Frozen/corroded bolt

[clydesdale]

Any tips for dealing with a mast head ss bolt (aluminum mast) that is stuck- salt corrosion has locked it in place and now I have rounded out Allen head hole. Have easy out bits but haven't tried them yet. Assume though just work for rounded out heads vs salt corroded bolts. Drill it out fully and retap?

[Eltreato]

https://www.youtube.com/watch?v=Ia80zN0dlhQ

[rtz]

You could use a large bit(slightly bigger than shaft of bolt) and drill down so it removes the head from the bolt. Then use a quality pair of vise grips on the remaining bolt.

[tegirinenashi]

What treatment do you recommend for brand new mast/head to prevent/alleviate such a problem? I don't actually intend to ever separate them, but still don't want rust to compromise the joint strength. I was thinking of covering bolt threads in some kind of glue or plastic to prevent water penetrating the thread. Any recommendations?

[Thecopterdr]

There are dozens of various anti corrosion products out there. I would get into the habit of pulling things apart on occasion as prevention is far easier than having to drill out a bolt. If you damage an insert then you really are in a world of hurt. Stainless steel does not play well with others....

[gilana]

First try is to get a left-handed drill bit, if it binds it will start unscrewing, which is what you want.

To prevent this in future use Tef Gel.

If all else fails, drill the screw to reduce the amount of stainless steel.
Go and buy a pound of Alum (KAl(SO4)2·12H2O) AKA hydrated potassium aluminium sulfate.
Commonly sold in pharmacies as a blood coagulant for shaving.

Crush it and dissolve in water, a strong solution, and then immerse the mast and screw in it. If you have an aquarium air pump leave it bubbling and agitated all night, by morning the screw should be gone.

[plummet]

I would soak it in crc overnight. Get a dremel out grind a blade notch in the head. Heat the mast up with a heat gun and try and undo with a blade screwdriver. Then if that failed it would be drill the head off drill into the bolt and extract with an easy out.

[clydesdale]

Thanks for the advice. Tried the extractor bit method but struggled with it. Took the mast to a local aluminum boat retailer and guy had a trick for corroded bolts. He used a hardened steel rod n hammer to bang on the bolt head a few times and that loosened up the stuck bolts and was able to get them out.

[edt]

Another trick next time this happens if you have rounded off the allen is to get the next size up wrench size and use a hammer to hammer it into the bolt. Hammering it in will create a new allen hole one size bigger. You can also use this trick with bolt heads that get rounded off, you go one size smaller and hammer on the socket size. Usually you end up having to throw away the socket used for this as it gets wedge in so good but worth it not to have to tap in a new hole. You can also put a tac weld on the socket to make sure it will stick again you'll have to throw away the socket but worth it not to have to tap new threads. I wouldn't actually weld a tac when you are so close to aluminum tho as you'll probably melt it but it's useful remember for other stuck bolts. If you do end up drilling it out, it's useful to buy a heli-coil so that after you tap the new larger threads, the heli-coil can be inserted so that you have threads that match your old hole and don't have to have this one odd sized bolt, you can use the same thread size as before.

[Jzh_perth]

I damaged the fuse on a LF Foil Fish trying to drill out a frozen stainless bolt. Drilling is really a last resort - I've learnt that lesson. Soaking in CRC, heat, larger Allen all preferable to drilling. On YouTube I've seen guys welding a nut onto a stripped bolt and getting it out that way. Lesson learnt.