now a hole popped up underneath!
It's not as big as the side hole was - not nearly as big.
But I should probably have another reinforcement plate put underneath.
I'm tempted to just JB weld the small hole underneath. It's near a drain hole for the frame.
Now that the side is welded then that part should be stronger than normal.
It's a MIG weld job.
Thanks to the shop!
So the crack is in the SEAM of the chassis weld.
and then there's a small hole - quarter inch about - right nearby.
The shop said the hole they put the reinforcement plate over was IN THE RIGHT PLACE.... yep!
It's too hot to weld today - so I got there early. They were nice to just go at it - right away - no wait time!! https://www.mig-welding.co.uk/forum/threads/weld-strength-welded-vehicle-seams.38935/
I chose not to reinstate the seam for 2 reasons,1. it would be a rust trap and 2. as per mot requirements all repair sections should be fully seam welded unless and entire new panel is being used.
Race cars are often seam welded so the suspension is doing the job it should and the stress cracks are caused when the body flexes; not avoided by allowing it to flex "a bit"
If you are welding a seam where there was none before (e.g. welding a patch to an existing panel, then it must be a continuous seam (to replicate the continuous metal that was there originally). However, if replacing an original seam then it is acceptable to weld it in a manner similar to the original (e.g. plug-weld it if the original seam was spot-welded).
you are right, if you cut a section of sill out that was to include the lower spot welded seam, you can then plug weld the lower seam of the repair but the rest must be fully welded as bill says.
simply put it has to be like for like
when carrying that type of load an that is why the chassis are bolted/rivetted not welded.
Every chassis except maybe a tank or excavator are designed to flexhttps://forum.millerwelds.com/forum/welding-discussions/6072-stitch-welding-and-chassis-fab
Anyway he claimed that stitching was the only way to get a nice looking bead with MIG (out of position) and that was how chassis' (esp. tubular) are built.
Stitch welding is NOT ACCEPTABLE for chassis welding, someone will die
Stitch welding is chicken scratch.....Run a bead, that's what mig is designed for.Oops...
On some chassis sections filling with expanding foam strengthens up that section incredibly.So maybe JB Weld is better anyway?
https://grassrootsmotorsports.com/forum/grm/anyone-foam-fill-their-chassis/92620/page1/
the stiffer the chassis, the higher its natural frequency, making the energy imparted to it by bumps less likely to excite the body's structure.
I'll add, as a guy who's welded up hundreds of rusty cars, foam in the rocker panels etc is a huge pain. We don't want to breathe it when we weld and we don't want to burn a car and our shop to the ground. Customers get to pay quite a bit extra to have us deal with it. I'll also say we've seen quite a few seam welded race cars where the welding was bad and did more damage than good--like knock the whole car out of true. Not to be a downer, but be careful.
Discussion What's your preferred glue to use for foam? - RC ...
Mar 20, 2016 - Are there fans of JB Weld for epoxy? Or is Foam Tac the way to go?? Thanks in advance! slipstick 02:49 PM Mar 20, 2016. It depends on what ...
in some parts of the world it is actually illegal to weld the structural chassis /frame of a vehicle for the reason of the weld altering the designed flex in the structure, most vehicles are designed to flex to save cracks or shear points.
if that part is likely to break and that weld is continuous its the parent steel that will crack usually one side or the other of the weld due to stresses imposed by the welding and the load applied, but if that weld is stitched there isnt the same continuous stress line and welding shear point therefore the joint is stronger due to the parent metal passing between the welds in places.
for the stitch weld, try this, weld two parts, 1 or 2 inches of weld on a corner joint, the first with the stitch method the second with a normal standard bead weld. put in vice and hit with hammer to simulate destruction and bending. where does it break / show stress?Chevy frame is WAY more stiff (30x more) than a Ford - can handle torsion way better - vid
A high strength steel frame - fully boxed - front to rear - All the way through. My engineers do the calculations - they tell me in torsional rigidity - we're more than 30 times stiffer than the Ford.
Independent front suspension.
I did think about cutting gaps in the seam or just splitting the seam
as seam welding alone is just chasing the next weakest link in the chain)
Rotted metal simply disintegrates when welding so you may think you're welding two pieces together but the result can be simply cosmetic covering of a huge problem. Proper welding technique and heat input on good sound metal is the only way to get good metal fusion. In addition, welding over paint or powder coating further contaminates the weld metal compromising its integrity. This frame in my opinion, was way past salvageable. Especially, where main suspension components attach. If a repair were attempted on such a critical part of the vehicle, a professional welder with a sense of structural reinforcement knowledge should be employed, but I fear a welder of that skill level would pass on this job. This is not a safe repair. I don't mean this to be criticism of your decisions, I just want to share with folks that may want to do the same in this safety critical part of a vehicle. There is sound structural welding, and there is cosmetic covering up of rotten steel welding that doesn't do much, if anything, structurally.
However if the chassis is able to flex to a limited degree, this absorbs some of the stress, and what stress exists is spread around the system. There is quite an history of smaller 4x4 trucks being given very rigid bodies, and the resultant manufacturer's recalls for metal cracking one or two years down the line. If you are off-road, a degree of flex helps you keep all 4 wheels on the ground, too.
The older pickups, less rigid, with chassis, hadn't had these problems, and people wondered why is the new one so bad?
Seam welding on patches was thought to introduce brittle areas which would eventually break under the normal flexing of the chassis.
