Showing posts with label Steel. Show all posts
Showing posts with label Steel. Show all posts

Wednesday, November 2, 2011

Steel weld pool is 'drawn' up onto the tungsten.

by John Fennell
(Hereford, United Kingdom. )

Hi there, may I first congratulate you on having the best welding information and resources website I have ever seen, it is truly brilliant! Now my question seems to be rather obscure, as I haven't found anyone else asking it online but here goes. I am teaching myself to TIG weld-with the aid of many YouTube videos, including some of your own, but I always have trouble with the weld pool literally being drawn up onto the tungsten. I use a 12 month old Lincoln Invertec 160, with a lanthanated tungsten and am trying to weld general steel between 1/8-1/4" thick. I did some TIG at my local college and didn't have the same problem to the degree I have on my own unit but there does definitely seem to be something wrong with my technique. I have done quite a lot of MMA and MIG in agricultural repairs, I took to gas welding like a duck to water but seem to be struggling with TIG. Hopefully I'm making a silly mistake but have tried holding the torch higher/lower than 1/4" from the puddle, fiddled with the current and gas flow to no avail. I try to use a little over 1/4" stickout which I was told by a lecturer at my local college was a good starting point.

Would really appreciate any help you can possibly give me,
Thanks, John.

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sometimes when using an amperage that is close to the maximum for a given dia electrode, it seems like the puddle jumps on but I think its the tip of the electrode actually melting and causing a momentary short.

other problems arise from coatings that outgas onto the electrode.

thanks,

jody

Tuesday, November 1, 2011

selecting the right rod for aluminum and steel fence fabrication also right amperage

My dad just purchase a lincoln 225 arc welder and I would like to know what rod we need to weld those square pipes sold at homedepot they're about 1" and hollow inside and we plan to stick em to a 2" side bar with the same thickness.

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for steel, I would choose a 6011 rod. probably 3/32 diameter because the wall thickness on what you describe is probably only about .063"

for aluminum, unless you have done quite a bit of stick welding, its gonna be a lot more difficult than the steel.
I would recommend going to a local welding supply and buying a small qty of aluminum stick rod and give them a try before you jump into anything.

Monday, October 31, 2011

argon mix for mild steel

what gas mix do you use for mild steel tig...

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I dont use a mix...just pure argon.

same for stainless and aluminum.

for thicker aluminum, i use a helium argon mix about 50/50 or as high as 80 percent helium.

mixes like the standard 75/25 argon/co2 mix used for mig welding, do not work well for tig welding.

Saturday, October 29, 2011

16 gauge steel hard wire

How to weld 16 gauge steel with hard wire
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thats a wide open question but here goes...

well the best gas to use with bare wire for 16 ga is probably 75/25 ar/co2

but co2 would work also.

downhill all the vertical joints and in fact any joint you can position to where it is slightly downhill will weld smoother.

.030" or .025" wire works best but .035" is still in the ball park and will work fine if you set it right.

depending on the machine, the voltage will probably be around 16-18

wire feed speed will depend on wire size used.

flow on the mig gun will also depend on the size of the nozzle and type of gas used but 25 cfh will probably get you going.

most mig welders these days come with some type of chart inside the wire spool panel.

those settings are usually a pretty good place to start.

er70s6 is the most common wire but er70s3 or 4 is fine also.

you may find that short runs of only a few inches help prevent warping.

Friday, October 28, 2011

How to Tig Weld Steel

tig finger This weeks video is Since last weeks video was building a stand for a Porter Cable Portaband, I thought maybe I would show how to tig weld end caps and feet on the stand.

I cut the end caps using the same portaband saw I was building a stand for.

Using a cheap dial caliper, I measured the inside diameter of the square tubing and added about .100" so that there would be some overlap. I cut all the end caps out of cold rolled 11 gauge sheet.

I like to tig weld outside corner joints. They are easy fun and sometimes do not even need any filler metal.

For this job, I used a little "trick" welding magnet tool called a MagTab.

Its made by Stronghand tools and you can get it from Amazon.com, Northern tool, Summit Racing, Airgas, and a bunch of other places.

I just checked on the price and while it was only about 10 dollars a year ago, The price of magnets has been rising so I think it costs about 13 dollars now.

