I've read about this many times. Newest Hot Rod, SCC Mag. but don't know what it is.

What is stitch welding?

 

It's when you weld a little bit, skip a little bit, and repeat. In other words, it may be 1/2" of weld and 3" gap, alternating. This is done often when materials are thin or warpage are a problem...and having a solid weld seal isn't an issue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">It's when you weld a little bit, skip a little bit, and repeat. In other words, it may be 1/2" of weld and 3" gap, alternating. This is done often when materials are thin or warpage are a problem...and having a solid weld seal isn't an issue.</TD></TR></TABLE>

IE weld in roll cag to the floor of a uni-body honda

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">

IE weld in roll cag to the floor of a uni-body honda</TD></TR></TABLE>

Wouldn't they want a solid seld all the way around it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">

Wouldn't they want a solid seld all the way around it?</TD></TR></TABLE>

more of a chance for something to rip and keep ripping that way. This way you have less of a chance of riping up the whole floor. (it is legal in NASA) and my cage builder likes to do it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">more of a chance for something to rip and keep ripping that way. This way you have less of a chance of riping up the whole floor. (it is legal in NASA) and my cage builder likes to do it</TD></TR></TABLE>

I see your point about it ripping all the way if welded solid, but the part is more likely to start ripping if it's only stitch welded. Personally, I'd rather prevent cracks than worry about how to control them if they happen.

It's "legal" to do stitch welding in some situations, based on ASME and AWS welding codes... but what I'm asking is whether it meets the rules that have to be followed at drag strips and race tracks.

 

the plates for a roll cage have to be fully welded in... if persay ur building a 25.5 cage and decide on cutting the floor out... then u can go and stitch weld the floor in pieces back to the cage...

 

When SCC says that a car was "Fully Stitch Welded" they mean that all the seams in the unibody were re-welded. This is rather then relying on the (weaker) factory spot welds. Overall strength and stiffness are improved. Usually you don't weld the whole seam for the reasons already addressed. This is a common practice when building a racecar.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by magnet &raquo;</TD></TR><TR><TD CLASS="quote">When SCC says that a car was "Fully Stitch Welded" they mean that all the seams in the unibody were re-welded. This is rather then relying on the (weaker) factory spot welds. Overall strength and stiffness are improved. Usually you don't weld the whole seam for the reasons already addressed. This is a common practice when building a racecar.</TD></TR></TABLE>
From the factory, most car bodies are spot welded. This is where two pieces are laid on top of each other and RESISTANCE welded (not mig, not stick, not tig).

If you lift up your hatch on many cars, and look around the seal area you can see some small dimpled spots. You may have to lift the seal to see it. This is where a copper piece clamped the two together and a sudden jolt of power was put through the copper points. This is basically shorting out the machine for a split second.

Ever see on TV when they show an auto assembly line and they show a bunch of sparks come from one area, and they are very fast, and don't last but a split second? This is spot welding.

Now, in the mag article, they were likely meaning that where the two pieces were laped over, somebody put a weld (lap weld joint) that was not a solid weld fron end to end, but maybe an inch welded and an inch skipped and so on. This is not a commonly done thing really, and isn't costly either.