When butting up the PUR adhesive, most windscreen fitters are taught to run past the starting point and overlap the joint. This technique envelops the join, and is the easiest one to program the OEM robots with. Is this the best way? Why does it matter?
This joint measured about 50mm in width, more than double the industry average. So what’s the issue? It’s a joint, and other than the somewhat abstract appearance, it looks like it ‘did the job’, right? Here’s what it looked like on the other side after cutting through it with a sharp blade:
As you can see on the left hand side, there was very little adhesion; about 4mm in fact. The shiny bit to the right of the image is cured PUR which was not making any contact with anything. If it’s not making contact, it’s useless; superfluous. A waste of product material, and potentially a catalyst for a defect in the windscreen, or glass performance.