This is the thread I was going to post before the electricity to my engine panel went dead. Now that the electricity to my engine panel has been restored via the "reset" button, I can finally post a blurb on my new DIY exhaust riser!
I made it out of black pipe and sprayed it with silver Rustoleum high heat BBQ paint like so many of you before me.
I used 1 1/4" black pipe and 2" x 15' of titanium heat wrap to prevent the noxious smoke that comes from galvanized pipe and fiberglass heat wrap during the initial break-in period. I am happy to report that no smoke came off my exhaust whatsoever. BTW, the titanium heat wrap is not made out of titanium, but it has a beautiful titanium-like sheen, which is how it gets its name. The wrap is actually made out of pulverized volcanic rock...how cool is that?!
I used hose clamps instead of those little heat wrap straps they sell, as hose clamps seemed more secure and are reusable.
For pipe dope I used Real-Tuff with Teflon as per Maine Sail's suggestion. I really caked it into all male and female threads to prevent exhaust fumes from escaping. So far no exhaust fumes have escaped whatsoever.
I included a union on my riser because I read some who claim it makes adjustment/alignment easier. Mine aligned pretty much perfectly, so I guess they were right.
I reused the exhaust flange and and studs, thus saving myself $90 and $30 respectively (not including shipping). I just took all the rust off of them with a wire wheel and they were good to go. As per advice I received reading this site, I was very careful NOT to scratch the mating surface of the exhaust flange while cleaning it up.
I bought a blue hump hose from Catalina Direct in the hopes of reducing vibration to, and thus extending the life of, my aqualift.
I bought two exhaust flange gaskets as per Stu Jackson's advice. As it turns out I didn't need it, so now I have a spare just in case (or for next time around). Also, I put the gasket on dry because I learned that's how they do it at the factory.
I had to make several trips to various pipe stores because nobody had exactly what I needed. The upshot of course is now I know where all the local pipe stores are located!
I would say the hardest part of the job was removing the exhaust flange from the nipple that connected it to the exhaust riser. It required a vice, lots of rust loosening penetrating spray, a large pipe wrench, and a long pipe to fit over the handle of the pipe wrench to give me leverage. This step alone took hours before the exhaust flange finally budged and began to slowly turn off the nipple it was frozen to. I'm not sure that I would have kept at it until the flange broke free if I had not read accounts of other C36IA members relating similar struggles to get that sucker to break free!
[B]QUESTION: When I hooked up the hoses from the riser injector nipple and heat exchanger to the anti-siphon in the cockpit locker, I couldn't remember which hose went on each side of the anti-siphon. My question is does it even matter which side of the anti-siphon they go on, or is it possible that I put them on wrong? [/B]
PS Almost forgot, I spent about $70.00 on black pipe. The stainless steel prefabricated M-35 exhaust at Catalina Direct costs $400, not including shipping. Big savings!
1993 Catalina 36 Hull #1259
Newport Beach, California