Advanced Rusty Fastener Removal?

[HotRodHudson]

I need some skilled advice here guys. I’ve become familiar with using Kroil & similar penetrating products and even had some success with applying heat with my little hand held propane torch but what to do when things fail, I’m at a loss.

For example, I have the exhaust manifold off of the 37 coupe and unfortunately in the process of removal broke the two studs in the manifold which attach to the intake manifold. Never wanting to admit defeat & wanting to do it all myself I tried lots of Kroil again over a few days then drilled the broken off studs with left handed drill bits. I was hopeful that as I went larger with each bit it might just break it free & spin out with the use of the left handed bits vs right handed bits. Unfortunately that didn’t work.

Through this I ended up drilling almost to the beginning of the threads and that’s where I stopped. Not having a large set of drill bits I couldn’t go larger without destroying the threads in the manifold. A buddy advised me to take it to a machine shop so I dropped it off there tonight even though I wanted to figure out how to finish doing this on my own. Now I’m having some regrets as it will cost $75 just to have the shop finish getting the drilled (3) studs out. Naturally I was thinking of the additional tools I could buy for $75 especially if I can buy what I need to do the rest of this myself. Plus I’m sure it won’t be the last broken stud I have. So I really need some wisdom & advice on how I could still possibly finish getting the studs out. I hope that makes sense?

 

[mrolds88]

Are you saying that you have drilled down into the manifold or just down to the surface of the manifold? If you are at the surface take a washer and weld it to the stud. Then weld a nut onto the washer. Use as high of an amperage setting as you can get away with. Then take an impact, set on a low setting and run it forward and backwards. Then try to remove it with a wrench. If you drilled it below the surface, and especially if you got into the threads a bit, get some toilet bowl cleaner (the stuff that you need to open the window to use) and fill up the hole for an hour or so. Tap the stud with a hammer. Then try your left handed bits. The acid in the cleaner will "eat" the rust.

 

[Stuart in MN]

Through this I ended up drilling almost to the beginning of the threads and that’s where I stopped. Not having a large set of drill bits I couldn’t go larger without destroying the threads in the manifold.

If your drilling was well centered in the hole, buying the right size bit could have worked (I'm thinking a regular right hand bit, since the left hand bits do only come in limited sizes.) Once you enlarge the hole so it's just touching the threads in the manifold, use a small punch or a pick to grab the top thread of what's left of remaining stud and peel it out. I've done it before successfully, but as mentioned the drill has to be centered really well. To do that, it helps to file the top of the broken stud flat before doing any drilling, that makes it easier to center punch the exact center of the stud.

 

[MoonRise]

$75 to remove three broken intake manifold studs doesn't sound bad at all.

As to removing **** broken and stuck fasteners yourself, my go-to has become intense welding-level heat.

Sometimes with an oxy-acetylene flame if the item is a bolt with the head still there. More often by arc welding a nut to the remains of the stud/bolt/whatever so that there is intense welding heat as well as something to grab onto to remove the offending stuck/broken item.

Got to be real careful though when applying intense welding-level heat to steel items that are stuck in aluminum items to make sure that the heat is on the steel and not melting the aluminum that melts at 2000F -lower- than the steel.

 

[djnordeen]

Hello,

Try these. You hammer it on and use a socket to remove. Be sure to use heat. Everything succumbs to the heat.

Lisle-19250-Stuck-Bolt-Remover

 

[EdT]

Unless the exhaust manifold nuts are something sacred, don't bother trying to unscrew them. Use a small cut off wheel like the 1" ones for a dremel to split at least one side of the nut parallel to the stud and the tension on the nut will be released and it should come off easily. Split on two sides if you can. I doesn't matter (within reason) if you cut the threads on the stud a little. Sometimes it helps, once the cut is made, to put a cold chisel into the cut and give it a smack with a hammer to open up the nut. There are also tools for splitting nuts but the only results I've gotten with one was a broken tool. You would probably end up throwing the nuts away anyhow so keep in mind that the goal is to get the manifold off without breaking the stud not see how many rusty nuts you can salvage. Once it's all done, you can chase the threads on the studs.

