An inexpensive 36" bending brake

[george wilson]

I was in our local Tractor Supply yesterday to buy cat food. Looking around,I found a very substantial 36" bending brake for $299.00. It looked plenty rigid enough to bend brass saw backs. It was rated to bend a 1/4" x 2" wide piece of steel.

It didn't take up much floor space. I liked that feature. Also,it would bend the metal way past 90 degrees,into a "V" shape. Beyond that,careful progressive squeezing along the saw back with a non marring vise would complete the job.

If any of you aspiring saw makers want a way to bend the backs ( which I guess is a hurdle for many to over come),you might check out this brake. I don't know how many places have a Tractor Supply store,but they sell many useful things even if you don't have a tractor!!

I hope it isn't against TOS to mention a store.

[Jessica Pierce-LaRose]

I'm guessing it was this guy, George?

http://www.tractorsupply.com/en/store/black-bulltrade%3B-metal-brake-with-stand-36-in-l

Tractor supply is a pretty neat place; I can get lost in there for hours, even though I don't need most of what they sell.

They also have Evapo-rust at the one local to me, for folks who like using that stuff.

[Zach Dillinger]

Evaporust, Oil Eater, lots of files and taps, lots of tools. Grinding wheels of good quality. Steel, aluminum, brass stock. Ni99 welding rod. Lots of reasons to go into Tractor Supply. Fortunately I'm there at least once a week to buy chicken feed and I have one about two miles from my house.

[Steve Voigt]

Evaporust, Oil Eater, lots of files and taps, lots of tools. Grinding wheels of good quality. Steel, aluminum, brass stock. Ni99 welding rod.

Sounds like paradise ! :)
There's one nearby, I don't know why I've never gone. I'll have to check it out.

[Jessica Pierce-LaRose]

I'll have to check again - I didn't see metal stock when I was last at ours, and the selection of files wasn't great, but ours hadn't been open that long when I went.

[george wilson]

They do sell hot rolled (black) steel rod and bars and square tubing. I DO NOT buy their plated steel bar stock. It is universally terrible steel,whatever it is.

I did see a quite nice looking FINE 8" Chinese made flat file. It was about $5.00. I thought about buying it,but really don't need it right now. I'll bet it's properly hardened,as opposed to Nicholson Mexican soft files. How well it would hold up,I don't know. The teeth looked perfectly nice. Usually I only see Chinese files in coarser cuts. This one was nice.

Joshua,yes,that is the bending brake. If you anneal the brass,as you SHOULD,to avoid cracking, I'm sure that brake will be fine for making saws. In fact,we annealed our backs twice. The second annealing was done after bending into a V shape. We had no trouble with cracked backs. We used 260 alloy. I didn't try 360 alloy,so can't recommend it. Our museum warehouse stocked 260.

[Paul Saffold]

Not to hijack the thread but Tractor Supply has rubber mat in rolls from recycled tires in 1/4" and 3/8" thicknesses X 4 feet wide. I got the 3/8" X 12 ' to go along my workbench. I love it. It isn't as easy to sweep clean as the cement floor but sure is easier on feet and knees (tools too). When I go back I'll pick up enough for the other side and ends.

[george wilson]

I just wear sneakers with extra Dr. Shoale's(sp?) rubber liners inside. I think I might trip over the edge of a floor mat. I haven't fallen in many years. I'm afraid I might jerk loose my back implant if I do.

[Zach Dillinger]

I just wear sneakers with extra Dr. Shoale's(sp?) rubber liners inside. I think I might trip over the edge of a floor mat. I haven't fallen in many years. I'm afraid I might jerk loose my back implant if I do.

And George wins the award for the heeby-jeebiest post of the day... holy moly that sounds awful.

[george wilson]

Whazzo hebbie-jeebie about sneakers with Dr. Shoales in them? Beats walking on concrete,and I get some ventilation for my feet.

