Lately I’ve been getting interested in heat-welding plastics, and so far some of the best practical, hands-on advice I’ve found within the tubes comes from this black-and-white Seelye Model 63 Plastic Welder manual posted over at amphibious / all-terrain vehicle enthusiast site 6×6 World.

It’s posted as low-to-middling resolution JPGs, so the quality isn’t great, but it’s definitely readable/usable.