1993 M900- It begins.....

[utopia]

Its a bit extreme, but Mr Gremlin once told me that concentrated nitric acid will dissolve steel but leave aluminium untouched.
But I can't confirm it from my own experience.

But it'll be preferential galvanic corrosion of the zinc plating, forming some sort of oxide, which is bunging up the works, I reckon.
So if you can dissolve or soften that with the vinegar then you might be getting somewhere.
Maybe even vinegar and heat.

Or.....I just caught myself wondering.......
Could you put a small location hole in the end of the bolt (using a centredrill perhaps) and then, using a pointed thing in the chuck of your electric drill, which was set to hammer, apply some high frequency hammering to the end of the bolt to jar the corrosion loose ?
Of course the pointy thing would just spin in the hole, but it would still apply the high frequency hammer blows.
Just a thought.
You could file a point on any old bit of steel rod that would fit in the drill chuck.. Even a very fat nail might do the trick, though something beefier might be better.

[spacemonkey]

Good idea- which is why I try my impact gun on it daily in both spin directions, but alas it's stuck solid. I have the concentrated nitric acid, but that's a bit extreme and the frame won't like it..

I reckon the weak acid would do it, IF I could get it in where the corrosion is. And that means braking the bolts to drop the engine and hoping that I can definitely get the remaining bolt bits out. And then you can see why I'm tempted to leave them in place and work around them can't you? Bloody scary...

[Dirty]

Nooooo, you can't give up now. Those bolts MUST be removed

[utopia]

Originally Posted by spacemonkey

I reckon the weak acid would do it, IF I could get it in where the corrosion is. And that means braking the bolts to drop the engine and hoping that I can definitely get the remaining bolt bits out.

Unless you were prepared to try the earlier, slightly less scary suggestion of drilling the small lateral holes through the crankcase into the engine bolt holes to get the acid in.
I can't see it causing any weakness if the holes were small.
You could even give up at that point, but keep applying the vinegar over the subsequent life of the bike until eventually it did the trick....perhaps.
In which case drilling down vertically might be the best option.

Point taken about the impact gun.....I may have omitted to check your earlier posts.
But then I got to wondering.....does the gun impact with a twisting motion or is there some axial impact as well.
If its just torque impact then maybe the hammer drill offers something a tad different as the impact is axial ?

This is my go to final option (the last resort) the thing I would do in your situation, if I really wanted that bolt out.

A impact socket (1/2" drive, or larger) 2 to 3 ft breaker bar, large hammer and a friend. Tell the friend something might break. Apply a loosening torque (heave on the bar) when applying your favoured max torque have your friend pound through the head of the bar and socket. Continue until the corrosion gives way or the bolt shears........... I did say last resort

I've painted an engine in the frame because of a situation like yours, and was never happy with the result, if I've taught you to suck eggs I apologise.

Stu

You could leave the engine be, rebuild and then use the engine's own heat to help the bolt removal process
I know that means a two stage rebuild but less drastic than the extreme measures

[spacemonkey]

Originally Posted by DrD

You could leave the engine be, rebuild and then use the engine's own heat to help the bolt removal process
I know that means a two stage rebuild but less drastic than the extreme measures

My thoughts too, which I might end up doing. I would take barrels off and paint them anyway, and could always remove the side covers too, which doesn't leave much to paint in the frame. At least I could ride it soon!

Originally Posted by Stued

This is my go to final option (the last resort) the thing I would do in your situation, if I really wanted that bolt out.

A impact socket (1/2" drive, or larger) 2 to 3 ft breaker bar, large hammer and a friend. Tell the friend something might break. Apply a loosening torque (heave on the bar) when applying your favoured max torque have your friend pound through the head of the bar and socket. Continue until the corrosion gives way or the bolt shears........... I did say last resort

I've painted an engine in the frame because of a situation like yours, and was never happy with the result, if I've taught you to suck eggs I apologise.

Stu

Thanks, all suggestions appreciated! This was the first thing I did but still got scared of shearing it in case there was an easier way. Could try with my sawn off sledge hammer instead of the lump hammer...

