Spiders, mirrors and frame

Feb 15, 2010

After welding enough spiders for two rows of mirrors, I decided to paint them so I could start gluing the mirrors to the frame. Since the raw steel is covered with a black grease or oil, I decided to construct a sandblasting booth using some canvas tarps. First, I removed all the bolts from the spiders (they were installed so I could "adjust" them using the C-Clamp.) and put them in a large pile on a metal grate, and then blasted them with the sand. Hopefully, the sand would hit more than one spider during its flight, so it wouldn’t take as long to sandblast the ones that were in the stack. The sandblasted spiders are very light-colored, and the part that gets attached to the mirror back has a "tooth" and almost feels like sandpaper. This really works the air compressor, so I did several, and then moved to the bench to paint them using a small brush. I’m using oil based premium RUST-OLEUM enamel that is supposed to provide excellent rust prevention when applied over bare metal. (The can says that for even longer lasting protection you can use a STOPS RUST primer.) After painting and sandblasting for most of a nice 70 degree F day, I had nine of them hanging up to dry. The second day, I got six more done, when a cold front arrived with a tremendous wind that blew down my sandblasting booth, rained on my sifted sand, and sent me looking for my jacket. It froze the water in buckets on the porch. Until it warms up, I can’t do any more painting outside. The strong wind got me to thinking about what would happen if I had a completed Helios sitting out there when the cold front arrived? I wonder if the wind would break the mirrors?

Feb. 17, 2010

The first nine mirrors are glued to the spiders and ready to be mounted. 60 watts/mirror X 9 mirrors = 540 watts. Time to build on the frame so I can start cooking something! The weather forecast looks good. Ice on the grass as I type this, warming into the 60’s this afternoon.

Feb 19, 2010

Yesterday, I welded the tabs onto the 1 1/2" square tubing that will hold the spiders/mirrors in the array. This is heavy-duty tubing with 1/8" walls, and the tabs may not have been required, but putting them on is extra security. Doing 54 of anything takes time, and it took me almost all day to get these aligned and welded. I also glued three more mirrors to their spiders. Now, I will rig up a step-ladder to hold the ends of these tubes to I can run them through the drill press and drill the 54 holes to be tapped. Also, If the humidity drops a bit, I need to sand blast some more spiders so I can paint them, watch the paint dry, and then attach the mirrors.