Welding

Post by **maverick** » Fri Dec 25, 2009 12:11 pm

Someone told me that you can no longer weld patches on the chassis in order to pass an mot and that all repairs need to be new sections. He said that this new rule came along a few months ago?

Is this true or is he talking rubbish?

Post by **deano69** » Fri Dec 25, 2009 3:00 pm

I was chatting to my dads mate about him putting a repair panel on my dodgy chassis leg.He was saying that he was happy to put a patch on but much happier to use a repair panel and he's an MOT tester so im guessing from that that patches are still ok to use.

Post by **8009STEVE** » Fri Dec 25, 2009 3:10 pm

afaik so long as it is seam welded, then fine

Post by **kennatt** » Fri Dec 25, 2009 8:39 pm

as long as the patch is welded all the way round then its ok,but funnily enough if you put a new panel on it only needs to be spot welded as per original,so whats all that about then,new panel not secured as well as a large patch. I was talking to my mot.er known him for thirty years,and he says that he(by rights ) should now fail welding he did years ago cos he only used to tack weld patches on sills.Says he's not going to cos he thinks its a stupid reg but there you go.Its all getting a bit mad. Won't be long before they stop us patch repairing underfloors and chassis legs,then the scrapage scheme will claim loads of classics

Post by **taupe** » Sat Dec 26, 2009 1:26 am

Kennatt

I think there is good reason for these rules.

A panel correctly spotwelded as original will be virtually as strong as the original construction and will be as originally designed. Obviously the metal must be properly prepared for spotwelding and the weld strength tested as you would a seam weld.

The number of poorly applied patches Ive seen even fully seam welded is in my experience where weakness and corrosion lie hidden. All the rust cut out and a patch fully seam welded in without an overlapped rust trap = virtually as strong as original.

Post by **rayofleamington** » Sat Dec 26, 2009 4:13 pm

this new rule came along a few months ago?

if that rule had come in, we'd have heard about it on the forum ages ago - I think someone got their wires crossed.

The rules changed about a decade ago, that any repairs within 300mm of a structural area need to be as per originally manufactured, and seam welded. There is (and alwyas was) a contradiction, as complete panels were spot welded, and replacing complete panels by spotwelding will satisfy the 'original manufactured'. Patches however have to be seam welded.

As mentioned by Taupe, even fully seamwelded patches can be rubbish too.
Areas like the front chassis leg eyebolt area have additional strengthening hidden inside. Patching this area won't be safe if the inner strength is rotted away. I'd only repair this area if desperate, as it takes a lot of time to rebuild the inner sections - and a good end result takes as much time as replacing a half leg using the new section anyway!

Post by **maverick** » Tue Dec 29, 2009 12:24 am

Thanks for the help guys i can press on without doubt

Post by **rich-legg** » Tue Jan 05, 2010 1:27 pm

rayofleamington wrote:
this new rule came along a few months ago?
if that rule had come in, we'd have heard about it on the forum ages ago - I think someone got their wires crossed.

The rules changed about a decade ago, that any repairs within 300mm of a structural area need to be as per originally manufactured, and seam welded.

That's within 300mm of suspension mounting/components.