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Discussion Starter · #1 ·
Just wondering what tech will want to see with a Moly bar. Being that it is only .083" wall tube, one tig pass without filler would do the trick. Does tech like to see reinforcement (a second pass for a cap) on the joint?

Kind of an off the wall question, just wondering how close they look. I'll more than likely put two passes on it anyways. I haven't built a car for the strip before. This is an 8 pt bar, car probably no faster than 11 sec.

Tom
 

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The guy who inspected mine said he would never pass a car with more than one layer. They also don't want it painted. You can paint it after the inspection. When I bought my car it had a full cage already in it and when I went to get it inspected it did not pass. Some of the bars were the wrong size and the welds were done poorly. I cut that cage out and had it done over and it passed with no problem. I had it inspected after the drag season and the NHRA inspector came to my house. He lived in the next town over. I remember it cost about $200-250 for the home visit. Good luck!
 

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Discussion Starter · #3 ·
Thank you very much. I'm glad I asked. I would have done two. I never really payed attention but noticed last summer that a moly bar on a car running at the track had one pass also.

Tom
 

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yeah, they only want one pass. no sanding no grinding... im going to say they want one pass with filler. i have a friend that has a chassis shop and i did a little cro mo at his place, not very much, but as far as i know you always use filler on a roll bar. i know if you try to put a big wompin hot pass in it, it will more than likely crack. ive seen roll bars stickwelded with 6013 and the cars were at the track running thier balls off. i doubt the normal sunday tech guy will really know the difference, as long as the weld is smooth and uniform. if you are really planning on just running high 10's to 11's. i really dont thnk you have to worry as you only need your normal saftey gear and the tech inspection before you race, as far as i know you dont need any type of chassis certification until you really start moving. i think under 10.0.
 

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Discussion Starter · #7 ·
AAOUTLAW said:
Don't tig .083 without filler rod.GEEEEEEEEEEEEZZZZZZZZZZZZ
Thanks everyone. I will use a filler. A reason I brought this up is we tig thinwall stainless pressure pipe all the time at work and an 1.5" pipe with .083 wall is going to get no gap and very little filler if any to make the weld. I just got it through my head that this is a fillet not pressure pipe.

Thanks jamesdart.

Tom
 

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Discussion Starter · #9 ·
AA-slingshot said:
you do need filler.....but which one?? **(*) **(*) **(*)
We use ER-80s on pressure pipe. If you are interested, I am holding a peice of 1.5 stainless tubing capable of passing a destructive test and no filler has been used. My turn **(*)

Tom
 

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Discussion Starter · #13 ·
I haven't gone to the site, but i assume thatyou are referring to the strength of the rod. A moly weldment is never as strong as the parent tube / pipe. We only use Moly pipe for extreme pressure steam piping due to its low coefficent of expansion over carbon steel for example.

How did I do? fullmoon

tom
 

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I've used ER- 70 with good results. Apparently it's less likely to crack than ER-80 and because the weld is thicker than the tube, there is no loss in strenght, apparently.

Tim

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i know what filler to use ;D slingshot knows what filler to use ;D...................aaaaaaaaaaaand weeee aint tellin fullmoon
 

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Discussion Starter · #20 ·
You're right sue, JB is fairly technical. I recommend starting out with Super Glue. The jell tends to be more forgiving at filling large gaps than the original formula :eek:

Here's an example of a 316ss 1.5" O.D. x 0.075" wall weld made without use of a filler rod. If you want I can post a picture of a foot pedal. Let me know. ;D



Tom
 
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