building up with tig

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I want to build up a lawn mower blade, its a for a gravely, about 3/8" thick and 3" wide. I want to build the ends up and reshape a bit if possible. It is tough steel but I don't know what it is exactly, I don't have a mig which I guess would be better for building up, but I am not familiar with it. would I lay down beads and then add to each side and the put a bead in the middle. Also would I be better off with just mild steel or stainless? thanks for any advice on this.
Reply:just remember it will need to be balanced IMO wouldn't it be cheaper an faster to buy a new blade (sharp an balanced)
Reply:Buy a new blade, in the long run, it will save you money.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by MicroZoneBuy a new blade, in the long run, it will save you money.
Reply:Its not for the money, I wanted to just see how to do it, and how and if it would work. a new one is  $50, I can just sharpen the old one, but I wanted to just get some experience with it. thanks for the replies.
Reply:I would never even consider welding a lawnmower blade at any cost.. Don't bother..Save the headacheIF it was to come apart for some unseen reason and anyone got hurt...Like yourself???Ouch!!...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Good advice. A 3/8 inch blade spinning at 3,000 or 4,000 RPM unbalanced. No thanks. John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:the gravely chopper blades only spin about 600 rpm
Reply:Okay, I don't even want a 3/8" piece of metal spinning unbalanced near me at 2 RPM ! John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:A guy i work with does that same with his blades. He builds up the metal with a stick welder and re sharpens them. I always thought, why waste the time, just buy new ones, but to each their own. Plus he did it on company time so no big deal. As for being balanced, theres really not a lot of science in a lawn mower blade. I am sure they arent even balanced new. As long as they are bolted down tight what could happen?
Reply:Are you serious? Spin something that isn't symmetrical and not balanced at ANY rpm for very long and you'll see what happens. Look at new mower blades, especially for riding mowers with double and triple blade setups. If you didn't have blades that were symmetrical and balanced, you'd have the blades hitting each other and vibrating the HECK out of the shafts, bearings and motor. In essence, tearing up the entire machine!Last edited by MicroZone; 05-05-2007 at 09:39 PM.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:My Dad retired from the small engine business.  He said no way their is just to many risk involved.  You take a brand new lawnmover and have the blade out of balance and it want take long to damaged the engine.  I sharpen blade and balance them and use and old balancer and new one like it would cost $150 to $200.
Reply:Well, I grew up and Kansas and wouldn't have  even given the the idea of welding on a mower blade a thought. Then I moved to Missouri. Around here rocks grow better than anything else. An old timer around here turned me on to some hardfacing rods that work great on mower blades. I trading him for a couple of dozen of these rods so I don't even have the box. I have no idea what they are but they're unlike any hardfacing rods that I've ever seen before. They're are hollow tubes filled with a power. Heat the base metal up with a torch and apply these rods to the metal like brazing. The deposits left behind wears much better than a standard mower blade but yet it's just soft enough to shape and sharpen the blade. I static balance the blades and have never had a problem. I only do this on the riding mower. If any body has any idea what these rods might be please speak up, I'm out of them.
Reply:Originally Posted by MicroZoneAre you serious? Spin something that isn't symmetrical and not balanced at ANY rpm for very long and you'll see what happens. Look at new mower blades, especially for riding mowers with double and triple blade setups. If you didn't have blades that were symmetrical and balanced, you'd have the blades hitting each other and vibrating the HECK out of the shafts, bearings and motor. In essence, tearing up the entire machine!
Reply:Mustang - I think you're talking about something different entirely. My buddy runs a very successful small engine shop and he has no less than 5 riders come in a day with worn out spindles/hub on the decks...from people sharpening and incorrectly adding material to their blades. Car engines is something on another topic. You think the crank and cam manufacturers just throw a piece of metal together? Please PM me with your thoughts on this, I'm curious to hear your ideas. I've never seen a 20% gain from balancing and blueprinting my engines...maybe I'm doing it wrong?John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by MicroZoneMustang - I think you're talking about something different entirely. My buddy runs a very successful small engine shop and he has no less than 5 riders come in a day with worn out spindles/hub on the decks...from people sharpening and incorrectly adding material to their blades.
Reply:Yep, nice old tractor. I'm familiar with tractors, my bud and I talk about them all the time. You'd be surprised how well the store bought tractors hold up...it's lack of maintenance that kills anything. BTW, he replaces blades...no sharpening....no building up of material. Easier, quicker and less liability. If you're gaining 20% from balancing a car engine, you should open a engine shop.  FYI - every motor, including your HF cheapies are built to a tolerance and specification to keep from vibrating, out of roundness or an out of balance condition. In relation to this post, give us all an example of something that spins, from a manufacturer, that's NOT built to a very specific tolerance. Anything that spins needs to be made to an exact criteria.  If it isn't...it fails or will fail.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by MicroZone You'd be surprised how well the store bought tractors hold up...it's lack of maintenance that kills anything.
Reply:Originally Posted by caosesvidaI want to build up a lawn mower blade, its a for a gravely, about 3/8" thick and 3" wide. I want to build the ends up and reshape a bit if possible. It is tough steel but I don't know what it is exactly, I don't have a mig which I guess would be better for building up, but I am not familiar with it. would I lay down beads and then add to each side and the put a bead in the middle. Also would I be better off with just mild steel or stainless? thanks for any advice on this.
Reply:well thanks for the information. I have ordered a new blade, I will just sharpen this one and balance it. This lawnmower, I have had for 20 years and was made in the early 80's, the same blade has been on it, and has never been balanced, It felt like it was getting a little out, so I thought that while I was at it I would try the welding thing also. I see it was not a good idea, so no need to do it. these things are built like a brick s house. I use it for  brush hogging and it will cut a 2' sapling down without coughing. As far as the spinning blade being dangerous, you ain't  kiddin, I hit an aluminum bat the kid left in the long grass one day, that thing went spinning out like a helicopter blade, if it had hit anyone it would have killed them. It took out a 3" cut of the bat on the thick end about 2 or 3" long. I don"t ever mow when there is anybody around or near anything ( i put the dogs in the pen) that can break. Its not a suburban type lawn mower, it a farm mower. The regular 4 wheel gravely is my main mower, also had for 20 years. thanks again for the information
Reply:Good choice caosesvida! Mustang - a 10% gain when balancing a car engine is even a high number. Most builders are lucky to see a 6 - 8% gain. The correction factor is thousandths of a gram. The harmonics of a racing engine or new rotating parts are already VERY true from an aftermarket manufacturer that it's tough to even see a 5% gain. The CNC machines today are much more exact out to ten-thousandths or even a hundred thousandths of an inch! Yes, perhaps in the 60's and 70's a few motor builders saw decent gains but not today. I run my motor in my Chevrolet, from the factory, to 7,200 RPM - the advances in engine technology are night and day. Thanks for agreeing to disagree. A good conversation, thank you...but you have much to learn.  Lack of proper maintenance on ANYTHING proves to destroy it quicker.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com