REMOVING SS screws from my aluminium Fortress Anchor

[salty001]

I'm back after a long absence from the forum. I need some advice about how to remove SS screws from my Fortress anchor's mud palms. My fortress anchor is a backup anchor one of three I have for cruising. Recently discovered the mud palms were tweaked a bit and Fortress has a lifetime warranty on the anchor. They have sent me replacements mud palms only now I can't get the old ones off. Fortress is an aluminium anchor and as we all know stainless screws in aluminium plus salty water is not a really good mix for corrosion.

I've tried drowning them in penetrating oil and using the biggest screw driver I can find but they haven't budged. I've heard that heating the aluminium might help and I'm wondering if a propane torch would work? I've also heard that an impact driver might help so I'm considering borrowing one from my local tool lending library. I'm in the process of trying to get my boat down to Mexico after bring chased out of the caribbean by Irma and Marie.

I've tried drowning the screws and nuts in penetrating oil plus using the biggest baddest screw driver that would fit the slot but no joy yet.

[salty001]

Help! I have a Fortress 23 aluminium anchor with mud palms. The palms are tweaked and Fortress has sent me replacement palms but I can't get the stainless steel screws and nuts out. They've been in there awhile and I've used the anchor on a couple of occasions over the years, so salt water plus SS screws plus aluminium seems to be maybe permanent, yikes!!

I've tried drowning them in penetrating oil and using the biggest screw driver I can find but they haven't budged. I've heard that heating the aluminium might help and I'm wondering if a propane torch would work? I've also heard that an impact driver might help so I'm considering borrowing one from my local tool lending library. I'm in the process of trying to get my boat down to Mexico after bring chased out of the caribbean by Irma and Marie. Thanks for any help! If I'm in the wrong forum please let me know best place to post.

[model 10]

Don't screw around with it, just break off the nuts with a big tool and buy new hardware.

[salty001]

Wish I could do that but it's impossible. I have all the new hardware but can't get the old hardware off not even by breaking it.

[a64pilot]

Originally Posted by salty001

Wish I could do that but it's impossible. I have all the new hardware but can't get the old hardware off not even by breaking it.

Well, yes you can. You either drive it out with a punch once you break off the nut, or you drill it out. Be sure to mark the center of the broken bolt with a center punch though so your drilling the center out.

I would give the impact a try first, they are real cheap, easy to use and I promise you if you have a Boat it will be used again.

Buy the cheap type you hit with a hammer, not the electric one.

If you drill SS, use a very slow speed, a sharp bit and lots of pressure and tap oil or your favorite drilling fluid, do not generate any heat, if you do the SS will harden as hard as a diamond.

[Benz]

Don't be afraid to apply some serious heat with a torch. Between that and penetrating spray such as PB blaster, added to impact, almost anything can be undone.
Re-assemble with Tef-Gel, or you'll be in the same boat in a couple years.

[model 10]

"Serious heat" is when spit just pops on the surface. It takes a lot of heat to do that, but there is no damage.

[ShellBack89]

What about heat with a heat gun?

[billknny]

Originally Posted by salty001

Help! I have a Fortress 23 aluminium anchor with mud palms. The palms are tweaked and Fortress has sent me replacement palms but I can't get the stainless steel screws and nuts out. They've been in there awhile and I've used the anchor on a couple of occasions over the years, so salt water plus SS screws plus aluminium seems to be maybe permanent, yikes!!

I've tried drowning them in penetrating oil and using the biggest screw driver I can find but they haven't budged. I've heard that heating the aluminium might help and I'm wondering if a propane torch would work? I've also heard that an impact driver might help so I'm considering borrowing one from my local tool lending library. I'm in the process of trying to get my boat down to Mexico after bring chased out of the caribbean by Irma and Marie. Thanks for any help! If I'm in the wrong forum please let me know best place to post.

Heat it hot. H-O-T. Both the stainless and the aluminum. When you think it is hot enough, heat it some more. It is all metal, you will not melt anything. You will not be able to get it glowing red hot, but that would not be too hot for this job. Better than propane would be MAPP gas, but propane will work, just a bit slower.

When it is really, REALLY hot, plunge it into cold water. Repeat. And repeat again. It WILL come apart with simple hand tools if you temperature cycle it hard enough and fast enough. I have never had anything resist more than two or three cycles.

An impact driver can help, but use a real one, not the kind you hit with a hammer. They are worthless.

And then reassemble with tefgel or lanicote--so it comes apart next time.

[Uncle Bob]

Originally Posted by billknny

Heat it hot. H-O-T. Both the stainless and the aluminum. When you think it is hot enough, heat it some more. It is all metal, you will not melt anything. You will not be able to get it glowing red hot, but that would not be too hot for this job. Better than propane would be MAPP gas, but propane will work, just a bit slower.

When it is really, REALLY hot, plunge it into cold water. Repeat. And repeat again. It WILL come apart with simple hand tools if you temperature cycle it hard enough and fast enough. I have never had anything resist more than two or three cycles.

An impact driver can help, but use a real one, not the kind you hit with a hammer. They are worthless.

And then reassemble with tefgel or lanicote--so it comes apart next time.

I think I would be very wary of following this advice, I have managed to blow a hole in alloy in the past and it didn't appear to be red at all!

[AKA-None]

Aluminum doesn’t get red it just melts

[skipmac]

I can confirm that from personal experience. I have also used the hit it with a hammer impact driver with good success. In some situations much better than electric or pneumatic.

[Zai]

You might want to ask Fortress before you start using heat on it, because you can change the hardness of aluminum quite easily with heat.

[Uncle Bob]

Originally Posted by AKA-None

Aluminum doesn’t get red it just melts

Thanks, that was the point I was alluding to.

Originally Posted by skipmac

I can confirm that from personal experience. I have also used the hit it with a hammer impact driver with good success. In some situations much better than electric or pneumatic.

Ditto on the impact driver, although an air driven industrial number is even better, though difficult on a boat.

[JPA Cate]

I am the observer. Jim is the worker. Time after time, I have watched him remove stainless screws from aluminum by the heat plus hammer-driven impact driver. It is what I would try if I had to do the job. The problem is the aluminum oxide built up by the galvanic corrosion. It is not a lubricative issue, hence the penetrating oil does not do the job. But, the physical shock of the impact driver loosens it. And then, progress happens! It needs both the heating and the jarring force.

Ann