TIG welding Moly ?

[Mr Froggy]

I'm considering building a FED.  I can fabricate, MIG and Stick good but I'm a rookie with a TIG.   I have a friend whos been welding for 30+ years and the last 20 years he's been at a food plant TIG welding (mostly stainless).  My thought is that I could build the chassis and tach it good with a TIG and have him finish weld it.  I haven't talked to him yet but was wondering if the experience he has would be good for welding Moly?    Whats your thoughts?  Thanks.

[dreracecar]

Its close, but it not like building kitchen stations, There is a welding sequence to keep thing from moving around and you can not grind and polish the welds afterwords.

[Mr Froggy]

No kitchen stations......All industrial.   I have the SFI book and realize the no grinding/polishing rules.  Its that way on mild steel also, no matter the welding process.   If he's not comfortable doing it I'll go to plan B.

[rooman]

There is no reason that you can't build a car yourself. Start by looking at guys running consistent, reliable cars for a guide to what works chassis wise, and as you already have a copy of the appropriate SFI spec you have that part of it covered. Make sure that you are comfortable in the car as to shoulder hoop/seat to rear end relationship and wear your firesuit when positioning controls.
 As Bruce notes, you can't start at one end and simply weld the tube junctions as you get to them but a bit of common sense goes a long way with everything in this world. If your guy is doing industrial standard work has should have no issues with 4130. Again, do a bit of research on welding forums etc and you should have no problems.

Roo

[Mr Froggy]

I'll give my comman sense a try!   

I would first build a good,solid, level Jig.  With the tubing fitted,clamped and tacked in the Jig it seems to me to start from the center of the chassis and work your way to the front and rear, back and forth, side to side. 

When welding one tube to another, lets say a comman T, I would start at 6 oclock and weld around to 9 oclock.  Then start at 12 oclock and weld to 3 oclock.  Then from 9 to 12 and finish with 3 to 6.

My thinking is to not concentrate alot of heat in any one place and start in the middle and work your way out while switching back and forth to keep it even.   

I know theres alot more to it but thats where I would start.  Please tell me where I'm going wrong.  I'm here to learn!

[dreracecar]

There are books on welding tubular airframes. I would start at the library or online

[Mr Froggy]

OK!   Thanks Bruce!   Like I said,  I want to Learn!   

Where did you learn?   Did you have a Mentor or by trial and error?  Or both?

[fuel749]

Good tube fitting is as important as anything here. Don't be afraid to throw away a poorly fitted tube and start again. Every chassis builder generates scrap from time to time.

[dreracecar]

My shop was next to Don Long for 20 years, might have picked up a couple things during that time period.

An interesting tidbit of info: When completely welding a 300" top fuel car, the wheelbase shrinks .250"

[We Bad]

"Construction of Tubular Steel Fuselages" by Dave Russo.  Published by Aircraft Technical Book Co.
ISBN 978-0-9774896-0-2

This is a good place to start reading.

[Mr Froggy]

Bruce,  Being next to Don Long for 20 years?  What more needs to be said.   

We Bad,   Yes, after Bruce suggested some reading I found the website you mentioned and found that book right away!

Thanks for the input guys!!

[masracingtd1167]

Welding tips and tricks. com is also a great place to learn about tig welding