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conduit as frame stiffiners?

2K views 24 replies 15 participants last post by  NEW INTERIORS 
#1 ·
this may be a rediculous question, but I am interested in putting subframe connectors on my 66 coronet. I have seen people use scrape tube steel to make them before. Why couldn't I use 2" round conduits to make my own subframe connectors? Is round tubing steel stronger than conduit. I have access to lots on conduit that is thrown away. i am not drag racing or anything like that. Just looking to help the ride.
 
#3 ·
you bet!!!!!!

As an electrician I use scrap conduit for all kinds of projects. I am not positive about the wall thickness when compared to steel tubing, but properly triangulated it makes an incredibly strong structure. I doubt it would compare equally to dom steel tubing, but it should suffice for your application.
Just use proper precaution when welding... those galvanizing fumes will harsh you out FAST!!!!
I have all sorts of stands to hold tools... fenders.. ect made out of conduit!!!!
 
#5 ·
I have a swing set in my back yard that I built for my kids from 2" conduit in 1988 that has gone thru six children without a hitch. If it is thickwall conduit for large electrial it is plenty strong.

Brian
 
#7 ·
Is there a problem with the ride? Is it rusty and flexing? I have and have had many of the 66-67 Belvederes and Coronets and they are built pretty well for a unibody car. A hardtop will benefit from using frame ties more so than a sedan will (sedans are pretty stiff) but any car will benefit from them if you are hammering on the car hard in turns etc but if you are looking to improve ride quality, I don't think you are going to notice much if anything unless the body is in bad shape to start with...
 
#9 ·
I wouldn't use Conduit on a car for ''nothing'' !!!! :nono: :nono: Don't wasted your time with conduit.. Do it right the first time, And you will be done.. Keep the conduit for what it was designed for.. Just ask yourself: HOW MANY TIMES DID I ''SEE'' CONDUIT ON A CAR ???? :confused: ''NEVER'' !!! :nono: (Just in the back of a truck going to a job) !!!! :D
 
#10 ·
I got the idea because when I cut out my old floor pans and was looking at the unibody crossmembers, they are nothing but bent sheetmetal. I see the frame stiffeners that are sold for these cars and they are nothing more than bent sheetmetal laser cut to conform to the bottom of the floor pan or else thin walled tube steel. I figured if a chain is only as strong as it's weakest link, then the conduit might be as strong as the unibody itself.
 
#11 ·
Some of you better welders can probably do it, but I consider any galvanized material to be a "dirty weld". That is, there is a bunch of different materials which go into conduit, and conduit coating, which become foreign matter during the welding process. It is sort of like trying to weld painted and rusted steel without totally grinding and cleaning it first. If you try welding together a few test pieces, I think you'll see what I mean.
 
#12 ·
xpsyclonex2002 said:
I got the idea because when I cut out my old floor pans and was looking at the unibody crossmembers, they are nothing but bent sheetmetal. I see the frame stiffeners that are sold for these cars and they are nothing more than bent sheetmetal laser cut to conform to the bottom of the floor pan or else thin walled tube steel. I figured if a chain is only as strong as it's weakest link, then the conduit might be as strong as the unibody itself.

Well... all we can do is give our advice..That's mine.. ;) It's your car, you have to like it.. :mwink:
 
#14 ·
NEW INTERIORS said:
I wouldn't use Conduit on a car for ''nothing'' !!!! :nono: :nono: Don't wasted your time with conduit.. Do it right the first time, And you will be done.. Keep the conduit for what it was designed for.. Just ask yourself: HOW MANY TIMES DID I ''SEE'' CONDUIT ON A CAR ???? :confused: ''NEVER'' !!! :nono: (Just in the back of a truck going to a job) !!!! :D
I'm using it for the rolls on the top of the bed on my rpu,but not for anything structural.
Shane
 
#15 ·
Conduit for chassis stiffening?

There is a reason why you don't use schedule 40 pipe for reinforcing car chassis's, electrical conduit is the exact same thing (but thinner!) with a galvanized interior and exterior plus a varnish layer to ease pulling wire through it.

I guess anything is possible but anything you gain in strength will be offset by the added weight to the car...I.E. not worth it. Might as well use exhaust tubing. :nono:
 
#16 ·
frame stiffners

I did my 5.0 Capri T top a few years ago .. The 80's mustang platform is weak to start with and when they cut out the roof it makes them worse. I bought the mustang tubes then made a ladder each side .. I used 1 X 2 .120 wall tube under the rockers and cut the rect tube with a hole saw to get good fit to the round tube. I ran a full length tube side to side under the front seats and under the rear foot well and the roll bar sits on top of the back full cross piece. I also cut and formed a piece of 1 1/2 angle iron to go under the rear seats . I could see stress cracks starting there. I also bent a piece of tubing to go across at the top of the radiator support , and welded a lot of the seams in the engine compartment. I scored the after-market cowl to shock tower bracing at a bone yard for $ 20. The rear tires really hooked up after it was stiffined up and it corners a lot better. What you need to do depends on where the weakness is in your chassis and how much horsepower . I had an old bug eyed sprite that had been road raced and the entire unibody had been rewelded. and extra metal added for the roll bar mounting. .
 
#17 ·
I see there have been many uses of conduit that I just would not have considered.

