continueous weld or inch welds?

[sprayerDrew]

Hi guys what is the reason. For when people put a wheel arch repair in or any patch and only do small inch welds every 3Inch or some will continueous weld all the way around? will the filler split if it is not continueous welded.

 

[the snooper]

the repair is much better when fully welded but its better to do it in very small stages so it doesnt distort the pannel as much.
an inch weld every three inches used to be allowed for mot repairs but ot any longer

 

[brightspark]

its not structual so theres no need to weld all the way

 

[the snooper]

its not structual so theres no need to weld all the way

stops movement and filler cracking though especially when the filler is thin

 

[brightspark]

stops movement and filler cracking though especially when the filler is thin :d

rite learning all the time

 

[langy]

Its to cut down on warping the panel, best done in short bursts if its an open panel, nothing to do with filler i'm afraid.

 

[Chickenjohn]

tack weld the panel once every inch, then join the tacks with a number of short pulses of weld- see "thin metal technique" under Mig welding tutotial on this site.

I would weld the two panels together continuously but by running a fraction of an inch of bead at a time, allowing a few seconds to cool between each pulse of weld. The idea is to minimise distortion by minimising the heat you put into the panel, so this minimises the amount of filler needed to flat the panel before paint.

 

[the snooper]

Its to cut down on warping the panel, best done in short bursts if its an open panel, nothing to do with filler i'm afraid.

so you obviously didnt read the the thread properly then

the question was
only do small inch welds every 3 Inch or some will continueous weld all the way around?

i said it was best to fully weld if you dont cracking can occur with any movement in the pannel

 

[Ratcatcher]

If the welding is done on a motor vehicle then it's got to be a full weld these day's,tack or stitch welds will leave you with a severe headache at mot time.......
A mate of mines been an mot inspector for years and if a motor fails for poor body work etc he requires it to be sorted and re-tested before you have it painted,might be o.t.t but he can't pass it until it's been proven that it is fully welded..........

Rat.

 

[the snooper]

that only applies to anything structual ie you could tackweld on new wheel arches and it would be fine.
just as some parts of a vehicle can have a hole rotted through and still pass the mot

 

[biosbill]

I was under the impression that the MOT reg's required the repair to be "fully seam welded" which makes sense. But I don't see how you cant get a pass (I just did..!) from stitch welding, but ensuring all the gaps are filled in. Without using this technique I wouldn't have been able to do mine as the steel was so thin!

Cheers,

William

 

[Chickenjohn]

I think there is some confusion here.

The welded seam has to be continous, i.e. no gaps but that does not mean you have to weld it in one go. Tack the repair piece in and join the tacks with a continuous seam made by pulse welding, allowing time to cool between pulses of welding.

Really, this is the only way you can mig weld car bodywork without blowing loads of holes.

 

[volition82]

It does make me chuckle, 'it must be welded to mot standard' or 'I can weld to mot standard'. What standard, there isn't one! I'm guessing that the vast majority of mot inspecters no very little about welding and as long as a plate is 'stuck' on their happy. Welding a plate over the top of a hole doesn't really do a lot to improve the strength of the structure but I suppose it's better than nothing.