[Jamie Bacon]

I have access to a heavy duty break at work that easily bends the brass to the V shape; where my trouble comes in is when I try to close the bend in a vise, the back always comes out looking like a sway-backed horse. I've never tried annealing the brass though. Maybe that would eliminate the problem? Is the proper way to anneal brass heating it to cherry red and letting it cool slowly, or quenching it quickly?

[Ryan Baker]

Heat it and quench. (Actually, I think slow cooling works too, just more slowly). It's kind of the opposite of steel. I'm sure George will chime in with details.

[george wilson]

Heat it just to red. Let it cool slowly to avoid distorting and cracking which I can guarantee if you quench while hot. It will get fully annealed left to cool slowly.

I haven't had the sway backed thing happen. Annealing might help that. I suggest careful,progressive closing of the back in small stages to prevent the bowing. I saw a guy hammering a brass back into a groove in hardwood just using a caulking(wide) chisel. Even that simple way works. It must be in your technique.

[Tony Zaffuto]

Speaking of the sway back, George, I picked up a vintage English back saw a few years ago. It has a minor sway back to the spine. The blade has a bit of a wave to it, which I attribute to the sway back.

Short of replacing the spine, what can be attempted to minimize the saw plate's wave?

[george wilson]

I suppose the sway back was caused by someone attempting to tighten the back's grip on the blade by hammering on it mostly on its open side. That would stretch the metal on the open side and make it a bit wider,producing the sway back.

Remove the saw back entirely and anneal it. With a soft mallet,lay the back's round (closed) side down on a piece of wood,and mallet it straight. Be careful to not get it distorted sideways. Or,with a smooth jawed vise,squeeze the back straight by holding it horizontally in the jaws and tightening,along with some careful malleting. In any case,annealing is necessary.

Re assemble the saw,handle and all. To get the waviness out of the blade,adjust a Crescent wrench,or make one of hard wood,that just fits the thickness of the back. Place the wrench right ACROSS the back. Twist (torque) the back while looking down the teeth. Twist until the cutting edge is straight. It helps to clamp the front end of the back in a vise while twisting the back. We did this to nearly every saw we made. I had to invent the technique,but it is probably exactly what other saw makers had done forever. I used a NON MARRING wooden wrench. It doesn't take a lot of force to twist an annealed back a small amount. Small amounts are all that is necessary,since the effect of the twist will be magnified by the width of the saw blade on its cutting edge.

The very minor twisting of the back in this manner will not be noticeable. Indeed,you might be straightening the back itself,except if your back was previously deformed by hammering it,no telling what is happening to it.

[Zach Dillinger]

Whazzo hebbie-jeebie about sneakers with Dr. Shoales in them? Beats walking on concrete,and I get some ventilation for my feet.

Not the sneakers part George... the "back implant being ripped out as the result of a fall" part :)

[george wilson]

Yes,that would cause instant,unbearable pain. I don't know if it's possible since it is screwed in with 2" long deck screw looking titanium screws. By now,they probably have healed over solid. I'm not wanting to take chances though.

[Keith Outten]

George,

If you have the need to bend sheet metal in the future drop by my shop in Gloucester County. We are just a few miles apart.
I have one of these:


http://www.youtube.com/watch?feature=player_embedded&v=zWvMW1Zxoyc

This is one of the most unique sheet metal benders I have ever seen. Warning the video has some loud music so turn your speakers down low, towards the end you can see how this machine will bend around a round metal bar.

[george wilson]

Thank you,Keith. What I really need is a shear that will do 1/8" brass. But,I can just saw it out with my metal cutting bandsaws. Probably just buy bar stock when Enco has a free shipping sale (they have one every month these days. It used to always be free.) Shearing saw blades needs to be done on a shear for sure. I can likely do it in Williamsburg. So far,I don't have active plans to make saws though. I have a saw toother,but no place to mount it yet.

[george wilson]

Zach, your message box is full.

