Broken bolt bravo 3 transom water housing bolt

I absolutely would not go the torch or welder route unless all your insurance is up to date. That's a quick why to lose friends and influence people in a bad way, really serious. That would need to wait until they can pull you out of storage.

Given the limited space and assuming you dont want to pull the engine yet.

Can you rotate the entire flange counter clockwise? tapping it lightly with a hammer. If you can free the flange from the stud/bolt then you may be able to get vise grips on whats left. Or rotate the entire flange off if enough room with the stud.
Finally what about just ordering a new flange? And cut this one up enough to break it up and get a vise grip on whats left?

 

That's not a flange, it's the transom assembly. If you do drill use a left handed bit, it might just spin out

 

I would spray Kroil on that, let it soak for a day or so.

 

Based om Utube you can loosen rusted components some times using air impact hammer and tension at the same time. It worked for me on a brake job getting off the bolt that holds the rotor to the drive spindle. No idea if it would work for you.

 

An air impact hammer against an aluminum housing may not be good. Use it lightly and don’t “hammer away” at it.

 

They make a tool that you wrap a thin wire around it and it heats it up red hot then would come rite up with vise grips.

 

An induction heater.
Here’s an option.
Magnetic Induction Heater Kit, 1000W 110V Hand Held Automotive Flameless Heat Bolt Buster Tool For Rusty Screw Removing with 8 Coils and Box https://a.co/d/7sJjokM

 

Yes thank you I have seen those work and they are awesome

 

I solved a similar problem on my 91 Corvette aluminum intake by cutting the bolt flush with the housing, drilling successively larger holes in the center of the fused bolt until the drilled hole was reaching the threads. I then tapped a new set of threads, inserted a high quality bolt with a nut threaded all the way the head of the bolt. I sealed the new bolt insert by using epoxy on the threads to seal the bolt in place. I then cut the head off the new bolt making a threaded stud instead of a bolt. Since I already had a nut on the bolt, I just removed the nut cleaning up the cut threads. That was two years ago. It is still working today.

I am not sure that plan would work for you, but you would not risk breaking your transom assembly that way.

 

If you go the mig route, hold a nut on the end of the broken bolt, reach through it with the wire from the tip of the welder, then weld the end of the bolt to the inside of the nut. A lot of times, the intense heat imparted to the bolt will allow the broken piece to be backed out. But, like @hughespat57 mentioned, you should probably wait until you can get it outside. The residual oil you've sprayed on it could catch fire. Please have an assistant close by with an extinguisher.

 

That's great

 

Hooray! Thanks for the follow-up.

 

Where are you located?

 

If you have sufficient material surrounding the threaded hole, you might want to look at “keenserts”

 

There are a few on eBay all seem to be in the $300-$450 range.

If the threads are the only issue, you may want to repair them.