Updated: Dec 23, 2020
I don't know, but we're praying for it...
I had a fun repair come into the shop a few weeks ago. One of my repeat customers threw a challenge at me. He had a very nice patio umbrella that got caught in some high wind. It blew out of its stand and crashed into a retaining wall, fracturing one of the internal trusses and bending another. He didn't want to have to buy a new one, but wasn't sure if the damage was repairable.
Here are some pictures of the damaged frame members:
My first thought was that I could carefully straighten the bent piece and "splint" the broken one with some aluminum angle bracket. I didn't hang onto that idea very long because the existing aluminum was very thin (about 0.043" or 1.1mm). I didn't think a splint would be sufficiently rigid enough for long-term reliability. I thought the holes I'd need to drill in the aluminum to mount the splints would weaken it too much. I also felt that the bent one would have been weakened enough that it probably wouldn't hold up to normal stresses.
I knew that if I could source the rectangular aluminum tube stock, it would be fairly trivial to fabricate a couple of new trusses. I discovered that the umbrella assembly came apart at the top with just four screws. The joints between the frame members were riveted, but the rivets were made of aluminum and would be easy to drill out.
After exhaustive internet searches and calls to local metal supply companies, I couldn't find an exact replacement. I was looking for stock that was 0.50" x 0.75" (12.7mm x 19mm) with a wall thickness of about 0.043" (1.1mm). The closest I could come was 0.50" x 1.00" (12.7mm x 25.4mm) with a 0.125" (3.18mm) thickness. Overkill in terms of strength, but sometimes you gotta run what you brung.
My main concern was the long dimension (1.00" or 2.54mm). I realized that the thicker bar would conflict with the cap at the top of the umbrella. I was reasonably sure that I could cut a small notch in the plastic cover. So, I cut a piece of wood that matched the dimensions of the available stock and mocked it up. It worked!
So, I ordered a couple 60" (1.54m) lengths of the stock (each truss was 54" or 1.37m in length). Once I received them, I cut them to length and smoothed the rough edges with a file and some 200 grit sandpaper. I used the old trusses as templates to locate the holes that I needed to drill, then assembled the trusses using stainless steel machine screws, flat washers and self-locking nuts in place of the rivets.
Here's what the mocked-up assembly looked like:
After test-fitting everything as shown above, I disassembled the trusses so I could paint them. I found some black matte-finish spray paint (Rustoleum 300607 Matte Hammered Black) that closely matched the original paint. I scuffed the new trusses with 200 grit sandpaper and cleaned them with acetone, then applied the paint. They turned out great!
I reassembled everything and delivered the good-as-new umbrella to a very happy customer.
What can I fix for you?