Welding on the frame

[GRINCH]

I have searched, read and even went over to pirate for some research...

I am getting conflicting information about welding on the frame. I am installing additional crossmembers for my fuel tank install. Will it hurt the frame to weld them in? I will be using a MIG welder . I can bolt the lower half in but no way to drill the holes for the upper mounts.

 

[Zeus33rd]

Weld away. Won't hurt a thing.

 

[DR]

Seems like when this question comes up the answers are 50 50. I have welded on my frame and so far no negative results. I would say go for it. I would make sure that there is nothing near where you are welding in the new cross member that you may have to remove later. Anything such as body mount bolts or lines etc. that the new cross member would be in the way of.

 

[Zeus33rd]

I don't understand why this seems so mysterious to people. There is nothing special about frame steel. The weld on frame braces for the steering box area have been around forever. People have been boxing frames for ever as well. The standard common sense stuff applies of course- don't weld around brake/fuel/oil/hydraulic lines. Proper prep etc....Otherwise, spark it up sparky.

 

[Hogback Fabrication]

I heard once that heavy duty (tractor trailer type) frames are heat treated and that welding on them will compromise a lot of strength.

Light duty truck frames are just regular mild steel and welding them is just fine.

 

[76zimmer]

I heard once that heavy duty (tractor trailer type) frames are heat treated and that welding on them will compromise a lot of strength.

Light duty truck frames are just regular mild steel and welding them is just fine.

That is the case. Weld away.

 

[GRINCH]

I tend to agree with the posts here. Just wanted to make sure before I started. My only concern was the flexing of the frame. But I guess the rivets they used don't move either.

Thanks for the replys.

 

[Fabrimacator21]

I don't understand why this seems so mysterious to people. There is nothing special about frame steel. The weld on frame braces for the steering box area have been around forever. People have been boxing frames for ever as well. The standard common sense stuff applies of course- don't weld around brake/fuel/oil/hydraulic lines. Proper prep etc....Otherwise, spark it up sparky.

A vertical weld in the wrong place could cause a severe weak spot.... other then that though theres not much too it.

 

[Zeus33rd]

A vertical weld in the wrong place could cause a severe weak spot.... other then that though theres not much too it.

Uhh, no.

Be realistic. The "severe" weak spot you refer to, if anything, will be so minimal as to be insignificant. Any stress to one of these frames large enough to damage it, regardless the presence of a vertical weld or not, would cause multiple failures of pretty much everything else.

In short, a vertical weld on one of these frames will not cause a failure.

 

[Fabrimacator21]

Uhh, no.

Be realistic. The "severe" weak spot you refer to, if anything, will be so minimal as to be insignificant. Any stress to one of these frames large enough to damage it, regardless the presence of a vertical weld or not, would cause multiple failures of pretty much everything else.

In short, a vertical weld on one of these frames will not cause a failure.

Really? Cause I've seen it happen more times then I can count on customers trucks and was the one to repair them in job shop.

There are certain places you shouldn't put vertical welds... any fabricator will tell you that.

 

[Zeus33rd]

Really? Cause I've seen it happen more times then I can count on customers trucks and was the one to repair them in job shop.

There are certain places you shouldn't put vertical welds... any fabricator will tell you that.

lol.

I think I know my way around a welder.....

 

[Fabrimacator21]

lol.

I think I know my way around a welder.....

Never said you didn't... Just saying I do this everyday for a living.


I've seen my fair share of cracked frames due to vertical welds in the wrong spot. Common problem when the "do it yourselfer" fish plates a frame.

 

[76zimmer]

care to extrapulate on that scenario?
I'm curious now.

 

[Zeus33rd]

Never said you didn't... Just saying I do this everyday for a living.


I've seen my fair share of cracked frames due to vertical welds in the wrong spot.

Just because you do it everyday "for a living" doesn't mean you're doing it right.

I looked at some of the pictures in your photobucket, if what you do for a living is represented by the pictures there, then you do entry level fabricators work. My guess is no more than $14-15/hr. Anyone can burn wire and make good looking welds...but that does not make you a fabricator. At 22 years old, there is no way you've got enough experience to call yourself a fabricator. A welder maybe, but not a fabricator. There's a BIG difference.

I feel kinda silly getting into a pissing contest with you, but once again, my self control fails me. I can't help it...

 

[ryoken]

I think the issue here is how and where the welding is done..

stress risers are a real thing.. thus why, fish plate frame repairs are diamond shaped usually, or that the weld on braces are not continuous...

it's not like it's going to "fail" catastrophically, but frame welds can certainly lead to sorrounding cracks if not planned properly...

 

[Hogback Fabrication]

care to extrapulate on that scenario?
I'm curious now.

Picture this, you're cutting out part of your frame and welding it back together (to make the frame shorter). If you weld vertically, the weld (or, if its a good weld, the metal next to it) will become a weak point because its in plane with the highest stresses.

Cutting the metal at 45 degrees and welding it that way is stronger in that application.

 

[Fabrimacator21]

Just because you do it everyday "for a living" doesn't mean you're doing it right.

I looked at some of the pictures in your photobucket, if what you do for a living is represented by the pictures there, then you do entry level fabricators work. My guess is no more than $14-15/hr. Anyone can burn wire and make good looking welds...but that does not make you a fabricator. At 22 years old, there is no way you've got enough experience to call yourself a fabricator. A welder maybe, but not a fabricator. There's a BIG difference.

I feel kinda silly getting into a pissing contest with you, but once again, my self control fails me. I can't help it...

Those aren't my welds... that was a kid who was helping out for the summers pictures. He took some of me and gave me a disc of all his work and some of mine. I have TONS of pictures where I've done some SERIOUS fab work on my phoned. Took over a highly sought after position in job shop at 18 years old doing all one off repair and fabrication(the guy that was there before me had 20 years exp). I was the ONLY 18yo kid in that shop and got picked from about 20 other employees. The owner (who has been in business for 50 years) saw one of the hydraulic cylinders I air arced and welded and told my boss that it was the most beutiful weld he seen leave this shop. Basically all the stuff they needed to be done right, clean, and come out nice came to me. Backhoe repair, building beds, panograph work, etc etc etc. I can assure you that my boss would back up my level of workmanship and knowledge. I've been welding/fabricating since 14.

I really don't know why I'm trying to prove anything to you... I made a statement about what I've seen and had to repair and you got offended and said you know your way around a welder.

Edit: photobucket updated.

 

[Fabrimacator21]

I think the issue here is how and where the welding is done..

stress risers are a real thing.. thus why, fish plate frame repairs are diamond shaped usually, or that the weld on braces are not continuous...

it's not like it's going to "fail" catastrophically, but frame welds can certainly lead to sorrounding cracks if not planned properly...

My point exactly.

 

[Zeus33rd]

Ugh...get back with me in 10 years, IF you stick with it, then you can tell me how much you DON'T know.

Must....resist....urge....to....talk....****.....

 

[GNEEnterprises]

As a mechanical engineer who endured fun courses like statics, dynamics, strength of materials, calc based physics, and others, I can chime in and simply say that there is a science to how a steel beam (frame rail) reacts to loads. If your weld takes away material in any way, it will be a weak point. The flanges (top & bottom) sections are more critical than the web (vert) so try to do the welding in the web area for cross members. Boxing on the other hand turns a C-channel into a an enclosed rectangle which will add a huge amount of stiffness to the frame a.k.a Viagra for the frame . Always over-engineer it. If you think a 1/8th inch piece will work, use 3/16 just to have a safety margin. These are not NASA projects we are working on so there is no need to get all that exact.

That's my $.02