Also in the future use A4 grade stainless steel hardware. A2 doesn't really do the job in marine environment.
To get it out, if you cannot find that extractor drill bit, you could drill it out with normal drill bit. Take your time, spray some lube as you go, and cool it down frequently.
Re: Please help to unscrew foil mast
Posted: Tue Jul 27, 2021 7:22 am
by Foil
easy job,
I see its a Moses mast fixed to a Groove Skate, same as mine then!
same fixing hardware, a few tried a tested ways to tackle this.( the hammering in a oversize HSS hex head key is a first try method but if that fails then this next method will not fail-)
firstly we know that's a stainless steel 8mm threaded stud under that now damaged button head, and the stud is clamping the boards mast track to the board using the brass T nut, there will be a small gap under the bottom of that 8mm stud, so use a 8mm HSS (black best quality) drill bit and insert it into a good mains powered hand drill, have a can of WD40 handy for cooling and lube, set on high speed and get your weight over you hands to control the drill as you carefully drill down, the job should be done quite quickly and easily, the top of the stud will spin free as you press through and then the stud that left will fall back to the bottom of the boards track, then your mast will lift clear, easy peasy.
the stud should then be easy to unscrew from the released Tnut after sliding it out of the track, renew all your mast bolts with either the ones from groove, or Bolt Base if here in the uk, and use only the best SSteel keys in future, these ones are the best, special ends to prevent damage to both key and button heads --
You can also get a torx but that is one size too big and just hammer it until it smashes itself in place. Thats what I try first.
You could complement this approach with a manual impact driver, eg:
The impacts tend to wedge whatever shape/size driver bit you choose to use into the remnants of the screw head while at the same time helping to 'shock' the seized bolt loose.
CAUTION: An impact driver is a handy option when dealing with heavy duty parts, like a screw that is rusted into something solid like an engine block. Not so sure I would want to use it on a delicate board though.
Re: Please help to unscrew foil mast
Posted: Tue Jul 27, 2021 1:50 pm
by Hugh2
Has anyone tried soaking something like this in vinegar overnight first, it would remove much of the corrosion that is locking in the bolt.
Has anyone tried soaking something like this in vinegar overnight first, it would remove much of the corrosion that is locking in the bolt.
I did that to take my NP Glide Tuttle head off the aluminium mast. The bolts wouldn't budge before using the vinegar.
I poured some white vinegar into the inverted mast and let it soak into the bolt ends overnight, then used a Torx levered screwdriver with the mast clamped tight and that was enough to unscrew it. The NP bolts had Tefgel on them, but I hadn't unscrewed them for about a year.
Heat (propane torch) combined with an ez-out style extractor tool. You may need to drill the head prior to using the extractor.
Just take a torch to the old epoxy carbon composite.
Not.
Besides ez out another thing you can do is just put a drop of epoxy in the socket and stick a normal hex wrench that would fit if the docket was mot stripped in it. Let harden over night and you may find it unscrews fine. If not, on to the hardware store got extractors….
Save the propane for the stove.
BWD clearly doesn't have much experience with seized bolts. You don't need much heat; a little goes a long way.
See this video for the non-believers.
Video for using extraction tool:
Yet another method using a Dremel:
Re: Please help to unscrew foil mast
Posted: Wed Jul 28, 2021 3:11 am
by bragnouff
Was that sarcasm???
You say that a little heat goes a long way, yet in the video you link to support your claim he's quite happily getting that aluminium mast "extremely hot". That wouldn't go too well on epoxy / carbon. And he actually says in the video that it would melt it...
Aluminium is also potentially sensitive to heat, some alloys lose some of their molecular properties when heated, when welded, for instance.
So taking that blowtorch out to achieve your goal should be at the very bottom of your list of options. And in that particular case, you'd want to heat/expand the brass Tnut in the rail, while keeping the bolt cool. That's not really accessible to your blowtorch, and the nylon of the US box wouldn't really like a heated brass nut.
Anyway plenty of mechanical options have been suggested.
And of course, cursing and swearing always help!
Re: Please help to unscrew foil mast
Posted: Wed Jul 28, 2021 4:09 am
by edt
Lol that aluminum lost all it's hardness. Take any aluminum thing throw it in the oven put it at 600f/315c and it will fold in your hands like putty. I've ruined some aluminum cooking trays that way before. Propane torches get up to several thousand degrees. Be careful with heat! Next hard tack that mast in the video is snapping in two. Hilarious how to not do it video. Steel can take a lot more heat don't use your bolt tricks for steel on aluminum and don't even talk about carbon it will catch on fire.
Just use the techniques everyone listed above we all use the same tricks