Patrick Reese 40 #1 Posted October 1, 2013 Nearing time to finish up our Commando 6 Project and would like to add a stack to the exhaust rather than the stock muffler. Is there a recommended pipe type to use? Galvanized or Black pipe? My guess is the Galvanized. Also do most folks just crank in an NPT nipple without any kind of sealant? Or is there a recommended pipe sealant used.. I'm used to doing plumbing work but not on exhaust pipes.. Our hope when it's all piped up is to get some sort of chrome pipe on there with a baloney slice. Might even experiment with a straight pipe no baffle.. unless that proves to be too loud. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,029 #2 Posted October 1, 2013 Long gone now but 40 years a go a local well established small engine shop used to remove the muffler from the engine every spring at service time. They used a black graphite grease on wire brushed threads. The conduit nut used to lock the pipe in place was also removed and cleaned. They then run the nut up the lubed threads as far as it would go. They turned the pipe fitting it as far as it would go by hand. Then back it off 1/2 turn and used the lock nut to lock the fitting in place the 1/2 turn out. Never seen one seized using this method. Do a search for Gravely 18543 for a good light weight muffler that makes the bend for you so just add a straight pipe. Garry Share this post Link to post Share on other sites
SousaKerry 501 #3 Posted October 1, 2013 Use black iron pipe(ok it's steel but the name never died) Galvanized pipe can give off a lot of nasty fumes when it gets hot. If you want it silver use header paint. I do use the conduit nut but have never used anything on the threads. Share this post Link to post Share on other sites
Patrick Reese 40 #4 Posted October 1, 2013 Thanks for the gravely muffler tip and the tip on lubing up the nipple with black graphite grease.. also will be doing black pipe. I didn't give much thought to the galvanized chemical fumes.. I would imagine they would cook off in short order buy why bother. Share this post Link to post Share on other sites
Ed Kennell 37,998 #5 Posted October 1, 2013 Here is a stack I made from an old chrome bed rail from a junkyard pick-up. I actually got 4 pieces with this bend. Just cut to length and weld in the correct size NPT pipe fitting . Share this post Link to post Share on other sites
953 nut 55,021 #6 Posted October 3, 2013 Another option for a low cost sharp looking pipe to sleve over the one inch black iron is a stainless steel bathroom grab bar, just cut the flange off one end and the bend off the other and you have it! 1 Share this post Link to post Share on other sites
C-101plowerpower 1,605 #7 Posted October 3, 2013 (edited) i used a piece of vacuum cleaner pipe, cut 4 slots in one end and clamped it on. Koen Edited October 3, 2013 by C-101plowerpower Share this post Link to post Share on other sites
AMC RULES 37,125 #8 Posted October 3, 2013 (edited) I've been hitting the new black pipe exhaust on my RJ with some red scotch brite I cut into strips. When you think of it, take a strip, wrap it around the pipe. Then using both hands, push pull the strip using moderate tension, back and forth, from a few different angles, left to right, to ensure your hitting all sides of the pipe. Maybe takes a whole minute to complete, looks a whole lot better than the rust that black pipe turns into once the black burns off. Check it now and then...once you see it bluing up...take a minute and just hit it again. I just popped the heat shield off to show you this process... notice the bluing starting to accumulate, it's been about two weeks since the last time I did this. Edited October 3, 2013 by AMC RULES 1 Share this post Link to post Share on other sites
tarcoleo 119 #9 Posted October 3, 2013 On the other hand, you could just use stainless pipe and fittings for a lasting solution. Tom Share this post Link to post Share on other sites
AMC RULES 37,125 #10 Posted October 3, 2013 Just working what I had. Share this post Link to post Share on other sites
Patrick Reese 40 #11 Posted October 3, 2013 Craig I see you chose not to use a conduit nut?.. any problems with pipes loosening? Also what if you were to properly paint the black pipe with high heat primer and black paint.? Share this post Link to post Share on other sites
AMC RULES 37,125 #12 Posted October 3, 2013 Nothing loosening to date Patrick. The high heat paint is an option, just using the scotch brites to keep the new pipe clean until I decide what I'm doing. Share this post Link to post Share on other sites
Hydro 131 #13 Posted October 26, 2013 Reminds me of gun bluing. Nothing wrong with that finish. Share this post Link to post Share on other sites
Patrick Reese 40 #14 Posted October 27, 2013 We opted for what I call a "ground pounder" exhaust. We're going with galvanized pipe.. a two inch nipple with a 90 degree elbow pointing down at a 45 to which we are going to attach the muffler. It will point down at the ground at a 45.. pictures will be posted on our restoration thread for Commando 6. Thanks for the tips. Share this post Link to post Share on other sites
Jake Kuhn 1,554 #15 Posted October 27, 2013 Could always go with a polished stainless stack. But I'll admit.....there not cheap. Share this post Link to post Share on other sites