So, if it was YOU welding this, what would you do?
OK Folks, please take a look at the pictures below:
http://i985.photobucket.com/albums/a...1/DSCF2944.jpg
http://i985.photobucket.com/albums/a...1/DSCF2942.jpg
http://i985.photobucket.com/albums/a...1/DSCF2943.jpg
This is a trailer hitch receiver tube that I am going to weld onto the front of my car trailer, facing backward, in the area between the hitch and the bed (near where the jack is). It will be used to mount my 4,000 lb winch when needed, allowing me to dismount the winch when not needed by simply pulling a pin and unplugging the power cable. All of the material is 1/4" mild steel, and I have cleaned off the mill scale and other crud. So, if it was YOU welding these joints, what would your setup be? I can lay the piece flat, so puddle control will not be an issue. My plan is to use 1/8" thoriated, 7lpm, #6 or 7 cup, and 1/8" er70s6 filler. Max pedal amps set at 220, and a little preflow.
This will need to have the strength to hold while pulling with the 4,000 lb winch and probably a pulley setup, which doubles pulling power. If I find that the winch lacks the power that I need, I already have a line on a 9,000 lb winch that I will use in the same setup, preferably without any modification. Once I have these welds finished,I will use 2" x 1/4" flat stock to put endcaps on the plates for added rigidity, and, because I can't fit the trailer in the shop, I will have to stick weld the finished assembly to the trailer outside. For that, I plan on using 1/8" 7018, based on the little bit of stick welding that I've done with my 250EX, I have no doubt that it will be up to the task.
So the question remains, if it was YOU, how would you approach this?
Gee Whiz, I thought I posted this in the TIG section.
Thank you Gunner, Jake, and whoever else got the point that I am TIG welding this part of the assembly. When I attach it to the trailer, I will open up the brand new 5 lb. can of ESAB AtomArc 7018 1/8" rod that I have, set the 250EX @ 130 amps, middle of the road for arc force, and go to town. I would guess that a single pass will suffice. The reason that I'm TIG welding this part is the same reason that a dog licks his balls, because he can!:D. But seriously, I have been stick welding for 37 of my 46 years on this planet (no typo), but TIG welding for only a little over a year, with less than 6 hours total in DC mode. For that reason, plus the fact that TIG welding is COOL, this part is being TIG welded. The only reason that I'm not TIG welding to the trailer itself is because I can't reach it, and according to Murphy's law, by the time I build an extension cord, drag my T size argon tank out close enough, and get ready, the winds will be 1mph short of hurricane force. So stick it will be.
So, anyway, I got everything ready, put a 1/8" Thoriated tungsten in with a #7 cup (I don't yet have a 1/8" gas lens), set the argon at 7lpm, Amps @ 200 max pedal, and went to town. About 4" in, I noticed 2 things. 1. Things didn't sound right. 2. The WP 20 was HOT!! Yup, I forgot to turn on the water cooler. I raced over and hit the power, praying that I wasn't about to see a flood. I was so PO'd at myself that I left the cooler running, lit a ciggy, and took a 5 minute stroll.
When I returned, I did a thorough inspection of the torch and verified that not only was it leak free, but when I pulled the return line at the cooler, coolant came blasting out the way it should. On my first TIG welder, I had a Genuine Weldcraft WP20 with the vinyl hoses, and I pulled this stunt twice before I learnt my lesson. Both times, the cable melted through the tubing all along the length of the assembly, one time even going through the return line. At the time, the LWS hit me for about $53.00 for the power cable, and another $33.00 for the return line the second time. I was pleasantly surprised that the Everlast WP20 torch assembly lived through this boo-boo and came out unscathed. So far, I will call the Everlast WP20 a GREAT buy. I will be looking for a way that the cooler automatically powers up with the welder to prevent this from happening again in the future.
This is what the first part of the weld looked like with the cooler turned off (before I discovered that I forgot to turn it on). Notice the big holes at the beginning and in the middle of the weld? what is this caused by?
http://i985.photobucket.com/albums/a...1/DSCF2948.jpg
After I got the cooler fired up, I continued with the first pass, and the same porosities kept bubbling to the surface. Penetration was excellent, and the arc was absolutely perfect. While it is true that I was filling in where the receiver tube is radiused, and the plate is square, I didn't expect this to happen.
http://i985.photobucket.com/albums/a...1/DSCF2949.jpg
I was using er70s6 1/8" filler for the first pass on both sides, and they both looked similar to the above picture. For the first pass on the other side, I cranked the ax pedal amps to 225 and turned the argon up to 8 lpm, which seemed like a LOT of gas, but also seemed to improve things. I like having the extra 25 amps, it allowed me to "cruise" down the bead at 200 or so and still have some "passing power".
Below is the first side after making a second pass. I used 1/16" filler for the second pass, as the objective was to get the porosity out, not build it up. I noticed that the puddle was MUCH easier to control, not needing to get down to the bottom of the groove. One key thing to inform those intending to try welding at these amperage levels, IT GETS HOT!!! I ended up putting on one of my stick welding gloves AND 2 TIG fingers to keep my hand from becoming fork-tender. Even then, it was at the limit of my heat/pain threshold.
http://i985.photobucket.com/albums/a...1/DSCF2953.jpg
Below is the second side after the second pass. I used the same procedure as the first side, except with a bump up on the flowmeter, and 25 more amps available at the pedal. The bead starts on the right and goes to the left. After the second pass with 1/16" filler, I still had a couple of pinholes about 2" from the left end, so I made a third pass over the last 2-3 inches of the bead, which explains why it's protruding a little more than the rest of the bead.
http://i985.photobucket.com/albums/a...1/DSCF2960.jpg
So, Now, I need feedback, explanations, and advice on what I need to do to improve my TIG welding skills. Please, feel free to comment.