Welding on the frame.

TaliaDPerkins

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VA, Clarke & Greene Counties
I looked through the two pages of links before asking the question. The search terms were "weld on frame". I found nothing I was looking for.

Specific to Thomas busses circa 2000, where on the frame would you find the mark telling whether it was heat treated or not? Maybe it was covered by rust proofing?

If it is not heat treated, then ostensibly welding on the middle third of the vertical web to the frame rails is fine. If heat treated, that's a No-No!
 
I looked through the two pages of links before asking the question. The search terms were "weld on frame". I found nothing I was looking for.

Specific to Thomas busses circa 2000, where on the frame would you find the mark telling whether it was heat treated or not? Maybe it was covered by rust proofing?

If it is not heat treated, then ostensibly welding on the middle third of the vertical web to the frame rails is fine. If heat treated, that's a No-No!
Hmmmm.....what year?
 
Rear engine Thomas would be built by Thomas. Otherwise by the chassis builder. If you need a vertical weld then no for any frame. A diamond shape is used on weldable frames. I drilled my frame. Too many computers to risk frying one by stray currents. 2005 Thomas HDX
 
I looked through the two pages of links before asking the question. The search terms were "weld on frame". I found nothing I was looking for.

Specific to Thomas busses circa 2000, where on the frame would you find the mark telling whether it was heat treated or not? Maybe it was covered by rust proofing?

If it is not heat treated, then ostensibly welding on the middle third of the vertical web to the frame rails is fine. If heat treated, that's a No-No!



In this thread, post #17 I uploaded from the Amtran Service manual the section that deals with frame repairs and welding. the manual is circa 1999.


I do not know if the specific information regarding the "Mark" is there but at least you now have OEM documentation regarding this topic...
Back in those days Thomas used International, GMC and Ford chassis.

I hope there is some useful information in that doc for you....
 
So, I am hearing from others the frame has no stamp, only a label, and that label has certainly been covered by the rust proofing material. I would do best if I insist on finding it, to remove the rust proofing gently in a strip down the outside side of the driver's side frame rail until I find it.

Eh . . .

Instead of any welding I'll just stick with no drilling outside the middle third of the vertical web of the rail, no hole size larger than 3/4", no hole edge closer to another than 2", and slightly chamfer and deburr and polish all drillings, then paint. Use bolt ups with grade 8 and torque to spec.

The hitch I want to put on it it is intended to be welded on, and the weldment would be vertical . . .
That manufacturer says have a professional welder do it. [ If full vertical height welds on a frame rail are verboten, would a professional welder do this? Maybe weld on a doubler and vertical weld only to the doubler? ]

Only possible saving grace is it goes on the end of the rail where stresses are at a minimum anyway.
 
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I've not heard of any limitations on "Hardness" affecting welding that much. When metal is heated and cooled quickly it hardens. An Master Blacksmith I know explained to me that you have to think of the steel molecules as round spheres touching each other.

When these molecules are heated they turn to cubes.

Obviously with a bunch of spheres there's space between the molecules, which makes it softer and bendable but when cubed, there isn't.

When steel cools down the cubes turn back into spheres. If you instantly cool the metal while molten or red hot, it locks the molecules into those cube shapes, thus "Hardening" takes place.

This is why samurai swords were folded 200 times. They'd heat and instantly cool, shape, fold, and repeat 200 times so every bit of that sword is perfectly hardened and why these swords are extremely valuable today.

But if you weld on hardened steel, I would think you can do it but it's all about the settings on the welder and capabilities of it. You'd want a high end welder. Possibly need to heat the area up to red hot with a torch and let it cool slowly on it's own so the cubes absorb oxygen between them and round out again, then you can likely weld the area.
 
I've not heard of any limitations on "Hardness" affecting welding that much. When metal is heated and cooled quickly it hardens. An Master Blacksmith I know explained to me that you have to think of the steel molecules as round spheres touching each other.

When these molecules are heated they turn to cubes.

Obviously with a bunch of spheres there's space between the molecules, which makes it softer and bendable but when cubed, there isn't.

When steel cools down the cubes turn back into spheres. If you instantly cool the metal while molten or red hot, it locks the molecules into those cube shapes, thus "Hardening" takes place.

