The Fabrication/Welding Thread

[MrA]

Screw TIG, damn I'm in love!

[ame="http://www.youtube.com/watch?v=aF1Srs_e1Aw"]How good is your TIG weld? (weld strength & oxy acetylene torch welding aluminum) - YouTube[/ame]

I need to learn this. Like now.

[Heist]

^Good info.

I fuse most of my exhaust, but remember that even if it's not load bearing it has to hold its own weight, engine flex, (heat) contraction, and all the other variables that it will face (lowered cars....). Basically do some good brackets and you can get away with a lot in regards to exhaust if you're N/A.

[SheaMoose]

The best way to sharpening the tungsten is to use the front face of a bench grinder and you will want to point the tungsten upward so the grain from grinding it will be going lengthwise on the electrode. This helps direct the flow of electricity.
If you use the sides of a bench grinder you can eventually wear a groove in the wheel which can cause the mass outside of the grooves radius to break off.

When you are trying to weld two pieces of aluminum with a gap then you will need to connect them by adding rod to both sides simultaneously, or just by building up each side. Your rod will ball up a bit on the end because of the alternating current, so if that is all that is happening when you say it's melting into the cup, then just pull the tungsten out more.

And for the exhaust, fusing will be perfectly fine because it's not load bearing, all it does is direct the exhaust fumes.
You will want to add rod on most parts that will be under load, or will be experiencing some sort of force.

Stainless steel is a great material to learn tig on because it will tell you everything you are doing after you are finished with the weld.

If it's shiny and very colorful then you got the heat and speed right.
If it's dark and matte then it was either too hot or too slow.

I can also help anybody trying to tig through pm.

I weld aluminum chassis for electronics in helicopters and satellites, and I also do lot's of stainless racks, so those are kinda my specialties haha.

[M.Doban]

Also if your looking for filler buy .035, .045 and 1/16 should cover most anything exhaust related

Thank you! I put that information in the first post.

[EasySpeed*Inc]

Gotcha. Thank you! I'll have to grab some thinner filler rod as the stuff I have right now is much too big.


Heist, both of those beads are joining two pieces of pipe.

Thanks! That answers my question too. I'll have to source some stainless now and give it a shot.

Also if your looking for filler buy .035, .045 and 1/16 should cover most anything exhaust related

[Nick475]

for all those asking, i was using my buddies welder (i dont have one) but i guess its just a flux? i'm not sure. but there was no gas involved

[Jlyons617]

Makes sense. Now I just need a small bandsaw.

[M.Doban]

Question for you guys.

I've been looking online for info on doing pie cut welding. Is there like a set of templates that people use for cutting out the sections so they are even or is it just by eye?

There probably are, but I have always just used a bandsaw and cut the pipe at an angle, rotated it 180 degrees, and cut again. Rinse and repeat.

[Jlyons617]

Question for you guys.

I've been looking online for info on doing pie cut welding. Is there like a set of templates that people use for cutting out the sections so they are even or is it just by eye?

[M.Doban]

The weld above is undercut this is fairly common when fusion welding, when you introduce filler rod appropriately this will not occur. You basically want a slight convex shape to your weld especially on tubing.

Gotcha. Thank you! I'll have to grab some thinner filler rod as the stuff I have right now is much too big.

wait those are actually two pieces of pipe joining? or you just went over the pipe to create those beads?

If those are two pieces joining that's pretty solid for steel and no filler. I often go without filler rod for a lot of my tig work if the metal has tight tolerance (good fit up is crucial to good tig welding). If you have any gap though, even more so with steel, filler is a must.

Try to grab some stainless scrap tube and join two pipes. Stainless has amazing bonding properties and will melt into the bead, thus hardly ever need filler if your tolerances (fit up) is tight.

Both of those beads are joining two pieces of pipe.

Thanks! That answers my question. I'll have to source some stainless now and give it a shot.

[EasySpeed*Inc]

Okay, so I have another question for the masters.

I tried my hand at TIG welding some mild steel exhaust piping together using the advice given to me from several people in this thread. It turned out so much better than previous attempts! However, I tried doing it without filler rod as to have one less variable to worry about.

After looking at the backside of the weld, I could see that it fully penetrated the steel. So my question is, at what point/situations do you need filler rod?

Here's how the welds turned out.The upper weld was my second attempt. Please critique me.

The weld above is undercut this is fairly common when fusion welding, when you introduce filler rod appropriately this will not occur. You basically want a slight convex shape to your weld especially on tubing.

[Heist]

wait those are actually two pieces of pipe joining? or you just went over the pipe to create those beads?

If those are two pieces joining that's pretty solid for steel and no filler. I often go without filler rod for a lot of my tig work if the metal has tight tolerance (good fit up is crucial to good tig welding). If you have any gap though, even more so with steel, filler is a must.

Try to grab some stainless scrap tube and join two pipes. Stainless has amazing bonding properties and will melt into the bead, thus hardly ever need filler if your tolerances (fit up) is tight.

[M.Doban]

Okay, so I have another question for the masters.

I tried my hand at TIG welding some mild steel exhaust piping together using the advice given to me from several people in this thread. It turned out so much better than previous attempts! However, I tried doing it without filler rod as to have one less variable to worry about.

After looking at the backside of the weld, I could see that it fully penetrated the steel. So my question is, at what point/situations do you need filler rod?

Here's how the welds turned out.The upper weld was my second attempt. Please critique me.

[mrg7243]

Just brushed it of with a steel brush. Splatter is pretty good also. And the flux wire is cheapo. 10$ for 2kg.

Yeah, the problem is you dont get great penetration with flux, and they usually dont look that clean.

[M.Doban]

Nick, like people have said, prep the surface. With rust, a simple wire wheel will not do. Grind off the rust. Second, it looks like you are either not using any gas or you had forgotten to turn the gas on.

For thin metal like that (sheet metal, exhaust tubing) don't try to lay a full bean down just yet. It's really hard and you'll either blow right through or warp the steel. Instead, do a bunch of small single tacks. Start with about three tacks spread out around the pipe to hold it together, then connect them with more tacks.

If you want to practice, grab some flat scrap steel, clean it up (no oil, grease or rust) and try tacking, laying beads on that. once you can do that, grab another piece and try to weld them together.