storage boxes

Welding: Frames

In my last post, I mentioned that I was starting a new welding class. This time, after a friend's suggestion, I chose to take it at PNCA, a small art college in Portland with continuing education classes. I was hoping for something that was a mix of open studio and also a guided design process which I felt was lacking at the classes I took at a different place last year. The eight week class meets weekly for three hour sessions and then we have access to the space one other weeknight and on the weekend. The class size is ten, which I feel is too big when there is just one instructor, one helper and all of us working on very different projects. I think a class size of about five would be great for faster feedback and help and then time to work independently. The instructor, Chris Gander, is a long time teacher and metal sculpture artist so he is able to help us tackle whatever projects we can think of. What I have learned is that it is best to have a project in mind when taking a welding class because while you can learn to weld with scraps, it is more rewarding to go home with something useful. Also, the actual act of welding is just a small part of working with metal which includes cleaning, measuring, marking, cutting, grinding and finishing. MIG welds don't have to look pretty since you are likely to grind them down flush in order to finish. Even beginners can make strong welds relatively easily. Welding is a somewhat difficult thing to teach because everyone is going to weld at their own speed and style (pushing or pulling, angle, etc.) and hands on doing it is the best way to learn. Ok, now on to my projects.

I had two main projects in mind when I signed up for the class: my interior sliding barn door and a couple of storage cubes. I planned to weld frames for both projects. I then planned to use an extra piece of the reclaimed corrugated steel leftover from my siding to infill the door frame and wood to infill the storage cube frames. Chris advised me to use 1 1/2" x 1/8" think angle for all of my frames since it was the best combination of rigidity and weight. I went to The Steel Yard to buy all of my steel. They were generally quite helpful and usually gave me a student discount.

Once I had all of the materials back in the studio, I started by making the cuts from my plans with the metal chop saw and bandsaw. The chop saw is loud and makes a lot of sparks but it cuts much quicker than the band saw, though the band saw can be more accurate and also takes away less material. I made all of the 90 degree cuts on the chop saw and the 45 degree cuts on the bandsaw. Once I cut all of the pieces, I used an angle grinder with 120 grit sandpaper to sand off the burrs on the ends.
To assemble the frames, I used a couple of jigs that a friend helped me make to line up the corners and clamp into place. I tack welded the face frames together and then for the cubes, I tacked the cross pieces to one face and then tacked on the other face. I used squares as guides and a tape measure to check my diagonals for square. 
It's best to tack everything together before making the full welds so you can more easily make adjustments by breaking the tack with a cutoff wheel. The metal heats up around the welds and can warp the frame out of alignment so a good strategy is to weld a line on one spot and then move to the other side of the frame and weld a line there, moving around the frame until all spots are welded. Note, most of the time a single weld on a joint is sufficient but for aesthetics it can look better to weld the entire joint because when ground down and finished, that seam disappears.
Stay tuned for my next post about the infill panels, finishing and installing!