Let’s Define Pinchwelds
For as long as I can remember, the term pinchweld has been used to describe the part of the vehicle on which we bond the glass. During my many years of training, defining a pinchweld was one of the most important preliminary steps to explaining automotive glass installation.
I speculate that the first use of the term was back in the days when windshields were transitioning from being in a surrounding frame fastened to the body by nuts, bolts and screws, to being attached to a portion of the vehicle that was formed by pinch welding the steel-outer skin to the steel of the vehicle frame. Referring to the “pinchweld” was easier than saying “windshield bonding flange.”
However, the pinchweld is not as easily described as it appears, though most automotive glass technicians know exactly what you are talking about when the term is used in context. So, I thought for the good of history I should attempt to define it completely.
First, the pinchweld is a term with a couple of parts to it. The floor of the pinchweld is the part that we bond the glass to or wrap the gasket around. It is, also, obviously where the term gets its name. It is here where the actual weld is formed. The wall of the pinchweld is the part that was used to attach clips so mouldings could be attached in the past. More recently the wall of the pinchweld is exposed for appearance and economic reasons.
There are also different types of pinchwelds. The “L” shaped pinchwelds are the most common and have been used on all sides of the window opening. The “flat” pinchweld is primarily used on the “A” pillar but has been used on the top pinchweld on convertibles. The “Z” pinchweld is exclusively used on the lower pinchweld and consists of the steel portion of the dashboard, the bonding portion of the frame and the upper portion of the firewall/cowl drain.
So here is the true meaning of the term “pinchweld” as used by the automotive glass professional. For those out there who are learning or researching the trade, now you know what we are talking about when we say, prepping the pinchweld for bonding. For those who have been referring to pinchwelds your whole career, now you know the differences between the different pinchwelds and their parts.