Cage: Moly or Steel

[tannerman]

I going to be looking at another car and it already has a cage.The guy who has the car doesn't know anything about it really. My question is how do I know if it is a Moly cage or a Steel cage. I presume that it is going to be painted or powder coated at this time.

[Seattle_Mike]

One thing, if it's moly it will have been TIG welded, so if it's obviously a MIG job, then it's not chromemoly.

[teddisnoke]

Price also. Having a chromoly rollcage is always a good selling point, and will usually increase the cost of the vehicle.

[Paul Wright]

Look for seams. ERW tubing has seams and isn't legal for most classes. You wan't DOM (Drawn Over Mandrel) seamless tubing. Look for tubing thickness and if it's got a certification sticker.

[Jake]

Look for seams. ERW tubing has seams and isn't legal for most classes. You wan't DOM (Drawn Over Mandrel) seamless tubing. Look for tubing thickness and if it's got a certification sticker.

ERW tubing is highly used in drag cars and has no problems with NHRA tech. Do I like the ERW tubing?, HECK NO. I prefer moly in all cases. The DOM can cost almost as much as the moly tubing I have found. Or atleast close enough that you might as well move on up to the moly. Other than that GOOD POINTS!:)

[Rich_1028]

can't you also tell the diff. from tapping it with your finger nail,and listening to the "Ting".(CM)...or the "thud"(mild)

[NOVACA1N]

take a piece of steel and a mig welder and try and weld it too the side of it....if its sloppy, its moly!:eek: :D

[Real McCoy]

The IHRA and NHRA tech guys have a fluid they apply and that tells them if it's moly or not. Moly must be tig welded as posted before. Most kits use the cheap welded seam 1 5/8 OD steel tubing and it will be .134 wall and the DOM which is more expensive is used by most higher cost custom shops and they use .120 wall to save weight. The advantage to moly is it is stronger so you can use thinner wall tubing and save weight. It costs more to install for material and the tig welding is difficult and slow compared to mig welding the steel tubing. You can use .083 wall moly for the main cage and .053 for the dash bar and rear supports. Steel has to be .118 minimum for all the bars. If you plan to pay much extra for the cage be sure it has a current inspection sticker on it. If it has no sticker it could be worthless. Many chassis are made of tubing that is to small OD or wall thickness, not constructed to present specs, and not legal or repairable to get legal. Then you have to pay to have it removed before a new one can be installed. I have a 91 Mustang in the shop right now that had an illegal cage. Took 3 days to remove all the junk so we could start on the new moly cage which is legal and will be certified. RM

[Paul Wright]

ERW tubing is highly used in drag cars and has no problems with NHRA tech.

That surprises me because SCCA doesn't allow ERW tubing even in the lower classes.

[Real McCoy]

SFI specs for a drag car in any sanctioned body is aircraft quality moly or seamed or seamless mild steel tubing 1 5/8 OD for all main members with .083 wall thickness for moly and .118 minimun for M/S. The spec sheets are very specific on what the various bar sizes can be with different design chassis. If you want to go faster than 7.50 the chassis MUST be moly. The fastest a M/S chassis of any design will tech is 7.50 and slower. RM

[TechGuy]

how do I know if it is a Moly cage or a Steel cage..

4130 smells different, like a greasy mineral

[Jake]

4130 smells different, like a greasy mineral

I LOVE the smell of moly when cutting and welding.LOL.

[Real McCoy]

I just cut up 5 lengths of moly and fit and welded a 14 point cage in a 91 Mustang. I have yet to smell anything from it. I always wipe it down with varsol so it's not so nasty to work with. You guys haven't smelled enough racing gas or paint reducer if you can smell moly as different than M/S........LOL. RM

[Jake]

I just cut up 5 lengths of moly and fit and welded a 14 point cage in a 91 Mustang. I have yet to smell anything from it. I always wipe it down with varsol so it's not so nasty to work with. You guys haven't smelled enough racing gas or paint reducer if you can smell moly as different than M/S........LOL. RM

LOL, I really am surprised I smell anything(usually dont) from all the darn brake cleaner I use in the garage. I havent smelled brake cleaner in a few years. But I sure am in a good mood when working in the garage,LOL.:D

[Real McCoy]

When tech guy posted that it smelled different I almost fell off the chair laughing. I'm thinking, who in the heck can smell a difference in steel tubing??? I can't smell much of anything, can't hear much due to the constant ringing in my ears, can't see to tig weld and use a 3.00 power pair of Walmart glasses under the hood, and techguy is IDing different types steel by smell........LOL. RM

[65 Post]

I just put an S&W 8 point in my 65 and it's MS and Tig welded. The real way to find out what you have is to have it sonic tested. Dave

[Real McCoy]

I have both an IHRA and a NHRA inspector less than 20 minutes from my house so getting certified is pretty easy. The sonic testers can't ID moly from steel, they only give you tubing wall thickness. I guess you could tell if the wall thickness is a standard for moly since steel is different. Andy has some chemical he uses if he's not sure about one. It turns color only on moly. RM

[69NovaSS]

I just cut up 5 lengths of moly and fit and welded a 14 point cage in a 91 Mustang. I have yet to smell anything from it. I always wipe it down with varsol so it's not so nasty to work with. You guys haven't smelled enough racing gas or paint reducer if you can smell moly as different than M/S........LOL. RM

Not to change topics here but RM where do you get your Varsol from? Back home in Ontario its easy to find Varsol but down here in GA I have yet to find any(maybe its under a different name???) I would love to find a 5 gallon pail of the stuff to use for parts cleaning...:)

[Seattle_Mike]

PPG Wax & Grease Remover seems to work pretty well. I've used it to clean tubing off as well as a lot of other things.

[Real McCoy]

I get my varsol locally from a company called McCraw Oil. They sell home heating oil but also carry various other solvents. I pay 3.50 a gallon but the engine shop pays less buying it by the barrel. What part of Georgia do you live in? Maybe try calling around asking some engine shops where they get theirs. Mineral spirits work decent if you get in a bind to clean something. RM

[69NovaSS]

I get my varsol locally from a company called McCraw Oil. They sell home heating oil but also carry various other solvents. I pay 3.50 a gallon but the engine shop pays less buying it by the barrel. What part of Georgia do you live in? Maybe try calling around asking some engine shops where they get theirs. Mineral spirits work decent if you get in a bind to clean something. RM

I live just south of Macon in a place called Warner Robins...I havent called anywhere yet but I have went to all the usual places you could get it back home and none have it...I can get mineral spirts however

I will call around and see what I can get...I like varsol cause you can drop the part in the pail...put the lid back on and come back tommorow (if your not in a rush that is) and 9x outa 10 its perfectly clean..and if it needs any works its normally just a quick brush...and Bobs your uncle....as they say;)