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Broken bolts...
Posted: Fri Oct 07, 2011 2:52 pm
by Ffoxy
Gudday / Gudarvo /G'nite... whatever takes your fancy guys! ;-0
Right so my pull-down continues & Im having some broken off bolt heads as probably many or all of you guys have had... so far I have 8....
2 on the RHS lower for where the front wheel spindle clamp is (2 of the 4)
The tank hold down bolt round about where my crotch will be when I'm done.
1 LHS on the top Headstock that hold down the instrument panel.
4 on the Head where the zorsts attach.
I did a Search but came up with nothing, so what do you guys think?
Soak in Plus-Gas for a few days then use an E-Z out?
Just drill out & re-Tap?
Use heat from a Propane torch?
What did you wizards do? I know there are gonna be more...
Re: Broken bolts...
Posted: Fri Oct 07, 2011 9:33 pm
by xtzrick
My prefered method is to weld a nut to any remaining bolt, wait about 2-3mins for heat to transfer to whatever the bolt is in, then unscrew.
If it feels like I'm going to break the nut off, I put the bits in an oven for a couple of hours (If I can get the bits in).
If the bolt is still stuck or I can't use the oven, I get my blacksmith mate to use his prefered method.
He uses an oxy/accetalin torch to quickly heat the bolt till it's "yellow" then he lets the bolt cool for 30mins, he repeats the process 4-5 times, then unscrews the bolt with his fingers
By heating the bolt quickly, it will try to expand quicker than the surrounding metal, so it expands in the only direction it can ie. lengthways.
Each time the bolt cools it gets a bit narrower & a bit longer untill it comes loose
The trick is to take the flame away before you melt the bolt
E-Z outs worked 1st time for me

, then failed everytime since
& I always struggle to get drill bits dead center for the drill & tap method.
Rick
Re: Broken bolts...
Posted: Fri Oct 07, 2011 10:07 pm
by Mezo
xtzrick wrote:My prefered method is to weld a nut to any remaining bolt, wait about 2-3mins for heat to transfer to whatever the bolt is in, then unscrew.
Yep that`s the best way of doing it by far.
Also whilst its hot squirt a smidge of penetrating fluid in there as well (WD40 or similar) and don`t forget to breath in the smoke its good for you.
Mezo.
Re: Broken bolts...
Posted: Sat Oct 08, 2011 12:14 am
by ActionManMelb
To remove broken bolts and studs, you need three things.
Patience,
patience and
patience
Welding a nut works great and heat from an oxy torch used WITH CARE is my second choice.
Drilling is the last resort, because you will almost always get the drill off-centre and damage the surrounding metal.
Real pro's use an electric spark erosion machine to remove broken taps and hardened bolts.(google it)
Re: Broken bolts...
Posted: Sun Oct 09, 2011 1:37 pm
by philb
Patience,
patience and
MORE
patience
Yep, Actionman hit the nail on the head there.....
I've used all of the above, and they all work as well as each other...Just pick the easiest to hand first. I prefer to drill out with ever increasing drill sizes and then tap out, Ez-outs never seem to work right for me

. If you are really lucky and/or careful you can pick out the remaining thread with a scriber sometimes if your drilling is spot on down the center of the offending sheared bolt/stud.
Phil

Re: Broken bolts...
Posted: Sat Oct 15, 2011 6:07 pm
by Ffoxy
Thanks for the tips guys, I think you are all better equipped than I am... no welding kit at all. So I'll have to trust my punching & drilling & take my time... looks like I'll have plenty practice!

Re: Broken bolts...
Posted: Sat Oct 15, 2011 9:50 pm
by Mezo
Ffoxy wrote:So I'll have to trust my punching & drilling
♫ ♪ ♫ ♪ "There may be trouble ahead, But while there's music and moonlight and love and romance,
Let's face the music and dance" ♪ ♫ ♪ ♫
Mezo.

(borrow a bloody welder Kieth)

Re: Broken bolts...
Posted: Wed Oct 19, 2011 11:07 pm
by Ffoxy
I cant see how a weld could be made on any of the bolts mate, they all broke off flush or just below flush, nowt stickin out...

Re: Broken bolts...
Posted: Wed Oct 19, 2011 11:45 pm
by xtzrick
Ffoxy wrote:I cant see how a weld could be made on any of the bolts mate, they all broke off flush or just below flush, nowt stickin out...

You need to do "Plug Welds" with a MIG welder.
Basically you place a brass washer then a steel nut over the broken stud, then point the mig wire at the center of the stud & start a weld "pool".
As the pool gets close to the top of the nut, start a circular motion so you weld to the nut, stop when the nut is full.
Let the nut cool for a few mins (weld another nut or 2) then hopefully you will be able to undo the 1st nut.
Rick
Re: Broken bolts...
Posted: Sat Oct 22, 2011 9:45 am
by philb
Take it to a local engineering shop Keith to sort out the sheared bolts/studs if you're not 100% happy or haven't got the right tools....if they cock it up they have to fix it.
Not worth the frustration if it goes wrong!
Cheers!
Phil
