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  1. #1
    Join Date
    Jun 2006
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    rochester, NY
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    Default tips for custom headers

    i gotta question for any of you who have made there own headers or have seen it done. i wanted to know if you guys have any tips to make it easier or cleaner. i can tig good beads, laps, and t joints, but i tried welding an extra piece of exhaust i had lyring around to a flat piece of steel, and well it wasnt so great. i had to keep turning the plate and stopping my beads, of the 2 or so inch diameter pipe, ide say theres a good 1/2 inch of decent bead. how do you guys do it and make it look good?

    67 Camaro SS 383 this winter. squeezin by summer.
    97 camaro Z28 30th anniversary bolt ons.


  2. #2
    Join Date
    Nov 2003
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    Paradise, Ca
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    how do you guys do it and make it look good?
    If you're good at other joints, then it's just a matter of practice for the most part.

    but i tried welding an extra piece of exhaust i had lyring around to a flat piece of steel,
    And that's the easy part. The tube-to-flange welds are simple. Just concentrate the arc on the flange and keep an eye on the top toe of the weld. If it starts dipping in (undercut) you know you need to do something.

    Some tips:

    For butt welds, grind your tungsten to a very sharp point. Say around 20 and don't put a flat on it. That will widen the puddle and give you better directional control. It will also lessen penetration to a slight extent.

    What size tungsten are you using? 1/16" tends to be best on the butt welds, but I'm finding that 3/32" 2% Lanthanated works well on everything. Its only fault is that it can be hard to start.

    What size filler were you using? .035" works best for most people on the butt welds, and maybe .045" on the fillets.

    If you have a pulser, use it on the butt welds. Try 50-75pps, 75% peak time and 10% background.

    Don't try to go further around the tube than is comfortable. Lots of well done starts/stops looks a lot better than long but shaky welds.

    To improve dexterity, at night when watching TV or whatever, spend 15 minutes with a 10lb dumbbell. Move it in a hap hazzard fasion...pretty hard to describe here. Roll your wrist up, down, side to side and radially. It looks stupid but it works.

    If you're building stainless headers, purging the tubes is a MUST. The picture I attached is of 2"x.065" 304 tube, butt weld with no edge prep, and purged.

    If mild steel, sand off all mill scale within 1/2" of the joint. This is not optional. And don't grind it off as it's too easy to get the tube too thin and drop through unexpectedly when welding.

    Consistent, full pen welds are a must. As much expansion and contraction as headers go through, any stress raiser is a bad bad thing.

    There's three schools of thought concerning how to weld the tubes to the flange. 1) Weld all the way around. Critics say this over constrains the tube (especially with stainless) and will create cracks over time. Proponents say it's more support for all that weight hanging off the flange. 2) Run two 1/2"-3/4" welds top and bottom. Basically the opposite arguments of #1. 3) Braze. Proponents say that brazing moves with the tube as it expands/contracts but still gives the gusset effect of an all around fillet. I like #3 but never do it simply because I have no desire to learn how to do brazing. I've allways used #2 and have good results, although #1 is done by a lot of well known header builders with good results too.

    Make yourself a fixture for cutting the U-bends. Look at the second attached picture and I'm sure you can figure out how it works.

    Do it right and form the first tube to match the profile of the port. Don't just leave it round and weld it to the outside of the flange because it's easy. You need to make a male mandrel out of wood or metal that matches the port in the flange, minus tube wall thickness. The goal is to form the end of the tube so the mandrel you made just slides into the tube the distance of however thick your flanges are, minus 1/8". That will leave you a lap weld on the inside of the flange to weld the tube to.

    There's lots more but that's all I have for tonight.
    Attached Images Attached Images    
    -Matt

    Welders: The only people that think a co-worker catching on fire is funny.

