Home repair that involves welding?

Tesla

Tesla

Tesla

Soldato
Joined
19 Jan 2003
Posts
17,601
Location
Bristol, UK
Hi there,

My brothers car has a badly corroded front cross member. He's bought a replacement and I am going to strip the front off of the car shortly.

I believe the existing cross member is spot welded on.

I have a few questions as am unsure on a few bits.

Removing the spot welds? Use a spot weld drill bit? Basically a drill bit which is flat at the end.

How about welding on the replacement part. I have no welding experience or equipment. I cannot drive the car to a garage after stripping it down.

My thoughts are either find someone who can come to me to weld OR drill the welds out all of the way through and then bolt the new crossmember on?

Would this bolting method be advisable or safe?

What would you expect to pay for someone to come out and spot weld it on?
 
I'd look at removing the old one fitting the new one and getting a mobile mechanic to put some spot welds on if your not confident, that way you'll be doing it as cheap as possible and getting a proper job, I've seen spot welds being replaced with self tapping screws but it's bad practice
 
Grind the old crossmember off or drill out the welds with a spot weld bit.

You aren't allowed to bolt, rivet or screw the crossmember back on - it's not a satisfactory repair and will fail the MOT. You can either spot weld the replacement crossmember on or you can plug weld it with a conventional mig welder. You are also allowed to seam weld the crossmember back on but I'd stick to plug welding it.
 
I nearly always plug weld panels, it's the most convenient and quickest method if you have a MIG welder. If you are getting someone else to do this, then you will need to make the holes for the plug welds - the best way by far is the use of a "joddler" tool that incorporates a hole punch. Trying to drill dozens of holes into thin sheet steel is a PITA and you will likely distort the panel when (not if!) the drill catches. You will also need a good selection of welding clamps and mole grips in order to hold the panel in the correct position prior and during welding.
 
I need to replace both sills on the Manta this summer - I'll be plug welding the top and bottom edges and then seam welding where it joins the 3/4 panel. The bottom edge won't be seen and the top edge is covered by the door rubber.

I've seen people seam weld cover sills on - it looks horrendous!
 
Thanks for the replies chaps.

I stripped the front down today and unbolted anything attached to the crossmember.

It's in a real sorry state, the middle of the cross member fell out. The rest of the car is corrosion-free but a bit of Googling reveals this is a common fault on several Nissans of this era (2000-ish).

I did pick up a spot weld drill bit and had good results but some of the spots were just inaccessible with the drill so I had to do these from the "wrong" side and these will have to be plug welded.

The very tops of the cross member are overlapped by the panel above (slam panel?) and these are then welded both to the subframe. I just don't have the tools or confidence to get this off!

I will try and get details of someone who can hopefully finish the job.

I am thinking I have still saved my brother a few bob as I imagine it's an hour or two's labour charge to strip everything off in order to access the crossmember.
 
It's an Almera N16 (the second shape).

I did accidentally drill a spot weld (all the way through both layers) that didn't need to be as it was joining a different panel. Can this be repaired?
 
My brother got hold of a mobile welder who is going to have a look in a couple of days time.

Here are some pic's for those interested:

IMG_0063.JPG


IMG_0064.JPG


I haven't removed the radiators (normal and AC) but am guessing they will need to come out.

The AC doesn't work at the moment so with the front off it could be an ideal time to get someone in to look at it!
 
The air-con condenser looks fit for the scrap pile, not surprising the system doesn't work.

Actually the rest of the car should probably follow it, are you sure that's the only rot in the car?
 
Dogbreath said:
Actually the rest of the car should probably follow it, are you sure that's the only rot in the car?
Click to expand...
A little harsh considering you have never seen the car and yes it's the only rot.

What makes the AC condensor look fit for scrap?
 
Tesla said:
A
What makes the AC condensor look fit for scrap?
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The fact that the tubes are corroded and the fins have become detached and pushed back into the core, and it has sagged badly in the middle. My MR2 one looked exactly like that and had the refrigerant holding ability of a colander. even if it doesn't leak it won't work very well.
 
Definitely an ideal time to replace it would be now then!

I'll see if my brother wants to go to the expense of sorting the AC out. If it hasn't been used for some time the entire system may be cream crackered.
 
Lopéz said:
You aren't allowed to bolt, rivet or screw the crossmember back on - it's not a satisfactory repair and will fail the MOT.
Click to expand...

On a side/comical note, in German your not allowed to weld it on you have to bolt/rivet it on. overzealous safety rules in place in both countries it seems, most likely implemented by bureaucrats with little to no mechanical knowledge.

Ahh health and safety rules, causing more trouble than their worth since the 1950's >.>
 
Have a welder coming out Tuesday, £50.

Going to get someone to look at the AC system too whilst the front-end is off, access is easy. There was no gas in the system as removed the battered condenser and radiator yesterday. Hopefully it's just a condensor, is there a way to test the rest of the system for leaks? Perhaps bridge the pipes between that would otherwise connect to the condensor?

My brother bought the car (Nissan Almera N16 1.8 Sport+) off of eBay. I didn't get involved too much, he needs to learn for himself (I've looked at cars in the past with him and gave him a check list). When I serviced the car a week or two after he bought it I then noticed the front crossmember was pretty bad, I went to pull myself under the front end and put my hand through it!
 
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