How to fix this crack

[ArlyA]

plug weld

In reference to the auto frame repaired with a fishplate, I note that a long rectangular plate is welded to the top of the frame by welding through holes drilled in the plate. What's that type of weld called (when you fill up a hole to connect plate to base rather than weld edges)?

 

[dickfoster]

I'm at a real disadvantage trying to help in these situation. The majority of my welding was done off engineered blueprints. Not really up for discussion with blueprints. You either do as the print says, or the company will find someone else to do it.

Yeah as in per MIL-TFP-FAC.

 

[jack707]

I cut a 250 gallon diesel tank to make into a pig roster I was going to hook a hose up to the tank but that was not wide enough so I filled the tank with H2O a cut it with no problem!

 

[jack707]

In reference to the auto frame repaired with a fishplate, I note that a long rectangular plate is welded to the top of the frame by welding through holes drilled in the plate. What's that type of weld called (when you fill up a hole to connect plate to base rather than weld edges)?

Plug welding

 

[IslandTractor]

Plug welding, that's it. Thanks ArlyA and Jack.

 

[Egon]

Got curious about the terminology! So went looking. Seems flitch plates may be used for joining or strengthening but bolts are used for the connections rather than welding.

 

[Mark @ Everlast]

It's fish plates guys. But it may be a regional thing to call them by an inappropriate term, as I've heard them called a lot worse.

But, you don't need any center holes in something like this, if you will weld it from underneath. This is designed t help strengthen the corners, and resist flexing while spreading out the load. If you can't weld from underneath, the a few 1/2"-5/8" holes drilled through the plate that line up with the inside edge of the frame will be perfect for plug welding with a 3/32 7018. I'm no engineer either, but from experience with this sort of thing, you want the legs of your triangle plate to be 3 times the width of the beam.

 

[prichard]

Looks to me like a flitch plate is a contrusion term for something used to extend a beam or a header.

 

[Shield Arc]

I'm no engineer either, but from experience with this sort of thing, you want the legs of your triangle plate to be 3 times the width of the beam.

Good to know! Thanks Mark.:thumbsup::thumbsup: I always depended on an engineer to tell me these kind of things.

 

[Mark @ Everlast]

I wish I was out there. Those are the kind of repairs I enjoy.

 

[IslandTractor]

I wish I was out there. Those are the kind of repairs I enjoy.

Making a field welding repair that you know is better than original is a great feeling.

 

[woodlandfarms]

I wish you guys were out here too. I live a couple hours south of Shield and if it wasn't for his crazy neighbor I would probably stop by and say hello ;-)

In all honesty I am going to make the Hajj to Shield one of these days if he will have me. A few hours under his tuteladge would be huge.

And thanks for the layout of the fishplate. Going to do me some welding next week.... Make sure I do it next to the house cause if the tractor goes, I want the house to go as well.

 

[Shield Arc]

I live a couple hours south of Shield and if it wasn't for his crazy neighbor I would probably stop by and say hello ;-)

Yeah she called the sheriff on me this morning. Said I have been running the tractor at 5:00 A.M. It doesn't get light until about 6:30. And I also sneak over to her place and steal rocks from her drive way.
I'm headed to central California on Wednesday for 10 to 11 days. You are always welcome to come play in my shop. Couple members here have come by for some welding lessons.

 

[Jesse masterson]

Well you could weld it , or just grind it some clean it and get a couple tubes of jb waterweld putty, dries hard and won't come off, it will work! Doesn't look as pro as welding but I have fixed several diesel tanks with the stuff . It's fuel resistant also. Try it you will like it. Don't tell my dentist but I used some to fix a filling that fell out. It's non toxic.

 

[MossRoad]

Well you could weld it , or just grind it some clean it and get a couple tubes of jb waterweld putty, dries hard and won't come off, it will work! Doesn't look as pro as welding but I have fixed several diesel tanks with the stuff . It's fuel resistant also. Try it you will like it. Don't tell my dentist but I used some to fix a filling that fell out. It's non toxic.

Its a structural crack.

 

[Jesse masterson]

I thought it was just a oil tank for holding oil. Maybe I missed something I'll read it all cause I haven't yet .

 

[jwmorris]

The one on the side is perfect. The one on the top would have been better if both ends were not welded and instead had the weld beads continue on either side towards the right side of the photo on both sides of the plate. A skip weld might even have been better if it is a torsional or "twisting" load so you let the metal work vs working your weld, everything flexes, until it fails.

The weld directly across the top member creates the "notch" that the "V'ed" plate on the side tried to avoid.

It might last forever but if it doesn't it will fail where the weld is 90 deg across the top, more than likely before even the punched hole to the left, because the weld goes to the edge and it looks like it's only "boxed" well before the end of the top strap. Just the "plug" welds would have been a better idea there.

Nice looking beads though and I know it's hard to not weld "everything" when you are doing good but sometimes it pays to not weld everything.

This is an older but good read on the subject.
http://www.pfri.uniri.hr/~bernecic/...orking - WELDING Welding Tricks & Secrets.pdf

Note page 7,24,25,26,27,32,35 and 36.

 

[Mysfyt]

Its a structural crack.

Like me, he probably was looking at what must be the fuel tank mounted on top.

I would do the fish plate mods to the frame, but I would look for a way to make the oil tank its own entity. I would cut the top off the original integral tank and fab up a tank that would set down in that space, securing it so it could 'float' in between the side rails. More work than most would want to dive into, but that's just me.

 

[woodlandfarms]

So I am going to go with ArlyA fish plate design. Still working on steel thickness, probably a 3/8 piece I have will be the answer.

Still more questions though.

Would you Mig this or Stick this?

Is Co2 / Argon heavier than air or lighter than air? Wondering about the purge I am planning.

Finally, I assume that the fish plate should be a bit (1/4" or so) smaller than the piece I am welding on to. Meaning, I do not want to make the weld from the side but from the top.

 

[Shield Arc]

Would you Mig this or Stick this?

If you have a powerful enough Mig welder, by all means use it. I just love Lincoln's L-56 Mig wire. If you are going to use a stick welder, use 7018!