evfreek Posted May 19 Hi. Using the technique I mentioned earlier, I was able to successfully weld a broken cast iron C-clamp. I used a small oxy propane torch and cast iron welding flux. The weld had no porosity. Oxy propane has a porosity problem with steel welding due to the heat being in the wrong part of the flame. But, there was a problem. EBay had 3/8" cast iron welding rod, but I was afraid it was too thick. That turned out to be correct. I found a cracked piece of cast iron pipe and hacksaw a 3/8 x1/4" rod from it. I couldn't get enough heat, so I ended up cutting it in half lengthwise and welding the two pieces together. This took a long time, but it worked great. I found out that piston rings aren't cheap! Hopefully I'll find some at a garage sale. Quote Share this post Link to post Share on other sites
Irondragon Forge & Clay Posted May 19 If you know any mechanics that overhaul engines, see if they will save the used piston rings for you. At one time I had about 20 pounds of them for free. Quote Share this post Link to post Share on other sites
evfreek Posted May 20 Wow. I overhauled an engine once, and just threw the old ones away. I don't have any friends who do this now, since the engines last so much longer. For now, I'm going to just use old pieces. But I will forge a tiny pair of tongs to feed the pieces since pliers don't work well and aren't safe. Quote Share this post Link to post Share on other sites
Anachronist58 Posted May 20 Where DID I put those old rings? Quote Share this post Link to post Share on other sites
ThomasPowers Posted May 20 Got an automotive program at a high school or VoTech? Quote Share this post Link to post Share on other sites
evfreek Posted June 2 I looked extensively at Craigslist and EBay, but only found expensive new rings. I've never seen these at garage sales. Then, at a storage unit clean out, I finally succeeded. They were seized and brittle, but I managed to break a couple out. They spark tested as cast iron, so that's good. They seemed a little hard, but a file will cut them. The third ring groove had a wavy thing and two thin springy rings which sparked as spring steel. I guess I can repurpose the pistons as pistonium as soon as I get a foundry setup working. Thank you for the suggestions. I'll report back on how well they work, but I have seen good results reported from the web. Quote Share this post Link to post Share on other sites
