I know it's bad but is it salvageable?

About ten years ago, I had a cage put in a car, however around the time it was done, I ran out of money and motivation. I slapped a quick coat of paint on it so it didn't rust away, and let it sit. I recently restarted work on this car, and I'm having real doubts about the build quality of the cage. The cage was put in by a "reputable" shop that races locally but after taking a wire brush to some of the welds (see  below), I really don't think it's safe. Additionally, the joints at the top of the cage are not completely welded all the way around. I realize it may be hard to diagnose the breadth of my potential problem over the internet, however I'm trying to get an idea if the cage is salvageable. Specifically, the welds; I think the overall design of the cage is good. Based on the pictures below can anyone tell me the following:

1. Unless I'm mistaken, these welds are marginal at best. Is it reasonable/possible to grind out the offending welds, and weld them correctly?
2. What is the best way to weld the top of the cage? I'm ok with cutting out parts of the roof.

Most of the welds look like this:

Bad fitment/Looks like they tried to fill in gaps:

Incomplete joints:

I have seen MUCH worse. They may be ok. If you are really worried about it cut one or two crosswise and see how the penetration of the welds are. 
 

One of my guys is a certified welder. He welded gas lines, worked on the Alaskan pipeline and had his own welding business before coming to work for me. I will show him the photos and relay his comments.  

I don't know why, but I can't see the pictures.

I can't see them either, you have to sign in to Google to view them.

No can see pics

No pictures for me either. 

Can't see pics either but going over the welds and maybe adding gussets might solve any issue that might be there.  
 

as for the tops of the legs not getting welded you can cut the roof at those spots, weld and then weld the roof back. 

My bad. Pictures rehosted

It's hard to tell how big the gaps where.  It doesn't look like fitment was to bad as overall weld bead width looks consistent.    But again hard to say. 

The short ~1/2" welds is wierd.  It's not a continuous bead with so many start stops it seems likely to be a cold weld joint.  Also the welds seem really "proud" of the base metal in some spots.  

Most sanctioning bodies allow for incomplete welds at the roofs with specs about how much can remain unwelded.  

It's not easy but if the design and specs of the tubing are correct you can carefully grind the welds out and have it rewelded.  

Is there a joint you could cut out (and replace) that you could inspect the welds?  Like cut out the door bar or something to inspect one of the welds and then determine what to do with the rest.  

I'm not convinced those welds are terrible. I think you may be confusing proper "stacked penny/ fish scale" welds with improper "bubble gum" welds. 
 

Weld quality is about penetration. 
 

Yes, there are some issues. But it looks repairable. 

Most of those look fine to me, aside from the incomplete welds that clearly need to be finished. Do you have pictures of the general design to check for issues there?

What do you plan to do with this car, which sanctioning body?
 

I would advise against grinding at all, that may cause you problems with cage approval.  Some tech inspectors will fail cages with grind marks as if a tube has been ground at all then it is no longer within spec for tubing wall thickness.   
 

To fix that, have a good welder finish the incomplete welds and weld over some others that they find questionable.  
 

+1 to Sonics remarks. Those aren't the prettiest, but I don't see any big red flags.

I don't hate it. I wouldn't weld it that way, but I've seen worse. Don't take a grinder to it. Grinder marks on a cage are pretty much an instant fail. 

To weld the top, you pretty much have two choices. Cut the roof and weld it, then patch the roof. Or cut the floor to drop the cage to get to the welds. I have done it both ways. If the floor plates are sized and welded properly, I would cut the roof. 

Too much wire, not enough heat, I'd say.  Hard to say without cutting through to judge penetration.  The fit actually looks pretty good to me.  With a mig, a bit of a gap isn't a bad thing.

Looks a little cold, but not terrible really.... 

Looks like stacked mig tacks instead of beads. 

Gets a nope from me.

The craters in each hump are indicative of MIG tacks. It is an inexperienced welders method of getting the "stack of dimes" look. 

I don't know the wall thickness of the tube nor how many amps the machine was running to be able to say it is insufficient. It does however look very amateurish to me.

Trent said:

The craters in each hump are indicative of MIG tacks. It is an inexperienced welders method of getting the "stack of dimes" look. 

I don't know the wall thickness of the tube nor how many amps the machine was running to be able to say it is insufficient. It does however look very amateurish to me.

It was done with a Mig. 1.75 x .095 DOM

Very amateur welds, It's not the worst cage but definitely look it over. 

In reply to Sonic :

I'm hoping to run NASA events/One Lap of America.

Picks of the cage design:

65-66 mustang?

Regardless,  if it were my ass in tbe seat, id take it to the resident old timer welder in town. Have him look at it. Hes probably laid more weld bead than the rest of us combined. 

I have a guy in my town whos judgment id.trust after he looked at it. I wouldn't know how to tell otherwise. 

Just an idea.

The design isn't horrible. The passenger door bar is a little funky and if it was mine I'd add a bottom bar on the passenger side as well. Other than that and finishing the welds at the roof, I'd drive it. 

While bird E36 M3 welds might not look pretty if there is good penetration they'd be fine. With that siad some of the welds look suspect to me, I'd have an expert look at it.

As for the top; we cut out an access panel in the roof of the Datsun to get to the top.

I'm with Trent and Bigdaddylee, that's clearly a big pile of MIG tacks on MIG tacks. For that reason alone, there is no way in hell I'd bet my life on that cage. MAYBE you have good penetration right at the center of the tack (although typically you don't take a cross section at a tie in or start/stop point or count that as part of the effective weld length and those beads are nothing but tie ins) but how does the area in between look? I can pretty much guarantee you have virtually zero penetration there. They're not even tied in particularly well. Then you get into each and every one of those craters being a potential source of crack propagation and that's a whole lotta nope from me.

Full disclosure: I'm not a CWI, nor am I even a particularly skilled welder, I've never teched a cage and I did not even stay at a Holliday Inn Express last night. But I do have an engineering degree and have sent enough parts for cut and etch tests at work to have a pretty good idea of what will and won't pass and what is and isn't a good weld. Thems ain't good welds 

Toyman01 (Moderately Supportive Dude) said:

The design isn't horrible. The passenger door bar is a little funky and if it was mine I'd add a bottom bar on the passenger side as well. Other than that and finishing the welds at the roof, I'd drive it. 

 

Id want at least one solid bar going from main hoop to the a-pillar downtube. That center stack of tubes that tie into each other just looks like a massive failure point.