Broken bolt removal advice

[Nom De Guerre]

I have a 5/16" - 18 SS bolt that threads into the bottom of a SS stanchion that was frozen. I got it started and turned out maybe an 1/8" before I broke the head off during removal, leaving approximately 1/4" of the bolt shaft protruding after removing the stanchion from the boat.

I figure there's another 1/2" worth of bolt still threaded into the stanchion.

I've been applying liquid wrench and rapping the bolt with a centre punch/hammer occasionally. I intend to put a torch to it before attempting complete removal.

My question is...

...which would you attempt first (most likely to succeed)?

-cut a slot and turn out with a large slotted screwdriver?
-clamp vise grips on as tightly as possible and turn out?
-drill a hole for an easy out and turn out?

Thanks!

 

[justsomeguy]

I'd start with the vise grips (sometimes, I'm an animal). How long have you been applying the penetrant?

 

[Nom De Guerre]

I've been keeping the bolt/thread interface wet since this morning (I have the stanchion upside down in a vise and have been using a q-tip to drip drops into the area).

 

[justsomeguy]

I've been keeping the bolt/thread interface wet since this morning (I have the stanchion upside down in a vise and have been using a q-tip to drip drops into the area).

Ah, I assumed the broken bolt was still in the deck. More time may be necessary for the penetrant to work, but if there's no chance of burning down your boat, some heat should help. Good luck.

 

[Tim R.]

Vice grips. Slotting the end of the bolt will not be strong enough and when the one side breaks off from the torque of the screwdriver, you will have less to grip with the vice grips. It is only 5/16. Slotting it big enough for a decent screwdriver will not leave you much left.

Heat could be the key here. Any discoloring on the finish can be buffed out. Try the vice grip without heat first to see if it starts to turn. Working it back and forth(clockwise/counter clockwise) will also help. You just need to be able to feel if it is going to break and stop before it does.

 

[Chris Burti]

It very likely may have galled (cold welded). If the visegrips don't work, save youself a lot of grief and aggravation by drilling it out with the proper bit and re-tapping the hole.

 

[redhead78]

Before u panic, let the pb blaster work, cut a groove, and use an impact screw driver, it should come out.Use heat first but be careful of glass below...Red

 

[Tejas]

Tapping with a hammer can sometimes also help to loosen-up a frozen bolt. Many medium strikes rather than a few hard seems to work better.

 

[Dan Hill]

Chris has probably nailed it. Stainless is notorious for starting to turn then galling and seizing up. If thats the case penetrating fluids won't help. Heat will help but the amount needed will more than likely damage the finish. If you can thread it back in just a little by what ever means you may be able to gradually work it back out. If not, drill and tap is the answer.

 

[Rich Stidger]

If you are really using "Liquid Wrench", stop and get some "PB Blaster". It is a far superior penetrate for loosening fasteners. I have had good luck with a 18V Ryobi (or similar) small impact driver and a screwdriver tip. The key is "impact" and making sure the screwdriver tip fits tight in the slot. Just torquing with a screwdriver will usually break it off.

Vice grips is not a bad way of going- I would work the bolt in each direction until it becomes free to remove. Heat would be my next method, and "Easy-outs" are a misnomer. They would be my last resort.

 

[alexco38]

There is a "bolt-out" counter clockwise punch that you can get from Pro metalwork shop. You drill a small hole in the bolt and punch this thing in. It's square and bite. When you turn it counterwise, it try to bite into the broken bolt. Worked for me a few times.

 

[jibes138]

I have never had luck with easy outs. In fact I broke one off in a bolt and then couldn't get the easy out out. I just had the fun of dealing with three 1/4 - 20 screws on my pedestal. PB blaster seemed to help a lot but rather than vice grips I used a pipe wrench. The vice grips seemed to slip and not bite deep enough. The pipe wrench once it got a bite would not slip at all. As others note I would try screwing it back in first before trying to further remove it. This will let the PB blaster get into areas where the threads were seized and give it some lubrication to help prevent the galling others described. Good luck and let us know how it goes.

When drilling stainless you will need some really good drills, HSS is a waste of time, get good cobalt drills or carbide drills from a good source, otherwise the drill will dull, the material will work harden and you will need an EDM machine to burn it out.

 

[Bill Roosa]

The trick is to turn it out till you feel good resistance then turn it back in all the way. turn it out again (a little farther this time as the corrosion has been crushed and is not packing up the threads) till you feel good resistance. Turn it back in, then out more, then in, then out......repeat till it come out. You might only get a 1/16 more turn each time till you get past the rough spot.

 

[Nom De Guerre]

I got it!

Gave it a few more good whacks with the punch/hammer, clamped the coarse-jawed vise-grip on hard, and then turned slowly, in and then out progressively, until free.

It helped that there wasn't as much left in there, gumming up the works, as I had feared.

Finished up by chasing the threads with a tap and I'm back in business.

Thanks for the advice!

 

[centerline]

when you install a new bolt, remember to use a good thread lubricant. in addition to lubricating, it helps displace the space so that air and moisture cant get in and cause corrosion....
others may have good ideas, but i have used the nickle formula anti-sieze for many years with great sucess... the nickle formula type of anti-sieze will prevent galling of all stainless steels under extreme conditions
for the past year I have been experimenting with lanocote, as it claims to be a good long life lubricant that will also prevent galling under normal conditions.... it shows good promise but time will tell

 

[Rich Stidger]

I got it!

Yea!! Murphy foiled again.....

 

[Chris Burti]

I've been a fan of LaniCote since the mid 1990's. It is over 80% lanolin and is a safe product to use and store. Bast product for turnbuckles in my view...displaces moisture in the threads and helps to avoid crevice corrosion.