Seized tang bolts in aluminum mast

[phorvati]

What is the best procedure to get these out. The one I managed to get out, has cracks in link bolt. See pics.

[roverhi]

Had a similar problem with a 3/8" bolt in my self steering vane. Used the jumper cable trick to alternately heat and then quench with penetrating oil and an impact wrench to get the bolt to turn. Would turh minutely at first but the range of rotation gradually increased over a period of a few days till it finally came out. Hit the bolt 3-4 times a day over a period of three days. Gave the penetrating oil some time to soak in. Reinstall with Lanacote so it won't happen again.

Jumper cable trick.
You might try the jumper cable trick. Hook jumper cables up to the battery as you normally would. On the other end put a bolt (1/4" x 2" bolt works fine) in the postive lead clamp of the jumper cable. Clamp the negative lead as close to the offending bolt as possible. Touch the bolt in the positive lead clamp to the head of the fastener. You set up what is essentially an arc welder. Will heat the fastener to a cherry red if left in contact long enough. It also gets the fastener way hotter than you can with a MAPP torch. It works really well to heat up just the area of the fastener and not burning up the surrounding country side like you do with a torch. Really the only way to get serious heat to a fastener if there is painted surfaces or plastics close by. Quench the heated fastener with penetrating oil. Try to remove the fastener with an impact driver, either manual or power. Repeat the process till you break the fastener loose. Other than using the trick to remove all the fasteners on a 44 year old mast, used it to get corrosion welded bolts out that passed through substantial aluminum castings on my self steering vane.

Having said the above, the hardest fastener to remove is not one that is threaded into aluminum but one that simply passes through an aluminum casting like cleats, etc. Getting the bolts out of the self steering casting took something north of 25 iterations, heating with the jumper cable and quenching with penetrating oil over many days. A good idea to coat the shaft of any fastener in aluminum cleats or castings with Lanocote.

[billknny]

Keep it simple...

It is all metal... just heat the crap out of it. Oxyacetylene if you can, MAP gas will probably work, even propane will more than likely work. You really can't get it too hot. No phase changes or other problems with aluminum.

The different coefficients of expansion between stainless and aluminum will break them free. I have never had it fail.

As an alternative, a nut splitter will get the nuts off. They are cheap to replace.

[sailah]

Use heat, although I like the jumper cable trick and will try that. I have a TIG welder I would imagine it's the same process.

But anyways use heat, try and apply to the aluminum vs the steel. As mentioned the differential in thermal expansion is your friend. I've used ice cubes to cool the part I want to shrink.

Then apply penetrant like Kroil not wd40 and let it work in. Do this entire process a few times. Impact helps if you have that available. I have a big 18v Makita impact wrench that has more power than my pneumatic tools. That, heat and penetrant are my first lines of offense. Heat is most important.

[sailah]

And that's a bolt yes does not thread into mast? If so I'd still try the impact to break the bond.

But loosen the nut so that you have all the bolt thread covered. Now you can hammer on the nut with out peening over the bolt threads. Once it starts to move you can use a brass drift to hammer against. If you start smacking the bolt it will peen over and jam in that aluminum boss.

[phorvati]

Using sledge hammer to hit the nut from underside is not feasible? Bolt does not thread into the mast. As you can see from the one I managed to get out, these bolts are big. 1/2" diameter. tang pin diameters are 5/8" and 3/4". there is a welded aluminum tube in the mast. Non threaded section of the bolt goes through it. And threads are only at the ends for both nuts. One nut is welded onto the bolt and the other is used to tighten, and also has a hole for cotter pin.

[Gary Mc]

If it just passes through the mast and is only held by the SS nuts then just take a mini grinder and grind the nuts off.



I took all fitting off of my mast to paint it. Had good luck with soaking it with Liquid Wrench and tapping the bolt/screw when applying torque. Got everything free which amazed me after 25 years salt water exposure!


Good Luck
Gary

[stormalong]

Battery idea sounds risky. Have you ever seen a battery explode? I have.

If you are in a boat yard with a metal fabricator get the guy to heat it with a TIG welder.

[Cheechako]

Those are a bitch for sure. Impact and heat. Coat the new ones with lanolin and they wont do that.

[DocHolliday]

If using heat, the candle trick works well: while the bolt is hot apply a candle to it, which will melt and wick into the gap between the stuck parts.

I steal all of the used birthday cake candles....

[roverhi]

Originally Posted by stormalong

Battery idea sounds risky. Have you ever seen a battery explode? I have.

If you are in a boat yard with a metal fabricator get the guy to heat it with a TIG welder.

If you are dumb enough to leave the jumper cables attached till the battery melts, yes there could be a problem. You only need to have them touching the offending fasteners for a minute or less to heat the bolt. Not nearly enough time to cause any problems. I've been using the jumper cable trick for years and it's almost always worked to free a fastener wtihout melting the surrounding aluminum or hurting the masts finish except where it's directly touching the fastener. Fasteners passing through large pieces of aluminum like cleats or the mast sleeve in this case are the hardest fasteners to get loose so. FWIW, an arc welder like a tig machine work the same as the battery cable but require AC source to work and cost a bunch of money if you don't already have one or one that you can borrow. Most of us already have the jumper cables in the car so it's the most cost friendly way to get heat to the fastener.

Anyway, if you want to try beating the crap out of the fastener, burning up the mast, paint, and possibly even melting the aluminum with an acetylene torch or the largely useless low heat MAPP or propane torch, have at it.

[Paul L]

Originally Posted by stormalong

Battery idea sounds risky. Have you ever seen a battery explode? I have.

If you are in a boat yard with a metal fabricator get the guy to heat it with a TIG welder.

Aren't those exploding batteries charging, not discharging?

[Cheechako]

Originally Posted by DocHolliday

If using heat, the candle trick works well: while the bolt is hot apply a candle to it, which will melt and wick into the gap between the stuck parts.

I steal all of the used birthday cake candles....

Interesting you say that. I worked in aerospace. We had this one part, a pneumatic duct part that was kind of a high pressure ball swivel assembly. They were made our of Inconel and probably $1000-1500 our cost.. An assembler had a problem with one that seized on the threads and nothing we could do would get it apart. We took it back to my German toolmaker, he started to put the torch to it and I said "No way"! He said, just watch. He applied a little heat and melted paraffin in there , let it cool and it unscrewed by hand.

[phorvati]

I think I'll do the head gun or MAP gas, and wax or parafin, with hammer and torque.

As far as batteries exploding....You cannot treat something like a black box and think it will explode. Things don't just explode. Hydrogen explodes. Lithium explodes....now you have to consider what contributes to volatile circumstance. If you don't want to describe precisely what takes place to cause an explosion when you draw 500A out of the battery, please don't spread the panic.
Battery has cold cranking amps rating. I would imagine that it has been tested extensively, at those current draws without explosion. Otherwise nobody would ever start the engine. I could limit the current to CCA rating by using longer 1/0 AWG welding cable and clamp on meter to know whats being drawn. This would not risk any adverse behavior if there are any.
1 minute sounds like a lot. At 600A that would be 10AH.

[a64pilot]

MAPP gas burns I think around 3,000f. Most aluminum alloys melt around 1400f if memory serves, so be careful.
You may want to drop by a welding shop and buy a “melt stick” it’s like a candle with different melting temps, or now that I think about it this is another use for your IR temp gun.
I think some alloys of aluminum will lose their heat threat if heated to about 1000f. Not sure, but surely you don’t need to get the aluminum hotter than a couple of hundred?

Actually it looks like you can anneal aluminum alloys as low as 600f
http://www.tinmantech.com/education/...-annealing.php