Help with sheared bolt....

[Eug]

Thought I'd put it out to the wealth of knowledge that's on the Nav forum.
I've got a sheared bolt on the outboard (for the torque tab/sacrificial anode), obviously found out the hard way about stainless steel's strength.

Tried to use an easy out bolt extractor but it just just snapped off inside the bolt, pretty sure I've removed most of what's left of it but there might be a few pieces in there. Much to my mate's disgust he reckons the bolt extractors are ALWAYS useless.

Now I have two options:
1. Build (weld) the bolt back up through the center of a nut and hope the heat frees up the bolt and just use a socket.
2. Go at it carefully with a dremel and hope the remnants of the bolt extractor bit don't get in the way.

A carton in it for anyone that can help me get it sorted, alternatively pointing me in the right direction would be just as great.

Thanks
Eug

P.S. bolt is an M5 or thereabouts...

 

[tatty]

I've been there before... Gosh how I've been there before! Bolt extractors tend to be a waste of time. They can work, but you can't go cheap.

Since it's snapped fairly far down, getting a dremel in there would be a bit hard, or so it seems.

If I were you, I'd take a drill to it (you have to do a perfect job!), and re-thread the inside, get yourself a slightly bigger bolt that will fit your new thread and get away with it like that. That's probably the easiest way.

 

[Dion]

The welder would be ideal provided you can get to it for a good penetration. If not, you're stuck with drilling it (if there's something to grab with stihlsons once the centre is drilled) or even better, thread it with a left-hand tap.

 

[Eug]

Thanks boys. Just seeing what my other options are.

 

[tommyhodgkin]

You could helicoil it?

 

[04SilverSTR]

Yeah id be drilling that out and hopefully the shell of the bolt may come out. Then retap the hole to clean the thread up.

Bryan

 

[Eug]

thanks, will give it a crack on the weekend and see how i go.

 

[tatty]

Actually, if you drill the smallest bit you've got through there, and slowly progress in size till just before the thread, you might be lucky enough to have the bolt fall apart on itself in there. Even if it doesn't, you could get a bolt, then, of the same thread, and try pushing it through with the help of penatrol.

 

[nakedape]

Actually, if you drill the smallest bit you've got through there, and slowly progress in size till just before the thread, you might be lucky enough to have the bolt fall apart on itself in there. Even if it doesn't, you could get a bolt, then, of the same thread, and try pushing it through with the help of penatrol.

By the look of it he's drilled slightly off-center - so he'll be out of the bolt into parent material before he can potentially get the bolt out. This may also screw him for just a drill & re-tap. These things are always bastards cause if you're not directly on-center then it can go to tears quickly - depending on what the parent material is.

Having said that I'd probably, carefully, give it a go - progressively increase drill size till just (bout a ml) before touching the thread (go slow, real slow), but try to drill right down through the length of the bolt, then try an easy out again.

 

[Eug]

I guess it is slightly off, might go at it with a small dremel to see if i can bring it right to the edge and have the bolt thread collapse in on itself. A suggestion I got given was to go at it with a gas soldering iron to get some heat into it and hopefully release the bolt.

 

[Leprechaun]

x2 on a helicoil kit.

 

[d22dave]

And when it comes out, use a good antiseize on the new bolt

 

[terryc]

Is this stainless into Aluminium?
You could try ammonia. apparently it frees up steel/aluminium bonding, then the ezy outs.
Or Penetrene(sp?) and a bit of heat, but that is for steel.

 

[Eug]

terryc: i think so, stainless bolt on an outboard motor. so i'll give the ammonia a go.
don't think i will try the easy outs again.

looks like i'll need to buy a few extra things so it might be more cost effective to get a mobile thread removal guy in to do it.
- cobalt drill bits
- penetrating oil (penetrene)
- helicoil or tap/die kit.
- gas soldering iron
- etc.

thanks for the responses so far... it sounds like a few of us have been in this position before.

 

[tatty]

I guess it is slightly off, might go at it with a small dremel to see if i can bring it right to the edge and have the bolt thread collapse in on itself. A suggestion I got given was to go at it with a gas soldering iron to get some heat into it and hopefully release the bolt.

I don't see heat doing a great deal for the bolt. I figure all it would do is soften the metal and cause the bolt to expand, but then how do you get it out?

I'd just drill it out. Even if you do stuff it, couldn't you put a long polished thread bolt on it with a nut on the end of the bolt?

 

[Eug]

I'd just drill it out. Even if you do stuff it, couldn't you put a long polished thread bolt on it with a nut on the end of the bolt?

There's no access to the other side but that might be a workable Plan B! Thanks.

 

[Eug]

have now got a timesert in there, ingenious piece of kit!

looks like poor prep from the manufacturer lead to the seizure of the bolt (new outboard and this bolt had never been undone), no anti-seize was apparent and looked like contaminating material was also in the thread. took a thread repairer close to an hour to get it out and went through 4-5 burrs.

cheers all for your help.
eug

 

[Aido]

Oh for fuc'ks sake. The easiest solution is to set fire to everything surrounding the damaged thread, dust yourself down and fetch a cold one from the fridge.
Boats are nothing more than a hole in the ocean you throw money into. Scuttle the bastard and walk away knowing you have saved yourself the equivalent of the Greek foreign debt.