Walker Bay’s “High Impact Marine Composite” (HIMC)
hulls are an injection molded “poly-something” plastic, to which nothing will stick
Plastic dinghies are most often made from roto-molded polyethylene (PE), or polypropylene (PP).
Variations include cross-linked, super-linear, or blow-molded polyethylene.
Roto-molding is a process where polyethylene pellets are fed into a heated boat mold
, and the whole mold
is spun and tilted in several directions to distribute the plastic evenly.
Cross-linked and super-linear polyethylenes have a slightly different chemical structure than normal, which result in stiffer, and sometimes lighter plastic boats.
Blow-molding uses the same polyethylene as roto-molding, but a blob of molten polyethylene is injected with hot air into a cold mold. When the blob contacts the cold mold, it cools rapidly and the plastic takes on a harder, stiffer finish.
I’ve had “limited” success with “welding” (fusing) a repair on my polyethylene dink:
First you need to acquire some polyethylene plastic or a polyethylene Weld Kit*. Rough up the area with sand paper 80-120 grit, prior to welding, as well as in between welds if you've allowed it to cool.
If you've got extra repair material it might prove useful to do little test repair, melting one piece of repair plastic to another just so you know how fast it melts and how they bond together.
I have an electric
“fusing” tool, which works great on smaller repairs
, but a mini propane
torch works best ,since it's easier to get enough heat, and control it.. A standard propane
torch can also work if you keep the flame low.
Heat the repair plastic more than the boat itself. You would like the repair plastic to fully melt but not fully melt the boat, for obvious reasons. I heat the repair plastic first, and get it melting then apply it to the boat - heating
both together, and making sure not to overheat/melt the boat itself. After allowing to cool sand or surform excess plastic
Most people are more interested in making the repair waterproof than making it look perfect. If you're repairing a crack and the finished look matters to you, use a dremel type tool to cut a vee along the crack. Fill in the vee with plastic strips. Sand or sureform any excess for a smooth finish.
I’ve never used products such as:
is an epoxy
for hard-to-adhere materials like PVC, ABS, polyurethane
, vinyl and polyethylene* plastics.
*Polyethylene must be flame treated, see detailed instructions.