Frame welding

Date 08-03-2007 04:58

There is no easy answer to Your questions. When a frame manufacturer builds a prototype frame they start with 1/4 size modeles on PVC and lexan plastics. these are subjected to fatigue and simulated crash tests. then full size steel prototypes are built based on what was learned from the plastick scale modeles. The steel prototypes are subjected to simulated crash and fatigue testing and modified versions are built and tested untill they think they have a workable unit. Then several entire prototype trucks are built and tested. You are atempting to eliminate all these steps and "just do it". Hopefully the TCI parts You are using are fully proven. They should be able to tell You exactly where and how to weld them to the frame, and You should follow that instruction to the letter. Aditionally, You should see what all the folks who are doing it all the time are doing, see how their conversions hold up over time, and if they are holding up, do Yours the exact same way. This is one of those jobs that if You have to ask, You probably shouldn't be doing. The devil is in the details.

By speedball1981 Date 08-03-2007 05:25

"if you have to ask you prolly shouldn't be doing" I think that is kind of a bad way to look at things, theres plenty of guys out there that are plenty capable of doing any one specific job, they are just not experienced, and i'm sure the first time it was done, I'm sure they didn't hire a bunch of engineers and use a bunch of pvc plastic models to do it, it was probably a guy that had similar skills to the average gearhead, and saw that the suspension under the mustang 2 would work better than the solid I beam suspension for his truck. If it were me I would go find a race car shop or hot rod shop, or go to a few car shows and talk to some people, and I'm sure you would find your answer.

By oldschool59 Date 08-03-2007 06:54

Those are pretty harsh words Mr. Boyer. This is not my first rodeo and I have never found anything I couldn't do given the right information and using a little thought. In fact I have accomplished quite a few projects in my lifetime that others may not have attempted. I'm just an ordinary guy that has plenty of common sense and whole lot of ability. I guess a better question would have been, has anyone in this forum ever done this? Thanks anyway.

By ssbn727 (*****)

Date 08-03-2007 17:05 Edited 08-03-2007 17:10

Hi Old school59!

I really do'nt see how you can interpret what Dave was trying to convey to you as harsh words...
I believe that all Dave was trying to convey is to proceed with caution and to gather up more info before you proceed with your project. No need to get upset with somone offering some sound advice to you because after all, is'nt that what you came here for???

If you do'nt think that you got enough help from one person without you explaining more in depth as to what you're actually attempting to do especially not mentioning anything about how you're going to join the components together, process to be used, any type of reinforcement, metal grade to be used for the reinforcements, etc. - well then,. I'm sorry but, we're not "Merlin the Magician" here so please, show a little more patience and respect towards folks that are only trying to offer help!!! I believe Dave deserves an apology at the very least!!! Now I know Dave can speak for himself, and I hope that he does'nt get offended for me my steppin in so to speak but, Man!!! Show a little respect to whom I know is very knowledgable in automotive Tool & Die assemblies and machinery!!!

BTW, the answer to your second question is: I have'nt but then again not many have - YET!!!

Henry

By bozaktwo1 (***)

Date 08-03-2007 17:09

I would like to know what you finally decide to do, and if you could take photos and post them that would be cool. I have done some minor frame strengthening, but never anything really in depth.

By DaveBoyer (*****)

Date 08-04-2007 04:13

The problems You have to deal with are ones of stress risers and fatigue. I have no doubt that You can weld the parts together, and make sound welds. I an sure You are smart enough to get this project together well enough to drive it around the block. What I am questioning is the long term service life of the modified truck frame & suspension. If this is a show car that You trailor to shows, pretty much anything will do. If it is an everyday driver, and especially if You use it for a TRUCK You need to be concerned about fatigue. If all the testing wasn't neded to design a frame, the auto manufacturers sure as hell wouldn't spend the money to do it. The manufacturers of the kit should be able to tell You what THEY have done.
Henry, no ofense taken with Your post.

By DaveBoyer (*****)

Date 08-04-2007 06:42

A little insight ito car & light truck frames: Modern car & light truck frames are designed to be manufactured with at least some welding, the car frames, Chevy truck and F150 frames are heavily welded, as is the military Hummer. The car frame prints for the GM frames built at Dana Parrish while I worked there ['84-'91] specified .05% Carbon Max. That low carbon requirement is for the sake of welding. Older frames that are all riveted with NO welds did not need to be made of extremely low carbon materials, and could be made from steel with a higher carbon content, as it is stronger. I don't know when these changes occured in each vehicle, but if a frame has factory welds It is made from a material that can be readily welded. If there are NO factory welds, You must procede with extreme caution. The weldability of the material is a different problem from that caused by stress risers, but higher carbon content will make the stress risers more likely to cause fatigue failures. In general atachments should be made to the web and not to the flanges of a channel frame, there are exceptions on production frames, and they have proven themselves in the lab and on the test track. With a modern box frame You willnotice that heavily loaded atachments often atach to 2 or 3 sides of the box section to distribute load.

By Bob Garner (***)

Date 08-03-2007 18:11

Besides TCI, there are a number of companies that make weld-in front suspensions, so we know it has been done successfully. I would think TCI should give you the specifics, it's their product and they want success.

But not knowing much about the frame steel, is there some place where you can remove some pieces from the frame for prequalifying and testing your welds? When we were young and stoopid, we thought nothin' about welding stuff to car frames like brackets for split wishbones and the like. But I suppose the steel in those old frames was some pretty low carbon crude. I've seen all those recent e-mail reports of cracking in later Chevy frames, in fact the cracks are at the factory welds, so maybe even the manufacturer can't do it right.

But don't give up. I think Edmond Hillary said, "To search, to seek, to find, and never to yield".

Let me know what happens.

Bob
('68 Olds)

By johnnyh (***)

Date 08-04-2007 20:12

I agree with Dave and Henry. If you are going to do it correctly so that chances for future failure are kept to a minimum you should def listen to their advice. Or you can just slap it on in there and keep your fingers crossed. The engineers on the 1-35 bridge in minnesota probably werent in their "first rodeo" either.

By weldsman (*)

Date 08-08-2007 14:45 Edited 08-08-2007 14:48

If it was already mentioned and I did not see it, Sorry!
Taking a welding class at your local college or school, if available, might be handy. Getting some hands on training in the positions with the material and thickness you want to work with, with the GMAW process could really get you ready for your project. Going to a mod shop, and getting some ideas from them would likely also boost your confidence.
While I respect doing things by the numbers and having perfect welds that are going to far outlast the rest of the car, I think you could, with a little training, easily be able to make superior welds that will perform as good or better than some of the welds I have seen from production line vehicles. As it has been said, the kits are already out there, GMAW is already in use for them (Miller and Lincoln both have good technical websites for custom automotive welding works). As you likely have an interest of doing a good job, it is likely that you will be honest with yourself in regards to a problem that would need re-work. Also, if you have a problem, try and get with the people on this forum or at a good shop, get some pictures to them and discuss your concerns. You will find that everybody will be able to offer some direction to help you.
The welding is very do-able. Most people do not realize what they are capable of because its easier to say that you cant do it. You just have to stick at it and figure it out! Its the way that you learn...
-James
1967 Chevelle Coupe and luvin it!