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SportAir TIG Class

On August 9, 2002 I climbed aboard my trusty BMW and motored south seventy-five miles to Griffin, GA to learn a little about TIG welding.  To my delight my expectations were completely blown away by the class, I learned a lot about TIG welding

.A   B    C    D    E  (click photo to enlarge)

Photo B is of the air side of the welding lab building at the Alexander Tech Center located on the SW corner of Griffen-Spalding County Airport.  The lab is outlined in purple on the photo.  Photo B is the big hanger that contains the SportAir builder support workshop, not to mention a King Air and Travelair.  

The instructor, Tony Polewchak in photo D above, is a Welding Technician for Lincoln with 35 years of experience.  His job is to develop the technical specifications for how to use each and every new piece of equipment that Lincoln makes.  His experience was obvious in how he could demonstrate technique.

The class, photo E above, came in for three days.  Friday night we had a classroom session on safety and general information and then we went into the welding lab and got set up.  Each student has his own welding booth with a Lincoln SquareWave 175.  This is the same welding machine that I have at home so it was just like being in the basement at home to me.  We ran a few samples of bead on plate to prove that everything was working and wrapped it up for the night.  Then it was off to Applebee's for dinner where we continued to talk about the subject matter of the weekend.

Saturday began with more bead on plate and then we went on to what ever we wanted;  lap joints, but joints, tee joints, tube on end, tube tee.  The material choice was our own as well.  I did a little steel in the beginning to prove to myself that I had already mastered that, then I moved on to Al and Stainless.  I spend the majority of the day equally divided between Al and Stainless.  On additional curve that Tony threw into the mix for me was to hand me some .125" Al plate to weld.  I had been working on .060" and was doing quite well.  The change in thickness significantly changed the current required and it took me a while to get it figured out.  First too little, then too much, then just right.  You can blow a 1/16" tungsten electrode right out of the torch with 175 amps.

The following pictures are of sample pieces that I did with comments to remind me what I learned.

Front                Back(click image for full size picture)

Sample 1 is bead on steel plate.  A little too much current was used and it can be seen on the back

Sample 2 is bead on Al plate.  Too much current is shown on the back.  In addition there is a crater at the end of the bead on the front.  Cratering is caused by turning off the current too quickly.  Al is the most sensitive material for cratering because it's melting point is so low.

Sample 3 is bead on Al plate.  The bead on the left (front) is what I did with out using magnifying glasses, it has way too much current.  The two beads on the right were run using magnifying glasses.  This was major breakthrough number one;  Most of my welding problem with Aluminum is that I cannot see what I am doing.  My glasses are about three years old and they most likely are no longer the proper Rx.  I tried Tony's helmet which has a 2.25 diopter magnifier in it and it was much better.  I stopped by K-mart and picked up a pair of 3.50 diopter reading glasses to wear over my glasses tomorrow ($8.99).  Once I figure out the proper magnification that I need to see what I'm doing I'll order a magnifier for inside my welding helmet.

Front                Back

Sample 4 Al bead on plate with edge welding to practice current control to keep from melting out the edge.

Sample 5 Al bead on plate start stop practice to avoid cratering.

Sample 6 Al bead on plate I let the edge get too hot and it melted.

Front                Back

Sample 7 is a steel lap joint, the left bead is with the torch too far away and too much current.  The right bead shows a much smaller heat effected zone and the rear shows the same penetration for both welds.

Sample 8 another steel lap joint

Front                    Back

Sample 9 steel but joint tack welded.

Sample 10 steel but joint welded through the tack weld.  This is good practice for what I typically do in welding tube.  It makes it much easier to learn current control and filler application when the joint is constantly curving away from you as it does on a tube.

Front                    Back

Sample 11 is stainless bead on plate

Sample 12 is a stainless but joint.  First it was tacked in three places and then welded across through the tack welds.  The contamination on the back shows the need for back purging all stainless steel joints.  Plate makes for a significant challenge but with a little Al foil and 5CF/M of Argon the back will be just as clean as the front.

Front                    Back

Sample 13 is 4130 steel tube welded into a tee joint.  I was supprised that I got good penetration and no holes around this complicated joint.  I first tacked it in four places and then welded around the joint.

Front                        Back

Sample 14 is an Al tee joint.  Center tack weld has a blob on the bottom and a blob on the wall.  This is caused by welding with too little current so the two do not flow together.

Sample 15 is an Al tee joint.  I changed from 1/16" to 3/32" filler.  This reduced the amount of feed required on the filler rod so I could focus on the torch control.  Feeding filler rod is a skill that needs to be practiced to become second nature.  I took a piece of rod to the hotel and practiced my technique.   I ended up slightly different than Tony but it works for me.  The object of welding is to be comfortable so you can work easily.

