# Don't put your blades on backwards



## jd99 (Jun 17, 2009)

I work at a saw sharpening shop part time to supplement my retirement a little bit.

We had this blade come in the other day from one of the mills, apparently the operator put the blade on backwards, and ran a bunch of sheets of T-111 through before they noticed something wasn't right....


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## RainMan 2.0 (May 6, 2014)

So did you fix it ? :|


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## fire65 (Oct 29, 2008)

Yeah, that should buff out. You would think someone might have noticed a small amount of smoke coming from that blade. I would say it amazes me that someone would do that, but it doesn't.


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## jd99 (Jun 17, 2009)

They said that something close to 100 sheets ran through before it blew up.

the original ID or hub size for that blade is 3 3/4" the blade is around 14" if I remember right, it mounts to a steel hub that is about 6" in diameter. the center welded to the hub, and then sheared off at the outside diameter of the hub.


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## jd99 (Jun 17, 2009)

Yea it was retipped flattened, sharpened and sent back.....


LOL


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## OPG3 (Jan 9, 2011)

My Dad told me I was wasting my time trying to make things that are "idiot-proof". I gotta say he had good evidence to back-up his statement.
Many years ago, while doing structural drawings preparation for projects for whom my Dad was the Structural Engineer; I got a call from a General Contractor. He had the Steel Detailer Conference-Call "patched-in". We all could speak clearly and be heard clearly. I had shown a bolted connection where the Steel Erector wanted to utilize a welded connection. - No big deal, that kinda thing happens frequently. The General Contractor was someone for whom I had his contact information for, and at the end of the conversation; he requested that I "fax" him a revised detail. "Sure, no problem" was my quick reply. The Steel Detailer (who I had never even heard of prior) said, "Hey, How 'bout faxing me a copy of that revised detail, too". I said, "No problem - just give me your number and I'll fax you a copy when I send the GC his copy." 

I revised the detail, plotted the revision, documented everything per the Architect's requirements and gave an 8.5 x 11 copy to my secretary for faxing. I put two "sticky notes" on the copy - one with each name and number - so my secretary could make the transmittals to accompany the faxes.

End of the day, my secretary comes to me and said, "Otis - the fax to the GC went with no problem - and everything is filed." She then said, "The fax to the Steel Detailer would never go through". I said, "Oh well, just try again tomorrow morning". That next morning, same problem. I instructed her to call that number and someone answered. She informed them that she was trying to send a fax to that number and it wouldn't go through. She verified their best number to receive a fax. Still no luck, now she had plenty of other stuff to be doing, but by lunch - she was shaking her head. I said, "Give me that phone and dial his number!" He answered and I informed him that we had been repetitively attempting to send him a fax, *AND HE SAID *(honestly you can't make-up this kinda stuff) *DO YOU HAVE TO HAVE SOME KIND OF SPECIAL MACHINE TO GET ONE OF THEM FAXES?* I SAID, "NO - JACKASS JUST GO LOOK ON TOP OF YOUR TOILET." Honestly, I was laughing so hard that I was unable to go out and eat lunch! *TRUE STORY!*

Otis Guillebeau from Auburn, Georgia


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## RainMan 2.0 (May 6, 2014)

Otis that's quite incredible the level of some people's intelligence lol. You wonder how they got threw life .



Danny , obviously I was joking . I'm thankful know one was close to the blade when it self destructed . I could hardly imagine that outcome .
At a saw mill where my buddy works , they had a huge blade come off and scoot down the floor and slice a hole right threw the wall . Would have hated to be in the way of that puppy .


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## BrianS (Nov 7, 2004)

Otis, when you try to make something "idiot proof" there are certain people who take that as a challenge.... 

Danny, that blade was on there long enough to turn that pretty shade of blue I would think SOMEONE might have noticed it. Sure glad no one got hurt!


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## furboo (Oct 12, 2015)

fire65 said:


> You would think someone might have noticed a small amount of smoke coming from that blade.


He probably thought they were "seasoning" the new blade. It must of made quite a racket when it came apart.


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## RainMan 2.0 (May 6, 2014)

I'm surprised it didn't take off the carbide tips ?


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## old55 (Aug 11, 2013)

Darwin Award contender?


