Now that I remember, I broke a tap in some motorcycle part a few years back & I brought it to a friend at a local machine shop. He clamped the part in a bridgeport & hogged it out with a carbide endmill. He destroyed the endmill, but broke the tap up. You should be able to polish that aluminum up. Good job.
Wel done in getting it out. A few thoughts come to mind, if you were in a hurry, making a smaĺl core drill or even open up the hole with a 8mm carbide end mill and cut the broken tap at the ssme time. Re chemical dissolving, heat speeds the reactoon, double speed for every 10C if school chemistry memory holds(?) but in this small hole relative to bubble size stops the solution from doing its job. Obviously the solution needs constant replenishment at the workface as it does its job and a bubble will prevent this, some form of forced flow like a from hypodermic needle and syringe would have sped things up. I did this when i got the broken tap out with cartridge case cleaner because I noticed the reaction worked but stopped very quickly figuring the acid was quickly exhausted and not being replaced by any natural flow.
Glad to see you got the broken tap out. The simple solution to getting a matching finish on the 2 heads that will look good is to get someone to fine bead blast them or vapour blast them for you.
Congratulations Andrew ! The repair looks good, and I'm sure it will work well also. I'm surprised that the alum did not work more quickly even at a lower temperature. There might have been a coating of cutting oil on the broken tap which prevented the alum solution from coming in direct contact with the metal except at the very end. The bubbles forming at the hole should have started shortly after initially placing the part in the solution.
Brilliant solution Andrew I think what the Alum did was to partially Anodise the Aluminium ( I may be wrong, and better chemists than me may disagree ) A superb catch. Trying your CNC router was an excellent idea and I have done this myself on odd occasions, but to get taps out you need much harder tools I use Diamond Burrs and lots of water It sounds expensive, but it isn't You can get them from China very cheaply, or , if you have a good relationship with your dentist, loads of semi spent ones gratis I spent many years as an electrical panel builder and have broken my quota of 3.0, 2.5 and even 1.6mm taps in my time It happens! now and again you break one despite all your care But your recovery from this was extremely clever
Many thanks for the info. I nearly purchased some dentist type diamond burrs via AliExpress. Now they keep on reminding me! I might just get some, just in case. Cheers Andrew
What a great result. No sign of the repair now. WD 40 polishes aluminium well. Not sure if it will work on a chemically corroded surface though. Worth a try as no expense involved.
@@learningturningmetal you could try anodising them both. I have never tried it but Mark Presling on his channel describes in detail how it is done. Doesnt look difficult once you have the necessary materials. The heads would look god in blue or red.
I’m glad you were able to work it out Andrew without re making the part. The Alum(grocery store spice isle) needs to be in saturation and kept hot. Also it is suggested to keep it in an ultrasonic. The ferrous screw will eventually just crumble away. Anyway. Thanks for sharing. Cheers.
@@learningturningmetal I use an ultrasonic cleaner that has heat. So keep solution warm and the ultrasonic waves helps break up the ferrous metal as it’s eaten by the alum.
@@learningturningmetal do you have Harbor freight stores They have a few. I’m sure Amazon lists a few. Mine is an older one I received from a watchmaker friend. Elma is good name brand and is used in watchmaking jewelry service but IMHO is probably overkill for just a hobby one. Also L&R I believe still makes them. Used them in the Police Dept to clean gun parts.
Well done. I wonder if the Alum would have worked if you had the water near boiling point from the start? BTW, completed our move from Surrey to Yorkshire!! Just outside Halifax. Rebuilding the workshop and a new mill coming soon - Sieg SX3.5XP. R8 - so some new tooling required!
Thanks Kevin - I think keeping the alum near boiling point from the start would have really helped. Blimey, I don't think I could face another house move - far too much heavy gear now. Good look with the workshop. R8 definitely the way to go. Cheers Andrew
I may be wrong but I believe alum will only de solve tungsten taps and will not de solve high speed steel, you can drill high speed steel with solid carbide drills but you have to be careful as small carbide drills are easily broken.
Interesting - I'm sure alum did have a chemical reaction with HSS - it just took a while and I should have kept the temp high throughout the process. Cheers Andrew
I tried alum at boiling point for about a week on an aluminium part to remove a broken tap. Absolute waste of time and money. The newly machined part went a dull grey like your part and then the aluminium started to pit, at that point I discarded the process. I eventually just beat it out with hardened punches.
