Brazing TC tips.

  1. Retired Forum Supporter

    Messages:
    363
    Location:
    Huddersfield. UK.
    Hi,

    I have a friend who uses lots of TC tipped tooling for trimming metal spinning. This tooling is secured in a long handle and used manually it being subjected to extreme forces.

    Whilst visiting a couple of weeks ago he showed me a tool which had failed after an attempt to braze on a TC (Tungsten Carbide) tip. I closely inspected the failed joint and it looked like a "dry joint" I asked the guy who had done this joint as to his method; he ran through each stage but right at the end he had pressed down on the tip to seat it? Perhaps this excluded the bronze filler?

    I came away with 22 TC tips these at 3/8" square x 1/8" thick and a short length of 3/8" square BMS to experiment with.

    It's over 50 years since I did this kind of brazing but then I was working in the pit with top class kit like oxy/acetylene. All I have in my workshop is a paraffin blowlamp and a Rothenberger cartridge blow torch.

    The tool bodies are 2 1/2" long. I was told it would be OK to simply braze a tip onto the body end but I thought I'd go a bit further. After cutting to length then marking out I cut out each recess by hand using hacksaw and engineers files; I don't have a mill but I do have a lathe; by the time I set the lathe up I could do the job by hand; I was taught to file flat to a thou of an inch as an apprentice so I enjoyed the exercise.

    I gave a lot of thought to the actual brazing and not wanting to end up with dry joints I did a bit of online research;

    https://vacaero.com/information-res...-joint-strength-vs-joint-clearance-chart.html

    As I type the tooling hasn't been tried in anger but in order to prevent a dry joint I came up with the idea of adding three light center pops to each tool "land" this would throw up a low raised circle for the tip to sit on? I also canted the tool body in the vice during brazing to ensure the bronze ran fully into the joint?

    I split the tools into two batches; the first batch I used brass shim cut to size. The tool land was fluxed using paste SIF flux mixed by adding powder to a drop of water and stirring; this was brushed on; the brass was cleaned using abrasive paper and a shim square placed on the land then more flux then the TC tip making a sandwich. This worked very well indeed the only snag was keeping the tip fully aligned.

    The second batch I added the center pops but used 1/16" Silicon Bronze filler rod the end of the rod heated and dipped into the powder flux. As before I set the job up and for good measure brushed on flux before adding the tip but I found my "third hand" to be extremely useful resting this on the tip. It was very satisfying to heat to cherry red from below and watch as the filler rod melted and ran the joint length; at this point I removed the heat.

    The TC tips as supplied had very poor faces so I hand honed each joint face on my Trend diamond bench honing stone; I also honed all four edges of each tip; the tips were left soaking in Acetone overnight and before brazing I vigorously wire brushed the tool body end using a stainless steel wire brush then these in turn were dipped into acetone. Cleanliness is important.

    This might seem long winded but I enjoy my workshop time and like to try ideas out; I'm now keen to see how the tooling stands up to use. Time now to get off my backside and wander down to the workshop.

    Kind regards, Colin.


    Brazing TC tips_0008.JPG
    Brass shim.

    Brazing_0001.JPG
    Method using third hand which worked a treat.

    Brazing_0002.JPG
    A number of finished tools.

    TC tooling_0003.JPG
    Preparing lands by sawing and filing.

    Tool bodies_0008.JPG
    Bulk of waste removed using hacksaw; quicker than it looks.

    Tool bodies_0010.JPG
    Light center pops.

    Tool bodies_0012.JPG
    Hand filing shoulder guide in use.

    Tool bodies_0015.JPG
    Tool bodies ready to receive tips.

    Tooling._0005.JPG

    Before and after honing using the diamond hone; this was the tedious part but well worth it.

    Spinning tools_003.JPG

    These are my own metal spinning tools; the bottom one has an HSS insert for trimming; trimming during metal spinning is highly dangerous; the two top tools are 42" long with 2" dia pitch pine handles; these are small compared to industrial hand spinning tools where 3" dia handles are used with longer lengths; considerable force is required using these tools; I broke a rib and many metal spinners too have broken a rib or two. Metal spinning is a fascinating process.
     
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  2. Dcal

    Dcal Forum Supporter

    Messages:
    2,224
    Location:
    Antrim Northern Ireland
    Thanks Retired
    Brilliant post and brilliant information.

    I love posts like this because i learn so much and get an insight into the thought process of people who have a lifetime of learning and working things out.
    Nothing worse then just showing the finished article in my opinion.

    Would be really interested in more information on the spinning too.
     
    Retired likes this.
  3. Retired Forum Supporter

    Messages:
    363
    Location:
    Huddersfield. UK.
    Hi,

    Thanks for your kind words Dcal; much appreciated. I'm pretty sure most welders will be familiar with brazing but I'm aware lots of novices join for advice so as I've just been doing this brazing thought I'd add the details.

