I stopped by my welder's house on the way home from work. He had two pots completed & was working on the third. I'm glad I did; because I had no idea of how TIG welding differs from wire feed or stick. I came away with a whole lot more respect for anyone who is a TIG welder.
In short he welded from the outside of the kettle while purging the inside of the kettle with Argon.
He used my false bottom & some cardboard from an empty case of beer to seal the lower portion of the kettle so he didn't have to purge the whole 15 gallon volume of the kettle.
He also welded the fitting flush to the inside of the kettle for sanitary reasons & also to allow me to use the original false bottoms for those brew days when propane will be used
He explained how important it is to get the weld to go thru to the inside. The Argon purge helps the weld pattern or "weave" on the inside to become smooth instead of like broccoli or sugar. It is critical that there are no pinholes or gaps for bacteria to gather. He inspects his weld with a mirror & found a pinhole so wouldn't release the third kettle until he has a chance to tweak it a bit more tomorrow
The thinner kettle & the thicker fitting presented a challenge. He told me that if he had to do it again he would have preferred the hole size in the kettle to be the same as the inside diameter of the fitting. He would have then "tapered" the outer edge of the fitting so the thickness of the contact point was thinner for better heat control. Since I punched all three kettles there was no going back. Looks pretty darn good to me...:rockin:
I'll pick up the third pot tomorrow & start mocking things up for chord length & such. Dave at "High Gravity" is building me two controllers & sending three unwired heating elements. I've decided to go with one 5500W element for the HLT, one 4500W element for the mash, & one 4500W element for the boil kettle. More later...