This is why samurai swords were folded 200 times. They'd heat and instantly cool, shape, fold, and repeat 200 times so every bit of that sword is perfectly hardened and why these swords are extremely valuable today.

But if you weld on hardened steel, I would think you can do it but it's all about the settings on the welder and capabilities of it. You'd want a high end welder. Possibly need to heat the area up to red hot with a torch and let it cool slowly on it's own so the cubes absorb oxygen between them and round out again, then you can likely weld the area.
What I have read is that vertical weldments on heat treated frames cause cracks in the heat affected zone of the frame, and, that heat treated frames have identifying stamps (or labels) indicating they should only be drilled in limited areas. The recommendation without regard to this by the hitch manufacturer is to have a professional welder weld on their hitch -- which will be a vertical weld.

If the frame I have is not heat treated, welding is far less of an issue.

I have reached out to Thomas, DTNA has been less than helpful.

So, I am guessing others have had the same issue and could say where they found this mark/label . . . but maybe not.

I have heard that welding a doubling plate with diagonal welds and welding the hitch to the doubler is the way to go.
 
This is why samurai swords were folded 200 times. They'd heat and instantly cool, shape, fold, and repeat 200 times so every bit of that sword is perfectly hardened and why these swords are extremely valuable today.

But if you weld on hardened steel, I would think you can do it but it's all about the settings on the welder and capabilities of it. You'd want a high end welder.
And if you weld on a Samurai sword it would ruin it. Not only in appearance, but the weld will produce an area of totally different hardness/brittleness. I don't know enough about metallurgy to offer good advice...just enough to know better than throw welds around on frame rails.

(Mine has welds for a hitch. I'm unconcerned because the frame only support a back bumper...rear collision is the most force it could ever see and I'll take the risk that 1' of frame acts a little different than designed.)
 
Instead of welding the htich and straying into "hardened" areas, why not just bolt it up?
Mine is bolted in, and the RV I am tearing apart right now for parts, has it bolted in...

Any welding shop can easily manufacture brackets to make this happen, no welding and no heat stress to the frame.
Just remember to use grade 8 hardware, and please, never tow without 2 safety chains!
 
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Instead of welding the htich and straying into "hardened" areas, why not just bolt it up?
Mine is bolted in, and the RV I am tearing apart right now for parts, has it bolted in...

Any welding shop can easily manufacture brackets to make this happen, no welding and no heat stress to the frame.
Just remember to use grade 8 hardware, and please, never tow without 2 safety chains!
Yep, I already mentioned Grade 8 above.

"Use bolt ups with grade 8 and torque to spec."

Thank you!
 
The drilling can suck. Speaking from experience. I used 1/2 inch Grade 8 in mine. use cutting oil. Start with a really small bit, and work your way up. Each hole will take about 3-4 drills through, and you'll probably need 6 holes. It's a pain, takes a few hours, but won't have to weld it in and worry.
 
Water is cheaper than cutting oil. As this topic is about hardness of the metal of the frame, the quickest way to kill a drill bit is to overheat it. I keep water on my bit to keep it less than 212F.
 
The drilling can suck. Speaking from experience. I used 1/2 inch Grade 8 in mine. use cutting oil. Start with a really small bit, and work your way up. Each hole will take about 3-4 drills through, and you'll probably need 6 holes. It's a pain, takes a few hours, but won't have to weld it in and worry.
If your gonna drill through a frame you will have a much less stressful time if you utilize a mag drill and proper drill bits.

Hand drilling with box store drill bits is no fun.
 
In this thread, post #17 I uploaded from the Amtran Service manual the section that deals with frame repairs and welding. the manual is circa 1999.


I do not know if the specific information regarding the "Mark" is there but at least you now have OEM documentation regarding this topic...
Back in those days Thomas used International, GMC and Ford chassis.

I hope there is some useful information in that doc for you....
Thank you!
 
I believe nearly all frames made in the last 40 years or as are indeed heat treated.
My Ford has a double frame service manual says it is If I remember correctly. I did indeed weld on it. In fact I lengthened it about 5 feet.
(All of my added length and weld was behind the rear axle.)
Fact is these frames are designed and built to twist.
This is why the OEMs are quite serious about “no drilling holes on Flanges”
 

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