    You can obtain lots of useful metal spinning information from both the web and YouTube; YouTube in particular has excellent videos on the subject showing both how to and how not to do metal spinning; it's an whole new world to explore but as I say it's dangerous; choice of aluminium is critical; 1050 grade is soft and the grade to use also lubrication is very important;



    Full credit to the guy in the video for sharing his failures; I too suffered a few until I obtained the correct grade aluminium and then soon mastered the basics; I use my much modified Graduate lathe for metal spinning and of course also use it for making the plugs.Just search YouTube for metal spinning. I bought a pair of vintage coach lamps for £3 at Rufforth Auto Jumble and restoring them I needed six new reflectors three different reflectors in each so I need three pairs so this got me into metal spinning; I love leaving my comfort zone to try new things.

    Kind regards, Colin.

    104_0313.JPG

    Fully restored coach lamp.

    Lamps._001.JPG

    The coach lamps were so rough I just about made new ones from scratch. Two metal spun items.

    Metal spinning._001_01.JPG

    Metal spinning certainly isn't easy but patience and stubbornness pays off and I've got lots of both.

    Metal spinning._003_01.JPG

    Almost there with this one; the tool was picking up due to insufficient lubrication. Please note the pressure pad at the tailstock; the circle is only secured by friction and it revolves like a circular saw blade; if it gets loose it can and will cause serious injury; trimming is the most dangerous part; metal spinners make it look easy but even they get caught out.

    More spinning_003_01.JPG

    One of the reflector wooden plugs.

    More spinning_005.JPG

    Another reflector wooden plug; care is needed to get these bang on because the finished item will copy any blemish.

    More spinning_006.JPG

    Two finished reflectors.

    Reflectors_001.JPG

    The six finished reflectors; I was interested in anodizing them but decided against experimenting not wanting harmful chemicals in the workshop; I can easily spin more if needed. Solvol Autosol was used for the final polishing under power in the lathe but definitely being aware not to wrap cloth around my hand or fingers this being extremely dangerous. I like metal spinning; frustrating at first as with most things if interested anyone can succeed.
     
  4. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,880
    Location:
    Skelton in Cleveland U.K.
    Superb info, Top class work.
     
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  5. Retired Forum Supporter

    Messages:
    363
    Location:
    Huddersfield. UK.
    Hi,

    Many thanks Gordon.

    I've just enjoyed an hour pottering around in the workshop. As an excuse to run my Lorch lathe I thought I'd play around machining "lands" for the TC tips. Chucking a four flute milling cutter I quickly cut four lands; these obviously have a curved shoulder which will be easy to file flat but it was just a bit of fun. I have a vertical slide and if I were to run a large batch of these tool bodies I could set up the slide and cut the lands in one pass leaving a perfectly straight shoulder to the tooling; I never tire of being in the workshop; sometimes I only go in to tidy up and oil the machines. A few pictures of my set up for interest.

    Kind regards, Colin.

    Lathes_0001.JPG

    Four flute cutter making easy work of this in one pass. I could set up the vertical slide if I had many to do but I was just enjoying myself playing around with my toys.

    Lathes_0002.JPG

    The new Poly-V drive I installed a few years ago; working at Brook motors I used to scrounge all kinds of things; one day I returned home with two 3 phase 1.5hp inverter rated motors; the research department used such motors for test purposes then they were scrapped so I was always on the lookout; I was also kindly allowed to bring home as many prototype "W" series motors as I liked on the strict promise I would never ever sell any of them.

    Lathes_0003.JPG

    My extremely rare floor standing Lorch Schmidt precision engineering lathe; I bought this as scrap after it had been stored in a scrap yard for over twenty years; I subjected it to a comprehensive rebuild; I disliked the flat leather belt drive so now having two suitable motors to hand I modified the drive giving variable speed with reverse; at 1.5hp it's well on top for power; the original drive is still installed it being single phase with the now obsolete DOL starter still attached. Fortunately it came with a full set of change wheels. Storage space is fully used as seen under the lathe. With power feed and long travel to the cross slide it's an absolute joy to own and use; it hides under a dust cover when not in use.

    Lathes_0004.JPG

    I used both inverter rated motors these being identical as to specification allowing me to also upgrade my Graduate woodturning lathe too; I have one 3hp VFD and this will run single 1.5hp motors without problem; I bought the 3hp in case I wanted to run a 3hp motor. The VFD is in the enclosure to protect it from dust; VFD's are dangerous to play around with and with this one VFD I run both my lathes from it. The switching was interesting to work out and I experienced lots of problems with the wiring at first; eventually I found the problem to be "cross talk" between the signal and power cables; I rerouted the cables and for the signal cables for the remote controls I used Cat 6 cable. I can only run one lathe at a time by the switching arrangement and as the two motors are identical once I set the VFD parameters I could then forget them. It works a treat. The lamp is a power on indicator not letting me leave the workshop without switching off.