  3. #3
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    Jun 2006
    Location
    rochester, NY
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    Default

    Quote Originally Posted by Matt@Lateral Dynamics



    Some tips:

    For butt welds, grind your tungsten to a very sharp point. Say around 20 and don't put a flat on it. That will widen the puddle and give you better directional control. It will also lessen penetration to a slight extent. I think i may have been grinding my points too long.(it looks more like a sharpe pencil tip than anything)


    What size tungsten are you using? 3/32"

    What size filler were you using? .035"

    If you have a pulser, use it on the butt welds. I dont know what a pulser is

    Don't try to go further around the tube than is comfortable. Lots of well done starts/stops looks a lot better than long but shaky welds.
    ^^my responses are in bold, because i decided adding stuff in bold was esier than typing [quote][quote] a million times

    Awesome help! im definately going to do a lot more practice before i start making my own headers and using em. like you said if im gonna do em, i gotta do em right.

    and lastly the welder, and all the steel i use etc. is supplied by my school. can i get a good/decent tig welder under 2 grand? (i browsed some other posts and that seems to be about what im gonna spend) Im a college student so money isnt exactly something i have much of right now.
    67 Camaro SS 383 this winter. squeezin by summer.
    97 camaro Z28 30th anniversary bolt ons.

  4. #4
    Join Date
    Nov 2003
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    Paradise, Ca
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    For future reference, in the reply screen, you'll see a quote bubble looking thing in the grey toolbar. Click that and it'll write the quote code for you. This is a lot easier for posters after you that want to quote you. (Like me)

    For clarification, when I say to grind your tungsten at 20, that is the included angle, and is very sharp. Just 20 from having no grind at all.

    If you want to spend less than 2k then you're not going to get a pulser, but I'll explain anyway.

    The pulser does just like it sounds: pulses the amperage output. Variables are:

    PPS (pulses per second)

    Peak time - The time the arc spends at full amperage within one pulse. A percentage.

    Background amperage - The amperage output whenever the cycle is not at peak amperage. A percentage.

    So my example above would be 50-75 pulses per second. The arc would spend 75% of its time at peak amperage within one pulse cycle, and it would go down to 10% of peak amperage for the remainder of the cycle.

    Pulsers are NOT for making welds "pretty". They are for lowering overall heat input, although in some cases they can be used for autogenious (fusion) welds on stainless.
    -Matt

    Welders: The only people that think a co-worker catching on fire is funny.

  5. #5
    Join Date
    Jun 2001
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    Winter Springs, FL
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    Default

    Here are some other tips and thoughts:

    1. Be sure and cut the tubes square. Matt's band saw method is a great idea, but you can use a cold saw, or an abrasive chop saw too. A belt sander can fix a cut that's off too.

    2. I find the hardest part of making headers is to "clock" the cut tubes and weld them where I want them. Use indexing marks, or hose clamps to help.

    3. If you don't want to back purge for SS welds, try Solar Flux.

    4. When you are routing the tubes, do the hardest one first. If you are trying for equal length tubes, do the front tube as staight as possible to the collector, with the idea that rear tubes will move forward and then back to the collector to take up length.

    5. Make a collector jig (4 tubes with a ID that matches your tube OD). Cut 4 2" sections and tack them together square. Tack the resulting 4 leaf clover to a square tube with adjustment. Use this to fix the location of the collector point. As you get tubes tacked together, this plus the flange will hold them in place as you work the remaining tubes.

    6. Consider merge collectors, or at least slip on collectors. Welding up the collectors yourself without leaks is hard, plus merge collectors add hp.

    7. Do the driver's side first. It's the hardest, and it will be easier to get the passenger collector lined up with driver collector than the the other way around.

    jp
    John Parsons



    II Much Fabrication's Blog -- New products, Fabrication sequences, etc.

  6. #6
    Join Date
    Jun 2006
    Location
    rochester, NY
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    Default

    ok thats why i didnt know what one is, our welders at school dont have them.(pulser)

    and thanks matt and jp for the great tips!
    67 Camaro SS 383 this winter. squeezin by summer.
    97 camaro Z28 30th anniversary bolt ons.



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