Originally Posted by utopia

Unless you were prepared to try the earlier, slightly less scary suggestion of drilling the small lateral holes through the crankcase into the engine bolt holes to get the acid in.
I can't see it causing any weakness if the holes were small.
You could even give up at that point, but keep applying the vinegar over the subsequent life of the bike until eventually it did the trick....perhaps.
In which case drilling down vertically might be the best option.

Point taken about the impact gun.....I may have omitted to check your earlier posts.
But then I got to wondering.....does the gun impact with a twisting motion or is there some axial impact as well.
If its just torque impact then maybe the hammer drill offers something a tad different as the impact is axial ?

Good point. Might try it- didn't think about that tbh..

I have ally welding rods so in theory could fill the holes if I tried that method too. Hmm...

Had a closer look and reckon I could strip more off easier than I thought, and with heat mat, I could get the blowtorch in there. My uncle reckons that you should rub a soap bar on the ally and it burns or goes black when the temp is right but before it melts. Anyone else tried this? Bloke at B&Q reckons propane won't melt ally anyway. Thoughts on that?


Thanks for all help so far.

[Mr Gazza]

What an absolute pig this is being..!!!

Picking up on the frustration in this thread and trying to think of a useful contribution.

My first thoughts are of "Spark erosion". I have not had any direct experience of this proccess, but I have heard of it working when all else has failed to get broken studs and bolts out of the cases of various Brit bikes in the past.
I'll be honest and say I don't know how it's done. I assume it's somthing like an electric welder, but the arc burns away the chosen item....How deep this will go I don't know, but I reckon it would remove the ends of the bolts so the engine could be removed from the frame ( or vice versa), and then the remaining part of the bolt could be dealt with in a fly press or some such??

On a simillar theme to the Spark Erosion, I though about when your welding rod sticks to the work and very soon turns cherry red up the whole length of the rod...!!

I wondered if a welder could be used in a simillar way to induct heat into the bolts very rapidly wthout heating the ally too much.?

I wouldn't know exactly how to go about that, but I am fairly sure it could be done.

I would definatly take the precaution of removing the alternator coils, pick ups and anything else potentialy at risk from the high current.

Sorry if this sounds a bit off the wall, I am just sensing your desperation...

[spacemonkey]

That is different indeed! Guess what went through my mind when reading this? Oh, the puns are dripping off this in so many ways:

http://www.youtube.com/watch?v=3zhqCccFsGc

[Mr Gazza]

...I can't deny crying out "She's alive" in a Frankenstien voice, after getting a rebuilt bike started for the first time..

Or I may go into Dr Evil mode if a particulaly daft idea actually does the trick, with a "Hoo hoo ha ha ha... It worked...Hoo hoo ha ha.."....We've all been there...Haven't we??..

[spacemonkey]

Ermm.... yes...

[spacemonkey]

Ok cannot get the bolts out and summer is fading, sooo... I have decided to mask and paint within the frame.

Couple of questions: I'm going to use the VHT paints recommended earlier which come in 11oz rattle cans. 2 coats primer, 2 thin 1 medium colour coat and 2 topcoat. Any idea how many cans will be needed?? they say 12 square ft per can but I cannot relate this, and you can't beat someone elses experiences... They also do a cast iron colour (SP 997) which looks a pretty good match for the early rocker covers. I'm also going to spray the foothangers etc the same engine colour. The cans say it must be baked for 20mins at 93c to cure, but is this a good idea in a gas oven or would a good session with a heat gun do the job??

I was going to use thier strip fast but I can't imagine it would be good on the remaining plastic and rubber bits, and don't want to risk any soaking through the masking to the frame.....

[Dirty]

You might get away with it with a heat gun but an oven would be far better. Much more even and accurate temperature.

[spacemonkey]

Bit worried about the gas flame and flammable fumes and all... and having a baby in the house.. Naturally I'd do it when baby out but worried about lingering fumes..

[Albie]

Hair dryer I use . Yep and I always ask too. Works a treat and wont scorch like a heat gun. Use the oven sometimes and the gas bbq too.