Instructions / Assembly
7 | P a g e  
Usage and Fabrication Guidelines 
WELDING  There are several methods for welding plastics. The most common are 
butt welding and hot air welding or gas welding. Note that welds on 
expanded PVC foam are usually not as strong as those of solid PVC 
Butt Welding  Butt welding is recommended for gauges 4mm and over. This method 
allows fusion by simply joining two ends together under pressure after 
ends have been heated to an optimum bonding state. This pressure 
must be maintained until the material is completely cooled. (see 
illustration 6) 
Hot Air Welding  Hot air welding is accomplished with the use of a hot air gun and a 
welding rod. (see illustration 7) The temperature can be regulated and 
this method allows great flexibility. Rods made of Type I PVC are 
preferred, but Type II can also work well. Welding is accomplished by 
feeding the rod through the gun and applying pressure on the rod as the 
sheet and rod are heated simultaneously. 
  For best results, the temperature of the air at the tip of the rod should 
be 680 degrees F. Welding pressure should be approximately 2 to 3lbs. 
depending on rod diameter. Under optimum conditions, welding 10 to 
18 inches per minute can be accomplished. 
INSTALLATION  Foam PVC is a low-density material that can be compressed relatively 
easily. When securing the material in place, make sure the clamping 
force is spread evenly over a large area. 
  All extruded products have grain determined by the direction of the 
extrusion which is the length of the sheet. The grain direction offers 
greater flexural strength when compared to the cross grain direction. 
Because of this characteristic, make sure the grain direction is parallel to 
the floor when making flag-type signs. 
  Note: 
  Most thermoplastics tend to become hard and brittle in cold 
temperatures just as exposure to wide variations in temperature and 