Hi Derek - it does seem to be a bit of a hit n miss process. Some people have success and others don't. I was concerned when I saw bubbles coming directly off the aluminium, and that is when I decided to call it a day. Some people suggest spark erosion but I guess you are talking £££. Cheers Andrew
Thanks Rick - as the aluminium will tarnish over time anyway, I've decided to put the other head in some alum to try to get a decent match. Cheers Andrew
If that engine head gets to the temperature at which Loctite dissolves, he’s gonna have much more serious issues. Generally it takes temps of between 300°-600°F or greater to melt Loctite depending on the formula.
Alum is an urban myth... use it at your own risk. Since the commencement of my apprenticeship in 1968, I have never broken a tap, probably due to proper apprentice training.
A true craftsman is one that can repair his mistakes , 😉. All came out nice in the end .
I'm glad you were able to safe it. Well done.
Thanks mate! 👍
Great result Andrew. Alloy is such a cow for tapping.
Regards.
Steve.
ANDREW
nicely done. Quicker than machining a new cylinder head.
👍👍👍👍👍
OL6162
Thanks OL. I got there in the end!
Cheers
Andrew
The repair is almost invisible, great work! That's ingenuity at its best.
Good result in the end Andrew. 👍 Persistence wins again!
Brilliant save. Awesome work.
Now that I remember, I broke a tap in some motorcycle part a few years back & I brought it to a friend at a local machine shop.
He clamped the part in a bridgeport & hogged it out with a carbide endmill. He destroyed the endmill, but broke the tap up.
You should be able to polish that aluminum up. Good job.
Great job mate, cheers
Wel done in getting it out.
A few thoughts come to mind, if you were in a hurry, making a smaĺl core drill or even open up the hole with a 8mm carbide end mill and cut the broken tap at the ssme time.
Re chemical dissolving, heat speeds the reactoon, double speed for every 10C if school chemistry memory holds(?) but in this small hole relative to bubble size stops the solution from doing its job. Obviously the solution needs constant replenishment at the workface as it does its job and a bubble will prevent this, some form of forced flow like a from hypodermic needle and syringe would have sped things up. I did this when i got the broken tap out with cartridge case cleaner because I noticed the reaction worked but stopped very quickly figuring the acid was quickly exhausted and not being replaced by any natural flow.
A brilliant save. The repair is invisible. Well done 👏👏👍😀
I had a carbon tap snap in a loco boiler. Left it in a week pickle for a month ! Eventually it dissolved . Took a while but saved the boiler .
Nicely Done!
Well done!
Glad to see you got the broken tap out. The simple solution to getting a matching finish on the 2 heads that will look good is to get someone to fine bead blast them or vapour blast them for you.
Hi Howard - thanks for the suggestion. To be honest the heads will tarnish over time anyway, so I'm not too bothered.
Cheers
Andrew
Congratulations Andrew ! The repair looks good, and I'm sure it will work well also. I'm surprised that the alum did not work more quickly even at a lower temperature. There might have been a coating of cutting oil on the broken tap which prevented the alum solution from coming in direct contact with the metal except at the very end. The bubbles forming at the hole should have started shortly after initially placing the part in the solution.
Thanks Earl - it was certainly an interesting exercise. Definitely worth another try next time I goof up🥴
All the best.
Andrew
Brilliant solution Andrew I think what the Alum did was to partially Anodise the Aluminium ( I may be wrong, and better chemists than me may disagree ) A superb catch.
Trying your CNC router was an excellent idea and I have done this myself on odd occasions, but to get taps out you need much harder tools
I use Diamond Burrs and lots of water
It sounds expensive, but it isn't You can get them from China very cheaply, or , if you have a good relationship with your dentist, loads of semi spent ones gratis
I spent many years as an electrical panel builder and have broken my quota of 3.0, 2.5 and even 1.6mm taps in my time
It happens!
now and again you break one despite all your care
But your recovery from this was extremely clever
Many thanks for the info. I nearly purchased some dentist type diamond burrs via AliExpress. Now they keep on reminding me! I might just get some, just in case.
Cheers
Andrew
What a great result. No sign of the repair now. WD 40 polishes aluminium well. Not sure if it will work on a chemically corroded surface though. Worth a try as no expense involved.
