RebekahsZ Posted March 2, 2013 Share Posted March 2, 2013 Not finished yet, but I thought I'd share a few things I've learned building my exhaust. Marking tubing: cutting a straight line can be difficult. Wrapping tape around the tube doesn't work (tape stretched). A piece of old seatbelt works great. For cuts in the middle of a bend: I tie a piece of string really tight with a surgeons knot. A string wants to find the shortest path between two points. You still may need to adjust the string a bit by eye before marking with a sharpie. Cutting tubing: I tried using both a band saw and miter saw but had a hard time holding the piece firmly. A 10-onch fiber blade on a chop saw jas flex and wanders more than i would have expected. A band saw blade has a "burr" where the blade is welded together-that but likes to yank the piece out of your grip and destroy your piece. My best results have been obtained by putting the tube in a vice and cutting with a thin fiber cutoff wheel on a cutoff saw or angle grinder. Rotate the piece as you go to follow the line marked with a sharpie. Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted March 2, 2013 Share Posted March 2, 2013 (edited) I bought the Ridgid 65S tubing cutter. This thing cuts my 304 stainless tubing with no problem and works on tubing from 1/4" all the way to 2.625". It comes with two cutting wheels, and I bought four extra wheels in case the stainless tubing dulled the wheels. After more than 100 cuts, I am still on the first wheel. http://www.ridgid.com/Tools/65S-Tubing-Cutter/EN/index.htm Edited March 2, 2013 by 74_5.0L_Z Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 2, 2013 Author Share Posted March 2, 2013 That would be awesome for up to 2.5" and one could use it for their coil-over convestion too! Can you use it in the middle of a 90-degree bend to make a little pie-cut section? That's where I really have trouble keeping it straight.... Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted March 2, 2013 Share Posted March 2, 2013 I don't know if it would cut deep enough to go through the strut tube, but it might. I used it to cut all of the pieces of my mandrel bends for making my headers. Starting with 18 ga 1.75" J-Bends bent on a 2.5" radius, I was able to make many cuts in the bend radius. As you probably know, all mandrel bent tubing is oval in the bent section (even the highest quality bends). So it is a bit more challenging to make the cuts in the bent sections, but I was able to use the Ridgid cutter to make all of my cuts. The key I found was to position the tube so that the section to be cut was straight up and down, and then align the cutting wheel on the mark with the cutter adjusted loosely on the tube hanging straight up and down under the influence of gravity. After alignment, slightly tighten the wheel against the tube and then slowly rotate the cutter while adjusting the wheel to account for the ovality in the bend. Make several back and forth passes to verify that the cutter is cutting in the plane and not creating threads. After alignment of the cut is verified start making full passes while slowly tightening the wheel into the tube. The cutter will leave a razor sharp edge on the inside of the tube. So deburr it immediately and be careful. Here is a picture of my passenger side header that I fabricated using this cutter. The picture shows the header mocked up on a junk engine and ready for welding. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 2, 2013 Author Share Posted March 2, 2013 I like your "spot welds" with hose clamps! With all the drip-thru of welding rod, I'm afraid my exhaust system is really more "exhaust routing" than any kind of performance system. I'm gonna try to cleanout the inside of the tubes as I go on the fender cutout section of my system so perhaps it won't be more restrictive than a squash-type tubing bender. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 5, 2013 Share Posted March 5, 2013 FYI... I make as straight a cut as I can using a band saw and make the cut about 1/16" longer then I need. Then I use a 14" disc sander with a machined table/vise to square the cut end. You can do the same using a hand sander/grinder with a 60 grit flap wheel and a T square. Quote Link to comment Share on other sites More sharing options...
madkaw Posted March 5, 2013 Share Posted March 5, 2013 I used a hose clamp as a guide for marking my pipe for a cut. And like John I cut the pipe a bit long so I could clean up the edge and perfect the angle with my 12" circular table sander. The sander was the best investment and I bought a cheap HF version. At 75lbs it is very stable and hasnt given me any issues. The mock up for my duals was done with PVC pipe from Lowes. It gave me an idea of how things would fit Quote Link to comment Share on other sites More sharing options...
madkaw Posted March 5, 2013 Share Posted March 5, 2013 I'll add that the pipe ( mild steel) should be degreased before welding. It took me a while to figure out that the small amount of oil residue on the inside of the pipe was messing with my welds Quote Link to comment Share on other sites More sharing options...
johnc Posted March 5, 2013 Share Posted March 5, 2013 ^ Agreed. All tubing should be cleaned inside and out and deburred. Ideally you tack weld the joint in four spots 90 degrees apart and run a continuous bead from tack to tack. But, that's hard to do with larger OD tubing. Quote Link to comment Share on other sites More sharing options...
yellowoctupus Posted March 9, 2013 Share Posted March 9, 2013 FYI... I make as straight a cut as I can using a band saw and make the cut about 1/16" longer then I need. Then I use a 14" disc sander with a machined table/vise to square the cut end. You can do the same using a hand sander/grinder with a 60 grit flap wheel and a T square. +1 I just started using my disc/belt sander for the last set of headers I had to modify and it worked fantastic. I used to use a hand 4" angle grinder and it was pretty difficult to get gaps less than 1/8" consistently. I don't use a band saw though, I actually prefer to use a hack saw with a high quality 18t blade. It cuts fast with a good blade and it's a lot easier to keep your lines straight because of the cutting speed. Maybe I just got too excited using a porta band the one time I tried header work with one, but I had a lot of post cut cleanup compared to hand cutting. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 9, 2013 Author Share Posted March 9, 2013 A table-top belt/band sander is definitely on my wish list. Any reason not to buy a cheap one like they have at Lowes for around $120? This will get sporadic use (damn, I'm done with the exhaust). Also, do you need special sand paper for it since I'm mostly doing metal fab and some around the house wood stuff? Do you pretty much just leave 60 grit on it most of the time? (Can I use this forum as fabrication 101)? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 9, 2013 Share Posted March 9, 2013 No. No. Yes. You already are. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 9, 2013 Author Share Posted March 9, 2013 Thanks, thanks, thanks, and thanks! Quote Link to comment Share on other sites More sharing options...
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