St60 wind transducer removal

[lustyd]

Went up the mast three times today trying to remove the old wind transducer. The vane is already off just need to remove the base.
The two stainless screws were entirely stuck and already rounded so either I’m not the first to remove or the installer ruined them.
Next, I tried drilling out one of the screws. No luck at all as it’s stainless and I was at the top of a mast.
Next I thought I’d cut the screw heads off using a multi-tool. Turns out the unit is a solid block of aluminium, but I did manage to cut both screws.

Unit still doesn’t move even a millimetre.

Either it’s glued down or the aluminium block was threaded. Does anyone know for certain whether these are just holes or threaded?

I’m out of ideas, I’m concerned that any more destructive methods may damage something important. I’m certainly not taking the mast down just for a wind instrument but really would like this sorted.

 

[Boathook]

Suspect the the stainless bolts and aluminium have both corroded together nicely. Would a cherry picker work, but then it might be cheaper to lower the mast.

 

[lustyd]

I think if going that route I’ll ask for a rigger in Plymouth and just pay, but wanted to see if the forum had any thoughts first as it feels like this should be easier.
I don’t know why some enterprising marina doesn’t have a platform for this kind of stuff by now

 

[ashtead]

We used a rigger in Gosport who sourced the part at good price but he fitted free as he was doing some other rigging work which originally led to my asking him if he could have a look when up mast and see what replacement part might work.

 

[lustyd]

I’ve had the B&G replacement for about 4 years so probably can’t use that one

 

[yotter]

I replaced my ST60 mast cable in 2022. The mast was down, so much easier. The screws were corroded into the alloy block, it was a bugger to get it off, I cannot remember how I did it. I am sure you will ensure Duralac is applied to the new screws, and perhaps new screw holes on the mast head if the old screws need to be cut off. I would not attempts this up the mast.

 

[lustyd]

Thanks just what I wanted to know.

I’ve got quotes coming from a couple of riggers now so hopefully they’ll get it removed

 

[sealutions]

The screws supplied with those Raymarine mast head units are generally stainless self tappers, so it's entirely possible that they have welded themselves in to the aluminium mast.

Definitely a mast down job IMO, you don't want to risk dropping your drill on your deck (or whoever is winching you up) from that height!

 

[lustyd]

I secured the drill, and the multitool, neither were difficult with a bit of dyneema cord.
The main issue is it’s tiring to keep going up to try different tools, especially in this weather.

Nothing looks too corroded but we’re already past the destructive point anyway so it’s now just how best to cut it away. Hopefully they’ll riggers will sort it, they quoted 3 hours.

 

[PaulRainbow]

I secured the drill, and the multitool, neither were difficult with a bit of dyneema cord.
The main issue is it’s tiring to keep going up to try different tools, especially in this weather.

Nothing looks too corroded but we’re already past the destructive point anyway so it’s now just how best to cut it away. Hopefully they’ll riggers will sort it, they quoted 3 hours.

If you have a tap and die set drill and tap a hole or two, 8mm if you can, squirt a little oil in and tighten them up, slowly. That should get it off. Easier said than done from my sofa though

 

[lustyd]

Thanks Paul, took me a minute to work out what you meant there but good idea. I’ll be watching the riggers from my sofa I think

 

[Moodysailor]

I'm pretty sure the base is the same as our ST50 one - the corroision between the SS screws and the alu block is what is holding it in place. I resorted to heat with ours in the end, once I could get it to move a little then a screwdriver underneath did the rest, but with a small amount of damage to the anodizing on the mast head. It fought me all the way off and was completely destroyed.

Good luck!

 

[KompetentKrew]

When I saw the owner of the boatyard had a cherry picker in I begged him to take me up, so I was able to get two kettles of hot water poured over mine. I had no effect trying a manual hit-it-with-a-hammer impact driver, but he was successful using a flat-bladed screwdriver bit as a chisel to turn the screws.