Hi kmills,

kmills wrote:Very cool project, I wish you the best of luck. Just as a heads up, welding of galvanized steel is considered hazardous from a health standpoint. It looks like both the washer and the nut are galvanized. I have done it and I am still here, just don't make a habit of it! I don't want to lecture but I also want to make sure you know whats going on. This link says the major risk is intense flue symptoms with no long term health effects. I would think anything that "will cause welders to think that they have the flu in a bad way" is to be avoided!
http://www.sperkoengineering.com/html/a ... anized.pdf

In the back of my mind I was telling myself someone is going to notice. I just did not want to make an extra run to the hardware store, I know about the risks. Just so you know I did this near the garage door while a strong breeze blew the fumes away from me. Happy to read this so that others will take notice.

Hi gary,

drgary wrote:Nice punt on the bolt, Jay. I'll be very interested to see if you get any better result with a bolt extractor. But with results like this so far, doesn't it look like the sticking point is that the threads themselves have lost integrity? The more we deal with these things on our similar projects, the more it looks like drilling them out will be the way to go.

I agree; however, the bolts have hardened due to reactions between high temperatures and quenching. Starting with drilling a pilot hole for a Screw Extractor would require a high carbon drill bit. Using a drill bit that is harder than the hardened stud invites more negative possible outcomes. These types of drill bits have a higher probability of breaking off into the work. You think removing a frozen stud is challenging.... You do not want this to happen. The studs/bolts need to be annealed.
Getting the bolt red hot and sustaining the heat at this temperature for a minute or two then allowing it to cool slowly anneals (greatly reduces the hardness) and the stud/bolt is now malleable:)
Heating while welding a washer and nut is my way of annealing and possibly reducing the quantity of holes to be drilled . If by chance one or more of the 8 studs ( seven now) come off the boiler GREAT! If not, then the the stud that is left in Attempt Three has undergone the annealing process and is ready for a pilot hole(using a less brittle drill bit). At least for now Dr. this is a method to my madness

I do not want to add "removing a broken drill bit to the list of techniques....

At this point I would just drill it out. Youre probably just trying to draw a coroded piece thru the threaded hole.

Drill a small hole as close to being centered up as possible and progress to larger bits. It wouldnt suprise me if during that process that it just spin the remaining piece into the boiler.

And more than likely the bolts are probably just low grade and have very little carbon to begin with, so they will not be hardened by the heating and quenching. You will know for sure when you center punch it for the initial hole. If the center punch leaves a nice divot then its certainly soft enough to drill. If it leaves no mark at all then you better look at some carbide bits.....

BTW I wouldnt try a screw extractor, if you twisted off the stud a screw extractor will probably either slip or snap off, and they are a bitch to drill out....LOL

JayCan wrote:Hi gary,

I agree; however, the bolts have hardened due to reactions between high temperatures and quenching. Starting with drilling a pilot hole for a Screw Extractor would require a high carbon drill bit. Using a drill bit that is harder than the hardened stud invites more negative possible outcomes. These types of drill bits have a higher probability of breaking off into the work. You think removing a frozen stud is challenging.... You do not want this to happen. The studs/bolts need to be annealed.
Getting the bolt red hot and sustaining the heat at this temperature for a minute or two then allowing it to cool slowly anneals (greatly reduces the hardness) and the stud/bolt is now malleable:)
Heating while welding a washer and nut is my way of annealing and possibly reducing the quantity of holes to be drilled . If by chance one or more of the 8 studs ( seven now) come off the boiler GREAT! If not, then the the stud that is left in Attempt Three has undergone the annealing process and is ready for a pilot hole(using a less brittle drill bit). At least for now Dr. this is a method to my madness

I do not want to add "removing a broken drill bit to the list of techniques....

Hi Jay,

I always expected there's madness to your method. I'm learning a lot from how you and others approach the stuck points in these restorations!

this is a man on a mission here! haha.

A this point, I vote drill out and tap.

I've been following Gary's progress (over on the other thread). Keep in mind, when you have to different metals, especially when liquid is involved, all sorts of crazy stuff can happen. Threads can fuse, melt together, etc. And when you apply heat, it doesn't always make things better. Usually with steel against steel, yes, it does. But when you introduce metals with two different melting points, it can go from bad to worse.

Frankly though, I think those bolts were there to stay before you guys showed up with the vice grips

When you assemble everything again, don't forget to use some high temp copper anti-seize on the threads.

Ray

Looking at how much more work that caused (or could potentially have caused), and the possible consequences of that much heat applied there, I would:
- Cut the stud off about 1/8 to 3/16" above the flange
- Grind the exposed end flat, smooth, and perpendicular to the flange's face
- Use a center finding tool or device of some sort to mark the exact center of the stud and punch that spot
- Use a rotary tool (Dremel, et.al.) and a small carbide bit to start a hole in the center of the stud
- Use a drill press with increasing sizes of Titanium Nitride bits to drill to the necessary depth through the stud.
- By the time you get near the threads of the flange, you will be able to use a larger size easy-out which will lessen the chance of it breaking off in the bolt.

This is a great thread! Very nice with all the pics, and the discussion, of how to deal with stuck bolts. I am about to start my own renovation project, so will probably face the same problems in a short while, all the experience from people who've dealt with these issues is of great help. Someone should publish a handbook: how to fix old espressomachines, and deal with common issues in restoration projects, I am impressed how much knowledge some of you guys have gathered!
Best regards
Ulrik

Here's your book, and it keeps growing as each of us works on a different machine with its unique quirks! I will summarize some of the steps of restoration on my thread when I'm done with it. That may be the start of a primer, or at least my version.

Hello everyone:)

First let me show you the results of my forth attempt, then I will go into details...


This pic shows you why I did not continue with drilling and tapping. I figured out what I now know to be the ideal solution

Notice the broken fragmented pieces leading up to tapping the first stud ( more details to follow).
Then notice the studs #2, 3 and 4 removed. The threads are clean showing no damage.
After using a screw extractor on the first stud that broke off... I can share that the screw extractor did not work and so I will be tapping out the first stud:(

Here is the broken stud from before, this is where I ended up a couple days ago.


This is the auto center punch tool in place.



Here is the stud with the center punched.


Drilling first hole 5/64th diameter.




Followed by a 1/8th diameter bit. Tape on bit is for indicating the maximum depth the drill can go.


There are two main types of screw extractors Tapered and twisted.


I used the tapered one first.


Then the twisted type.


The screw extractors would either slip or twist as though they were about to break off:(
So I just drilled as close to the threads as possible with a larger diameter drill. ( prepare for tapping the hole).


At this point I really-really dislike screw extractors.
So instead, I heated around stud #2, then 3 followed by #4 stud with a torch avoiding the stud(s) (not red hot but close) then used the vise-Grips and with little resistance the stud(s) came off






Half way there with 4 studs remaining for tomorrow:

Very nice, and well documented!