How do I get a stainless pin out of an aluminum masthead?

[bstreep]

Funny story: Had a Hood roller furler. SS fasteners stuck in aluminum casting (that's why the replacement is a Schaefer - every fastener has an insert). I tried everything from different penetrating products, acid, base, calcium carbonate (chemical reaction), heating/cooling. You name it.

I finally got a BRILLIANT idea. My 91 year old father (at the time) was a corrosion engineer (why didn't I think of this earlier?) So, I called him. Ran through the huge list of things that I had tried.

A bit of a pause on the phone... Then I heard "Son, don't you own a hacksaw?"

[RaymondR]

If it's not excessively long you can drill down almost through it and use a largish pin punch in the hole to drive it out. Effectively you are pulling it rather than driving and less likelly to rivet it into the fitting.

[stormsvale]

https://www.amazon.com/Buster-Power-.../dp/B074438D7D

Take a look at this....

Ciao

Mike

[double u]

cut pin outside & inside as close to aluminium as possible until only the portion in the holes - 2 little cylinders of stainless-remain.
Drill through center of these with bits, increasing their diameter
sooner or later you will be able to easily push the remaining Stainless out
don't hammer
don't heat excessively
if pin has to be saved at all cost: twisting effort. You can't damage much apart from the pin if you overdo it

[double u]

...& my "credentials": getting stuck axles of reefing lines at front & back end of boom out

[Jdege]

I was able to detach the mast heads from the masts without trouble, (though if the amount of crud around the threads is any guide, it'd not have been so easy if I'd left this for not so many years.)

So I have the heads in the shop, where I can use vice, drill press, etc. I basically want to take everything apart and put everything back together.

Is there some kind of protective goop I can use to prevent this kind of thing in the future?

[George_SD]

My father just helped me remove a stainless screw with a round head from the aluminum mast, even though it seemed to sit there "For good". He used Knipex Cobra (channel lock type of a tool) that has an unbelievably good grip and just rocket it back and forth until it started to move a tiny bit, then more and then just unscrewed it.

It gripped the round head without issues and didn't damage anything.

[RaymondR]

Is there some kind of protective goop I can use to prevent this kind of thing in the future?

Sikaflex 209 or equivalent to keep the water out. The yellow chromate stuff doesn't appear to work as well since they de-carcinagated it.

[Jdege]

Sikaflex?

I was thinking more on the lines of Lanocote - though I didn't remember the name when I asked.

Does Sikaflex work better.

[lifeofreilly57]

Tapping the pin with a hammer will.mushroom the end and possibly deform the groove for the retainer clip.
Try any form of penetrant and a soft hammer.
If that doesn't work try heating the aluminum with a propane torch. The aluminum will absorb heat faster and expand, breaking the corrosion bond. You don't want to heat the aluminum too hot since it can cause issue with strength and stress cracking, just enough to break the bond.
In my previous life I was a Journeyman Millwright, I had to take apart many ancient corroded assemblies, especially in chemical plants. Corrosion is not my friend.
When reassembling use a compound like Lanocote, it will make it easier to get apart in the future.
That includes any fasteners of dissimilar material going back into your mast, it also helps prevent future corrosion in those interfaces.

[RaymondR]

Originally Posted by Jdege

Sikaflex?

I was thinking more on the lines of Lanocote - though I didn't remember the name when I asked.

Does Sikaflex work better.

You need something which stays flexible over time. I put aluminium cleats on the deck of my steel boat 30 years ago and there has never been any corrosion at the cleat/deck joint in all that time.

It proved that effective that I started to Sikaflex thin aluminium gaskets under anything I might need to remove, such as turning blocks, winches etc, to paint the deck or which might be inclined to move under load.

[Jim Cate]

Originally Posted by double u

cut pin outside & inside as close to aluminium as possible until only the portion in the holes - 2 little cylinders of stainless-remain.
Drill through center of these with bits, increasing their diameter
sooner or later you will be able to easily push the remaining Stainless out
don't hammer
don't heat excessively
if pin has to be saved at all cost: twisting effort. You can't damage much apart from the pin if you overdo it

An interesting approach! By cutting the pin into two short pieces you immediately reduce the friction by half on each one, and that can be significant. And then if one is forced into the "drill it out" method after all, the depth of the hole is MUCH shorter and it becomes practical to do with a hand drill.

I'd never considered this method before, and hope to never need it, but thanks for the idea... hope I remember it if the time comes!

Jim

[Don C L]

The seized pin in my spinnaker pole is now marinating in weasel piss (transmission fluid and acetone mix)... never tried this remedy, will report back in a few days!

[oiam]

had a similar problem on an aircraft part,,, soak with pb blaster or other similar product. immerse if possible,,, anything with a linseed oil (personal preference) in it will creep into the joint,(linseed oil has a characteristic of creeping and spreading thin as possible on all available surfaces),, 24 hours should do the trick.
then just tap with hammer

[LWatson]

We used to hit the stuck part with a good shot of Freon 12, very cold and worked well. Of course that cannot be done today but I bet there are other gasses to use, nitrogen comes to mind, just be careful.