Welding Tips and Tricks

Hello all,
Here are some pics of my first TIG welds on aluminum. The good, the bad, and the (very) ugly.

The metal is mostly 1/8th inch, and most of the welds went pretty well, though not very pretty. The biggest problem I had was trying to weld 0.051 inch flat expanded aluminum to the 1/8th inch angle. As you can see in the pics the heat from the torch quickly melted back the expanded aluminum. I eventually ended up dropping the amps to 11, and building up a glob for filler on the expanded then upped the amps and established a puddle on the 1/8th inch angle and quickly feathering the glob into the puddle.

In the ugly picture you can see the 1/8th inch angle heated up and sagged badly. I started out by lowering the amps, but then figured I needed to increase the amp to get a puddle going faster.

Appreciate any feedback.

Well honestly, first welds on a first project = not a good idea, unless it is scrap-able in the end. It looks like you're having trouble with fusing the expanded metal to the sheet/angle/whatever. So what welder do you have, what settings, etc.?

Oscar wrote:Well honestly, first welds on a first project = not a good idea, unless it is scrap-able in the end. It looks like you're having trouble with fusing the expanded metal to the sheet/angle/whatever. So what welder do you have, what settings, etc.?

Machine is a Thermal Arc 186.

For the 1/8th inch: Cleaning set to 30% (adjustable from 10% to 65%), Amps about 150, 17 CFH on the argon, Preflow .5 sec, Post flow 5 sec, Freq 125

For the Expanded: 11 Amps, Cleaning 35%

The expanded aluminum is probably 3000 series to make matters worse. I used a spool gun recently to do something very similar.

I think you're already on the right idea whats giving you the problem. You need to heat the 1/8" fast before the expanded heats up, which would probably be very difficult to control if you're new to it.

I would try and pre heat the thick material up to annealing temp, which is quite close to melting.
Mark the metal with a Sharpie and heat until it disappears then try to weld again. If you already have welded some parts of the expanded metal you might need to bend it up slightly so it doesn't suck up the heat while pre heating.

AndersK wrote:I think you're already on the right idea whats giving you the problem. You need to heat the 1/8" fast before the expanded heats up, which would probably be very difficult to control if you're new to it.

I would try and pre heat the thick material up to annealing temp, which is quite close to melting.
Mark the metal with a Sharpie and heat until it disappears then try to weld again. If you already have welded some parts of the expanded metal you might need to bend it up slightly so it doesn't suck up the heat while pre heating.

If I preheat the thicker stuff enough would I be able to reduce the amps to 15-20 for the 51 thousandths expanded, and be able to get a puddle going in the 1/8th inch at the lower amps?

Does the 186 have a spot weld feature, and if so, do you have a on/off momentary switch you can utilize for said spot weld feature? Personally that is what I would be doing, but then again, I've only experimented on aluminum. But found good results from said experiments.

The 186 I have doesn't have a specific spot timer. But I bought the version with the torch mounted controls. It has a momentary switch you can use like a spot timer. You can use it in the 2T function and set on delay or ramp down. Or any combination of pulse to get a desired effect.

Neosec wrote:

AndersK wrote:I think you're already on the right idea whats giving you the problem. You need to heat the 1/8" fast before the expanded heats up, which would probably be very difficult to control if you're new to it.

I would try and pre heat the thick material up to annealing temp, which is quite close to melting.
Mark the metal with a Sharpie and heat until it disappears then try to weld again. If you already have welded some parts of the expanded metal you might need to bend it up slightly so it doesn't suck up the heat while pre heating.

If I preheat the thicker stuff enough would I be able to reduce the amps to 15-20 for the 51 thousandths expanded, and be able to get a puddle going in the 1/8th inch at the lower amps?

Unlikely. The 1/8" material won't weld with that low of amps, no matter how much preheat. A preheat, a 1/16" tungsten and a 1/16" wire (or smaller) and favoring the 1/8" is about your only option with a TIG.

Extremely Difficult for a new person - you could just rivet through washers or bolt through washers.

