Weld repair of lawn mower blade question

[lupinus]

That'd go over real well.  Might suggest that as it gets closer to winter, it's too hot to sleep outside right now.

All of it gets mowed, every time.  I used one of the walk-behind wheeled string trimmers for the original cutting - getting it down to a manageable height.  I don't want to think about how long it would take to mow the yard with one of those now, it takes 8+ hours on a 48" riding mower.

I've got a similar setup for the hand-held string trimmer.  On that, the system works so-so.  I'm looking for reviews on the Meg-Mo system now; what I've found so far hasn't made me want to call in an order tomorrow.  One user said they're not good for spring-time use, the heavy wet grass causes the knives to fold back and not cut.

Have you considered fire?

[charby]

8+ per week mowing? I can mow 5 acres at my gun club with a zero turn mower in a little less than 3 hours.

I'd be getting goats also.

[zxcvbob]

Let her see how cute baby goats are.  Aww.   (they don't stay cute for long, but don't tell her that)  

[charby]

Let her see how cute baby goats are.  Aww.   (they don't stay cute for long, but don't tell her that)  

If all you have are nannies they stay pretty docile.

They do make nice woven portable electric fence that you can rotate your pasture. http://www.maxflex.com/Nets_page1.HTM

One of my friends has a business that rents goats to landowners who need areas cleared out. In the warm months all you need to do it keep them rotated and give them water. Winter time you will need to hay them with some sort of goat ration. You will also need a small enclosed shelter and more durable paddock for them also for the winter. 

[Tallpine]

If all you have are nannies they stay pretty docile.

They do make nice woven portable electric fence that you can rotate your pasture. http://www.maxflex.com/Nets_page1.HTM

One of my friends has a business that rents goats to landowners who need areas cleared out. In the warm months all you need to do it keep them rotated and give them water. Winter time you will need to hay them with some sort of goat ration. You will also need a small enclosed shelter and more durable paddock for them also for the winter. 

Do they rent pigs?   

[charby]

Do they rent pigs?   

They have a few oinkers in a sty they raise for slaughter. I image anything can be done for the right price.

[Tallpine]

They have a few oinkers in a sty they raise for slaughter. I image anything can be done for the right price.

Tell them not to do it.

A man that wants to rent pigs is hard to stop 

[Scout26]

Okay, tell her to mow the yard 

Does she not like goat cheese?

[Cliffh]

Have you considered fire?

That was one of my first thoughts once most of the non-flammable trash had been removed from the backyard.  Even called the local VFD to see if they wanted some practice - they never returned the call.

I've thought about this a little and see your point on building up the cutting edge. The reason you are going through blades so fast is that only the original cutting edge is hard. Once you sharpen past that you are beating the weeds with soft steel.

I think you're onto something there.  When new I could mow a couple times between sharpenings, after a couple sharpenings they get dull fast.

I guess I'll be the guy to suggest it...

It might not be a good idea, but I've used hardfacing rod on my lawnmower blades.  Nothing came apart [yet], a good weld should be metallurgically as strong or stronger then the base metal.  I haven't inspected the blades since trying that rod, so I can't tell you how well they've held up.

I can't tell you what rockwell hardness those rods get to, but it's at least file hard.  So, shaping must be done with a grinder.

ETA: Looked at the box.  They are Forney Supercote [link].  Hardness is listed at Rockwell C52-58.

Ok so if your going to do this job you might as well do it right.
You should use a harder rod to build up the cutting edge, maybe a 11018 or something like that.
Then on the backside the wears away use a hard surfacing rod, these are usually used on teeth or bucket edges.

Thanks!  I'd forgotten all about hardfacing, and that's just what I was hoping for.  I've got a couple old sets of blades (6 total) that I can use to work up a technique, (destructive testing will be included), before starting on the ones I'll use.

And yep, it takes 8 or so hours, which is why it gets mowed more like every 10 to 12 days instead of every week.  The riding mower isn't as fast on the straightaways as a zero turn and it's a lot slower on turns.  Have to back & fill 3 to 5 times around each and every one of the trees and bushes, and there are a lot of them.  A zero turn is on my wish list.  I'd have to get rid of some of the trees and/or bushes though - the 48" deck just fits between some of them.  And I'd have to get or build a shed for the zero turn, again the 48" barely fits through the doors on it's shed.

