7018 Vs. 7018AC, Need Layman's translation please:

[Shield Arc]

Something to do with piles....

You're pretty quick! :laughing:

 

[shade tree welder]

You're pretty quick! :laughing:

How the heck you been buddy!!! We have missed you. Check your pm' shortly.

 

[Shield Arc]

How the heck you been buddy!!! We have missed you. Check your pm' shortly.

I'm just like an old penny, never know where I'll show up!

 

[Big Wave D]

It is a typical fatigue failure the material has been worked back and
forth thousands of time likely do to loose fittings.

You are EXACTLY correct.

The old girl belongs to a friend who lets me use it periodically. I try to improve her each time he does: Replace missing/bad bolts, changed gear oil, grease dry u-joints, repair cracks/rips, etc.

However, I couldn't do anything with lift pins. They were horribly slop-filled. Finally had a 'eureka moment' and tack welded pin to hold it firm so impact wrench could actually do some work.

Now I'm wondering if tightening them was like opening Pandora's box. Did their slop protect the arms from some of the racking forces while in use, so to speak?

If these are now going to do nothing but keep snapping, what is best course of action? Should I try to buy new arms from somewhere (anybody got any suggestions)? Buy materials and try to make them myself (don't have a drill press though, can 1" holes be drilled by hand?

Forgot, to sum up plan of attack: Clean, get bevel and spacing correct, use 6011, heat optional but not necessary, make sure proper setting for rod to achieve good penetration and fusion

 

[Shield Arc]

I would replace with new steel.
Yes you can drill 1-inch holes by hand, start with a small drill bit and work your way up to 1-inch. Maybe no more than 1/4-inch at a time.

 

[Mark @ Everlast]

Big wave,
Sorry, I had a post going but it got wiped out...
I do see a few things that might not be mentioned yet...But I concure:

Having sold and worked on that product countless times, that is NOT cast iron or steel. Its simple mild steel.

A 6011 would work but I believe there is something better. Here is where a 6013,7014 or even a well sealed, fresh 7018 would come in handy in multiple passes.

A double bevel joint likely with a knife edge would be the best thing. I see what shade tree is talking about, but I think I see porosity and/or slag as a main culprit in the one photo. Its hard to make certain anything with photo size limitations.

Did you completely remove the hitch to weld it flat? I would have removed it to get the best weld.

There is probably some metal fatigue, yes. But I think you might be alright with rewelding it and grind all the old weld out. I would have liked to have seen the weld from the flat surface. I'd give it one more try before giving into paying $$ for the metal to replace it. Also don't forget, you can reinforce the side of the hitch with a "scab". Not pretty, but good enough for farm work.

 

[Big Wave D]

I would replace with new steel.

I think that in the end, Shield Arc, your advice is probably the best.

I can redo everything and maybe it holds, but mostly likely not do to age and fatigue factor.

I don't want the owner to be using his equipment and deal with something that happened on my watch.

Thanks to all who have helped me with their good advice. :thumbsup:

 

[Shield Arc]

Mark has a good point about trying it again. What do you have to lose except a little time. Anyway good practice. Proper joint prep is the key here.

 

[gauthier]

You would think it would be mild steel and if it is it shouldn't have broke again that fast,,but you don't show your weld[that I could see],,pictures you show don't tell me much,,but kinda lean cast ironish???? break that is,,can't tell,,,

if you know you got a good weld on it,,and it broke for no reason,,than it must be something,,but can't tell what kind of welder you are with the pictures I see.

 

[Big Wave D]

Mark has already read this, but I thought I'd share it with all of those who have helped and commented on my problem.

"I think in the end, for peace of mind, I have to go with new metal. I'm not the owner and I don't want him having to deal with my fix going south on him (most likely at the most inopportune time, thanks Murphy).

I've priced materials and additional work (depending on how much I want to try and do myself. I'm not really properly equipped for the bending and drilling parts of the repair. Plus, I'd have to buy the proper sized bits.):

$20 for 2 pieces of 21/2" x 1/2" x 31" long, $12 for punching 4 holes for me (I don't have a drill press or big enough bits), and $20 more for them bending them to shape for me (I have an O/A torch but it is only hobby sized)

All in all, $52 plus tax for piece of mind and continuation of a good friendship I think is well worth it. Besides, I can't rent one for all the months he's let me use it for that. "

Yes, I'd like 'another shot' at it just to prove to myself that I CAN do it, but I can't take the chance.

Take a look at the prices and tell me if I'm getting gouged; I'll price it out with another shop, but it didn't seem that bad to me.