A possible cause of the equator depression. Re the "split" around the seam on the second heating, I've never seen raw gutta percha but at the start of the video it appeared to have a slightly fibrous element to it. Many polymers are fromed from strings, if gutta percha is the same, then when it was compressed in the mould the surface layer would have been squeezed out to form the fin and some of the fibre strands forced out too. Then cutting the fin off would cut the fibres and create a weak point so that when reheated the ball would expand slightly and the cut would separate.
That's really amazing, thank you for the video! My only question is where could one find GP? Is it something you can just look up online and purchase or would it be better to go to a certain type of store and look for it?
here's what I've learnt... it is very very very difficult to get hold of natural gutta... in fact somebody stated that none...zilch...had been commercially produced since 1995 in Malaysia and even then it was about 500 GBP per kilo!!! The piece I obtained is at least 40 years old. I am considering chopping it into ball size lumps and selling it.
@@timewarpgolf I guess this means dental gutta percha points have been produced with backstock inventory of raw gutta, then? From everything I can find in the dental literature, endodontic gutta percha points are still made using natural gutta, along with fillers and rheological modifiers.
Would it be fair to say a professional ball maker (no disrespect intended) would be able to estimate the weight of the GP needed, rather than using 3 seperate pieces, which seems to me to have an inherent weakness. But that then raises the question - did the ball makers ever use all those trimmings to make balls ?
yeah, they no doubt became skilled at taking a much more accurate chunk. I also seem to remember it came in "rope form"...i.e a rolled sausage so much easier to gauge.
A possible cause of the equator depression. Re the "split" around the seam on the second heating, I've never seen raw gutta percha but at the start of the video it appeared to have a slightly fibrous element to it. Many polymers are fromed from strings, if gutta percha is the same, then when it was compressed in the mould the surface layer would have been squeezed out to form the fin and some of the fibre strands forced out too. Then cutting the fin off would cut the fibres and create a weak point so that when reheated the ball would expand slightly and the cut would separate.
yep, that seems very logical. I think you've got the nail on the head...thank you Nick.
Where does one find a big slab of GP like that?
That's really amazing, thank you for the video! My only question is where could one find GP? Is it something you can just look up online and purchase or would it be better to go to a certain type of store and look for it?
here's what I've learnt... it is very very very difficult to get hold of natural gutta... in fact somebody stated that none...zilch...had been commercially produced since 1995 in Malaysia and even then it was about 500 GBP per kilo!!! The piece I obtained is at least 40 years old. I am considering chopping it into ball size lumps and selling it.
@@timewarpgolf I guess this means dental gutta percha points have been produced with backstock inventory of raw gutta, then? From everything I can find in the dental literature, endodontic gutta percha points are still made using natural gutta, along with fillers and rheological modifiers.
Would it be fair to say a professional ball maker (no disrespect intended) would be able to estimate the weight of the GP needed, rather than using 3 seperate pieces, which seems to me to have an inherent weakness. But that then raises the question - did the ball makers ever use all those trimmings to make balls ?
yeah, they no doubt became skilled at taking a much more accurate chunk. I also seem to remember it came in "rope form"...i.e a rolled sausage so much easier to gauge.