[Cliffh]

Finally got a set finished and installed.  I was able to get an hours worth of work out of them before the engine started acting up; down on power, rough idle, won't achieve full rpm etc.  I've installed new plugs, checked the carb bowl & linkages, fuel & air filters, compression (relative) and fuel flow - no joy.  Since it's been using a bit of oil lately and is still under warranty it's the shops' problem now. 

I wasn't able to find anything other than 11018 locally, so I went with that for now.  I've got to say that I could learn to dislike that rod, especially in 1/8" when used on material of 1/8" or less.  I started at 90amps, went to 105, ended up at 150 to 175, depending on the exact location of the weld.  Damn buzz box doesn't have an infinite adjustment on it, there are only specific settings to choose from.

Went through 6 lbs of the 11018; put a little on, grind a lot off, repeat.  Used every grinding tool in the shop - bench, 7", 4 1/2" and die grinders.  On the last day of the project, the brushes in the 4 1/2" crapped out.  The local hardware store had a limited selection of grinders - one Skil.  Not on my recommended list.  I do miss the unlimited compressed air supply that was available on the shipyard.

What was the most "fun" was building up the cutting edges where they'd worn back over 1/2"  Used a backing block to try to keep things where they belonged.  Only had to cut it loose a dozen times or so.  I used 3/32" 7018 to replace some of the missing material, then covered that with the 11018.

I'm not thrilled with the results using the 11018.  After the hour or so (maybe 3/4 acre) the cutting edge was already worn back by slightly more than 1/32".  They would still cut, but I had to slow the travel speed more than I want.

I'm going to order some of the hardfacing rod soon and give it a try.

[Regolith]

Let her see how cute baby goats are.  Aww.   (they don't stay cute for long, but don't tell her that)   

Nigerian dwarfs. Cute little buggers, even when fully grown. They're small, trainable, and easy to handle.

[Blakenzy]

RoundUp from orbit... it's the only way to be sure.

[Boomhauer]

What is curious to me is that you were only able to find 11018 rod locally. Down here thats not a rod seen often on store shelves.

Got a tractor supply, lowes or home depot in reasonable range? TSC carries several types of Hobart rod and lowes/hd carry Lincoln rod. Personally I like Lincoln rod but the Hobart stuff is servicable.

[Tallpine]

So it only takes about twice as long to build up and sharpen the blades as it does to wear them down   

 

[Cliffh]

There's a Tractor Supply close by, they don't carry either hardfacing rod or the 11018.  Called 4 local hardware stores, none of them carry either rod.  The closest welding supply store is about 45 miles down the road, they at least had the 11018.  Didn't check Lowe's or Home Depot, they're further away than the welding supply store.

Hard to believe that, with all the farm & ranch equipment around here, none of the local stores carry the good stuff.  At least Amazon will deliver.

[never_retreat]

The 11018 rod is hard stuff, try avoiding putting on much more than you need.
That will eliminate extra grinding.
Get yourself a hunk of aluminum plate to use as a backer.

[Boomhauer]

Why are you using 11018 instead of the more general purpose stuff such as 6011 or 7018? Also TSC stores that I have seen carry hardfacing rods in the small 4 rod pack. And it's expensive as *expletive deleted*it...

Also are you using an AC only buzzbox? Some rods don't like to run on AC and you have to get an alternate type. 7018 for example, is like this which is why they make 7018AC. Same goes for 6010, which is why 6011 exists.

[Gowen]

I've got a bush/tree in my back acre that has 1" thorns on it.  The goats ate every leaf that they could reach, it made it real easy to use the glompers on the rest of it.  I cut down a branch and they strip it clean.  Next year I don't give it a chance at growing, they will nom nom the new shoots.

[Nick1911]

I'll be interested to know if hard-facing rod fares any better.  11018 appears to be high carbon steel.  Don't think I've ever used it, though.  While that's certainly good strong metal, most hard-facing rods contain a goodly amount of nickel; it might help with abrasion resistance and hardness.

