Broke a hot cut today

[humphreymachine]

While cutting a length off of a ¾ x 2 ½ bar a chunk of the cutting edge broke away. I was quenching the tool frequently to prevent it from becoming too hot but obviously it hardened and then shattered. It can be reforged or ground back but I enjoy antique/vintage tools and hate to bust them up.
 
Anyone else had this issue with hot cuts or punches.

[Stephen Olivo]

Yes but it really only happens when someone who isn't used to working with a striker or with my tools uses them.  Then its just a matter of teaching them the right habits. 

[petere76]

Humphreymachine,

That happens all the time. On thick stock you have to limit contact to one or two heavy blows, then cool and repeat. Also, watch for and limit any twisting. That unit you have is still a good tool, just reforge it into whatever cutting tool you might want.

Peter

[Jim Coke]

Greetings Hump.

 

Stuff happens ...  I'll bet your stock got a little cold and you went for the last smack...   The tool is fixable but I would invest in a porta ban saw .. LOL

 

Forge on and make beautiful things

Jim

[John McPherson]

Maybe its the lighting, but it looks like rust in the break to me. If so, it has been cracked for a while.

[ThomasPowers]

pretty blunt end it's been over heated in a cut before!

[humphreymachine]

The rust you see is just a powdery coating which happened almost immediately(it is not on the chip). I was half way through the cut and continued to use the tool after the piece split off – once again dipping it in water after every few hits to prevent over heating. This repeated dampening formed the fine oxidation powder. I believe I allowed the chisel to overheat on a previous project and then inadvertently hardened it when cooled in water. I think the lesson is – especially when cutting heavy stock – cool after every strike or two – don’t cool at all, or maybe have several hot cuts and rotate their use every few hits.

[humphreymachine]

Jim –

 

I have an abrasive cutoff saw which fills the shop with a super noxious smell and may push my neighbor’s buttons if used too frequently outdoors.

 

I definitely could use a band saw but don’t have room in the shop for one of the larger units and hadn’t thought of the little portable units. Are they a good product?

[rockstar.esq]

Porta-bands are very good tools.  They excel at hollow metal cutting like conduit, pipe, and the like.  The RPM's are low and the torque is fairly high so it'll power through most stuff.

 

They're really for cutting the short dimension of long stock because the throat is limited.  But they won't make turning cuts as easily as an angle grinder.

 

When I was an apprentice it was fairly common to rig up a fixture with an arm on a hinge to replace the front grip of a portaband.  The result was a porta-band - chop saw.  I've even seen sparky's rig them up with a toggle switch and receptacle set so when the saw completes the cut it throws the switch and kills the power just like a metal shop would have. That auto-pilot feature is really nice when you're cutting large diameter stuff that takes a while.  The weight of the porta-band is enough to keep the blade feeding without bogging down.

 

They are much slower than abrasive wheels but they're blissfully quiet and stink-free.

[Stephen Olivo]

Porta bands are awesome as long as it isn't hardened.  Yes they have a limited throat but they still can do a lot.  I use my cheep one all the time and am looking at investing in a much better one soon, I would advise anyone to invest in a high quality one, as I use it so much this one is dieing.  A while back I replaced the little forked "platten" with a piece of angle iron and a piece of steel for a platen.  I now use it almost entirely in a vice vertically to cut all sorts of sheet and bar and what have you including wood.  This setup allows you to run it in a vice as a vertical bandsaw for smaller work and more decorative or finer work or to in seconds take it out of the vice and use it to cut down long lengths without doing anything to the machine.  Partly why I went this route is that most places I go I will have a vice with me if I have the portaband and its simple. I have found it to be as useful if not more then my angle grinder.  I use the angle grinder on springs or other hardened material as most won't cut on a bandsaw.  Bed frames you can cut with it though. 

 

Here is what I did to mine.  

http://ipneto.deviantart.com/art/Platten-modification-for-bandsaw-323162990

[arkie]

I see a lot of guys using hot cut tools who just do a quick dip in their quench water, not leaving it there for a short count to really cool the tool down sufficiently.  I know time is of the essence when your work piece is cooling down, but a little more hesitation on the dipping may save your hot cut tools.

[Jim Coke]

Greetings Hump,

 

Porta band saws  are a must.... I have 4 and could not function very well without one... I suspend one on a machinery counter balance like a yo yo that hangs freely ..  It makes it a pleasure to use and allows for more accurate cut..  No load...  They now make stands for about 120.00 that converts them into a table top...  The blades are only 020 thick and will go through material like butter....  What more can I say    By a good one..Milwaukee variable speed.. is best...  I hope this helps..

 

Forge on and make beautiful things

Jim 

[Rashelle]

A couple of things that might help with keeping your hot use tools cooler. Try using beeswax instead of water or oil to dip the tool in as it'll quench slower and you don't want to harden the tool. Also if you can remove the tool from the cut between blows, the air will help it keep cool, as opposed to absorbing heat from the work piece. If doing multiple heats let the tool sit in the wax to cool as much as possible while reheating.