Sample 16 is an Al tee joint.  I used too much current which is can be seen on the back.  Also the edges are burned through showing that I did not reduce the current as I approached the edge.

Front                    Back

Sample 17 Al tee joint .125"  This required significantly more current than I had been using.  It took a while to figure out my problem.  The current was too low and my feed rate was too slow.  The back shows the my first attempt using way too little current and burning it up without welding it.  The wall was used to run bead on plate and attempt to get a good "dab and move" technique established.

Sample 18 Another Al tee joint .125".  This sample is beginning to show some dab and move in the joint between the floor and wall.

Sample 19 back to .060" Al, we ran out of .125".  The front shows good technique.  The back shows poor starting technique.  Too little current at the beginning to heat the piece quickly so the filler did not flow well.

Front                    Back

Sample 20 is stainless tube practice.  Very poor results.  I have become a master at filling holes.  Unfortunately, the reason for this new skill is all the holes that I am burning through the tubes.  

Sample 21 more stainless tube practice with marginally better results.

Sample 22 stainless tee joint with pretty good results.

Front                Back

Sample 23 and 24 are stainless steel elbow joints.  Sample 23 and the left half of sample 24 show good dab and move technique.  The right half of sample 24 shows a current starved weld.  Good penetration on the wall but poor penetration on the floor.  The back of both samples shows the need for back purging stainless welds.

Front                        Back

Sample 25 is stainless and sample 26 is Al.  Both are bead on plate practice with the added twist of writing names.  This pointed out that I could be very successful when I use my normal technique of left to right migration of a weld.  This made it obvious that I have to work very hard to keep the torch angle and filler in proper relationship to the work.  It started as a gag but ended up showing me I needed to improve my flexibility.  All welds are not straight from left to right.

Sample 27 is Al bead on plate.  The bead that runs down the edge has two holes that correspond to the times that I needed to advance the filler rod.  My technique is to advance the rod as my hand moves back and then introduce the filler by moving my hand into the weld.  A better technique is to hold your hand steady and advance the rod into the weld.  This is something I will need to practice.

Front                Back (photo omitted by popular demand)

Sample of yours truly practicing stainless steel filler rod advancement in the hotel room.  For those of you needing all the details the rod is 309L.  Note the handy dandy genuine simulated liquid cooled torch.

I stopped by K-Mart and picked up a pair of 3.25 diopter reading glasses Saturday night and tried them out on Sunday.  They worked great.  Now I need to find a 3.25 magnifier for my welding helmet.  Sunday we worked in the lab from 8:00 AM to 1:00PM and skipped lunch so we could get out at 1:00 rather than 2:00.  In that five hours I worked on my Aluminum and Stainless skills.  

Final                    Tack up of second (right) tube

Sample 29 was joining stainless steel tube.  I burned two holes in the first (left) tube.  Tony advised that I start the tack away from the edge to prevent the hole problem.  The tack up shows my success with this technique.  Four tack welds and no edge holes.  I welded around the tube in short arcs being careful about my torch angle to the work.  The work is not great looking however it is very serviceable.  The right tube in the final picture above shows the results.

A        B        C        D        E

Sample 30A shows an aluminum box.  Sample 30B is the tack welds of the four sides into two elbows.  Sample 30C shows the elbows being held up to be welded.  Sample 30D shows the change from 1/16" to 1/8" filler rod.  This weld was consuming filler much faster than I could feed it in so the joints were getting much too hot waiting on me to advance the filler rod.  Sample 30E shows the completed box.  The welds on this sample tended to use much too much filler.  This is the result of being too timid on bringing up the heat in the beginning.  With aluminum you need to put in a great deal of heat in the beginning because it is such a good conductor of heat that it bleeds the heat away from the weld area.  Once you get the weld puddle moving you can back down on the current to the minimum current required to continue the puddle flow.

A            B            C

Sample 31A shows me welding up a sandwich box.   By bringing in the current much faster and using the puddle as the gage it gained much better results.  I ran out of time so I gave up on making the top.  That will be a project for another day.  The weld quality on this box is much superior to the previous one.  You can see dab and move technique in most of the welds.

A            B

Sample 32 was my last project.  A stainless steel box welded out of 1" x 4" plate.  I only had 30 minutes to complete the box so I tacked it up and left the final welding to be done at home.

The Class

Here's a photo gallery of the class in progress.    (click photo to enlarge)

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