Drilling out JB Weld from exhaust bolt thread?

Nice story and pics. Personally, i would have bought a used head and been done with it weeks ago. LOL

[Gorminrider]

5 stars! for Kodak's "Inferno"! (I didn't count- are there nine circles of hell you went through?) Good script and cinematography. Entertaining throughout! Recommended...

seriously, I must save this somewhere...I'm so sure this will be deja vu when I need get some headers off.

Do you have the photos still? I'm guessing the Alum eventually worked?

Jason

I took photos and ran this experiment for you! haha.

Alright the stories and photos I promised yesterday.

A Quick Recap and Results of My Attempts

• Thought I was drilling out old JB Weld- WRONG, MOSTLY. It was a JB weld plug that uncovered old bolt that I mostly drilled out
• Broke a tap thinking I was almost doing a great job- WRONGISH I was actually tapping through the thread remnants of the bolt, because I was drilling off angle I didn't clean out the old bolt completely, as a couple of you pointed out this caused uneven stress that snapped the tap
• Attempted to drill out tap with everything but carbide- KINDA WORKEDf I tried even a carbide end mill but that was doomed from the start it was the wrong type of cutter
• Used super saturated solution of alum and water to dissolve tap- Jack Diddly but Promising Results In Experiment So I used around four tablespoons of alum to one cup water dissolved at near boiling temp. Poured that into the hole with the tap still snuggly in deep and left it for around 48 hours. I changed the solution a few times and cleared out the hole and making sure hot solution went in. This didn't work at all. What it did do was cause some rust to form, revealing the old bolt threads that I didn't drill out all the way. Here is a photo showing what it was like after 48 hours of soaking in the alum solution

HOWEVER, I put a pyrex cup of solution with the broken tap that didnt get stuck in the head in front of my halogen light as I worked with a set of carbide cutters on the stuck tap.

Here was the tap at the start in below room temp solution


Here is the tap not but two hours and some change after sitting very closely in front of the halogen light which as we all know get hotter than a ghost pepper


This solution was reallllly hot and as you can see this tap was chooching right along, tons of steel was falling into solution. So we can deduce from this that this reaction is either a very endothermic reaction or it has a high activation energy needed to encourage the reaction to take place. Neither of which is very practical with maintaining a high temperature while unattended and having such a small reaction chamber where the reaction could slow down before the bolt or tap is even close to being capable of extraction. So my conclusion is possible but highly improbable. Now back to the real question of this whole thread, what got this tap out?!
Using A set of double cut carbide cutters - DING DING DING WINNER WINNER CHICKEN DINNEr. I hopped on amazon and ordered a set of these for next to nothing


The two flat end cylinders did all the heavy cutting and had the tap ground mostly out within 30 mins or so. Cleared the hole every couple seconds and used the lighted amount of cutting oil. I intentionally didnt grind the whole tap out, I left a little. I was getting too close to the bottom and saw how bad my attempt at redrilling a new hole went. Terrible. Didn't want to chance anything and figure full depth isn't critical in this area. I may have to end up getting a new head if this doesn't hold up. Which I why I went with the helicoil over the timesert. Realizing how bad by retap was


I mean look at that, what the heck even happened, I've seen wind swept trees grow straighter than that. Even a venn diagram showing the realtionship between the NRA and Pacifists looks better than that mess. Either way, got enough tap out of the way to send in a helicoil. Hole was just barely small enough to use the tap helicoil provided. So yes, a timsert from what I could tell is the better permanent solution however I'm still trying to get this bike to run on all four cylinders and until I confirm this bike can ride and run I'm not spending $70 to then find out I need to get a new head or what have you.

So to wrap this diatribe up, you guys are awesome. If you contributed to this thread and continue to, game ain't over till she cranks over, I appreciate all of the insight and opinions. This is why I bought this GS850. The support on this forum is world class. Everyone knows a little about something and together we know a lot about something. Look forward to posting positive results in my build thread and get to the fun part of cleaning the brakes, painting, cutting, and testing the electrics!

Major update...coming later tonight. Just thought I'd give a little teaser for anyone following this thread. Got most of the tap out, found out how bad I done messed up attempting to tap the hole originally, it's embarrassing but I'm posting the pictures in the name of technical endeavors, I've retapped and helicoiled the hole. I will defend my position on purchasing a helicoil over a timesert tonight, and finally found out with great results that alum solution does dissolve a tap...Pictures and musings to come!

Do you have the photos still? I'm guessing the Alum eventually worked?

Jason

so I found this and thought it quite relevant to the topic lol

https://youtu.be/1uwz7BhAWZE

yeah, broken taps blow big time! I had to do head gaskets on the 72 gmc c15 I had forever ago and while trying to clean the threads in the block(the last one or two holes I had to do of course) the tap snapped. I almost ended up pulling the motor, but we were able to build enough heat on the tap to get a nut to stick to it with a mig welder. that was about 5-ish nuts. and I tried just about everything including the tap extractors. extractors won't do anything on a jammed in tap.

one thing that I noticed from the alum thread that was posted is that the alum takes quite a bit of time, and perhaps you were just getting a little impatient, especially with a hardened item like that?

