Winches through bolted to mast?/unsticking bolts

[Cavalier]

Firstly, Nick: either that or just scuttle it and be done with it!

On a more serious note...
FWIW I would follow Jim and Cheechako's advice in that order: impact-driver first followed by filling out the offending screws. The type that have been used will probably be poor quality anyway as the A4 which should have been used (along with a suitable anti-cease or anti-cold-weld compound cost considerably more than their cheaper/softer/weaker cousin.

I'd avoid excessive heat around the mast as much as possible: you don't want a cold-extruded section to suddenly become a considerably weakened "heat affected zone" due to the near-weld temperatures - your stuck screw problem could be turned into a weak-mast problem due to a heavy-hand! and that would be unfortunate....

Brains with a little brawn will bring a sweet resolution to this one: plus your forearms may still have enough strength left in them to lift a celebratory glass at the end of the job!

[Cavalier]

Arrrgh: I meant drilling not filling.. bl00dy iPhone auto-correct is the Bain of by existence!

#firstworldprobs

[Cheechako]

Originally Posted by Nemo55

What is so hard to understand ?? the momentary arc causes the rust and or Corrosion to burn away leaving you with clean thread.

Yeah.... I'm having a tough time believing this one. Definitely would like to hear if it works though. Somehow I'm visualizing a slot head screw (which arent worth crap to start with) with the slot melted into a mess that you cant put a screwdriver in......

[daddle]

There may indeed be nuts on the bolts. Spar builders have very long arms ... and some other tricks. Sometimes there is a slot nearby that is used. Or a hole under a fitting nearby. Or they mounted them while the spar was in the shop.

[Cheechako]

This is a good point missed along the way.... I remember putting nuts on something when the mast was in the yard. taped the lock nut into a wrench that was taped to a broomstick...!

[Nemo55]

The arc will travel first to the weakest grounding spot,,which for our purpose is the rust/corrosion around the threads.
In no way am i suggesting to bring the contact long enough to deform or overtly heat the offending Nut or screw.
Thus...i am not suggesting to damage the Aluminum mast in any way.
And of course if you can use good old Armstrong power then it gets better yet,,The Arcing method is usually used by someone who knows what they are doing in any case.

[roverhi]

The only way you can destroy the slot in the screw is with the screw driver. I suppose if you held the positive side bolt against the screw head you could weld the two together. So far, haven't been able to do that even though occasionally heating the fasterner to a cherry red color. The beauty of using electricity is that you heat the bolt and only secondarily transfering heat to the aluminum. The bolt expands quickly which helps to break the hold of the corrosion. When you spray the heated bolt with penetrating oil, it rapidly cools hopefully sucking some of that fluid into the threads. In any case, with fasteners threaded into the aluminum extrusion, the trick has worked everytime I've tried it and I'm working on fasteners that have been in the aluminum for 43 years.

A torch, at least MAPP gas, doesn't seem to work possibly because you are heating the mast as well as the fastener. There isn't as much heat applied directly to the threads or as great a differential of expansion around the threads.

Haven't used it on aluminum cleats and aluminum winch mount castings, however. On my mast, had drilled the heads off the fasteners to remove the reel winch before someone turned me onto the jumper cable technique. These are serious corrosion problems because of the large area of the fastener that is exposed to the aluminum. Will be tackling that shortly. Did use it on fasteners in the aluminum castings on my self steering vane. Took several days and multiple heating and quenching but the fasteners came out eventually.

Try it, you might like it. It's also motivation to buy a set of jumper cables, if you don't already have a set. No one should be without jumper cables.

[Cheechako]

Originally Posted by roverhi

The only way you can destroy the slot in the screw is with the screw driver. I suppose if you held the positive side bolt against the screw head you could weld the two together. So far, haven't been able to do that even though occasionally heating the fasterner to a cherry red color. The beauty of using electricity is that you heat the bolt and only secondarily transfering heat to the aluminum. The bolt expands quickly which helps to break the hold of the corrosion. When you spray the heated bolt with penetrating oil, it rapidly cools hopefully sucking some of that fluid into the threads. In any case, with fasteners threaded into the aluminum extrusion, the trick has worked everytime I've tried it and I'm working on fasteners that have been in the aluminum for 43 years.

A torch, at least MAPP gas, doesn't seem to work possibly because you are heating the mast as well as the fastener. There isn't as much heat applied directly to the threads or as great a differential of expansion around the threads.

Haven't used it on aluminum cleats and aluminum winch mount castings, however. On my mast, had drilled the heads off the fasteners to remove the reel winch before someone turned me onto the jumper cable technique. These are serious corrosion problems because of the large area of the fastener that is exposed to the aluminum. Will be tackling that shortly. Did use it on fasteners in the aluminum castings on my self steering vane. Took several days and multiple heating and quenching but the fasteners came out eventually.

Try it, you might like it. It's also motivation to buy a set of jumper cables, if you don't already have a set. No one should be without jumper cables.

This sounds pretty cool. I'm having trouble understanding exactly how you do it though...? How do you put the neg lead on the inside of the stuck bolt? Then you just touch the pos to the head of the bolt? How big a battery do you need? how long does it last?