    Lathes_0005.JPG

    My fully restored and much modified Graduate woodturning lathe; it now having the 1.5hp motor I can use it for metal spinning; the variable speed on both lathes is highly useful. Under the left black bin bag is my 12" thicknesser under the right black bin bag is my morticer; there is little space left to cram more machinery in. The bandsaw too is fully restored by me.

    Lathes_0006.JPG

    The lathes 3 phase power switch it being an heavy duty rotary switch. 1 is the Graduate 2 is the Lorch.

    Lathes_0007.JPG

    The switch for the remote controls.

    Lathes_0008.JPG

    The Lorch control.

    Lathes_0009.JPG

    Showing the simple motor mounting allowing the lathe to remain original if it's ever removed.

    Lathes_0011.JPG

    The VFD which has been brilliant for years never missing a beat. VFD user manual and my circuit diagram stored for reference. I'm doing a bit of doodling whilst enjoying a mug of tea and biscuits but time now to wander back down to the workshop.
     
  6. mtt.tr

    mtt.tr Member

    Messages:
    3,357
    Essex England
    Brilliant work, that spinning is superb
     
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  7. Dcal

    Dcal Forum Supporter

    Messages:
    2,224
    Location:
    Antrim Northern Ireland
    I thought Lorch was a typo or you had a fancy welding rotator or something until I saw the photos.
    Great stuff and brilliant to see the work you have done.
     
    Retired likes this.
  8. grim_d

    grim_d Unlikeable idiot.

    Messages:
    2,952
    Location:
    Scotland - Ayrshire
    Excellent work for sure but why is everyone painting their lathe neon green these days?
     
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  9. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,880
    Location:
    Skelton in Cleveland U.K.
    Lorch were or maybe still are makers of lots of watch makers lathes,
     
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  10. Retired Forum Supporter

    Messages:
    363
    Location:
    Huddersfield. UK.
    Hi,

    Thanks mtt.tr; I got off to a bad start with the metal spinning because I bought some scrap aluminium sheet from our local scrap yard to practice with; I didn't know there were so many different grades of aluminium and the sheets I got could have also been anodized; it's a long story but I'm now friends with the owner of a metal spinning company who has been absolutely brilliant since first meeting him. I was so different to his regular visitors who are only interested in how much and when not in the actual spinning. We have a great deal in common both with mechanical interests so we enjoy long natters when I visit. I was generously set up with 1050 grade aluminium circles; lubricants and even tooling all as gifts which truly amazed me considering just how selfish the world seems to be these days; with spinning advice from him I repaid him by quickly producing the reflectors so it wasn't a case of me being a time waster; I've since bought aluminium supplies from him but unfortunately due to this terrible virus we're now grounded so I can't visit him. I do hope to incorporate metal spinning and woodturning just for fun;

    Woodturning_001.JPG Woodturning_001_01.JPG Woodturning_001_02.JPG

    Thanks Dcal, I enjoy sharing ideas and information; many stick with just one hobby but I like to try lots of hobbies then I don't become bored; I've joined vintage radio forums; woodworking forums; gardening forums; DIY forums and now this excellent welding forum. It beats me why anyone would be bored; I dislike sport and would never pay to watch someone kick a ball around in fact I couldn't be paid to watch it but we're all different. Our money goes into our home; car and hobbies where we can see something for it. I'm happy with my newly acquired hobby of tig welding aluminium; I'm a 72 year old dinosaur; never been abroad; never been on a ship or plane; don't touch alcohol or drugs and don't smoke; my wife and I are just different from others as we like being together at home.

    Thanks for asking grim_d; people often copy what I do. :D By the way I'm hopelessly colour blind; one day my wife and I sat at the computer and ran a colour blind test consisting of twenty six samples; my wife got all of them correctly I managed only three; I couldn't say the lathe is green I just liked the colour.

    I think Lorch stopped making lathes years ago gordon; Lorch watch/clockmakers lathes are very small but highly sought after commanding high prices; when I first obtained my Lorch lathe I spent hours on the web trying to find a similar model but without success;

    http://www.lathes.co.uk/lorch/

    A friend has a Lorch watchmakers lathe which is a little beauty. Here is my Lorch as bought.

    Lorch as bought..JPG

    I tried tig brazing as an experiment and failed miserably on this TC tooling; I had hoped to heat the tool end to cherry red and lay on a skin of bronze rod but I ended up with a huge lump of bronze instead; rather than waste lots of time I then turned to my canister gas torch; I also tried using my paraffin blowlamp but couldn't get the metal hot enough; the Rothenberger torch though did a good job without any drama or fuss.

    I've just enjoyed another mug of tea so now I'm heading out into the garden Cleaver hunting; I've declared war on this invasive weed so each time one pops it's head up I rip it out before it goes ballistic and seeds; there's always jobs needing doing but it keeps me fit and active. :thumbup:
     
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