View Full Version : broken exhaust stud on an aluminum head
09-08-2005, 07:48 AM
the stud is broken flush with the manifold, is it ok to build up the stud to weld on a
nut to remove the stud without damaging the head?
09-08-2005, 08:42 AM
I think some folks weld a washer to the broken stud first then weld a nut to that.
09-08-2005, 08:58 AM
You would maby be better served buying some of that special rod for removing broken studs below the surface of the casting. I don't remember the name but your local welding supply should know. A tot of regular rod may do it but you will only have 1 shot at it to do it right. You probably should soak it in PB Blaster or a similar high quality penetrating oil as long as possible beforehand. FWIW if you happen to know any aircraft mechanics and get inclined to chicken out of trying it yourself consider asking them to do it. Airplaine engines are positively famous for broken studs in aluminum castings; real expensive ones. These folks have lots of practice.
09-08-2005, 12:44 PM
Mig weld a washer to the stud and then a nut to the washer.
09-08-2005, 06:13 PM
Your local welding store has (or can get) MG600, made by Messer. Two pound box is about $80 (Harris-Welco makes Super Missle Weld, almost identical except the minimum is ten pounds for $350)
Messer tech line will go through all the details with you & fax an instruction sheet (I'll fax mine if you supply your fax number).
I've tried everything else with poor results. MG600 is all I use now for broken bolt, stud, and tap removal, even if broken three or four threads below flush.
09-08-2005, 08:36 PM
i build them up a ways then weld a piece of fairly heavy bar stock to it so it can be worked back & forth with a hammer to loosen it up.
09-10-2005, 12:57 AM
Is it possible to drill into the stud and use a spiral extractor?
I used one this morning infact to remove three 1/4" bolts that had sheared off flush with the face of a boss. Worked great.
09-10-2005, 01:18 AM
Depends. Yes, it's usually worth the first try, but sometimes being able to weld on something with more leverage is the way to go. I usually try the left-handed drill bit, followed by an extractor first. Sometimes the drill bit does it all by itself when you get lucky on something that hasn't seized too much.