Hi guys and girls,
I've been asked to do some welding on a friend's car but my judgment is making me question doing so.
It's a small sports car and he would like the panhard rod (track rod I believe they are called in the US) cut and have an adjuster installed, these adjusters are sold as suited to this make and model however I have concerns that the original rod is designed to fit inside the adjuster and be plug welded through two holes and fillet welded all round. This concerns me that the HAZ from the fillet is not reinforced at all and could become a failure point is this an actual concern or am I over thinking it? My friend whose car it is, is a very talented engineer and doesn't see it as a concern but it has me worried.
Also he would like a seat bracket made to weld to the standard seat rail so a recaro seat can fitted. Once again I'm worried about the HAZ on the seat rails due to being a critical component is this actually a concern?
I'm not worried about my welding or skills just the fact its my friends life is dependent on this stuff not failing. I've done plenty of structural and light gauge work however never both in the same item so I'm just question it.
Anyway I've attached a photo of a test run of my new tig torch and an old exhaust pipe weld to give you guys an idea of my skills.
Having said that, it also depends where you are over the legality of what you're doing. Here in Oz everything is so tightly regulated about seat and suspension structural modifications, that without engineering approval and suitable welding qualifications, the vehicle would be deemed unfit for road and highway use and void their insurance. Might pay to check that area out first. If you're in the US, it would seem (to us here) that anything goes.
Now that one is aside, you could look at the original part and see how it is constructed and go from there. Or you could grab a wrecked one from your local car junkyard that basically costs nothing and cut it apart for a better look.
As for the seat, I would be a little concerned myself, but if you look at the welding on the original item you could be forgiven for thinking chewing gum would hold better.
My concerns about a HAZ problem on the seat mounts would be less than that of placement where you don't add stresses that will weaken the connection. If your friend is the right kind of engineer, he should be able to calculate those out for himself and factor in the relevant safety margins. Seats undergo enormous stresses in collisions, so he should be paying attention to that himself.
I agree with you about being concerned about the safety of what he is asking you to do. If it fails, it could come back on you. However, with proper thought research and design, those factors should be reduced significantly.
When you say plug weld and then describe it as a fillet weld I get a bit confused. When I think of a plug weld I think only the first pass could be described as a fillet weld. Because after that you fill the hole you drilled or cut in the tube compleatly till its flush with the surface of the original tube. Is that what your planing ? Or did I miss understand?
I'm in OZ as well and I've been through the regs I've even said to him to get it certified but his opinion was it was safe so he wasn't worried. I'm a qualified boilermaker so I am able to get my work certified if it were to be engineered so I think I'll probably only do it if he agrees to get it inspected and certified. I'm sure we could design it safely but it's more of a risk than I'm willing to take I think. Thanks for the input I thought I might of been overreacting glad to see you think the same
You're welcome Chopper.
I'm a boily in Oz too. We both realise that car mods are a legal lottery here when it comes to highway use. Just changing your tyres from the type the manufacturer supplied to another here will sometimes make your car illegal for road use.
As an example, BMW supplied some of their cars here with run flat tyres. At about $700-900 each, some owners tried to replace them with normal tyres as they wore out, only to get told their cars had been modified and would not pass safety inspections.
What I do know is modifying suspension, steering and seat anchors outside prescribed manufacturers limits is a big nono without approval. Just being an engineer does not necessarily make it right.
Off road use is a different kettle of fish, but even in those circumstances, certain codes have to be complied with if it involves safety and being around other people.
The_Fixer wrote:You're welcome Chopper.
I'm a boily in Oz too. We both realise that car mods are a legal lottery here when it comes to highway use. Just changing your tyres from the type the manufacturer supplied to another here will sometimes make your car illegal for road use.
As an example, BMW supplied some of their cars here with run flat tyres. At about $700-900 each, some owners tried to replace them with normal tyres as they wore out, only to get told their cars had been modified and would not pass safety inspections.
What I do know is modifying suspension, steering and seat anchors outside prescribed manufacturers limits is a big nono without approval. Just being an engineer does not necessarily make it right.
Off road use is a different kettle of fish, but even in those circumstances, certain codes have to be complied with if it involves safety and being around other people.
I feel your concerns are legitimate.
Wow...and I thought the United States government was oppressive. Smart people stay away from critical welding as you never really know your friend until you meet him in court. Aftermarket parts are readily available...let the aftermarket get sued.
Yeah that's what I thought initially big companies have legal teams to cover this sort of stuff.
And yes Australian regs are up there with the toughest of them. 25% due to the Aussie attitude of "she'll be right mate" 25% Engineers on the regulations boards putting in sound engineering requirements and 50% bureaucrats/politicians showing they are tough on our hoon problem.
If your not familiar with the terminology of hoons or Australia's "hoon problem" please YouTube -A current Affair hoon problems. It'll entertain you with stupidity and how our media gets the politicalians to crack down on car mods.
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cb400chopper wrote:Yeah that's what I thought initially big companies have legal teams to cover this sort of stuff.
And yes Australian regs are up there with the toughest of them. 25% due to the Aussie attitude of "she'll be right mate" 25% Engineers on the regulations boards putting in sound engineering requirements and 50% bureaucrats/politicians showing they are tough on our hoon problem.
If your not familiar with the terminology of hoons or Australia's "hoon problem" please YouTube -A current Affair hoon problems. It'll entertain you with stupidity and how our media gets the politicalians to crack down on car mods.
Sent from my HTC_PN071 using Tapatalk
So you're saying that the US isn't the only country run by idiots and buffoons? Heck, somewhere around here we had a thread about birdshit welds and shade-tree mechanic bonehead car and truck mods. I have seen some absolutely crazy dangerous stuff done to vehicles over here...maybe your laws aren't that bad after all. I watched some hoon videos....hoon must be Aussie for "asshole driver". We have a country full to the brim of those!
In our litigious society it's an easy decision. It is not if you can do it, it is should you do it. I have no problem welding a pipe that holds 2500 psig of super heated steam. I am under the protection of tons of insurance and procedures that show the due diligence of doing everything by the book. Can I weld a simple hitch on my neighbors truck? In my sleep. But if he piles that thing up on the highway and the insurance company gets involved, everybody is dirty in their mind. If my last name was REESE (For non USA a hitch manufacturer) and I had the infrastructure fine, but I am just the guy next door that can weld.
Attorney: "Mr. Lewis I see from what was submitted in discovery and have learned from your testimony, you have experience and knowledge in welding high pressure steam pipe, structural steel and pressure vessels. What I DO NOT see is any evidence you have welded trailer hitches. If I said you had limited experience in welding trailer hitches would that be an accurate statement?"
Give me an effing break.
AWS D1.1 / ASME IX / CWB / API / EWI / RWMA / BSEE
Scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality." Nikola Tesla
Heck, somewhere around here we had a thread about birdshit welds and shade-tree mechanic bonehead car and truck mods. I have seen some absolutely crazy dangerous stuff done to vehicles over here...maybe your laws aren't that bad after all. 
