I know this was a chuckle, but I am going to answer it as a serious question.

Here is an example of a simple high pressure pipe weld.
Stick Welding 2 inch Pipe Cover Pass - 6g Pipe Welding Test 2" Schedule 80 - YouTube

The joint needs to be a single-Vee or a single-U...

.

As the pipe size gets smaller, the difficulty goes up.
* Heat control, burn holes.
* Collapsed tube.
* Blocked tube, penetration/slag.
* Grinding the outer diameter.
* Boring and cleaning the tube bore.
Then comes the fun.

You must use stress relieving, and I prefer annealing.

After welding, you can do high temp stress relieve at 1250° F, for 1-1.5 hr per inch of material thickness, 1 hour minimum, as opposed to a true anneal. Furnace cool if possible.

After welding low carbon steel (under 0.25 carbon) I usually normalize which helps "homogenize" the material.
To anneal then normalize is called "double draw", which is critical if you plan to carburize or do other heat treating later.

Annealing range for 1018 steel is 1575° F -1650° F. Time at temp 1/2 hr for small section (13 mm or less), 1 hr for 25mm section.
Recommended furnace cooling rate of 50° F/hr over range from 1575° F to 1300° F for HB 111-149.
(from metals handbook)

*********************************

From my cost perspective:
# 3-4 hours labor.
# Weld and Annealing furnace fuel $50.00
# Building a solid and safe (small) Annealing Furnace, $200.00 + 24 hours labor.

IMO all of this is possible for the most skilled professional or most tenacious hobbyist.
It is not cost effective.
A single mistake in any of these processes will frequently turn the (used part) work piece into scrap metal.
The failed line may have formed preliminary stress fractures on the other end, just waiting to break.


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__________________
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https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
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Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

I had the same problem this summer. it was the #4 for me.

I found a complete set of used lines. including ALL the brackets. (here in the for sale forum!!!)

It turns out I was missing a few.

replacment is your best bet. New from the dealer they were $60-$70 each!

__________________
87' 300DT (Grey w/ red leather)
87' 300TDT (silver w/ palamino tex) SOLD

2012 VW JSW TDI (on tdiclub.com all the time "btcost")

If you weld a fuel line, you pretty much are going to get scale on the inside. This will end up clogging the nozzle & necessitate R&R'ing or at least cleaning that nozzle. 60 bucks is a one time fix.

I have both tig & mig, they are not perfect in the garage. -corne-

Well I just had this same thing happen to me yesterday while I was on a road trip. #3 started squirting fuel from the nut. First thing I noticed was a Loss of power then a minute or two later I could smell diesel. I just wanted to ask if this could of caused any other damage I didnt drive the car much further maybe 4 or 5 miles after I found it. Parts are on their way just nervous hoping that's all that broke.

Only additional damage is environmental. No mechanical damage from lack of fuel to one or more injectors.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

I got behind a Nissan murano yesterday spilling gasoline from underneath every time he turned. Tried to catch him and tell him before the car went up in flames but he turned into a neighborhood and I lost him. I didn't see a fried car on my way to work today, so maybe he figured it out. God knows everyone behind him could smell it.

Hey Max would you go through the trouble of replacing all of the fuel lines & brackets? Contemplating replacing all of it.

Replace what's broken and move on with life. It's important to ensure that all of the plastic clips and rubber bumpers are in place on these engines. Missing plastic clips are a common problem and are likely the primary source of broken lines.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

A pencil torch and thin brazing wire found at any hardware store will fix the crack. I have done this a number of times in the past. I still highly recommend getting a new line but for the time being it works. Better than a wobbly smelly drive!
Also yes, not having the lines clamped is absolutely why this happened and usually it happens pretty quickly. I have had three lines crack within a two week span before I realized the error in my ways.

__________________
Dan
2005 E320 CDI - 246k
1987 300SDL TD05-16g, Herlevi pump, Elbe manifold, 2.47 LSD - 213k
Past: 1987 300D - 264k

Got to about 300k miles on my first 87 300d and three lines broke within a few hundred miles. Of course the clips were gone. I replace all of the lines and clips. And I'm going to do it on my new 87 now - preventative medicine. The clips on mine have been gone for years probably. Failure is predictable.

__________________
DS
2010 CL550 - Heaven help me but it's beautiful
87 300D a labor of love
11 GLK 350 So far, so good
08 E350 4matic, Love it.
99 E320 too rusted, sold
87 260E Donated to Newgate School
www.Newgateschool.org - check it out.
12 Ford Escape, sold, forgotten
87 300D, sold, what a mistake
06 Passat 2.0T, PITA, sold

Las Vegas NV