded end (with nut still attached). The force should be enough to raise the bolt, even if its enough to get a blade under the head and cut it off.
Slow and steady is the key to not cause surrounding structure damage.
It’s worth a try.

 

[Rich Stidger]

C Clamp?

Putting a piece of wood across the top of the cleat and using a C-clamp from the top of the wood to the bolt was my first idea. Unfortunately my largest C-clamp wasn't big enough. I will try again with a 1/4" steel plate instead of a 1" wood piece. That could still work.

 

[sailcapt340]

Rich,
Looking at your picture again I can see you’ll need a large clamp. They’re available. And the steel plate is a better idea on the cleat than wood. You just need constant pressure, lubricant and patience. Good luck your on the right track.

 

[jhkessler]

If you have the clearance, I would use a large "C" clamp as a press, put a large Deep Well socket over the bolt head to clear the chock's ears, much better control than a hammer. Good luck

 

[JamesG161]

But I can give the Kroil a try. Nothing to lose...

Try brake fluid, it worked than PB Baster in study I found.

Jim...

 

[RoyS]

Regarding penetrating oil, magic spells work just as well.

 

[Crazy Dave Condon]

@Rich Stidger

Maybe time to talk with Joe Kerr or Al Fooks on the help desk as they are former Hunter employees