Maybe that's because in about 1964 when we had a fuel dragster, I saw a dragster crash at probably less than a hundred miles an hour. The car was destroyed, the guy not seriously hurt, but ..... the chassis was made out of conduit as revealed when the paint fell off.

Is this place great of what? I can now see where conduit might be a resonable choice for a couple of items on my project. Yup, cheaper (that's me) and easier to bend than 4130. Although, I love tigging chrome-moly and hate galvanized. I gues I hate galvanized because I don't prop it preperly....
cute huh?
 
#19 ·
NEW INTERIORS said:
I wouldn't use Conduit on a car for ''nothing'' !!!! :nono: :nono: Don't wasted your time with conduit.. Do it right the first time, And you will be done.. Keep the conduit for what it was designed for.. Just ask yourself: HOW MANY TIMES DID I ''SEE'' CONDUIT ON A CAR ???? :confused: ''NEVER'' !!! :nono: (Just in the back of a truck going to a job) !!!! :D

ummmm.... just this week... Rod and Custom feature car article "Recurrent Dream" page 27 bottom pic... caption-"Mark recreated the entire rear clip from scratch the same materials Bill used: a first-gen Corvair, CONDUIT, and hand hammered sheet." Recreation of an older show car.

Also just this week...Custom Classic Trucks Tech "Get Shorty Part 17" page74
the guy used conduit to build his seat frames and to shape out his center console.

Would I use it to build a tube chassis??? HELL no. The poster who started this thread was looking for (I thought) a cheap sub-frame connector. Would conduit work?? You bet!!!! Cheap??? You bet!!! Equal to a factory produced after-market???? NO chance!!!!

If you are looking for a cheap frame to skin... it can't be beat. If you are looking to use it in a high stress, major component application, let me know what your ride looks like , so I can steer clear of you on the street.
As in my previous post... I have mostly used it to build shop tools or fixtures.
But I can see the potential for its use in a non-stress application.
 
#21 ·
JaggedEdge said:
I have all sorts of stands to hold tools... fenders.. ect made out of conduit!!!!

I'm not sure how much steel is where y'all are from, But I can build a set of connector out of Real ''STEEL'' for not very much more,Then you can out of Conduit.. And will be right.. Don't half a** when doing your car.. :nono:
Building stand's, Is a different story, Then telling someone that conduit will work fine to use as a ''cheap sub-frame connector'' ...Sorry!!!!! it isn't any good for that,, Put a little HP in that car, And you will learn a EXPENSIVE lesson really fast.. Like I said.. It's his car to do like he want's.. I build cars ''EVERYDAY'' sun up to sun down,( In a lot of time's later then that).. Conduit wasn't made for a car.. Call Art Morrison and tell then what you would like to use.. Then come back and post their answer here.. :D Would love to hear their answer... :D Telling someone to use Conduit on a Car can get someone ''KILLED'' !!!! Sorry !!!! I'm done With this post.. :nono: :nono:
 
#22 ·
People get killed doing stuff like this. Not that subframe connectors will be that big of a deal; it's just the idea. Taking short cuts or trying to save a few bucks when your a** could be on the line is just, well, not real bright.

Way back, there were lots of race cars that used exhaust tubing and conduit for frame tubes, straight axles, and roll bars.........and some of these folks arent' here today. I remember Wild Willie Borsch, who had one of the fastest AA/FA cars in the country. He used to brag about using exhaust pipe for the front axle of his car. Easy to repair, he said. He survived. He was lucky.

Now, thanks to NHRA and the tech guys, those days are pretty much over. You'd be surprised, though, at how many guys in the past ten years or so, have bought old front engine rails and alterreds for nostalgia racing, and got them home.....only to find the frame or roll bars made of exhaust pipe.

I'd listen to the others, for whatever reason you think you need these connectors, do it right. Leave the conduit for the electricians.
 
#23 ·
dalesy said:
People get killed doing stuff like this. Not that subframe connectors will be that big of a deal; it's just the idea. Taking short cuts or trying to save a few bucks when your a** could be on the line is just, well, not real bright.

Way back, there were lots of race cars that used exhaust tubing and conduit for frame tubes, straight axles, and roll bars.........and some of these folks arent' here today. I remember Wild Willie Borsch, who had one of the fastest AA/FA cars in the country. He used to brag about using exhaust pipe for the front axle of his car. Easy to repair, he said. He survived. He was lucky.

Now, thanks to NHRA and the tech guys, those days are pretty much over. You'd be surprised, though, at how many guys in the past ten years or so, have bought old front engine rails and alterreds for nostalgia racing, and got them home.....only to find the frame or roll bars made of exhaust pipe.

I'd listen to the others, for whatever reason you think you need these connectors, do it right. Leave the conduit for the electricians.

Very well said,, And true.. :thumbup:
 
#24 ·
I was going to use conduit for forming curves on my ratrod project. $1.65 for a 6' length was tempting. but being the price of a bender is $50.. I'll use 1/8"x1/4" flat stock, I can bend it around a tree and not have to worry about the galvanize.. and the steel yard only charges like 35 cents per foot.
 
#25 ·
matt167 said:
I was going to use conduit for forming curves on my ratrod project. $1.65 for a 6' length was tempting. but being the price of a bender is $50.. I'll use 1/8"x1/4" flat stock, I can bend it around a tree and not have to worry about the galvanize.. and the steel yard only charges like 35 cents per foot.

Wise choice !!!! :thumbup: :thumbup: :thumbup:
 
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