[Cliffh]

Why are you using 11018 instead of the more general purpose stuff such as 6011 or 7018? Also TSC stores that I have seen carry hardfacing rods in the small 4 rod pack. And it's expensive as *expletive deleted*...

Also are you using an AC only buzzbox? Some rods don't like to run on AC and you have to get an alternate type. 7018 for example, is like this which is why they make 7018AC. Same goes for 6010, which is why 6011 exists.

'Cause the 11018 is the hardest/strongest stuff available locally.  Welding shop guy looked it up in his book and said it had pretty good abrasion resistance.  Guess not all TSC's carry the same stock since I called, stopped by & looked and asked a worker-bee for it.  Also asked if they could special order it - nope.

I don't recall if this welder is AC only or not.  So far it's run 6011, 6013, 7014, 7018 and 11018 in various diameters with no problems other than operator error.

I found it hard to not get too much weld on, 1/8" rod put down a relatively large amount unless there wasn't enough penetration.  A lot of the grinding time was cleaning up the toes of the weld to make sure all the slag was removed and there was a good, smooth surface to put the next bead down.  Pretty much followed the procedure the welders used on the sub pressure hull welds: lay a bead, smooth the surface and blend in the toes, visually inspect for inclusions/porosity/etc. and put down the next bead.  Once there was enough built up, grind to shape & thickness.  Even put a magnet to it since the grindings were fine enough to show any cracks. 

Unfortunately I only have some small, thin aluminum angle right now.  I'm going to keep my eye out for larger piece (1/4" or thicker) of either aluminum or brass to use as a backer for the next go-round.  Even with the steel backer I blew too many holes through.  Getting better at filling 'em back in.  One thing that made this set even harder to work with is they're mulching blades with all sorts of compound curves.  Which is another reason for so much grinding, I'd have to build up a 3/8" (or so) thickness then grind top and bottom to the correct shape.

The welding shop guy agreed that even though the 11018 had a high tensile strength, the hardfacing rod would have a higher Rockwell hardness and probably last longer in this application.

It'll be a few weeks waiting for the mower to come back, the rod to come in and the time to be available to try again.  This is one project that will stay near the front of the to-do list and I'll make sure to post back with the results.

One of my ex-girl friends had a fair sized ditch (about 15 yards wide x 10' deep x 50 yards long) chock full of berry vines.  One goat was able to clean it to mow-able length in less than 3 weeks, might have been closer to 2 weeks.  I'd stake him out for the day, and move him along the ditch as he ate it down.

Since brass and aluminum have a lower melting point than steel, will there be any problems with the backer melting?  Not concerned that the brass or aluminum would mix with and contaminate the steel, more concerned about the backer melting into some odd shape that would be worthless afterwards. 

[Gowen]

I call my goats walking poop factories, food would go in one end and pellets come out the other.

[never_retreat]

Since brass and aluminum have a lower melting point than steel, will there be any problems with the backer melting?  Not concerned that the brass or aluminum would mix with and contaminate the steel, more concerned about the backer melting into some odd shape that would be worthless afterwards. 

Ideally the aluminum should dissipate the heat better and not melt.
Steel melts at about 2500 degrees and 1200 for aluminum.

[zxcvbob]

Aluminum has a much higher specific heat than steel (takes about twice as much energy to raise it one degree), as well as higher thermal conductivity.  You're not going to melt AL unless you are *trying* to melt it.

[Cliffh]

Ideally the aluminum should dissipate the heat better and not melt.
Steel melts at about 2500 degrees and 1200 for aluminum.

Aluminum has a much higher specific heat than steel (takes about twice as much energy to raise it one degree), as well as higher thermal conductivity.  You're not going to melt AL unless you are *trying* to melt it.

That's good to know.

[HankB]

Several folks mentioned the temper of the blades . . .

Which begs the question . . . are the lawn mower blades actually heat treated at all? The blades on most walk-behind mowers I've used have been very soft - to the point where I could easily sharpen them with a file. Read that they were made that way so they'd be less likely to fragment if you hit a rock or something else that was hard.  (The one exception was an old Jacobsen 4-blade mower - my father made a fixture to use a surface grinder at work to sharpen those blades.)