 

[HotRodHudson]

I wish I’d taken some photos of it before I dropped it off at the machine shop. I even tried to swing by this morning but they aren’t open on Friday!??! Looking at my bits, I used a 1/4” and was almost at the threads but my next largest was 5/16” and that would have taken the threads out.

Since I had drilled all the way through the stud & the stud came out into the inside cavity of the exhaust manifold I can’t fill it with any chemicals, but I like the idea & will remember that one!

Since the studs broke off pretty much flush with the surface, I did grind them flat to get a center point to drill on. One is perfectly centered the other is a tad off but if I can drill the hole a smidge bigger, I may be able to peal or pick the thread metal out. Sounds like I need a much better assortment of drill bits!

I was looking at a HF set of 100 plus bit set & their sae tap & die set, both seem to get decent reviews so that may be an answer. I’ll have to take a look at them this weekend. If worse case occurs & I drill the threads out can cast iron be re-threaded & are there issues to be aware of if I end up going that route?

 

[HotRodHudson]

I like that thinking out of the box.... sacrifice the nut & save the stud!!!

 

[kbs2244]

I would not be surprised if the re-tapped the hole.

 

[TheEquineFencer]

I'd have welded a nut to the stud, then heat the entire section to glowing hot, throw some cold water on it and the stud will back right out...

 

[no704]

Sounds like you are looking for an excuse to buy more tools! A transfer punch set could have gotten you closer to center on these studs.

 

[TheEquineFencer]

Sounds like you are looking for an excuse to buy more tools! A transfer punch set could have gotten you closer to center on these studs.

Yep, more tools....just throw it in a Bridgeport with a center cutting end mill and be done with it...

 

[ilovevocs]

Yep, more tools....just throw it in a Bridgeport with a center cutting end mill and be done with it...

My thoughts exactly. Oversize the hole and heli-coil, done.

 

[TheEquineFencer]

My thoughts exactly. Oversize the hole and heli-coil, done.

I'd just mill the bolt body out leaving the threads in and then just tap the old threads out.

 

[HotRodHudson]

Exactly what I did, milled out the stud body. Then tapped out the threads.

I’d love a dam Bridgeport or even a drill press for now! Kinda a pain getting a center mark with my handheld center punch as it’s kinda thick & hard to really see the point for centering. I’m definitely tired of using some kinda brake free spray, it wastes way too much time. Thus, the drill & tap or drill & heil coil it are quickly becoming a favorite method since my little propane torch can’t get things hot enough. It’s more like a glorified cigar lighter!

Now to find some studs to replace those I drilled. Any suggestions on where to look for those?

 

[HotRodHudson]

The intake too:

 

[no704]

Get a set of transfer punches!

 

[joe49]

McMaster-Carr

 

[48RON54]

If you didn't destroy all the studs, I would take a good one and go to Ace to match it up.

 

[theoldwizard1]

The trick on getting studs out of a manifold is heat the stud to dull red and apply some kind of wax and allow it to seep into the threads. Unscrew with locking pliers. If it starts to get difficult, repeat.


The trick to drilling out any stud/bolts is to start with a good center punch. You need to get is as close as possible to the center. If you have the mating part, line it up and use a transfer punch.

Then start with a good (new ?) center drill.

Finally, switch to good quality (Made in USA) drill bits. Start small and work your way up. At a minimum, you want an M7 HSS bit. M42 has more cobalt in it. I don't think external coating make that big of a difference. If you have good left handed drill bits, use them as you are closing in on the size.

 

[jessesandy]

Punch in the center as close as you can, but don't forget to lean the drill over and steer the hole where you want it to go.

 

[bullnerd]

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