Cage welding question need to know ASAP

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dvanhorn
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Cage welding question need to know ASAP

#1 Post by dvanhorn » Sat Jul 18, 2009 4:10 pm

I know that C.M. is supposed to be welded with a tig welder. Here is the question I have a chance to buy a car that has a 10 point C.M. cage but it has been mig welded if I grind out most (almost all) of the mig welding and get someone to tig it for me would it pass cert.? Thanks, David

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supernova
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Re: Cage welding question need to know ASAP

#2 Post by supernova » Sat Jul 18, 2009 5:54 pm

I would pass on it. Your talking about a lot of work and the cost of the tig welding. I my opinion you can find a car that doesn't have this problem. Mig welding over heats the CM and will make it brittle. In these hard times you can get a car off of some one that needs to sell cheap. Keep looking.

My 2 cents
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Re: Cage welding question need to know ASAP

#3 Post by dvanhorn » Sat Jul 18, 2009 10:06 pm

Thanks what I needed to know.

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Re: Cage welding question need to know ASAP

#4 Post by supernova » Sat Jul 18, 2009 10:10 pm

Your welcome.
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Re: Cage welding question need to know ASAP

#5 Post by wikd69 » Sat Jul 18, 2009 10:20 pm

supernova wrote:I would pass on it. Your talking about a lot of work and the cost of the tig welding. I my opinion you can find a car that doesn't have this problem. Mig welding over heats the CM and will make it brittle. In these hard times you can get a car off of some one that needs to sell cheap. Keep looking.

My 2 cents
Thats something I didn't know about chromemoly. Not that I know a lot to start with :mrgreen:
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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Re: Cage welding question need to know ASAP

#6 Post by supernova » Sat Jul 18, 2009 11:15 pm

wikd69 wrote:Thats something I didn't know about chromemoly. Not that I know a lot to start with :mrgreen:

I think your very smart-ass :smt003 :smt003 :smt003 ! :thumb: :thumb: :thumb: :thumb: :thumb:

Oh I mean I think you know alot! :smt003 :smt003 :smt003
Blackhoodmafia!!!! :mrgreen: :mrgreen:

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et: 5.28
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Re: Cage welding question need to know ASAP

#7 Post by wikd69 » Sun Jul 19, 2009 1:06 am

supernova wrote:
wikd69 wrote:Thats something I didn't know about chromemoly. Not that I know a lot to start with :mrgreen:

I think your very smart-ass :smt003 :smt003 :smt003 ! :thumb: :thumb: :thumb: :thumb: :thumb:

Oh I mean I think you know alot! :smt003 :smt003 :smt003
<Note to self: *Never* give Chris an opening...> :roll: :smt003
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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Re: Cage welding question need to know ASAP

#8 Post by supernova » Sun Jul 19, 2009 3:27 pm

Gotcha !!!!!!!!!!!!!! :smt003 :smt003 :smt003 :smt003 :smt003 :smt003
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
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et: 5.28
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Re: Cage welding question need to know ASAP

#9 Post by race9899 » Thu Jul 30, 2009 5:39 pm

Actually welding 4130 with a Mig is a preferred method by many industries...

It is just the Drag Racing community that frowns on it, and no one can ever give a straight answer on why it is not allowed, the best answer I have seen has to do with early rail cars being built with ultra thin tubing that was mig welded cracked pretty quickly, but the Tig welded did not last much longer because of the flexing these cars endured..

This is straight from MILLER

MIG Welding 4130 Chrome-Moly
By Galen White, welding engineer, Miller Electric Mfg. Co.

Grade 4130 steel, while containing both chromium and molybdenum as strengthening agents, is considered a heat treatable low alloy (HTLA). Generally referred to as chrome-moly, this HTLA is used largely for aviation, racing and welded tube structure applications.