It is a small but innovative welding magnet that utilizes a V- pad swivel along with an adjustable tab holder to create one of the handiest little welding tools to come along in some time.

The MagTabs primary use is to hold small tabs on round tubing while tack welds are made. The old way of hold tabs, and way I have done it for years is to hold the tabs with your fingers.

Holding small parts for tack welding is much safer with the MagTab. But what I did not anticipate is that it saves time too.

Usually, when something is safer, that translates to "less useful" "cumbersome" "time consuming", etc.

Not so with this little nugget.

Today, I found another use for it other than hold tabs...Holding end caps in place on square tubing.

I will be honest with you. I used to just hold them in place with a finger while I tacked. Its easy to get complacent after years of welding.

A few weeks ago, I was doing this, and the arc jumped right through my glove and gave me a deep burn on a finger tip and it hurt like a bear. Like worse than stubbing your little toe on the bed leg at 2am.

While the burns have long since healed, the memory is fresh enough that I actually turned around and drove back home on my way to the shop, after realizing I forgot my MagTab in my garage.

So back to todays video...

There are 5 different types of weld joints. ( this is a common question on written welding tests)

1. Corner Joint

2. Lap joint

3. Edge joint

4. Butt Joint

5. Tee Joint

Luckily, The first letter of each actually makes a word.

CLEBT

That is how I remember the 5 types of weld joints.

Corner joints are very common and are often welded from the outside and then are called "outside corner joints".

Lap joints are a very common weld joint too.

In this video, along with some tips on tack welding and the Magtab thingy, I show some tips for how to tig weld outside corners, and laps.

I know I have written about tack welding like a laser before, but it does work very well.

Here is a review.

Using a torch switch and with the machine set to 2t, and with zero upslope and zero downslope, I set the amperage to roughly twice what it takes to weld the joint.

then, using a sharp electrode, I position the tip of the tungsten electrode within about one electrode diameter from where I want the tack.

Then I press the torch switch for about half a second or less.

A caution.... try this on scrap metal first to get used to it.or you might blow some holes.

Once the end caps were tacked, I tig welded them all using several different tig welding techniques.

some with no filler metal

some using 309 ss filler metal

some using small circles

I used as low as 80 amps, and as much as 130 amps to weld the end caps and feet.

With a simple torch switch, and no amperage control, you can still make some adjustments by just traveling faster or slower.

tig finger heatshield

Friday, September 23, 2011

Tig Welding Steel Parts

Tig Welding Steel and fabricating small parts


Whether you are fabricating something big that takes up the whole table, or just fixturing small parts together, modular fixturing helps.

I just tig welded 4 small steel parts on my StrongHand table...and I was reminded again, just how much I like it.

In fact, there are only 2 things I dont like about it...

1. Sometimes things fall thru the slots.
2. the rubber o rings on the fixture bolts are starting to split...I need to get some new ones

The steel parts I tig welded for this job are for the commercial aircraft industry and are built per the drawing so I needed to make sure everything is straight, plumb, and dead nuts. Otherwise the parts wont work, or they might get rejected and that would mean rework.

I am doing this welding job for a friends machine shop... and my job is just to put the parts together like a puzzle and weld them.

I like doing work for machine shops because usually the metal is clean and ready to weld.

I show up when its ready to weld or have the parts dropped off at my garage shop, weld them up, and deliver them...or have them picked up.

gravy.

But these parts are hot rolled steel and tig welding steel with mill scale on it sucks. It has to be ground off or it will be ugly...like the part in the video that I forgot to clean.

When hot rolled steel is ground clean, it welds great... just like cold rolled. But when it is not cleaned, it is like welding in a bowl of cornflakes.

I had some foot pedal issues on my tig welding machine( like it was broke) so I had no choice bit to use the torch switch. I prefer a foot pedal, but with upslope and downslope controls, and even a 4t function if I choose it, I still have a lot of control. about 130 amps was about right. ...here are the basic machine settings.


125-135 amps

3/32" 2% lanthanated electrode 2.4mm

er70s2 1/16" filler wire 1.6mm

#5 cup

10 cfh argon

When I pulse ...like when the weld is close to an edge, I increase the amperage while arcing on a piece of scrap until I get the same readout of around 130 amps of output.

tig finger Tig Welding Steel...Learn more about the Tig Finger Heat Shield in the video