After the drama of a few weeks ago, I finally get news about my secondary mirror assembly: the repairs are done, and pleasantly affordable. I go on to order the missing bolts for the mounting prism and a replacement for the damaged knurled-head screw. Two days later I get something in the mail. Without the screw. So I try to bore out the remains of the original strut’s thread from the knurled head screw, without success. That bit is stuck so incredibly tightly that I probably will have to re-order the screw.

Meanwhile, I give throught to the best method to get the ‘scope’s tube back into shape. It consists of pretty thick sheet metal, which is thickly coated in black paint; glossy on the outside and matte on the inside, the better to absorb stray light. I have blackboard lacquer, which I normally use to cover up pin gaps in my solar filters. That should be usable for the inside. On the outside, I am going to use a well-known branded rustproofing product, of which I have a bit left over from a different project. The tube is made of aluminium, so won’t rust, but the paint sticks well and looks good. The dent in the tube I am going to carefully beat out using a small hammer and an anvil so as not to thin out the material unnecessarily. That would reduce the diameter of the hole the knurled head screw is supposed to fit in, and I do not wish to add another round of workshop hijinks to my to-do list than necessary already.

Nice to have planned all that… now, I only have to find the time to actually do the repairs.