Welding Strength

[waz77]

Problem with weld repairs is you don't know the grade of material used, a lot of materials need pre heating prior to welding and heat treating after welding to stress relieve it otherwise you can get cracking in the heat affected zone. All this talk of mig welding only being good for thin materials is bobbins, we used to weld upto 10" plate with fillet welds upto 6".

[Mortimer Firewood]

Problem with weld repairs is you don't know the grade of material used, a lot of materials need pre heating prior to welding and heat treating after welding to stress relieve it otherwise you can get cracking in the heat affected zone. All this talk of mig welding only being good for thin materials is bobbins, we used to weld upto 10" plate with fillet welds upto 6".

 

In what trade were you using mig to weld 10 inch fillet

 

I've been on some of the biggest steel construction jobs in Europe and never seen mig been used on small fillets let alone mid size

[renewablejohn]

If you are referring to a drawbar jaw then it will almost certainly be heat treated so very dangerous to weld this

 

Sounds like I have been very lucky. I presume with hindsight the drawbar jaw should have been bolted rather than welded. Cannot understand why the engineering co would weld if they new it was heat treated. Having trouble finding a replacement jaw that will handle 10 tonnes most of the ones I have found are rated 5 tonnes and below. Any suggestions

[aspenarb]

Is welding strength increasing or decreasing. Only ask as my MB Trac was "professionally" converted by a well known Unimog engineering company and the welding standard seems atrocious. To date the rear light frame and steps have fallen off and the PTO stub shaft is bent at 45 degrees. Final straw is the drawbar hitch which seems to be a bodge of a rockingham hitch which would be fine for a drawbar trailer but appears to be inadequate for a forwarding trailer as the lower jaw has broken off at the weld.

 

Any suggestion for a stronger drawbar its only pulling a 9t Kesla forwarder with probably 12t max.

 

John it reads like its more a combination of poor engineering , design and welding , not just the one thing. If you have paid for it to be done take it back and vent your concerns, its easy for us armchair welders and mechanics to comment but no one here has seen it.

 

Bob

[waz77]

I didn't say 10" fillet I said 10" plate with fillets upto 6". I was a plater/welder/pipe fitter in another life, used to fab and weld oil rig structures for thyssens, gearboxes for ships and submarines that were as big as a small house for David Browns, turbine steam chests for power stations, the biggest job was a 400t press for a car manufacturers called aida in Japan.

[renewablejohn]

John it reads like its more a combination of poor engineering , design and welding , not just the one thing. If you have paid for it to be done take it back and vent your concerns, its easy for us armchair welders and mechanics to comment but no one here has seen it.

 

Bob

 

Problem is I am not an engineering expert I am sure it is shoddy workmanship but loads on here really rate this company and I dont particularly want to rock the boat without knowing where I stand.

[Mortimer Firewood]

I didn't say 10" fillet I said 10" plate with fillets upto 6". I was a plater/welder/pipe fitter in another life, used to fab and weld oil rig structures for thyssens, gearboxes for ships and submarines that were as big as a small house for David Browns, turbine steam chests for power stations, the biggest job was a 400t press for a car manufacturers called aida in Japan.

 

My point was not that it could not be done I was just surprised it was used as it's all way looked upon as been second class in steel construction

[aspenarb]

Problem is I am not an engineering expert I am sure it is shoddy workmanship but loads on here really rate this company and I dont particularly want to rock the boat without knowing where I stand.

 

Post some pictures of the thing and we can crucify it for you

 

Bob

[waz77]

Are you meaning in steel erecting etc? If so mma is favoured because of its advantage in working in the elements, all the components will have been mig welded where poss before assembly, some metals like cast iron are welded mma because the wire would be unusable in mig, other than that mig trumps mma in most things, the wire can be flux of metal powder cored for specialist applications, the only thing better for heavy fans is submerged arc welding but that can only be done on v butt welds not much good for fillets

[renewablejohn]

Sorry its dark outside but you might be able to see

 

 

First picture is upside down and second needs rotating 90 degrees. You can tell I am useless at this

Edited March 18, 2015 by renewablejohn