hot water dent repair/ modification

[driftwood]

I have heard of the boiling water trick to pop out a dent, and was thinking you could use it to do the opposite of a squash job (remember modifying playboats?) The idea would be to add volume in this case

Or instead of heating the water you could fill the boat with cool water after you had preheated the area you wanted to add volume. the pressure of the water pushing out would reform the hull or deck.

Crazy?

J

[arhdc]

For sure the idea of using cool water is a no go, the thermal capacity of the water is so far in excess of the plastic hull that you would just get cool plastic with no change in the shape. Water can almost instantly cool molten steel from over 2000 degrees to just warm in seconds.


From Wikipedia

Polyethylene is a thermoplastic polymer consisting of long hydrocarbon chains. Depending on the crystallinity and molecular weight, a melting point and glass transition may or may not be observable. The temperature at which these occur varies strongly with the type of polyethylene. For common commercial grades of medium- and high-density polyethylene the melting point is typically in the range 120 to 130 °C (248 to 266 °F). The melting point for average, commercial, low-density polyethylene is typically 105 to 115 °C (221 to 239 °F).

What this tells me is that even boiling water is not going to be able to do more than soften the plastic slightly with its theoretical maximum temperature of 100°C (212°F). The other issue is that unlike a squash job where you are applying the squash to exactly where you want it and you are merely changing the shape, to add volume you are talking about stretching the plastic into a larger sheet. To do this uniformly would be horrendously difficult.

If anyone out there knows different feel free to chime in. The physics/engineering just does not seem feasible to me.