Thanks Tim. I'll give WD40 a try.
Cheers
Andrew
@@learningturningmetal you could try anodising them both. I have never tried it but Mark Presling on his channel describes in detail how it is done. Doesnt look difficult once you have the necessary materials. The heads would look god in blue or red.
@@timjoinson7232 interesting 🤔
I’m glad you were able to work it out Andrew without re making the part. The Alum(grocery store spice isle) needs to be in saturation and kept hot. Also it is suggested to keep it in an ultrasonic. The ferrous screw will eventually just crumble away. Anyway. Thanks for sharing. Cheers.
Hi John - I must explore ultrasonic. Can you advise?
Cheers
Andrew
@@learningturningmetal I use an ultrasonic cleaner that has heat. So keep solution warm and the ultrasonic waves helps break up the ferrous metal as it’s eaten by the alum.
@@johnvaluk1401 hi john, can you recommend an untrasonnic cleaner for a hobby model engineer like me? I know nothing about that type of product.
@@learningturningmetal do you have Harbor freight stores They have a few. I’m sure Amazon lists a few. Mine is an older one I received from a watchmaker friend. Elma is good name brand and is used in watchmaking jewelry service but IMHO is probably overkill for just a hobby one. Also L&R I believe still makes them. Used them in the Police Dept to clean gun parts.
@@johnvaluk1401 thanks John I'll investigate.
Thanks for sharing 👍
Thanks Craig!
Well done. I wonder if the Alum would have worked if you had the water near boiling point from the start? BTW, completed our move from Surrey to Yorkshire!! Just outside Halifax. Rebuilding the workshop and a new mill coming soon - Sieg SX3.5XP. R8 - so some new tooling required!
Thanks Kevin - I think keeping the alum near boiling point from the start would have really helped. Blimey, I don't think I could face another house move - far too much heavy gear now. Good look with the workshop. R8 definitely the way to go.
Cheers
Andrew
I may be wrong but I believe alum will only de solve tungsten taps and will not de solve high speed steel, you can drill high speed steel with solid carbide drills but you have to be careful as small carbide drills are easily broken.
Interesting - I'm sure alum did have a chemical reaction with HSS - it just took a while and I should have kept the temp high throughout the process.
Cheers
Andrew
Wire EDM. Should have made the plug a liquid nitrogen slip/press fit.
Sounds expensive. 🤑I am only an enthusiastic home model engineer with limited funds.
I tried alum at boiling point for about a week on an aluminium part to remove a broken tap. Absolute waste of time and money. The newly machined part went a dull grey like your part and then the aluminium started to pit, at that point I discarded the process. I eventually just beat it out with hardened punches.
Blimey - that is a bit of a concern!
I tried Alum on my broken tap in a steam engine cylinder block, also did nothing whatsoever 🤷♂️
Hi Derek - it does seem to be a bit of a hit n miss process. Some people have success and others don't. I was concerned when I saw bubbles coming directly off the aluminium, and that is when I decided to call it a day. Some people suggest spark erosion but I guess you are talking £££.
Cheers
Andrew
Hi Andrew, soak the other head in alum and they will both have the same patina.
Dick B USA
Thanks Dick - you read my mind! The other head is currently undergoing a similar process.
All the best.
Andrew
You can chemically brighten with an acid solution
Thanks Rick - as the aluminium will tarnish over time anyway, I've decided to put the other head in some alum to try to get a decent match.
Cheers
Andrew
Spark erosion.
🤑🤑🤑🤑
As that head gets hot in use i hope the loctite doesn't give way.
If that engine head gets to the temperature at which Loctite dissolves, he’s gonna have much more serious issues. Generally it takes temps of between 300°-600°F or greater to melt Loctite depending on the formula.
You always seem to find a way to get there in the end. I'm looking forward to seeing the engine running: won't be long now. Regards.
Hi Clive. Loctite 638 is amazing stuff - check out the spec!
Try piano wire, which is hardened and tempered... it will not break so easily as your iron pins.
I will try to remember that one Gordon.
Cheers
Andrew
Alum is an urban myth... use it at your own risk. Since the commencement of my apprenticeship in 1968, I have never broken a tap, probably due to proper apprentice training.
Interesting!