Cabin Heat Valve

Today I stopped by to visit my new friend Alan Waters. I asked him to weld some flanges onto my adapted cabin heat box, but instead he offered for me to come over and do it myself. This was an awesome opportunity that I didn’t want to miss! This box needed an additional hole and flange, and one of the existing flanges was too large. My plan was to cut kerfs into the flange so that I could shrink it down around a 2″ tube, but Alan suggested that we just cut the old one off with his milling machine.

Carburetor/Cabin Heat Box

Removing the old flange

The Bridgeport milling machine was like an etch-a-sketch, with one wheel to control left-right and one to control front-back.
Bridgeport milling machine

After milling

Alan was showing me how to use his lathe, so we trimmed the ends of the tube flanges.
The Lathe

We used the lathe to make the tube end square. It wasn't really necessary, but it was fun.

With the pieces ready to weld, he set me up with some practice parts and his TIG machine. I hadn’t used a TIG machine on aluminum since I became comfortable with steel welding, but it is much easier than I remember. Well, until I touched the electrode to the aluminum, then it made a mess. Alan was very patient and talked me through several practice beads.
Aluminum TIG Welding

Here is a practice bead.

Aluminum Welding Practice

The top bead isn't mine, but you can see on the far left where I touched the tungsten to the aluminum.

Another Practice Bead

Here's Another Practice Bead

With a few hours of practice, I tried welding the part. I got distracted at one point and burned a big hole in the flange.
Mouse Hole

I was doing pretty well until I burned a hole in it. Alan fixed it for me.

Ready To Install

Now it's ready to install. We used the milling machine to remove some of the material around the hole that I made.

In the end the box is just what I need, and best of all, I learned a lot from Alan. I was also able to make a quick trip to the hangar in the afternoon. The picture below shows why I’d rather not use the crimp-on terminals that I got from the welding place.
Sloppy fit welding cable

I thought that the crimp-on end left too much space around the conductor.

While I was playing with those, Tabitha did a bit more filing on the window frame areas.