REMOVING SS screws from my aluminium Fortress Anchor

[Jim Cate]

Originally Posted by billknny

You can NOT melt a chunk of aluminum in the open air with a propane torch. it conducts heat away much too fast.

Come on people, this ain't lead we are talking about.

Metals will glow red (yes ALL metals even aluminum) at about 500 deg F. They change to yellow by the time you get to 1000F. Aluminum will not melt until over 1200F. I promise you with a large piece of aluminum and a propane torch you will not get it to 500.

Agree that melting is unlikely, but wonder about annealing the metal to the point of strength and stiffness reduction.

Jim

[a64pilot]

We heat treated aluminum in a molten salt bath if memory serves that was right at 800F.
Propane burns roughly at 2000 F, Mapp gas about 3000 F and oxy acetylene above 5000 F from memory, rough numbers.
Aluminum melts about 1200 F, again on memory, so yes Propane and pretty much any other torch can get hot enough to both melt and anneal aluminum.

But it would be tough to do because aluminum is such a good conductor of heat.

Just drill them out, and be done with it.

[HopCar]

I learned the heating trick from an outboard mechanic. He used an acetylene torch to heat aluminum engine blocks to remove stainless bolts. He never melted anything but he was really good at it. I’ve done it several times with propane and never damaged anything but paint.

The same mechanic taught me to coat the threads with Permatex #3 Aviation gasket sealer. It prevented the bolts from getting stuck again. I suspect Locktite would do the same thing.

[anacapaisland42]

"MOUSE MILK" .....from aircraft supply shop....soak over 5 or so days
Bill



https://www.mousemilk.com/





[QUOTE=salty001;2749366]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

[frank huybers]

Originally Posted by 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.

The best way to deal with removing ss bolds in or from aluminium base is to weld a nut on top of the corroded countersink bold you use a welding stick stainless or normale 2,5 mm .
make shure je weld the nut from insite to the bold head
the gererated head will dissolve the corosion and expand the surounded
alu base . When the nut is welded to the screw head and is red hot just wait a bit and use a socket key M8 or M 10 to undue the jammed bold
i did hundreds this way special at mast and boom fastenings replacement

best regards franky Blue water sailing

[Cherod]

Originally Posted by frank huybers

The best way to deal with removing ss bolds in or from aluminium base is to weld a nut on top of the corroded countersink bold you use a welding stick stainless or normale 2,5 mm .
make shure je weld the nut from insite to the bold head
the gererated head will dissolve the corosion and expand the surounded
alu base . When the nut is welded to the screw head and is red hot just wait a bit and use a socket key M8 or M 10 to undue the jammed bold
i did hundreds this way special at mast and boom fastenings replacement

best regards franky Blue water sailing

Totally , ( see post 21 ���� )

[Reefmagnet]

Stainless screws weld themselves to aluminium because the aluminium oxide expands and forms an oxide that looks like slag. This both "glues" and wedges the stainless fastener in place. Propane is all but useless. If it's bad you need an acetylene torch (although mapp gas could possibly work, too). The heat will cause the oxide to break down into a sand like powder - breaking both the bond to the stainless and relieving the tension. Focus the heat on the ss screw until it becomes red hot and don't apply unnecessary heat directly to the alloy (I've removed very well stuck 3/8" bolts from a casting and barely burnt the adjacent paint). Let it cool and the screws should remove with little effort.

[Woodland Hills]

Only molten aluminum glows red and that at 1400 degrees. If you want to avoid melting the alloy apply a layer of acetylene soot to the metal, it will burn off around 1000 degrees, below the melt point. If the soot is still there your temp is ok.

[Mike Banks]

I had no idea Fortress did not make a proper Galvanised heavy anchor. In that case--if you like that type of anchor--get a Danforth.

As for putting acid on alloy anchors--I would not recommend that either.

I am kinda surprised that insurance companies have not come out against aluminium as an anchor. Light in weight is about the last thing an anchor needs to be. Many manufacturers add lead to iron and steel anchors making them heavier for better penetration..

[bpratt1152]

To remove the old nuts I would recommend a 4.5 inch grinder with a cut off wheel. Then purchase new hardware.

[Benz]

Originally Posted by Mike Banks

I had no idea Fortress did not make a proper Galvanised heavy anchor. In that case--if you like that type of anchor--get a Danforth.

As for putting acid on alloy anchors--I would not recommend that either.

I am kinda surprised that insurance companies have not come out against aluminium as an anchor. Light in weight is about the last thing an anchor needs to be. Many manufacturers add lead to iron and steel anchors making them heavier for better penetration..

The beauty of the aluminum Fortress anchor is that due to it's design it has very high holding power with a very low weight. That makes it possible to row it out in a dinghy and deploy it as a kedge, which would be impossible with an anchor who's only critera is weight. If you have not experienced the awesome holding power of a Fortress for yourself, perhaps it's hard to understand, but a Fortress has been my first choice for a kedge for sixteen years. I've run it out by dinghy scores of times and never dragged it in a bad blow, though I make sure it's the primary load-taker when riding out storms.
But though I don't care what insurance companies think, I'm sure they haven't spoken against aluminum for anchors because properly designed alloy anchors work really well.

[lewisa]

An impact hammer that you hit with a hammer has always worked for me. I have removed SS screws from aluminum that had been in place for 30 years. Has not yet failed to work.

It's certainly worth a try.

[tomtriad]

I find PB Blaster the best for loosening corroded fasteners. That and some heat cycles, making sure the hot tip of the flame is on the fastener. This will expand the bolt - then hit it with the Blaster to cool it and try the screwdriver/impact driver. Repeat several times.

Never tried welding a nut onto the fastener - sounds like a good technique.

If the fastener gets buggered you will have to drive it or drill it out. If drilling, be sure you have a good centered punch to start, slow speed, lots of oil. If the bit slips you will easily go through the aluminum.

I would remove the anchor from the boat before trying any of these methods.

[Me-and-Boo]

Originally Posted by Cherod

( if you have access to welding equiment / servicing ) weld a dirty big nut onto the seized stainless screw and turn with a big socket , the heat will help also .

This is one of the tricks we use in engine building if a bolt or screw is seized. Welding on a nut to a screw swells the threads, breaking any rust or adhesions, and gives a strong piece to turn on. Then you can unscrew it. If it is a bolt head, weld on a copper stud, which does the same thing.

[dario4754]

Hi, I would suggest making absolutely sure the surface is flat and than carefully center punch. If you are trying to drill it out use left hand drill bit and begin with small diameter so you are sure to hit the center. Using some kind penetrating oil is also good. Left hand drill bit will force the screw counterclockwise which is what we are trying to do. If possible use drill press rather than hand tool, you will have better control a specially if you can secure the anchor to the drill press table.
If the part to be removed will do so if the screw heads are removed it could be an good idea to only drill the heads of using a drill bit the size of the bolt and stop when the head pops. That will remove the strain on the screw. You will than have some length of protruding bolt to maybe grab on to and the other methods can still be applied.
You could also start hitting the rim of the head with fixed center punch and try to move the screw heads counterclockwise. It works surprisingly well sometimes.
Generally heat is good but one has to work it while hot and aluminum dissipates heat quickly. I´m often starting with the least destructive method first. BTW, if the thread gets damaged in the process an insert thread can be mounted, like Helicoil, there are kits for that. Good Luck