A hand-held hot-air welder melts small spots or a light continuous line along the overlap, holding the sheets together while the gun lays the bead. Tacking is used around patches, boots and detail work. It carries no design strength, and heavy tacking that scorches the sheet is a defect in its own right.
Heard on the job
Tack the patch down all the way around first, then come back with the gun.
Also heard as
- tacking
- tack weld
- hot-air tack
Related terms
Extrusion weld
Geomembrane seam made by laying a bead of molten polymer along the edge of an overlap, used for patches and details.
Patch
Piece of geomembrane extrusion-welded over a hole, defect, destructive sample cut-out or failed seam section.
Gun
Installer slang for the hand-held extrusion welder used on patches, boots and detail welds.