Friday, 2 October 2009

Commentary and criticism - plastic welding

Thanks for all the positive views about on my work expressed here, personally I feel that although my technique has improved over the years , my eyesight and brush control is not as good as it was. However praise is always gratefully received, as well as constructive criticism.

At times, I am asked how I achieve a particular effect, and wherever possible I will try and respond, but sometimes it is difficult and I admit to failing to respond on my plastic welding techniques for adding lances and poles to standard bearers. This is not due to lack of interest or desire to share knowledge, but rather the difficulty of defining a very subjective technique.

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Adding a metal lance/pole is tricky as the metal has to be warm enough to melt the plastic but only as such as it will rapidly harden back again again around the pole. This is dependant on three/four factors:
  • The thickness of the metal pole - if it is to thin the heat rapidly dissipates and the plastic just melts without reforming over the pole (with or with out help) too thick and the plastic will just melt completely away from the pole, as a general rule thinner is better.

  • heating the relevant pole sections - it is difficult to old the wire without injury so I use a pair of pliers to hold the metal while heating in a candle while ensuring most heat is concentrated on the points of contact. A rule of thumb is a count of three is a weld and a five will cut.

  • adjusting the technique for the figures plastic - some figures have a much lower melt point such the Mars which causes major difficulty in getting the right heat into the wire. Some such as the new Italeri have the opposite effect and several attempts are needed before the pole is fixed in place

  • Finally there is physical assistance (with care) - if the pole is still warm (hot) it is possible to close the models hand securely around the pole. gentle pressure with small nosed pliers is often all that is needed.

Obviously taking photo's of the above in progress is far to risky.

Alternatives and other techniques

Welding plastic lances/weapons - sometimes it is not possible to use a metal lance/pike/pole because of the stance of the figure or the weapon can't be replaced by a simple metal rod. In these cases I either use:

  • Most recently Loctite super plastic, the two part starter and super glue set to fix the item in place.

  • or traditionally, positioning the weapon and then heating a pin (see below) in a candle running it along the join to fix the weapon in place.

The pin is firmly held in a pin vice so that it is easy to (use just like a brush) I also use it as a means of "removing flash" then heating it and then runing it along the moulding line

1 comment:

Andrei Smith said...

Hey mate, these techniques are awesome!

Plastic welding is such a difficult process to master. I usually have a hard time working on hot plate plastic and welding large and irregular plastic parts with contours and joint lines. I guess, it's a matter of time. Practice makes perfect.

-Andrei
Midwest Metal Products