Welding question

[Mieran]

This might sound a bit daft but whats the difference between stitch welding and seam welding? :confused:

I've always thought that stitch welding is where you weld an inch and leave an inch gap on the seams. So whats seam welding then?

[Spudly]

That is correct, 'seam' welding is where you run a constant bead of weld all the way along a join.

From what i gather 'stitch' welding is far better in cars for strengthening them as it allows some of the natural flex of the metal/car to be retained:thumb:

[AlanH]

^^spot on spudders. when stitching chassis i use 'weld an inch, miss an inch'

[Mieran]

Yeah I've heard that a constant weld will do more bad than good and will warp up the shell

[L14MNP]

Stitching is mostly done due to it being easier and for in the event of an accident, the car can still crumple as designed - to an extent.

[AlanH]

yeah it makes the chassis too stiff, meaning that when the metal flexes during hard cornering etc. it will not return to its original shape, causing it to warp

[AlanH]

fancying a go at it yourself? just realised you're from newcastle. im local to you, let me know if you need a hand

[MK999]

If you seam weld it you're basically strengthening along the seams with a weak panel in between which has been heat treated and cooled, i.e brittle. This means when the panel flexes it will crack along the weld pattern, if you stitch weld instead it allows a little more flex while still strengthening the seam, and does allow it to crumple a tiny amount, although it's more for the reason of making the car last more than one track day lol

[Mike]

Seam - continuos line of weld
Stitch - dot dash dot dash type affiar

[Jack]

Plus if a weld fails on stich welding then no big deal, you have x number of other welds still holding strong. Where as with one continuous seam weld, the point of fail could weaken the whole thing, cause the rest to split.

[loggyboy]

Indeed, the main reason doe stitching is that if a weld fails, the crack is less likely to carry on along the whole seam. Same reason that people drill holes at the end of a crack in fibreglass, it stops the crack from spreading.

[draper]

although to add, my shell has been seam welded (and rallyed hard) and everything still measures up within a few millimetres - wether it stands upto my driving remains to be seen lol

[novasrikev]

although to add, my shell has been seam welded (and rallyed hard) and everything still measures up within a few millimetres - wether it stands upto my driving remains to be seen lol

when it ever gets on the road hahalol lol lol

[draper]

when it ever gets on the road hahalol lol lol


what can i say, waiting to get it painted took longer than trying to find a pretty feminist that will cook dinner without moaning :p

[BRoadGhost]

Jack's exactly right for the proper reason behind it.

[Bubba]

rule number one...make sure you wear a mask lol



i didnt :(

[General Baxter]

rule number one...make sure you wear a mask lol



i didnt :(

ummmmm :roll:

[shed-on-wheels]

i have my gte seam welded and also my sri was seam welded never had a prop they were both hard track cars the only thing my gte dide was crack where the tie rod bolts on the front pannel

[Sturge]

Generally these days when people refer to seam welding they mean stitch welding. Welding the whole seam is just plain daft as it causes more problems and adds more weight than you really want.

When stitch welding the general rule of thumb is weld an inch, miss 2 inches. Mark it all out first and try to work it so you have a stitch on as many of the corners as possible as this is where the stress concentrations are. Smaller components may benefit from weld an inch miss an inch, but as much from an aesthetics point of view as anything else. Also, don't get too carried away with where you're welding!
Apart from engine mounts and suspension pickup points you don't really need to go past the front or rear turrets as beyond these it's not critically structural. This will also leave you with something resembling a crumple zone if the worst does happen

hth