Welding On Motorhome
I have a 2006 Newmar gasser, can I weld on the frame on the back of it and not hurt anything? Any Ideas would help
Forum Discussion
There are many forms of steels that require a pre-heat and post weld heat treatment. The use of pre and post weld heat treatment can be based not only on material chemistry, but on the thickness of the material, service or process it will see, stress that is induced due to joint configuration, work hardening, or forming process.
In mild carbon steels the most common reasons to perform a pre-heat and post weld heat treat (PWHT) is material thickness, process it will be exposed to, or to relieve stress in the material due to work hardening or joint configuration.
Solution annealing or annealing can also be used to render certain properties back into the material.
Welding on materials that have seen PWHT should not be taken lightly. There are engineering design reasons for going to the extra time and expense to perform this.
There are many different types of carbon steel filler metals with chemical compositions that give certain properties to the weld metal in the as welded condition. As an example the increase Molybdenum (found in 7018-A1 and 7018-Mo for instance) will in part a slightly higher Moly content to the weld metal. This is used when added ductility is desired.
Some materials that have been PWHT'd can be welded on with the application of pre-heat, and then controlling the cooling rate after welding. These processes are spelled out in the qualified welding procedure and specified by the design engineer.
While this has been a long post it is just a brief and limited example that is not all inclusive.
While some have not had problems with grabbing the MIG gun and disconnecting the batteries. The area they have welded on may not have the stress' or they have just been very lucky.
While not in vehicle frames, I have seen material failures due to lack of or incorrect pre and pwht of carbon steel materials. Sometimes the failure is immediate and in the worst cases it has happened years after the welding. The worst cases are in my opinion because at the time of failure those injured had no clue that the failure was happening.
Sorry for the long post and rant.
In mild carbon steels the most common reasons to perform a pre-heat and post weld heat treat (PWHT) is material thickness, process it will be exposed to, or to relieve stress in the material due to work hardening or joint configuration.
Solution annealing or annealing can also be used to render certain properties back into the material.
Welding on materials that have seen PWHT should not be taken lightly. There are engineering design reasons for going to the extra time and expense to perform this.
There are many different types of carbon steel filler metals with chemical compositions that give certain properties to the weld metal in the as welded condition. As an example the increase Molybdenum (found in 7018-A1 and 7018-Mo for instance) will in part a slightly higher Moly content to the weld metal. This is used when added ductility is desired.
Some materials that have been PWHT'd can be welded on with the application of pre-heat, and then controlling the cooling rate after welding. These processes are spelled out in the qualified welding procedure and specified by the design engineer.
While this has been a long post it is just a brief and limited example that is not all inclusive.
While some have not had problems with grabbing the MIG gun and disconnecting the batteries. The area they have welded on may not have the stress' or they have just been very lucky.
While not in vehicle frames, I have seen material failures due to lack of or incorrect pre and pwht of carbon steel materials. Sometimes the failure is immediate and in the worst cases it has happened years after the welding. The worst cases are in my opinion because at the time of failure those injured had no clue that the failure was happening.
Sorry for the long post and rant.
