Spud Gun Building Materials
Spudguns are typically built out of plastic pipe as it is cheap and available. It is also quite durable, but other options remain for experiemnters or those with bigger budgets.
Plastics
ABS (Acrylonitrile butadiene styrene) - Another popular plastic piping material, more expensive and less common than PVC but available in the same sizes and pressure ratings. Unlike PVC it is used in compressed air systems as it splits rather than shatters on failure. It also has a greater temperature tolerance (-40°C to +80°C compared to 0°C to +60°C for PVC).
Both PVC and ABS piping are also available in forms which are not pressure rated. Use of unrated plastic piping and fittings is a common source of cannon failure and poses much more of a risk to a cannon operator.
Metals
Steel - The very high pressure rating of steel piping makes it a familiar sight on high-powered hybrid cannons. It is however much more expensive than any other common piping material. The extra weight and joining difficulties are also a consideration.
Copper - As a common plumbing material, copper pipes and associated fittings are readily available. They have higher pressure ratings and flow compared to similar plastic piping. The drawback is that copper is up to four times the cost of PVC or ABS pipes of similar external diameters and of greater weight.
Aluminium - Aluminum is a lightweight metal with good corrosion resistance. Aluminium pipes are sometimes used as barrels on spudguns on their own and machined aluminium is a popular material for particularly unique designs.