[Nemo55]

The average welder uses between 90amps and 120amps,,your batteries are rated for minimum 80amps(one battery)the amps go up with more batteries in the circuit.
You really don't need very many amps to perform this trick.
Case in point have you ever crossed the terminals on a car battery whilst jump starting? and you notice the bright flash and very hot results??
What you have seen is the Arc which is nothing different from what you will see from a welder.
As yo connecting up your cable terminals, you only have to make a solid connection at the mast itself
(as near to the offending bolt or screw as you can get) i use vise grips to make the connection solid.
Then use another set of vice grips or suitable spring loaded jaws of the jumper cables to a suitable bolt(this is what you will momentarily use to produce the arc) and make contact with the bolt or nut on the mast.
Because you are sending the voltage from each side of the battery through the mast from one side, and the bolt/nut from the other side the arc will occur mostly at the rust or corrosion.
Resulting in the freeing up of the bolt.(this goes much better if you have some one twisting the stuck bolt/nut off while you arc it.

I can show you how to de-rust steel or stainless using electrolysis as well if you ever need to. using battery DC power also.

Originally Posted by Cheechako

This sounds pretty cool. I'm having trouble understanding exactly how you do it though...? How do you put the neg lead on the inside of the stuck bolt? Then you just touch the pos to the head of the bolt? How big a battery do you need? how long does it last?

[roverhi]

The negative lead gets clipped as close to the offending bolt as possible. It doesn't have to be attached to the bolt, just something that will conduct electricity from the bolt. The extruded mainsail slide track is a convenient place on my mast.

The amperage draw is high but of very short duration. Even multiple applications doesn't draw much juice. Suppose if you were doing production work like a spinnaker track you could run the battery down but I've never done it. Have not had a problem running the battery down. Normally hook it up to the relatively small starter battery, group 24 IIRC.

When you hit the head of the fastener with the hot lead you get a snap as the arc current flows. A little unnerving at first. Have held the lead on the fastener head long enough that it got a bit sticky but as long as the current is flowing, you won't weld it to the fastener.

[FrankZ]

When taking the mast head off I had some issue with seized machine screws. What worked for me was a hammer, a tight fitting screw driver with squared shaft and a wrench.

Have someone tap and you apply pressure to the wrench fitted onto the shaft of the screw driver. At first it didn't seem to make a difference, then you realize it is turning, slowly. As you break the corrosion it goes a little quicker.

Time and patience can work wonders.

[roverhi]

The fasteners are out but the mast head still won't move. I've about resigned myself to sawing it off and adding a 2" riser at the mast base.

[hellosailor]

I wouldn't use heat on the mast, I'd be afraid.

What about using a grinder to grind the heads off the bolts, or a cobalt bit to drill them out if they are not "headed" ?

My first choice would be to hit them with PBlaster a couple of times, hours apart over 48 hours. If that and an impact hammer didn't work, I'd grab the old CO2 bottle and ice them down, which tends to loosen up everything. Loctite also sells a new freeze spray penetrant in a can, worth a try. Or you can buy a block of dry ice, smash it up into chips, mix it with alcohol to make a slush, and apply the slush with a towel over the area. That'll also ice it down nicely.

Thermal shock, impact hammer, grinder or drill if you have to. They'll come free.

Maybe someone really clever threaded them into the mast, or eased a backing plate inside of it while it was horizontal.

[FrankZ]

Originally Posted by roverhi

The fasteners are out but the mast head still won't move. I've about resigned myself to sawing it off and adding a 2" riser at the mast base.

I had to convince mine with a hammer and a piece of wood.

[Tellie]

Originally Posted by Nemo55

The average welder uses between 90amps and 120amps,,your batteries are rated for minimum 80amps(one battery)the amps go up with more batteries in the circuit.
You really don't need very many amps to perform this trick.
Case in point have you ever crossed the terminals on a car battery whilst jump starting? and you notice the bright flash and very hot results??
What you have seen is the Arc which is nothing different from what you will see from a welder.
As yo connecting up your cable terminals, you only have to make a solid connection at the mast itself
(as near to the offending bolt or screw as you can get) i use vise grips to make the connection solid.
Then use another set of vice grips or suitable spring loaded jaws of the jumper cables to a suitable bolt(this is what you will momentarily use to produce the arc) and make contact with the bolt or nut on the mast.
Because you are sending the voltage from each side of the battery through the mast from one side, and the bolt/nut from the other side the arc will occur mostly at the rust or corrosion.
Resulting in the freeing up of the bolt.(this goes much better if you have some one twisting the stuck bolt/nut off while you arc it.

I can show you how to de-rust steel or stainless using electrolysis as well if you ever need to. using battery DC power also.

Maybe I'm missing something here. You're describing dead shorting a house bank battery. Just because it's rated for 80 amps does not mean it will only deliver 80 amps when shorted. You could blow a 600 amp fuse with a 80 amp rated battery by dead shorting the fuse. A welder and a battery are two different sources of amperage. Two different things all together, and what happens when you touch this rig and the bolt instantly welds itself to the bolt trying to be loosened?
Again maybe I miss understood your rig, but I'd be real careful suggesting this procedure.