Here is my suggestion, incorporating the previous contributions also:

Heat up head of bolt with small and pointy but hot flame (watch out not to
melt alu), next once the heat has transfered to the threaded stuck part ,but
alu is solid, hammer the bolt head in as to nail it in to the thread.
Obviously you dont want to pulp the threads (so dont use a sledge), just
loosen it, apply WD40 or similar and keep repeating these steps.
After 2 o 3 of these cycles carefully try with a wrench ; try both
directions , yes tighten it ,and move bolt if reasonable force will do it.
Again dont force, dont twist off bolt head; be really carefull.
Start the heat procedure again. Persistence pays off, and you should get new
bolt , but this time use antiseize compound suitable to location (galvanic
reaction).
Drilling out is the last resort and sort of problematic because alu is much
softer than S/S and drill bit tends to wander. Start with small bit right in
center.If you apply penetrants through that small hole to the deep end of
bolt/hole it just may come off .
Remember you are the skip ,you are the boss not the bolt!!!

cheer miks

One other suggestion: when you do put a wrench on the bolt, try tapping
the wrench handle with a hammer as you apply moderate pressure. And as
Miks says, as soon as you get any motion, try going the opposite way
instead of doing what comes naturally, i.e., applying all your muscle
in the unscrew direction. This will result in removing the bolt head,
not the bolt!

Rob

In article .com,
says...


One other suggestion: when you do put a wrench on the bolt, try tapping
the wrench handle with a hammer as you apply moderate pressure. And as
Miks says, as soon as you get any motion, try going the opposite way
instead of doing what comes naturally, i.e., applying all your muscle
in the unscrew direction. This will result in removing the bolt head,
not the bolt!

Many thanks to all for your suggestions. The bolt is not threaded where
it is within the aluminum casting so it is really more a pin with a
threaded end on which is screwed a reataining nut. Ha! Quite unnecessary.
Don't want to use heat. Attacking the bolt head started to twist it off.
I am going to get a cutoff wheel, cut through the pin on both sides of
the turnbuckle to free the forestay then drive out the remnants of the
pin, or drill them out.

Gogarty wrote:
In article .com,
says...


One other suggestion: when you do put a wrench on the bolt, try tapping
the wrench handle with a hammer as you apply moderate pressure. And as
Miks says, as soon as you get any motion, try going the opposite way
instead of doing what comes naturally, i.e., applying all your muscle
in the unscrew direction. This will result in removing the bolt head,
not the bolt!


Many thanks to all for your suggestions. The bolt is not threaded where
it is within the aluminum casting so it is really more a pin with a
threaded end on which is screwed a reataining nut. Ha! Quite unnecessary.
Don't want to use heat. Attacking the bolt head started to twist it off.
I am going to get a cutoff wheel, cut through the pin on both sides of
the turnbuckle to free the forestay then drive out the remnants of the
pin, or drill them out.

Good news.
But consider leaving one side intact so you have smething to twist a bit
when the pin begins to move and keep soaking in penatrating fluid to
help lub it on the way out. If you take a fitting or small diamiter pipe
just larger than the pin that someone can hold on the other side of
where you are hammering the pin the impact will be much greater and put
less strain on the aluminum cast. Aluminum fractures easily.
Let us know how you make out.
Good Luck.