When welding 4130, preheating to 300°F is strongly recommended by the American Welding Society (AWS) to relieve stresses in the metal. When choosing a wire, most people opt for ER80S-D2 or ER70S-2. ER80S-D2 will provide the most weld strength. The ER70S-2 is easier to find and provides a strong weld, but you’ll be sacrificing some strength by choosing this filler metal over ER80S-D2. When it comes to shielding gas, 75/25 (Ar/CO2) is recommended for most applications and 98/2 (Ar/CO2) for anything over 3/16 in.
Wire Size-Amperage Range- WFS Range Relationships for Short Circuit Transfer on Steel
Wire Size

Amperage
Range

Wire Feed Speed
Range
.023"

30-90

100-400
.030"

40-145

90-340
.035"

50-180

80-380
.045"

75-250

70-270

Cleanliness is critical when welding 4130. Make sure that all mill scale and oils are removed using mild abrasives and/or acetone. When you strike an arc, keep your heat input low to reduce stresses in the metal.

Post-weld heat treatment of 4130 varies from one application to another. If ductility and toughness are your goal, post-weld heat treatment is recommended up to 1,200°F. If the material you are welding is thinner than .120 in., stress relief through heat treatment is not as critical.
WFS Rule of Thumb:
1 ampere for every .001 thickness
1/8" material=.125=125 Amperes
Wire Burn Off:
.023-3.5" wire/amp - 125 amps=437 IPM
.030 - 2" wire/amp - 125 amps=250 IPM
.035 - 1.6" wire/amp - 125 amps=200 IPM
.045 - 1" wire/amp - 125 amps=125 IPM

Welding 4130 is a lot like welding mild steel and is easy if you know how. These are just some of the reasons 4130 is considered so flexible and is used on everything from airplane engine mounts to bicycle frames.

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Re: Cage welding question need to know ASAP

#10 Post by John_Heard » Thu Jul 30, 2009 6:13 pm

I have to agree with Jeff here... I've got a number of things on my car that are chrome moly that I welded with the mig to mild steel. No problems whatsoever.

Would I buy a car with a mig welded CM cage? No... Not because it's not a safe practice, but because there will likely be issues getting it certed, and should you want to sell it down the road, it's not going to be worth as much since everyone believes you can't do it.

We used to weld stainless to mild steel where I used to work in production. There's a bunch of people that say it can't be done. BS - Go look at the hydraulic parking brake on a big UPS delivery truck. The weld on the cylinder to the plate is MIG. It's called a Maxi-H Brake, sold by Aeroquip, then Midland, Then Haldex. BUNCH of those out there in the field.

I'm not sold on NHRA's safety procedures or rules. Like requiring CM tubing in a 25.2 car. Or the difference between the 1/8 mile and 1/4 mile on cage requirements. Lots of BS going on that costs you the racer lot more money.

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Re: Cage welding question need to know ASAP

#11 Post by supernova » Thu Jul 30, 2009 8:33 pm

John_Heard wrote:I have to agree with Jeff here... I've got a number of things on my car that are chrome moly that I welded with the mig to mild steel. No problems whatsoever.

Would I buy a car with a mig welded CM cage? No... Not because it's not a safe practice, but because there will likely be issues getting it certed, and should you want to sell it down the road, it's not going to be worth as much since everyone believes you can't do it.

We used to weld stainless to mild steel where I used to work in production. There's a bunch of people that say it can't be done. BS - Go look at the hydraulic parking brake on a big UPS delivery truck. The weld on the cylinder to the plate is MIG. It's called a Maxi-H Brake, sold by Aeroquip, then Midland, Then Haldex. BUNCH of those out there in the field.

I'm not sold on NHRA's safety procedures or rules. Like requiring CM tubing in a 25.2 car. Or the difference between the 1/8 mile and 1/4 mile on cage requirements. Lots of BS going on that costs you the racer lot more money.

I agree with you but the track that you want to race at askes you to have a cert sticker before they let you go down the track does not agree! What are you going to do?

A cert guy will cert the main cage and doesn't care about the extra's that are mig'ed he just care's about the main cage. Rules are rules. (not my rules)at that.

I run most of the time at a track that is an NHRA track. They have stiff rules about following the NHRA rule book. So tell me, do you want it right and race or not and go home with a car they won't let you race?

I think it's best not to mislead someone that might end up with paying for a car they can't use or get rid of. Bending the rules is one thing but not follwing them at all is another. It's best to start out legal so there is no hassel. Some track's, org's. and assn's. don't check for being legal. Out of the 6 track around the area all but one checks.

