Broken back blade
k9fletch
Join Date: Jul 2003 Posts: 52 Whittemore, MI Pics |
2005-01-28 105119
I was given an old back blade (Dearborn 1950's era) where the prior owner had welded the main beam(a very thick wall hollow tube), which leads from the 3pt to the top of the blade. While using the blade the weld broke and the blade is in two pieces. I currently only own a mig welder so I took it to a friend's shop so he could stick weld it, better penatration. He believes that the main tube is cast iron which would require nickle rod and the main tube would most likely break again.
I guess my question is has anyone ever heard of a manufacture of that era using cast iron instead of steel and would I just be better off spending $300 on a new blade?
I like using this blade, it seems to work well with my tractor and property conditions, if that makes any sense.?
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Broken back blade
Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada Pics |
2005-01-28 105120
I would be surprised if it were cast, more likely it is just the difference in steel.
Bear in mind, following WW2 there was quite a while before any steel of decent quality was available and they had huge stockpiles of war-era scrap metal in the system, following the war this scrap was used up on stuff like your blade.
IMHO, you should use welding rod designed for good adhesion on bad metal, either of 7018H4R (Lincoln JetWeld LH-70) or good old 6011 (Lincoln Fleetweld 35) with the appropriate size and current settings for the thickness of that material.
You might also want to consider some plate gussets over the welded area to re-inforce an already weak section.
BTW, I've had good luck patching stuff like that by grinding the area back till the pieces meet at a 45° then 'backing' the weld area first by tacking a scrap of plate 1/4" or better inside one half and then using that to support the liquid rod until you have built up enough material for it to take a full current pass without burning through.
Best of luck. ....
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Broken back blade
k9fletch
Join Date: Jul 2003 Posts: 52 Whittemore, MI Pics |
2005-01-28 105122
Thanks Murf, I was intending to repair this similar as how you described, I had even purchased the 6011 rod, I'll have to get my friend's dad, the master welder, out of retirement to teach his boy (and me) some metal identification:) ....
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Broken back blade
Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada Pics |
2005-01-28 105124
If you get some 4" C-channel to patch across the mended section it will make it a LOT stronger.
The advantage is if the repair is square tube you can put the channel's 'back' flat against the tube and get a good long patch to take some of the stress off the tube. If it's round tube, just weld it on open side to the curved wall, this makes a guaranteed fit and will still be just as strong, although you will need to make multiple lighter passes this way since you will be welding the thin edge of the web to the tube.
A foot of channel will add a LOT of strength.
Best of luck. ....
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