Or lay a 1/8" thick flat strip over the mesh and rivet, bolt or weld.

cj737 wrote:

Neosec wrote:

AndersK wrote:I think you're already on the right idea whats giving you the problem. You need to heat the 1/8" fast before the expanded heats up, which would probably be very difficult to control if you're new to it.

I would try and pre heat the thick material up to annealing temp, which is quite close to melting.
Mark the metal with a Sharpie and heat until it disappears then try to weld again. If you already have welded some parts of the expanded metal you might need to bend it up slightly so it doesn't suck up the heat while pre heating.

If I preheat the thicker stuff enough would I be able to reduce the amps to 15-20 for the 51 thousandths expanded, and be able to get a puddle going in the 1/8th inch at the lower amps?

Unlikely. The 1/8" material won't weld with that low of amps, no matter how much preheat. A preheat, a 1/16" tungsten and a 1/16" wire (or smaller) and favoring the 1/8" is about your only option with a TIG.

You say, "...about your only option with a TIG", is there another welding process that would weld the thin expanded to the 1/8th inch angle better/easier?

MinnesotaDave wrote:Extremely Difficult for a new person - you could just rivet through washers or bolt through washers.

Or lay a 1/8" thick flat strip over the mesh and rivet, bolt or weld.

"Extremely Difficult for a new person..."

Yup, I suppose it is. I'm a stubborn old bstd though and will probably keep working at it till I figure it out.

The other option is to use a MIG welder with a spool gun (this is an aluminum wire). Spool guns are inexpensive means of converting a DC MIG to weld aluminum. MIG squirts so much wire so quickly that the added wire overcomes the burn off of the expanded screen. You still need to use care, but welding thin-to-thick stuff like this, Spool Guns are the ticket for mere mortal welders.You'll be running 0.030 wire so it works a treat.

Neosec wrote:

MinnesotaDave wrote:Extremely Difficult for a new person - you could just rivet through washers or bolt through washers.

Or lay a 1/8" thick flat strip over the mesh and rivet, bolt or weld.

"Extremely Difficult for a new person..."

Yup, I suppose it is. I'm a stubborn old bstd though and will probably keep working at it till I figure it out.

I would sharpen a tungsten and direct my heat into the 1/8 until I see it start to puddle then add a drop of filler onto the 1/8 then walk it to the expanded. You will need to have your torch at a 90 to the 1/8 material just off the end of the expanded but not close enough to melt it. Once you get the 1/8 to puddle and take filler you can reduce the heat a little move toward the expanded and add heat and filler. I do some thick to thin at work and this is my usual trick. Try to get the filler to flow to the expanded.

Sent from my SCH-I545 using Tapatalk

MinnesotaDave wrote: Or lay a 1/8" thick flat strip over the mesh and rivet, bolt or weld.

Or clamp a steel bar on the mesh. Leave a few mm of the mesh sticking out and hit it hard. The bar will stop the mesh from melting to far until the 1/8 melts.

Warrenh wrote:

Neosec wrote:

MinnesotaDave wrote:Extremely Difficult for a new person - you could just rivet through washers or bolt through washers.

Or lay a 1/8" thick flat strip over the mesh and rivet, bolt or weld.

"Extremely Difficult for a new person..."

Yup, I suppose it is. I'm a stubborn old bstd though and will probably keep working at it till I figure it out.

I would sharpen a tungsten and direct my heat into the 1/8 until I see it start to puddle then add a drop of filler onto the 1/8 then walk it to the expanded. You will need to have your torch at a 90 to the 1/8 material just off the end of the expanded but not close enough to melt it. Once you get the 1/8 to puddle and take filler you can reduce the heat a little move toward the expanded and add heat and filler. I do some thick to thin at work and this is my usual trick. Try to get the filler to flow to the expanded.

Sent from my SCH-I545 using Tapatalk

I gave that a shot and it worked better.
I set the Amps to 75, cleaning to 10% (so more heat on the 2% Lanthanated Tungsten), Switched the tungsten from 3/32 to 1/16, increased the Argon to 20, and tilted the torch away from the expanded just a bit. This resulted in less melting back of the expanded. I need practice with peddle control, but the result was welds that penetrated and seem fairly solid though not too pretty.