Frame Fixing Guidance Please

I'm starting some clean up and repairs on the CJ6 frame I got from Baja Edition (Thanks Jim). Both front frame horns have tears around where the shackles were and cracks along the edge of the C as shown. The crack gets more faint, but extends about 9" to where the yellow mark is.



I'll be using McGruff's plate to box this area, but what's the best way to repair the long cracked section? Should I make a cut with a disc along the length so I can get a good connecting weld between the two sides? I've read about drilling a hole at the end of the crack the keep if from spreading - Good idea or not?
Thanks.

 

Stop drilling a crack is frequently done on air vehicle structural members. However, a doubler is installed over the damaged area to allow a suitable load path over (or around) the crack.
Some may consider the following repair overkill, and that's OK. If that were mine though, I would stop drill the crack with a 1/4" - 5/16" bit. A repair angle, of equal or larger gauge, should then be nested inside the damaged area that extends approximately 3/4 of each flange width (that is inboard for the upper flange & down on the outer flange). The angle should start as far forward as possible and extend aft at least 4" past the stop drill. (This is a tough distance for me to evaluate given the one picture) The front of the repair angle can be cut parallel with the end of the frame (square). The aft end however, should be angled on each leg so as to taper to a smaller cross section as the angle terminates. If you have to transfer any holes to the repair angle, do so prior to welding. If they break out the edge of the angle, they should be blended so no sharp corners exist. A cut along the cracked portion should be done, so when it's welded, it will join to the repair angle as well. It can then all be welded in place.
Adding a boxed section to that area is always a good idea.

 

Thanks for the detailed description. The nested angle iron on the inside is a great idea.
I was also thing to strap it per w3srl. All that along with boxing it seems like it would take care of it.

 

Yes, I'll be boxing the frame horns and more than likely the entire frame since it is bare and easy to work on at this stage.

Here's another part of the frame with an issue. For this I was thinking of making a metal rectangle the same height as the inside of the C, then inserting it and hammering it down the line to push the crushed part back out. I was also gong to temporarily weld on a support tube to the outside of the opposite rail.

 

Roger that. I'll remove a portion of the strap before attempting. Thanks.

 

frame is looking good, glad someone is getting use out of it. You should see the 67 now with the winch on it. I have those last few elusive projects to do on her and I start the 70 project

 

Yeah, it needs a little TLC, no biggie. Thanks again. I think I'll still be ahead of the game as opposed to stretching shorter frame. Pretty sure I'm going to box the whole thing. Saw your Bumper on another forum. It came out nice.

I was going to stash the frame behind my garage until later, but I started tinkering with it already. Here's what its going under:http://www.coastaldimensions.com/CJ6B.html
It will be a fun project.......I think.

 

I wish my frame was that nice. Turns out mine was twisted and rusted out in the rear, so I'm going to get some 2x4 3/16 and build a frame soon here, to CJ6 specs. I can't wait to get started, good luck with your frame it looks much nicer than mine was.

 

Bumping this old thread to ask some similar questions since I am making a game plan to repair some cracks I found on my frame. Here's some pics. Wondering if the above advise still holds for crack repair - drill, grind out a "V", then patch? Note - this is the bottom of the frame as it's upside down. I have just a little more wet slurry blasting to do today and then I'm going to buff off the flash rust all in one go.

 

I drilled mine out, ground a groove the length of the crack and welded em up. Then I boxed the frame.......

 

Like Norcal 69 said. They all crack in those same locations over time.

 

I would be careful about adding plates, it some times puts the stress at the end of the repair and it will crack in a new place. Never make a square plate and weld across the frame, I like to use a diamond shape to let the stress taper off in the repaired area. I hope this makes sense, just a suggestion.