[Zach Dillinger]

Try it now George.

[Tony Zaffuto]

George,

Thanks for your response as to curing the sway back issues one of my back saws have. I've decided to let things be as I may do more damage than curing. Can't recall the saw name (an English saw), but I've got plenty of other saws to use, so this one will remain as is.

T.Z.

[Keith Outten]

George,

Sadly I don't own a shear but I do have a Safety Saw that will cut 24" long brass/aluminum sheet up to about 0.040" thick. I never heard of a Safety Saw until Mike Null listed his saw for sale in our Classifieds Forum. Its an amazing saw that produces beautifully clean cuts using a 3" diameter saw blade at 6,400 RPM. It will also cut wood and plastic up to 1/4" thick.
.

[Tony Zaffuto]

Well, I have a brake, roller, shear, stretcher/shrinker, iron-worker, nibbler, complete machine shop, complete tool making shop and a powder metal plant to go with the aforementioned toys!

[Sotos Patistas]

Keith,

Does that saw go by any other name? Google doesn't turn up anything like what you're describing.

Thanks.
Sotos



George,

Sadly I don't own a shear but I do have a Safety Saw that will cut 24" long brass/aluminum sheet up to about 0.040" thick. I never heard of a Safety Saw until Mike Null listed his saw for sale in our Classifieds Forum. Its an amazing saw that produces beautifully clean cuts using a 3" diameter saw blade at 6,400 RPM. It will also cut wood and plastic up to 1/4" thick.
.

[Keith Outten]

Sotos,

Its a New Hermes Safety Saw.
Here is a link to a picture.

http://bellcoinc.com/shopsite_sc/media/Saw_250-VA10.jpg

They are table top saws, very accurate and they cut metal as clean as a shear.
Look for a used one, new ones are very high priced machines.

[Keith Outten]

Tony,

Would you be interested in moving to Virginia :)
I'd love to have a neighbor with a shop like yours.....come on down.
.

[David Weaver]

.. and a powder metal plant ..

That's something that not many people on here are going to match.

[Sotos Patistas]

Thanks Keith. That looks very handy, I'll have to keep an eye out for one.



Sotos,

Its a New Hermes Safety Saw.
Here is a link to a picture.

http://bellcoinc.com/shopsite_sc/media/Saw_250-VA10.jpg

They are table top saws, very accurate and they cut metal as clean as a shear.
Look for a used one, new ones are very high priced machines.

[Bruce Haugen]

I don't have a back implant, so can't comment on that. However, I do have an implant on my left tibia that has been held in place with 8 nasty looking stainless screws with deep threads that have been holding very well for the last 41 years. They haven't let loose yet even though I've given them good reasons to do so. Good luck with yours, George.

[Tony Zaffuto]

Keith, David and anyone else,

If you're eve crossing I-80, get off at the DuBois exits (97 & 101) and give me a call, (814) 375-9399, and stop in!

T.Z.

[Noah Wagener]

Do i need to anneal steel before bending it? Can angle steel be used since it is already halfway home? Can it be annealed with a MAPP plumber's torch.

George, you have said that 2 torches are better than one. Are two propane torches better than one MAPP? What do you recommend for a low outlay setup?

Can you talk a little more about twisting the backs with a wooden wrench? You were twisting already straight backs to straighten wavy spring steel that did not respond to being in the back?

One should never hammer a back to straighten it? How about bending like this?


https://www.youtube.com/watch?v=tzc4tQ5CRxk

How did you fold backs at Colonial Williamsburg?

[Phil Thien]

Sotos,

Its a New Hermes Safety Saw.
Here is a link to a picture.

http://bellcoinc.com/shopsite_sc/media/Saw_250-VA10.jpg

They are table top saws, very accurate and they cut metal as clean as a shear.
Look for a used one, new ones are very high priced machines.

That is slick. I also found them called Varga Safety Saws.

That thing would be handle around my place.

