REMOVING SS screws from my aluminium Fortress Anchor

[HopCar]

When you heat a piece of metal with a hole in it, the hole gets bigger.
Heat the aluminum more than the stainless and the bolt will break free.
A propane torch will work fine. You might have to heat and cool it a couple of times to break it free.

If you want to have some fun, hit the hot metal with penetrating oil. What doesn’t burn off will penetrate better. It will burn so be careful and do it outside where you won’t burn the house down. Have a fire extinguisher handy.

[TheOffice]

Try soaking in vinegar. It works as well as PB to dissolve corrosion.

[Dooglas]

Originally Posted by a64pilot

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.

Yes, try this first before trying to drill out the fasteners. I have successfully removed many badly corroded fasteners from alloy motorcycle engines this way.

[Var Korall]

Nut splitter or side grinder with metal cutting blade.

[jmschmidt]

I would not heat anything with a torch before trying an air or electric impact tool. This always works for me. As mentioned, aluminum doesn't turn red from heat, it just melts, but if you are replacing these parts anyway just melt them anyway. If this anchor is only used occasionally reassembly with copper grease or, as mentioned, Tef-Gel. Disassemble periodically and re-grease.

[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 .

[Nicholson58]

Grind them off and punch the remains out. Don’t take a knife to a gun fight.

[Scott Berg]

Just use a nut breaker and drift out the bolts; next time use TefGel on them from time to time. this is what a nut breaker looks like.

[model 10]

Originally Posted by Nicholson58

Grind them off and punch the remains out. Don’t take a knife to a gun fight.

Yep, If you can't just break them off with a flex handle, cut them off. Everybody has an angle grinder right?
A hand impact driver and a big hammer on a Fortress on a boat sounds dangerous to me.

[bigman1]

Fortress anchors are not made of ordinary aluminium,they are made of aluminium magnesium alloy,be very careful with heat.I remember when as a young turner(UK machinist) i was machining a friends motor bike wheels made from the same alloy,the dust that had collected in the lathe pan suddenly flared up like gunpowder flares up.Get advice from Fortress about the use of heat.

[thinwater]

Personally, I'd just bend the palm back before I put material heat onto the crown extrusion. A bent-up palm is cosmetic, so long as you get the shape close. The extrusion is structural.


I doubt you would do any harm since you are some distance away... but it's simply not worth it, not at at all.

[Mike Banks]

Having rescued TWO boats using these anchors, both of which went ashore, the anchor shanks were bent out of alignment and the anchor useless--if it has a guarantee get your money back.

The LAST thing one needs aboard is a failure-prone anchor. Hang it on the wall in your den--not on the end of your mooring chain.

The galvanised heavy duty Fortress anchor is a different thing altogether. They are useful as a back up because they lie flat when stowed and generally hold well. Lotsa luck in weed or hard mud bottoms though.

[Jim Cate]

Originally Posted by Mike Banks

Having rescued TWO boats using these anchors, both of which went ashore, the anchor shanks were bent out of alignment and the anchor useless--if it has a guarantee get your money back.

The LAST thing one needs aboard is a failure-prone anchor. Hang it on the wall in your den--not on the end of your mooring chain.

The galvanised heavy duty Fortress anchor is a different thing altogether. They are useful as a back up because they lie flat when stowed and generally hold well. Lotsa luck in weed or hard mud bottoms though.

Umm, Mike, Fortress does not make any galvanized anchors... they are ALL aluminium.

And despite your experience (and were those anchors properly sized for their applications?) Fortress anchors are very effective in low sheer strength mud bottoms... more so than any other anchor tested so far. For folks who routinely anchor in such bottoms, they make a good primary.

For more general applications, like we who routinely anchor in a variety of bottoms, other types make more sense. We don't know exactly how the OP uses his Fortress, so it seems bad advice for him to dump it rather than repair it.

IIRC, Fortress anchors are made from 7000 series alloys, and uncontrolled application of heat might indeed be poor practice. In the OP's place, I'd consider asking the folks at the factory for advice re heating. They have a good rep for customer help, as well as a very understanding guarantee policy (hint).

Jim

[a64pilot]

I have seen a Fortress bend.
I’ve never seen a broken one though, and I’ve not seen a bent shank, although I’m sure it has happened. I’m thinking you have confused a Fortress with a cheap Danforth copy, of which there are Millions.

[billknny]

Originally Posted by AKA-None

Aluminum doesn’t get red it just melts

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.