Strengthening an automoblie frame

I don't know how less weld can be stronger, but they may be right in stating that you won't gain any beyond 33% continuous.

To rebox the frame on my Dad's '66 Impala SS convertible we laid strips down the bottom and welded the full length of it. This was a Twin Cities car that had been driven a lot in the winter. The frame was really bad. It was patched enough so that we could enjoy the car for awhile before dismantalling it for restoration. Eventually a new frame/body was sourced and everything is in the process of being changed over(interior/drivetrain/trim/etc). It will hopefully be on the road this summer.

Can you find a proper convertible frame? That would be much easier and better. Check Windy Hill in Minnesota or consult Hemmings.

The problem with finding another convertible frame is that being boxed they held in the water, salt and leaves and are usually rotted worse. I'm starting with a really solid conventional frame and only want to do this once. Right.

Not to be rude, but have you looked? One can weld a frame and increase the strength, but it is a lot of work. With the body off, it will be significantly easier, but it is still going to require a lot of welding/fitting/grinding.

I realize boxed frames have their issues, but if you look in the right region of the country you can find some very clean stuff. I have a '67 Camaro from California that has almost zero rust. It was never undercoated and still has gray steel underneath. The only rust is in the fenderwell where someone decided to add some goofy mudflaps.

parts cars - 1964 Oldsmobile Slippery Rock, PA Parts: 64-87 CUTLASS, 442: FRAMEs, rust-free bodies and parts at our 2 convenient locations, MC, Visa; ship UPS, truck or pick up.

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frames - 1964 Oldsmobile Cutlass Slippery Rock, PA Parts: 64-87 FRAMES, CUTLASS, clean southern FRAMEs, ship truck or pick up. 724-794-6827, PA.

I have had clients ask me about what to do about strengthening frames, etc. (I build drag engines, some streetable) In the past I have referred the person asking directly to a chassis fabricator or trustworthy shop that does frame accident work. I have heard different answers on different problems or desires from the same builder on different cars. To box in the rear is no big deal but doing it right is- Talk to some speed shops and do a little detective work. You might find a cost effective approach or you may wind up with a frame-off rebuild (A really cool project if you have time). There are things as mentioned that will eat up a boxed frame in no time... The weld is the least of your concerns other than a double chamfer, clean, good penetration, I have done TIG,MIG,&good ol' stick for myself, no problems....

Rob

Fraser Competition Engines Chicago, IL.

Just as a point of reference: I located two boxed frames. 1400 & 1600$ not including transportation (and unable to verify condition before purchase). The frame I found is rock solid and cost 300$.

Wow. A full frame and shell for Dad's SS cost $1900 delivered from CA to SE MN. This body is really clean and the frame is just as nice.

In any case, what is it going to cost you to get the frame welded up, or can you do it yourself? If you have to pay someone, it is probably going to eat up the difference between those two frames pretty quick. If you do it yourself, you are still going to have many hours/days in this project.

Do you know that a convertible and a hardtop use the same body mounts? Sometimes things get moved around quite a bit.

Are Cutlass frames that hard to come by?

JW

Excess weld metal can hurt the integrity of the frame. Welds don't fail (i.e. crack) by not being strong enough, they fail because they are too hard. Instead of bending, stretch, and flexing like the rest of the part to elevaite stress, they crack because they are too hard to bend or stretch. This problem is only exacerbated by further restraining the weld, (i.e. adding more metal). That is one reason why long welds in structures are often done like a sewing stitch. If any of you are involved in the construction industry you might be familiar with this concept from the AWS D1.1 code. Some times, less is more.

Mark Lorenz Welding Engineering THE Ohio State University Lorenz dot 42 at osu dot edu

See kids- This is why I stick to engines and farm out what I don't know!!!

Rob

FCE

Huh? Doesn't strength have a direct relationship to hardness?

don't fail

are too

weld, (i.e.

structures are

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from the AWS

As you will, but "not being strong enough" and "too hard" don't compute.......

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It's not a direct relationship. There is some relationship, but it is relatively incidental.

Materials can be very hard and yet not very strong and conversely can be very strong but not very hard.

Now that it is pointed out to me, I do remember this being mentioned before. Frames have a certain amount of flex designed in to them. Stiffening them up without taking this into account will result in a cracked frame. Instead of flexing, stress will get concentrated into the frame where it will find a weak point and eventually yield.

JW

Well, actually, there is quite a direct relationship, in steel, (and I presume that's what we're welding) between hardness and strength.

conversely can

mentioned

them.

in a

"cavedweller" wrote in news:henXd.6579$If1.1380870 @read2.cgocable.net:

Strength and hardness is not the same thing. Consider this: wich is hardest: a piece of chewing gum or a piece of glass? Try throwing both out the window from 10th floor, and see the result when they hit ground. Hard can also mean brittle. An old tip from a taylor: never sew a garment with a thread thats stronger than the fabric. Henning

news:henXd.6579$If1.1380870

don't

throwing both out

ground.

Pffttt....the feather will hit the ground at the same time.

Should be simple to box the frame you have. Those were 'c' frames or perimeter frames where the middle portion of the frame was boxed on the convertibles. The inside frame or the 4th side was not boxed with a flat strap but rather with a sideways V shaped piece ( more flat on the bottom and running up to the c frame) welded into the factory c resulting in a wide center frame tapering from the thickness of the factory c ( your original frame) on the outside down to a roll on the inside. Here's a link to a picture of one.