The Cal-look Lounge

Cal-look/High Performance => Pure racing => Topic started by: 71CALRIPPER on November 24, 2008, 14:25:24 pm



Title: Chromoly or Mild steel
Post by: 71CALRIPPER on November 24, 2008, 14:25:24 pm
OK in a right state trying to decide which metal to go for. Jim Smith has been a saint and said at the end of the day its down to what i can afford.

Bit of background the Fiat 600 is having a full cage and rear gearbox cradle work to make it all fit, wieght isnt a massive issue with the car as it weighs nothing anyway.

So anybody thoughts would be great.

Thank you in advance.
Rob


and incase you dont already know the car :)
(http://i100.photobucket.com/albums/m38/54oval/320306.jpg)


Title: Re: Chromoly or Mild steel
Post by: benssp on November 24, 2008, 14:36:57 pm
Big Pete runs a CDS cage in his car, might be worth having the weight in something so small.


Title: Re: Chromoly or Mild steel
Post by: Neil Davies on November 24, 2008, 15:11:05 pm
Absolutely, and with CDS you can add any brackets or further bars easily with a Mig welder - you have to Tig onto Cromoly - plus cromoly has a lifespan fo 9 years according to the MSA


Title: Re: Chromoly or Mild steel
Post by: 71CALRIPPER on November 24, 2008, 15:26:01 pm
So yes weight would be an issue but there is a plus side to Mild steel CDS, as i am not worried about the weight its a good choice and Pete is very successful with his fiat running a CDS cage.

Neil and BenThank you
Rob


Title: Re: Chromoly or Mild steel
Post by: leec on November 24, 2008, 15:51:41 pm
Absolutely, and with CDS you can add any brackets or further bars easily with a Mig welder - you have to Tig onto Cromoly - plus cromoly has a lifespan fo 9 years according to the MSA

Thats interesting, why 9 year life span? Is CDS much longer then?


Title: Re: Chromoly or Mild steel
Post by: Neil Davies on November 24, 2008, 16:57:55 pm
Absolutely, and with CDS you can add any brackets or further bars easily with a Mig welder - you have to Tig onto Cromoly - plus cromoly has a lifespan fo 9 years according to the MSA

Thats interesting, why 9 year life span? Is CDS much longer then?

Not entirely sure! Just something I remember reading several years ago. I had a cromoly cage in my last car, but the new one will be CDS. I think it gets brittle and can fracture around the welds - it is very easily damaged by heat.


Title: Re: Chromoly or Mild steel
Post by: SteveW on November 24, 2008, 18:15:17 pm
(http://i227.photobucket.com/albums/dd37/StripTeaseRacing/59RHD/rear-of_seats.jpg)

All of this is in CDS! Yes there is a decent amount of weight saving to be gained by having the cage in chromoly but as you know its more expensive! We couldn't afford to have the car built how we want it out of 4130 so we went with CDS and got the cage you see here  :) If you can afford 4130 then go for it but if you can't or would rather channel the saved money into more parts then don't feel like CDS is the cheaper cousin as I don't believe it is! Your car sounds like it's going to be really cool when its done so get cracking!  ;D ;D


Title: Re: Chromoly or Mild steel
Post by: 71CALRIPPER on November 24, 2008, 21:00:01 pm
Thank you all for you input. GOing to put it to good use :)

ROb


Title: Re: Chromoly or Mild steel
Post by: Fasterbrit on November 24, 2008, 21:08:23 pm
Using cro-mo will save about a third in weight due to the thinner wall thickness. However, if weight is not an issues CDS is much more user friendly. And it's about a third of the price compared to moly! As Neil points out, CDS can be mig welded. Cro-mo can only be tigged otherwise it becomes brittle. I reckon I could have saved a small fortune in cash and about a week's worth of work had I have used CDS on my car :o


Title: Re: Chromoly or Mild steel
Post by: Steve D. on November 25, 2008, 01:52:22 am
(http://i227.photobucket.com/albums/dd37/StripTeaseRacing/59RHD/rear-of_seats.jpg)

That's a nice looking jungle gym you have going there Steve, where are you going to put the swings and the sandbox?  ;D  (seriously though, beautiful looking car.)


Title: Re: Chromoly or Mild steel
Post by: SteveW on November 25, 2008, 07:12:20 am
Oi!! That'll be your jungle gym when your over next ;)


Title: Re: Chromoly or Mild steel
Post by: danny gabbard on November 25, 2008, 17:30:04 pm
Both chromoly and mild steel can be mig and tig welded both can be stress releaved at the weld joints. Mild steel needs to be thicker wall to be as strong as chromoly. Yes chromoly is a more brittle material and mild steel will bend before failure as chromoly will crack and brake but it takes alot to bend chromoly. Just my 3 1/2 cents


Title: Re: Chromoly or Mild steel
Post by: flatfire on November 26, 2008, 23:25:32 pm
Using mild steel for your project sounds like a great idea for weight. As far as chromoly is concerned I think the stress and the concern probably is associated with the high end of drag racing. When you see a top fuel car coming off the line its like a scalded cat, the flex/stress is amazing.  There is a British developed material from WW2 that has as good if not better qualities than chromoly its called T45.
http://uk.youtube.com/watch?v=I5hc4ZJS0zs (http://uk.youtube.com/watch?v=I5hc4ZJS0zs)


Title: Re: Chromoly or Mild steel
Post by: 71CALRIPPER on November 28, 2008, 08:52:38 am
Both chromoly and mild steel can be mig and tig welded both can be stress releaved at the weld joints. Mild steel needs to be thicker wall to be as strong as chromoly. Yes chromoly is a more brittle material and mild steel will bend before failure as chromoly will crack and brake but it takes alot to bend chromoly. Just my 3 1/2 cents

knowledge is power


Title: Re: Chromoly or Mild steel
Post by: 58vw on November 29, 2008, 18:15:46 pm
looking good..cant wait to see it all done with that cage and the wheels on it...and i would go with mild steel like everyone agrees with the weight issue especially with what your putting in that for a motor ;D


Title: Re: Chromoly or Mild steel
Post by: Fasterbrit on November 30, 2008, 19:24:07 pm
Both chromoly and mild steel can be mig and tig welded both can be stress releaved at the weld joints. Mild steel needs to be thicker wall to be as strong as chromoly. Yes chromoly is a more brittle material and mild steel will bend before failure as chromoly will crack and brake but it takes alot to bend chromoly. Just my 3 1/2 cents

Hey Danny. How do you stress relieve cro-moly when it is mig-welded? That would be a useful tip. Thanks