What is the trick to making leak free welds?

[franklin2]

Take a bit of skill and a lot of practice with correct filler material and welder (tool) that is good too.

I can to it (or could when I was doing it on regular basis) but one thing to remember is to over weld the start/stop points when doing it. Start welding well beyond the the crack on solid material and work OVER the crack and keep welding PAST the spot the weld ends. FIRST clean out ALL the oil, heat it with torch if need be and remove grease paint ahead of time. If it is heavy or higher pressure grinding out the crack some on thicker material is needed with multiple passes each one overlapping start and stop points.

M

Ok, so your starting and stopping points can make a flaw in the weld, so it's better to go beyond into a good part of the line and stop? I will try that. Thanks.

 

[franklin2]

if the line was not open it will vent and the venting will cause a pin hole,

Most all the time the pipe has been taken off and cleaned out. I have noticed that if you do not get the line very very clean, some gas from burning oil or paint will bubble up through and make a flaw in the weld. Thanks for the response.

 

[franklin2]

This would be better in the welding section. I would like to see the answers.

http://www.tractorbynet.com/forums/welding/

Duh, didn't know we had a welding section. I will try it there also.

Here's the link to that one.

http://www.tractorbynet.com/forums/welding/320020-what-trick-making-leak-free.html#post3870570

 

[KubotainNH]

Duh, didn't know we had a welding section. I will try it there also.

Here's the link to that one.

http://www.tractorbynet.com/forums/welding/320020-what-trick-making-leak-free.html#post3870570

Cool, I'll go subscribe to that one.

 

[Gordon Gould]

With my ability, or lack there of, I would have a much better chance of success by braze welding the crack. I realize it is a different operation from welding. I am just wondering if there would be a problem if the repair was a braze welded. A braze weld is quite strong.

 

[RPW]

I've brazed steel lines before and I find it a lot easier.

 

[BHD]

I have always brazed hydraulic line breaks as a stick welder is a little difficult on that thin material,

 

[BHD]

I have always brazed, steel hydraulic line breaks, as a stick welder is a little difficult on that thin material,

 

[jenkinsph]

Sitting here while it is raining outside makes me think about how long it has been since I brazed anything. Been about 40 years, I still do a lot of silver soldering, but haven't bought any brazing rods or flux. Fortunately I haven't had any problems with any of my steel lines to need it.

 

[dfkrug]

I have not had any success at MIG welding steel hydraulic lines either. They would become
embrittled. I recommend brazing as others have mentioned.

That said, I do MIG weld cylinders and tanks, and what I do to avoid and fix pinholes is:
never weld contaminated steel. Especially oil-contaminated steel. Clean, clean, clean first.
Acetone, heat, whatever it takes. Air pressure-test the result, and fix any pinholes by
grinding/rewelding.

Also, pinhole-free MIG welding requires excellent shielding gas coverage, so flush the torch
hose before welding, and use plenty of flow in still-air conditions.