Just keepin it streight!!!! The NHRA aren't welders but they are the rules makers and inforcers!!!
Last edited by supernova on Thu Jul 30, 2009 8:41 pm, edited 1 time in total.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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supernova
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Re: Cage welding question need to know ASAP

#12 Post by supernova » Thu Jul 30, 2009 8:39 pm

race9899 wrote:Actually welding 4130 with a Mig is a preferred method by many industries...

It is just the Drag Racing community that frowns on it, and no one can ever give a straight answer on why it is not allowed, the best answer I have seen has to do with early rail cars being built with ultra thin tubing that was mig welded cracked pretty quickly, but the Tig welded did not last much longer because of the flexing these cars endured..

This is straight from MILLER

MIG Welding 4130 Chrome-Moly
By Galen White, welding engineer, Miller Electric Mfg. Co.

Grade 4130 steel, while containing both chromium and molybdenum as strengthening agents, is considered a heat treatable low alloy (HTLA). Generally referred to as chrome-moly, this HTLA is used largely for aviation, racing and welded tube structure applications.

When welding 4130, preheating to 300°F is strongly recommended by the American Welding Society (AWS) to relieve stresses in the metal. When choosing a wire, most people opt for ER80S-D2 or ER70S-2. ER80S-D2 will provide the most weld strength. The ER70S-2 is easier to find and provides a strong weld, but you’ll be sacrificing some strength by choosing this filler metal over ER80S-D2. When it comes to shielding gas, 75/25 (Ar/CO2) is recommended for most applications and 98/2 (Ar/CO2) for anything over 3/16 in.
Wire Size-Amperage Range- WFS Range Relationships for Short Circuit Transfer on Steel
Wire Size

Amperage
Range

Wire Feed Speed
Range
.023"

30-90

100-400
.030"

40-145

90-340
.035"

50-180

80-380
.045"

75-250

70-270

Cleanliness is critical when welding 4130. Make sure that all mill scale and oils are removed using mild abrasives and/or acetone. When you strike an arc, keep your heat input low to reduce stresses in the metal.

Post-weld heat treatment of 4130 varies from one application to another. If ductility and toughness are your goal, post-weld heat treatment is recommended up to 1,200°F. If the material you are welding is thinner than .120 in., stress relief through heat treatment is not as critical.
WFS Rule of Thumb:
1 ampere for every .001 thickness
1/8" material=.125=125 Amperes
Wire Burn Off:
.023-3.5" wire/amp - 125 amps=437 IPM
.030 - 2" wire/amp - 125 amps=250 IPM
.035 - 1.6" wire/amp - 125 amps=200 IPM
.045 - 1" wire/amp - 125 amps=125 IPM

Welding 4130 is a lot like welding mild steel and is easy if you know how. These are just some of the reasons 4130 is considered so flexible and is used on everything from airplane engine mounts to bicycle frames.
This is vary good info!!

Thanks,
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

race9899
Posts: 153
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Re: Cage welding question need to know ASAP

#13 Post by race9899 » Thu Jul 30, 2009 11:02 pm

If you intend to run where you need a sticker Buying a Mig Welded 4130 car would not be smart..

But if it was a steal and you ran an outlaw track.. there is nothing wrong with it..

I posted what I did to try and dispel the myth that you cant mig weld 4130... Here is the funny part... NHRA does not allow mig welding 4130... but if they check Driveshafts... most of the CM drive shafts in race cars are Mig welded!

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Re: Cage welding question need to know ASAP

#14 Post by tigwelder » Fri Jan 29, 2010 3:21 pm

race9899 hit it right on with the driveshaft point. I think the sfi/nhra welding ruling is directed at keeping inexperienced tig welders from welding chrome moly. circle track(sprint cars) are mig welded alot. as well as late model dirt cars etc, but the tig process is totally different. the thing about moly is it is so hard you need concentrated instant heat in a very small area to make a good weld. I built a lot of 25.4 cert 7.5 cars that are tigged mild or moly steel. I pulse tig weld all joints and this keeps the area next to the weld from becoming brittle. as to the original guestion, grinding out the mig weld and tigging it would work but there would be no real way to tell if the metal next to the weld has been weakend,I wouldn't want to risk it. it would pass a visual inspection and thats all tech sees is the weld area. when they sonic test the wall thickness it will all seem ok. i still don't thinks it good idea.
just a thought, I know alot of time has past but I was reading old posts and figured I'd toss in my opinion, thx later

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