Sunday 1 January 2012

Tutorial: Hot Pin Test

After a busy Christmas the shop is back up and running, and I am busy trying to sort out more items to upload for the new year. One of the items I discovered on my treasure hunting sessions was a small crochet needle.

It is a lovely creamy colour, but is it plastic or bone? It is often difficult to tell, a lot of early plastics are made to imitate bone or tortoiseshell. So the question is, how do we tell? Luckily I know a nice little test to see which it is. Firstly, we have to do a health and safety talk.

WARNING: This test involves using a naked flame/hot temperatures. I would recommend using oven gloves and possibly a damp cloth when holding the hot pin. Also, please bear in mind that this test may damage the surface of the material you are testing.

You will need:

  • metal pin
  • metal tweezers
  • oven gloves/damp cloth


Method:
1. Get the item ready that you want to spot test. Choose an area on the material that is discreet in case the surface is damaged by the testing.
2. You will need a naked flame - we have a gas hob which is perfect. Light the gas ring - not too high mind, just so long as you have a small flame.
3. Make sure you put on the oven gloves or wrap the damp cloth around you hands and pick up the tweezers.
4. Using the tweezers pick up the pin at the blunt end and place the pointy end of the pin in the flame until it burns red.

6. Hold the pin against the surface of the material.
7. If it is bone or ivory it should not melt the surface (if the pin is hot enough it might burn slightly leaving a small dark mark but this did not happen during my test)).

8. If the material is plastic then it will melt the surface and small indentations will be visible in the surface (we tested the method on a toothbrush to compare with the crochet needle).



Remember, please be careful when doing this test, but good luck. What were my results? A beautiful bone crochet needle, look out for it on the etsy shop soon.

xx

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