[george wilson]

Without re reading all 3 pages of this old post,I make hardwood "wrenches" that have throats that are just wide enough to slip the saw backs into. Then,to straighten a curved blade,look down the tooth line,and TORQUE the saw back to make the tooth line straight. The saw back will not be noticeably bent from this process. I usually clamp one end of the saw back in a vise before twisting it.

Sheet steel is already annealed,Noah. I can't recall if we found it necessary to re anneal half way through the folding process. We DID with brass backs. To anneal steel,I'd use 2 Mapp gas torches to get the steel back red hot. Then,just let it air cool. Let brass cool,too in the air,until it is well below red hot,or it WILL crack and distort. Best to just let it cool completely in the air.

Since we had to make many backs in Williamsburg,I made a simple press with "V" shaped jaws longer than the longest back. 2 hydraulic jacks from Northern were used to crank the press shut. The backs were first bent into a V shaper,then the V shapes were annealed again. After that,the V shapes were carefully put into the press jaws EXACTLY on edge,so neither side would bend more than the other. Then,the backs were squeezed into the proper narrow "horse shoe" shape (as seen on end),and squeezed till the gap was a bit thinner than the thickness of the blade that would be inserted. The top edges of the blades were quickly ground into a small bevel,so they would not cut the brass backs when inserted. Then,the blades were driven into the backs with a plastic or wooden mallet so as to not hurt the teeth.

You can effectively bend brass backs by using a wide caulking iron type of chisel. Open the wood lined jaws of a woodworking vise about 1/2" apart. Progressively and evenly hammer the caulking iron down the center of the back,gradually starting to bend it into the desired V shape. The key is to do this patiently and EVENLY so you keep the back nice and straight. Once you have the V shape,the vise can be used to progressively flatten the V into the closed shape you want.

I DON"T hammer saw backs because it would leave dents that would have to be filed or ground away. I want as clean a job as possible to save a lot of damage cleanup,and to keep the back full thickness.

[Noah Wagener]

thanks George.

Do you fit the mortise in the handle to that horseshoe shape?

Leaving aesthetics aside, do you have a preference for brass or steel for backs. The cost difference is quite substantial. Two Cherries has a folded brass back gent's saw cheaper than flat brass sheet. Paul Sellers said brass makes a better performing saw.

Do you change the gauge and/or the depth of the back for different sized saws? Would you use a thinner gauge steel than brass for the same sized saw?

I am surprised you could use those hydraulic jacks. Someone from Williamsburgh said he had to shave the orange home depot paint off his pencil.

thanks again

[george wilson]

We were not in public in the Toolmaker's shop. It was a behind the scenes facility to make sometimes large numbers of tools for the Historic Area. Haven't you noticed the pictures I have posted of the benches full of planes and saws we made?

Around us you can see machinery.

Yes,pencils had to be shaved of their paint,until I discovered where plain cedar pencils with no paint could be had. They had no erasers either. After that,more modern pencils did not have to be used. The main difference in the pencils I found and original ones were that the leads in the 18th. C. were square,sawn out of thin sheets of graphite. Must have been a tricky and messy job! Graphite would be a pain to saw without breaking it,and just as much trouble to inlay into grooves in the pencil bodies' halves without breaking.

European countries had no natural graphite deposits,and England jealously guarded theirs,refusing(as far as I know) to sell graphite to the Europeans. For one thing,early on,in the 1500's,the government glommed onto the graphite deposits as important military resources. They could make semi permanent cannon ball casting molds from graphite.

After many years of experimentation,Conte in France finally figured out how to make a suitable artificial graphite for pencils from various baked clays. This was in the 19th. C..

About brass backs: I prefer them. They add weight to the saw,making it cut better,and probably dampen vibrations better than steel backs.


THOSE saws you show have backs that are too thin to be good. They need to be made of much thicker brass before you will get any gain in weight to aid sawing,or in vibration damping.