Register now to get rid of these ads!

Tech: Exhaust fabrication tips

Discussion in 'The Hokey Ass Message Board' started by SimonSez, Jan 12, 2010.

  1. SimonSez
    Joined: Jul 1, 2001
    Posts: 1,632


    I was making some exhaust pipes the other weekend for Firefly's 34 pickup and thought I would share some of the tricks I have been using to make it go a little faster.

    The first one is to make a carboard pattern that matches the bends that you are using.


    You can then use this as a pattern in the car to decide how much of the bend you need. When it is the right angle, fold the pattern where you want to make the cut.


    Then take the folded pattern and lay it on top of your u-bend and mark it. This also has the advantage that your cuts are square across the radius of the bend.


    Once you have the bend cut and sanded for a perfect fit, the next problem is how to hold it in place while you weld it. I have tried a few different ways, but the easiest and quickest I have found is just to use masking tape!

    Clean any oil off the pipe, and tape the join tightly with masking tape. When you go around a few times, it ends up fairly rigid and the pipes are well aligned.


    Take it over to the vise and cut a short section of masking tape out for a tack weld.


    Then tack it together. The tape gets a bit hot, but still holds together.


    Then flip it over and repeat on the other side of the join. When both sides are tacked, you can remove the tape and clean off the adhesive residue.

    Heres another example, showing how you can use witness marks on the joint to make sure that it didn't move while you were taping it up. In this case, the bend was more complex and I couldn't support the joint in the vise while welding it. The tape was still tight enough to hold the two pieces together to weld together though, and it came out fine.


    Heres the finished pipe, ready to fit.

  2. SniffnPaint
    Joined: May 22, 2008
    Posts: 434


    Cool thanks for sharing.
  3. pasadenahotrod
    Joined: Feb 13, 2007
    Posts: 11,776

    from Texas

    Nice work. Thanks.
  4. harrington
    Joined: Jul 22, 2009
    Posts: 421

    from Indiana

    Great tips, these can all be applied to fabbin'up headers too.

  5. rob lee
    Joined: Jul 30, 2006
    Posts: 1,327

    rob lee
    from omaha,ne

    Thanks for the tip!
  6. redlinetoys
    Joined: May 18, 2004
    Posts: 4,301

    from Midwest

    Nice little set of tips using actual experience. Every little bit helps. Thanks for posting!
  7. Wildcat Garage
    Joined: Jul 3, 2007
    Posts: 59

    Wildcat Garage
    from Marion,NC

    I just finished my exhaust.I wish that I had known about these great tips.Thanks!
  8. fitzee
    Joined: Feb 26, 2003
    Posts: 2,862


    Some time the smallest tips are the best. I really like these.Thanks.
  9. I like your masking tape joint, real eazy and real cheap. I have used hose clamps with 3/8" holes drilled in them to tack the joint through. It works OK but the tape Idea might just work better, I'll definitely give it a try on the next set of pipes I build.

  10. retromotors
    Joined: Dec 10, 2008
    Posts: 1,045


    Great tips ... thanks for posting!:D
  11. fiftyv8
    Joined: Mar 11, 2007
    Posts: 5,157

    from CO & WA

    Great tips thanks.
  12. jonzcustomshop
    Joined: Jun 25, 2007
    Posts: 1,927


    I like it !cheap and easy!
  13. stovbolt
    Joined: Jun 14, 2006
    Posts: 61


    very usable tip thanks !!
  14. Mark H
    Joined: May 18, 2009
    Posts: 1,461

    Mark H
    from Scotland

    Wish I'd seen this before I started building my headers!:D
  15. Cshabang
    Joined: Mar 30, 2004
    Posts: 2,458


    good tips..and ill take it a tad further...make a master set of bend template and photocopy it...Id end up losing mine about 50 times while i was fabbing
  16. budrow
    Joined: Jun 25, 2009
    Posts: 115


    great tip thanks
  17. SimonSez
    Joined: Jul 1, 2001
    Posts: 1,632


    I hear ya - I made a template for a tighter bend as well but lost that before I even started !

    The template is made of cardboard, so probably easier to trace a couple of spares rather than photo-copy them.
    Joined: Mar 31, 2007
    Posts: 355


    Nice work!

    Thanks for the tips!
  19. 3onthetree
    Joined: Feb 25, 2008
    Posts: 161


    Great job!! Thanks for taking the time to post it. I recently finished fabing the exhaust for my car and truck. The template trick sounds like a good idea, I'll definitely have to keep that in mind for next time.
    I used a hose clamp snugged around the pipe, and traced around it with a sharpie marker to make my cut lines. I've also had good luck by using a few magnetic traingles to help hold the pipes in position for welding.
  20. crs36
    Joined: Feb 17, 2008
    Posts: 67

    from Alberta

    very straight forward, I like it.
  21. langy
    Joined: Apr 27, 2006
    Posts: 5,735

    Member Emeritus

    I do it the same way, I've tried the hoseclip with a hole in it as well but the tape works much better.
    I find the tape leaves glue behind so after tacking i clean the joint.
  22. banzaitoyota
    Joined: May 2, 2004
    Posts: 547


  23. onlychevrolets
    Joined: Jan 23, 2006
    Posts: 2,307


    thats how I've been doing it for close to 33's not hard, just take your time and make the joints as tight as you can. Some times I get them so tight my old ass eyes can't see them to TIG weld them. If you get them that tight no filler rod is needed you can "fuse" them together, that makes a very tiny bead. I always try for that fit.
  24. Great info! Thanks for taking the time to post and provide photo's. Much appreciated.
  25. 31-5window
    Joined: Aug 19, 2007
    Posts: 226

    from Michigan

    Great tips thanks for sharing.
  26. Royalshifter
    Joined: May 29, 2005
    Posts: 15,592

    from California

    Simple techs are very cool for a small brain like mine.
  27. zman
    Joined: Apr 2, 2001
    Posts: 16,592

    from Garner, NC

    all tech week to the top 11
  28. Correy Smith
    Joined: Jul 6, 2015
    Posts: 1

    Correy Smith

    Simon, these are some fascinating tips that you provided on doing a custom exhaust fabrication. You know, this is something that I am preparing to do for work. Well, since a client of mine wanted me to do for upcoming week.

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.