Major update...coming later tonight. Just thought I'd give a little teaser for anyone following this thread. Got most of the tap out, found out how bad I done messed up attempting to tap the hole originally, it's embarrassing but I'm posting the pictures in the name of technical endeavors, I've retapped and helicoiled the hole. I will defend my position on purchasing a helicoil over a timesert tonight, and finally found out with great results that alum solution does dissolve a tap...Pictures and musings to come!

I hear you have to apply heat when using the Alum, have you tried that yet?

I am interested in this, since I have a head that is mostly good, with the exception of 6 broken off exhaust bolts. I am faithfully watching your thread to learn what works.

So this is our dilemma, with the motor off the bike we've got great access to the bolts or in my case the broken tap, which makes creating a reservoir to hold the concoction easy. Heating it however is that real task. I can't think of a way that is safe to leave unmonitored for 24hrs+. I've had success with left handed twist drill bits for bolts. I've soaked them in PB blaster for several days. Heating up the area and letting it cool down a bit. This is my first trial with a broken tap. Harder in the most double entendre possible.

Maybe they would have dissolved in my alchemist potion! Haha!

I hear you have to apply heat when using the Alum, have you tried that yet?

I am interested in this, since I have a head that is mostly good, with the exception of 6 broken off exhaust bolts. I am faithfully watching your thread to learn what works.

You have a Dremel / die grinder? Use it to "centre" the hole before you drill it for the tap.

Yes I do! I purchased a grinding stone for it and that actually helped make a dimple in the tap for me to grind some of it out. My center punches just shattered at the tips when I tried to punch the tap. I will say part of me wishes the tap was Chinesium and not made in the USA. Maybe they would have dissolved in my alchemist potion! Haha!

[hillsy]

I didn't think about this. I knew I was slightly off center. With the engine off the frame I can align my drill far better. Hmmm, maybe I can think of something to ensure I'm drilling on center despite the crappy oblong opening I have to start with.

You have a Dremel / die grinder? Use it to "centre" the hole before you drill it for the tap.

Yes, your learning curve has been quite steep! You deserve compliments for hanging in there so far - others would have quit long ago!

I would like to make you aware of one thing as you move forward and prepare to insert (hopefully) a Timesert in that hole - please be aware that the hole appears to be off-centre towards the bottom-left of the original centre point. You will need to tap and insert whatever fixing you choose on the correct original centre-to-centre hole spacing to the other (good) hole, or else your exhaust collar will not bolt up easily (or if you use studs, they will not go through the holes in the collar

I didn't think about this. I knew I was slightly off center. With the engine off the frame I can align my drill far better. Hmmm, maybe I can think of something to ensure I'm drilling on center despite the crappy oblong opening I have to start with.

[Steve]

Compared to a coiled style helicoil its like a Bently compared to a VW bug.

You can have them both, Chuck.



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[2BRacing]

I understand what your guys are saying. I know the largest cost so far is the sunk time instead of working on the seat pan and electrics. Fortunately I don't have too much sunk into the tap removal. But you're right about having it for life. I just have to take into consideration when I'll be needing an M8 timesert as opposed to using the carbide burs again that I've just ordered. I will say for as much complaining I've done while drilling this sucker out I'm having a peachy time learning as I go and from everyone chiming in on this thread. I've learned about the various ways to grind out a tap, learned about EDM, tempering, and the cost of not drilling out a bolt all the way before tapping threads! This is what I signed up for when I bought this bike!

Yes, your learning curve has been quite steep! You deserve compliments for hanging in there so far - others would have quit long ago!

I would like to make you aware of one thing as you move forward and prepare to insert (hopefully) a Timesert in that hole - please be aware that the hole appears to be off-centre towards the bottom-left of the original centre point. You will need to tap and insert whatever fixing you choose on the correct original centre-to-centre hole spacing to the other (good) hole, or else your exhaust collar will not bolt up easily (or if you use studs, they will not go through the holes in the collar easily).

I am holding thumbs for a successful completion of this task!

[AMK]

I understand what your guys are saying. I know the largest cost so far is the sunk time instead of working on the seat pan and electrics. Fortunately I don't have too much sunk into the tap removal. But you're right about having it for life. I just have to take into consideration when I'll be needing an M8 timesert as opposed to using the carbide burs again that I've just ordered. I will say for as much complaining I've done while drilling this sucker out I'm having a peachy time learning as I go and from everyone chiming in on this thread. I've learned about the various ways to grind out a tap, learned about EDM, tempering, and the cost of not drilling out a bolt all the way before tapping threads! This is what I signed up for when I bought this bike!

Great attitude man. I'm hoping you win this fight.