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## JOAT (Apr 9, 2010)

Whenever something 'idiot proof' is invented, along come a superior idiot.

I used to get a LOT of 'I know that's what I said, but it's not what I meant'. I had to redo a LOT of jobs.
The difficult we do immediately, the impossible takes a little longer, we don't do magic because we lost our magic stick.


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## jd99 (Jun 17, 2009)

RainMan 2.0 said:


> I'm surprised it didn't take off the carbide tips ?


Shows you how good we are at retipping blades :wink:


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## schnewj (Nov 18, 2013)

Although in this case, which graphically illustrates "what not to do", some operations can recommend mounting blades "backwards"! 

Vinyl siding is one prime example; several of the siding manufacturers suggest mounting a fine toothed blade backwards in a circular saw to cut the panels. This does work very well; much better then some of the other methods of cutting the panels. 

However, like all pieces of machinery, if you don't know what you are doing you should keep your hands off. In the case of the blade above they were lucky, that nobody was hurt because of someones ignorance.


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## Cherryville Chuck (Sep 28, 2010)

jd99- "Shows you how good we are at retipping blades"- I was looking for a new rip blade and I saw a local tool place had some Avanti, made in China, sold through Freud, blades on for $10. Then I read a review about someone using one and it started throwing teeth. Cheap isn't always cheap and not everyone does a good job of brazing the teeth on. I would still be worried about throwing teeth like that.

Schnewj- "Vinyl siding is one prime example; several of the siding manufacturers suggest mounting a fine toothed blade backwards in a circular saw to cut the panels. This does work very well; much better then some of the other methods of cutting the panels."

That's about the only material I would try it with. I have used a circ saw with blade on backwards to cut metal roofing sheets but I've also thrown a tooth or two doing it so it's still not that safe and nowadays I use an abrasive wheel on the circ saw instead. (Besides being a bit dangerous it was ungodly noisy using the backwards circ saw blade.)

I recently needed a lot of strips cut out of leftover HPL that I was going to use for drawer slides. An old 100 steel toothed ply blade and zero clearance insert on my TS worked great as long as I controlled the tendency of the HPL to want to flutter. It's all about the right tool for the job and using it correctly.


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## TenGees (Sep 12, 2012)

So that's why they put an arrow on some blades to show the direction of rotation!


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## RainMan 2.0 (May 6, 2014)

TenGees said:


> So that's why they put an arrow on some blades to show the direction of rotation!


All this time I thought that was for blonds ?

Not long ago I intentionally had a panel blade on backwards on my Miter saw , as I was cutting plastic .
Then I proceeded to reinstall the regular wood blade , only to find it didn't seem to cut worth a dam . Took me a few cuts , but then I realized I had mistakenly installed it on backwards . Luckily the blade seemed ok and all the carbide teeth were still there


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## Cherryville Chuck (Sep 28, 2010)

I have a slot cutter set that I accidentally installed the cutters on backwards once. About the time my shop filled up with smoke I realized what I had done. They rub going backwards instead of cutting and can get pretty hot.


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## schnewj (Nov 18, 2013)

Cherryville Chuck It's all about the right tool for the job and using it correctly.[/QUOTE said:


> Absolutely!


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## TwoSkies57 (Feb 23, 2009)

I wired in a 3 phase roof top unit blower motor wrong once,,,ONCE!! *LOL*... damn, did that thing blow a cloud of dust out


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## furboo (Oct 12, 2015)

I've done some pretty stupid things in the past, including with tools, so I have some sympathy for whoever did this. I bet he won't make the same mistake again.


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## AndyL (Jun 3, 2011)

furboo said:


> I've done some pretty stupid things in the past, including with tools, so I have some sympathy for whoever did this. I bet he won't make the same mistake again.


You would hope so, wouldn't you, but apparently he already made the mistake 100 times  



jd99 said:


> They said that something close to 100 sheets ran through before it blew up.


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## Biagio (Mar 2, 2013)

I once had a one-hour layover in Bahrain turn into an eight-hour layover, although we could see our plane arrive and park at the terminal. Turns out the service guys emptying the toilet tanks switched the pump from vacuum to blow. Plane had to be towed away to have the interior steam-cleaned, and we had to wait for another plane to fly in.


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