A bolt-on chassis would generally be expected to have more flex than a frame welded to body construction, weight for weight.https://www.wranglerforum.com/threads/drilled-some-drain-holes-in-my-frame-i-got-pics.139227/
1st, your looking at a BOXED FRAME, NOT a Channeled Frame. Drilling a 1/2" hole even in a Channeled Frame WILL NOT hinder the integrity of the Frame, SO with a Boxed Frame, that possibility is even far less. Having owned my own Restoration Shop for many years, We have cut, drilled and Modified countless Frames on Resto Mods, Hot Rods, and Custom Fabricated Rides for many years. Even Vehicles with an excess of 500 HP. I had a Competitor that more often than not, would make numerous Mods on Frames, ie, 3" holes drilled through Frames for running Custom Exhaust Systems in Veh. running in excess of 900 HP. So put your Minds at ease, 1/2" Holes shouldn't even be given a second thought.
I would look at it this way - Rust is going to weaken your frame WAYYYY more than a few small holes ever would. Not drilling a hole because you're afraid it will be weakened only to let rust eat right through it from the inside seems kind of backwards to me.
Just did Eastwood internal coat today. I recently removed skid and welded new metal in place cleaning much of the rust out then. Found more today and got as much as I could out with the air gun. I drilled 4 holes, all about 1/2inch I believe (was a while ago). I really worry about rust inside the frame... I almost want to seal the side holes up with some metal tape and have the bottom holes I drilled exposed, at least when I go wheeling and maybe winter time.
I couldn't find a frame failure from drilling. Didn't think I would. Ya it's weakens it but how much over designed crap has holes drilled in it to make it lighter?
I think you are way over thinking the strength of your frame. Boxed frames are very strong, especially if we're talking one in good condition like yours.
There is no doubt that those round factory holes allow the tires to throw water and debris into the frame.
yep - that's what happened for sure.
Adding a hole will technically increase stress in loaded metal components. Yet, these increased stresses are quickly dispersed into the very near portions of the metal and can be neglected when considering load ratings. We do this all the time when designing thin and thick walled high pressure vessels (i.e. 10,000+ psi).
It has been my experience that welded repairs to boxed structures are very hard to keep from rusting internally and patches over existing steel leave a air gap between the two pieces that unless 100% air tight will start to rust and u can't see it because it is between two layers of steel. I think proper cleaning, treatment, and coating is a better way to go if u catch it early enough like u did.
How to remove rust from inside the frame of jeep wrangler.https://www.wranglerforum.com/threads/how-to-remove-rust-from-inside-the-frame-of-jeep-wrangler.1219793/
I had struggled to find a solution to get rid of rust from the interior of my wrangler's frame and then treat / paint it with some sort of rust inhibitor. There were no tools to remove the big / large chunks of rust flakes that accumulated inside the frame. So I ended up creating one for $7 dollars. Here are the steps involved.
Step - 1
Make the simple tool shown below to break the large flakes of rust inside the frame to smaller manageable pieces. I made two sizes, one was a foot long and the other two foot long using 1/4 thick metal stranded cable with plastic sheath from home depot. This tool when used correctly will chop large rust flakes into much smaller pieces for easy removal through holes. Most large rust flakes will become as small as rough sand. The chain used must be slightly free to rotate on the cable. This way the chain will rotate when the cable rotates under normal conditions or will be loose enough to remain stuck inside the frame and only the cable inside it will rotate keeping the tool itself intact. This tool will cost you around $7.
Step - 2
Cut 1" x 2" holes on the underside of the frame where the frame is pretty strong and close enough to the most rusted areas that can be reached with the tool you just made. I am not sure if this will weaken the frame or not. Alternatively you can opt to use the existing factory holes instead and make the tool long enough to reach the rusted areas from these holes.
So it turns out that was NOT a "seam" welding crack since the car has a light truck Hydroformed frame - and I should have used a High Frequency Arc Welder! Wow!
The breaks came not from too much power but too much twisting and the torque from 130:1 gear reduction. Even retrofitting by boxing the frame on 3 sides was iffy. So, be sure you have a very good fabricator to do the job not just a muffler changer. I do know that Dodge uses a hydro formed, heat treated frame, so any welds on it must be torch heated up before welding by someone who knows what they are doing. I would not tackle that job any more, but one thing I did learn was to have equal thickness material, way longer than you think you need, no vertical welds, use a high frequency arc welder with 7018 rod which has a high nickel content and, compared to mig welding requires actual technique, suitable for use even on cast iron, and be sure to fish mouth the ends.https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27925813/print/true.cfm
Don't abruptly end the boxing added plate with vertical end especially in or near a high stress area nor should you weld in a highly stressed area. That's why you taper both ends of an added plate that forms the box. A frame rail must flex a little rather than fracture or propagate a crack. Abruptly ending the boxed area simply chases the solid non-flexing area to where the frame's now weak point will now be. If you don't realize or know where the high stress areas are, go to someone who actually does. I hope that helps you to understand better.Still I think it will survive... I hope?
it was always shocking to see the number of frames that were cracked,
So this is the Hydroforming chassis tube frame when under pressure -
https://www.tatasteeleurope.com/static_files/StaticFiles/Automotive/Tube%20Hydroforming%20in%20Automotive%20Applications.pdf
Resistance Weld on Hydroform tube vid
Wow - so it's a Hook Crack - and a Cold Weld fixes it! Dang - so I CAN use JB Weld!
https://ro.uow.edu.au/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=2411&context=aiimpapers
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