Hi,
I've been forced to DIY a bit of welding on this old car I'm doing up for the MOT which involves replacing a jacking point which was badly rusted. Never having used a MIG before (and don't it show) I made a bit of a mess of it. Question is, ugly as it undeniably is, would it make MOT standard as it stands? If not, how about after a couple of coats of really thick underseal?
Id say the final result looks reasonably consistent and working overhand is never easy, even when it's clean metal etc.
I can't see why not. They'll probably give it a few taps with a small hammer and if it doesn't fall off, say it's ok? ;-)
I think some of them like to see the repair before you cover it up, if it's been done 'for' the MOT etc. Not sure if there are any rules that cover such but coming clean at least removes the element of doubt.
Thanks for reminding me why I built the kitcar and it's nice heavy duty box steel ladder chassis and fibreglass body. ;-)
Cheers, T i m
I think the key point is whether it is near a suspension point. I assume of course that you have tested the structural integrity by jacking the car up to get two wheels off the ground, if it were mine I would overload it too by opening the nearest door and jumping up and down on the exposed sill.
My impression is that MOT testers are more cautious than they used to be, perhaps they are subjected to more random inspections.
*Personally* I would have discussed it with a tester first.
It may not be pretty but is better than some welding I have seen.
Once you cover it with black underseal or alternative it should look ok too.
The criteria is a continuous seam weld, if you're there the examiner might ask. He'll struggle not to agree that is continuous. Not long ago it was 25mm weld with 50mm gaps. The only test of it's structural integrity is firm thumb pressure. If it doesn't move and seems sound he'll should accept the repair.
His testing is limited:
Visual inspection Use finger and thumb pressure to assess the extent of the corrosion If necessary, carefully scrape or lightly tap the affected areas with the corrosion assessment tool
Use of the corrosion assessment tool must be restricted to ascertaining that the failure criteria are met and not used for heavy scraping or poking of the affected areas.
FYI the corrosion assessment tool is a joke. Most testers don't use one but obviously have one at hand just in case they have a visit from an inspector.
has it already failed mot on that section of floor best thing is to take it to the garage and ask them to take a look ?most? garages want to keep you as a customer and are happy to help.
Unbelievable. Just as well you provided a source or I'd have assumed you were joking. Dunno what I was worried about, then!
ISTR back in the day ('70s) they'd use a massive screwdriver and jab it violently up against any suspect areas, thereby exposing all the chicken wire and scrunched-up newspapers. Regs must have got relaxed since then, I guess.
Glad it was of use. I would paint it up or use black goo. Obviously it's going to look new unless you can make it age, so the repair will be obvious.
Structural failure is rare where by far the majority of accidents are down to driver error or misfortune. To be honest visual inspection and feel are pretty good at gauging corrosion and perforation.
I genuinely don't think a tester would fail your repair. You may wish to post the same question in uk.rec.cars.maintenance as there are some there who don't frequent this group and may have more experience.
I have only known one instance many, many years ago where a tester nicely perforated a sill with a screwdriver.
The problem is what happens to the crash resistance if the vehicle is involved in a crash ?. What might be fine for a general runabout might not provide the occupants with the same degree of protection that the manufacturer designed at anything faster than 30mph after an impact.
30 years ago, I occasionally saw 10+ YO vehicles involved in minor crashes and the hidden rust was spread all over the road, with serious deflection and distortion of the body shell. These days that doesn't seem to happen (though that might be because I don't go out for 50 miles bike rides any longer so I miss them). Mark 1 Ford Ka's were notorious for rust even at 7 years old but the newer models seem better.
Back in the 1960s, I was introduced to a car body repairer: George, the only person I know who can weld two pieces of rust together
The trouble is that heavy scraping or poking is liable to damage the protective layer of paint and promote rusting, so they could be accused of causing damage.
Lighter poking, maybe with a piece of wood, would likely reveal any serious corrosion with holes or flaking layers and with no real chance of damage.
Looks like you could grind the welds down a bit more. Do they seem to have penetrated both bits of steel? Looks don't much matter, but I'd need to be sure the weld is strong. Covering it up with gobs of underseal is going to make the tester look far more closely. And rightly so.
That's the main issue with MIG: you can't really tell! The truth is I just don't know. I've jacked it up and belted it with a club hammer and it ain't goin' nowhere. HOWEVER, whether it would survive intact after a smash is another matter altogether. A complete unknown.
If you're going to have a head-on in a Ka you've basically had your chips, rust or no rust, you ain't coming out of it with a pulse.
actually you are wrong. head ons are well catered for. Its side impacts that are worse
I remember watching a racing mini go straight on into a concrete wall at
100mph with only a layer of tyres in between. It jumped about 6 foot in the air, crashed down on its wheels, and the driver got out and swore loudly.Wasn't much left in front of the firewall, but it did its job, and leaping in the air slowed down the deceleration in the passenger compartment.
Of course it had a roll cage, which a Ka doesn't have, but a Ka doesn't do 100mph either...
"Ford Ka gets zero star safety" is the title of the clip you've cited in support of your claim?? I'll give you ten out of ten for humour if nothing else! :-)
I'd try belting a few random globs of weld with a hammer and punch. If they stay in place, they'll have penetrated.
I'm an expert at really bad welding. Despite practising and even modifying my MIG to give a better slow speed wire feed, I've never mastered welding thin stuff.
What type of wire do you use, and what was the shielding gas?
Cleanliness is key. It's tricky to get the feed right at low currents and any contamination of surfaces will create vapour that destroys the shielding gas properties.
I found gasless wire might be good outside but gives a pretty poor result.
That gassless process is not suitable for thin guage metal IMO. It's too close to MMA welding and it's far too easy to blow holes in thin stuff. For car panels, you really must have plain steel wire and CO2/Argon 15/85 or thereabouts.
I couldn't use an old fashioned transformer stick welder to save my life, but I find I can weld thin stuff better with a Lidl inverter MMA than with MIG gasless.
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