1967 Shelby Tail Light Aluminum Trim Ring Stud Removal ?

[FordGT]

Anyone know of any tricks on removing frozen studs out of the aluminum tail light frames?  Some of the studs are broken off already just above the face of the frames.

Thanks

[BGlover67]

Best way to remove rusted steel bolts from aluminum parts

1. Use a propane torch to heat the bolt.
2. Cut the bolt at almost surface level then. Do a cone drill and a cone bolt tip, arc weld the bolt. Do a passing-through drill almost the bolt diameter to make it weak, then pass another threader, and then the one the bolt was.
3. Use salted water electrolysis to dissolve steel.

[Bossbill]

Can you try again on number 2? I don't understand it.

[427heaven]

x2- I thought it was just me.

[FordGT]

I'm also still scratching my head on #2?

[BGlover67]

I just googled it. 

[Bossbill]

Ok, I ran into that explanation after you declared it was found using Google.
I get the idea they are using a Varibit which is a cone bit on the tip. Do the same with a piece of extra stud stock, but in reverse. (make it a cone shape like the bit -- in male form). Weld it to the broken stud. The rest is pretty vague, but I would then thread two nuts on there and use the nut's internal thread as the drill's max OD.
The nuts will help guide the drill bit into the center of the new stud. Assuming all of this is lined up right. When drilled out you should be able to unscrew the double nut of the welded on stud and remove it. Doubt you can do all of this with this small of a size ...

I had a run at this about a year ago.
My opinion is that the bolts were cast into the aluminum.
I bought some threaded rod stock, a regular tap and a bottoming tap in hopes that I could get any of them out. Uh, no, not on my first attempt.

Most of the processes used to extract studs/bolts from aluminum were not counting on the extremely small size of these.

[BGlover67]

Ok, I ran into that explanation after you declared it was found using Google.
I get the idea they are using a Varibit which is a cone bit on the tip. Do the same with a piece of extra stud stock, but in reverse. (make it a cone shape like the bit -- in male form). Weld it to the broken stud. The rest is pretty vague, but I would then thread two nuts on there and use the nut's internal thread as the drill's max OD.
The nuts will help guide the drill bit into the center of the new stud. Assuming all of this is lined up right. When drilled out you should be able to unscrew the double nut of the welded on stud and remove it. Doubt you can do all of this with this small of a size ...

I had a run at this about a year ago.
My opinion is that the bolts were cast into the aluminum.
I bought some threaded rod stock, a regular tap and a bottoming tap in hopes that I could get any of them out. Uh, no, not on my first attempt.

Most of the processes used to extract studs/bolts from aluminum were not counting on the extremely small size of these.

Bill,  did you ever get any out?  Hard to believe they would have been cast into the frame, but anything is possible.  I have a set that are broken right at one of the studs, a really common scenario.  Looking at the cross section, it seems to just be a tapped hole.

[Bob Gaines]

Ok, I ran into that explanation after you declared it was found using Google.
I get the idea they are using a Varibit which is a cone bit on the tip. Do the same with a piece of extra stud stock, but in reverse. (make it a cone shape like the bit -- in male form). Weld it to the broken stud. The rest is pretty vague, but I would then thread two nuts on there and use the nut's internal thread as the drill's max OD.
The nuts will help guide the drill bit into the center of the new stud. Assuming all of this is lined up right. When drilled out you should be able to unscrew the double nut of the welded on stud and remove it. Doubt you can do all of this with this small of a size ...

I had a run at this about a year ago.
My opinion is that the bolts were cast into the aluminum.
I bought some threaded rod stock, a regular tap and a bottoming tap in hopes that I could get any of them out. Uh, no, not on my first attempt.

Most of the processes used to extract studs/bolts from aluminum were not counting on the extremely small size of these.

Bill,  did you ever get any out?  Hard to believe they would have been cast into the frame, but anything is possible.  I have a set that are broken right at one of the studs, a really common scenario.  Looking at the cross section, it seems to just be a tapped hole.

No , the studs are not cast in . Yes they get corroded being dissimilar metals and get frozen. I have had to do it many times over many years. You can sometimes coax them out using heat and wax (see utube) . I work them back and forth.The studs are very fragile being so thin and you have to go very slowly and if you meet a lot of resistance start the process over again with the heat and wax.  I haven't been successful getting the stud out once it has broken off almost flush. At that point I had to drill them out . Sometimes it can be done without going all the way through and sometimes not.It is also hard to keep the drill bit on center. Since it is aluminum you can weld them up but many times the aluminum weld repair can be seen in the metal as a different shade. This issue we are discussing is the reason why they evolved into the trim ring with the holes and separate long machine screw.   

[2112]

Might want to consider spark erosion, EDM machining.

https://en.m.wikipedia.org/wiki/Electrical_discharge_machining

It is insanely accurate. I had .060" oil feed holes machined into the outer casing of a fully assembled camshaft roller bearing without harming the rollers inside.

[Bossbill]

Brian,

   I drilled into mine using a stop on the drill bit, but it went through anyway when the stop slipped. Even in a drill press it's just difficult to get a center.

As I said it was opinion as to which method was used to built these in the first place. Is it more difficult to suspend these as casting is done or to drill and tap these numerous times?

My next try on the few I have broken flush was to grind the stud to get to fresh metal and place a nut over the stud and try and weld the two together though the nut hole with a MIG. Might try a jamb nut style I can get the rod through to the broken stud through a thinner nut with greater ease. Getting heat into the broken stud may expand it enough to break it loose from the aluminum.

I've tried the wax method and it works pretty good.
Wax on -- wax off.

[KR500]

Brian,

   I drilled into mine using a stop on the drill bit, but it went through anyway when the stop slipped. Even in a drill press it's just difficult to get a center.

As I said it was opinion as to which method was used to built these in the first place. Is it more difficult to suspend these as casting is done or to drill and tap these numerous times?

My next try on the few I have broken flush was to grind the stud to get to fresh metal and place a nut over the stud and try and weld the two together though the nut hole with a MIG. Might try a jamb nut style I can get the rod through to the broken stud through a thinner nut with greater ease. Getting heat into the broken stud may expand it enough to break it loose from the aluminum.

I've tried the wax method and it works pretty good.
Wax on -- wax off.

Bill
Weld a larger dia. flat washer on the stud first, then weld the nut to the washer.
Rodney

[Bossbill]

Good idea! Thanks.

[peterj9#388]

I could try to put them in my EDM to remove them. No guarantee but willing to try, Let me know.

[2112]

I could try to put them in my EDM to remove them. No guarantee but willing to try, Let me know.

^^^Hope someone takes Peter up on this. Amazing machines those EDMs.