Hello, thanks David, I didn’t know the chemistry so that opens my
eyes. Perhaps it was coincidental that we had a flurry of diamond
burning with the jeweler and handyflux I mentioned earlier in the
thread. She was a really bad technician to start with! When you say
excessive heat and the presence of Oxygen, are suggesting that a
reducing flame would eradicate or at least decrease this potential
problem? Also, why does the surface of the diamond burnt areas seem
to follow a fluid pattern similar or identical to the flux on the
surface? Dennis
are suggesting that a reducing flame would eradicate or at least decrease this potential problem? Also, why does the surface of the diamond burnt areas seem to follow a fluid pattern similar or identical to the flux on the surface?
Hi Dennis;
I think that when we are talking about the kind of heat that burns
the surface of a diamond, there is probably enough ambient oxygen
from the torch or the atmosphere to burn it in any case. You have to
get them well above a red heat for it to happen, but if there’s
combustible material on the diamond, that can increase the
temperature, especially with baguettes, which seem perticularly
susceptible to burning, but that may be also due to the grain in the
diamond when it’s cut that way. As for the fluid pattern, it’s
possible that what you are seeing is not the fluid pattern of where
the flux was, but the fliud-like pattern of where the flux wasn’t. At
any rate, there’s no good reason to get a diamond above a faint red,
and rarely would you get them that hot, unless you were in a habit of
doing prong work with 20 karat white weld solder, which some people
do. One thing to watch out for is re-tipping on platinum. You are
going to be limited to white gold solder (unless you have a laser),
but the platinum will act as a heat sink, so by the time you get the
solder and the metal hot enough to stick, you’ve been torching the
diamond for some time while heat has been soaking into the platinum
article, and it’s easy enough to overheat it. On a gold article, you
might start melting stuff long before. But yes, keeping the diamonds
well fluxed will help protect them, just don’t push you luck, it’s
too expensive.
David L. Huffman
I think that when we are talking about the kind of heat that burns the surface of a diamond, there is probably enough ambient oxygen from the torch or the atmosphere to burn it in any case. You have to get them well above a red heat for it to happen, but if there's combustible material on the diamond, that can increase the temperature, especially with baguettes, which seem perticularly susceptible to burning, but that may be also due to the grain in the diamond when it's cut that way.
thanks for responding. I agree with all you said. it makes sense
that it may be the lack of flux that shows up the burnt area. I
personally haven’t burnt a diamond in years. Then it was a little
set of 5 pointers in a ring that had been repaired poorly many times
by apparently many different jewelers. CAN of Worms. It was good to
pursue this thread, I just retipped a 2carat round Friday. Kind of
scary to do since we were discussing this. I used 14y medium solder,
very soft heat [propane], cleaned the diamond for 4days in strong
ultrasonic, steamed many times and then viewed the cleanliness thru
the microscope of my laser welder. I coated the stone as we have be
discussing with fresh alcohol and boric acid. I made sure that the
table was perfectly coated. This took a couple of applications. It
worked like a charm. I used to use 14k hard or 18k hard depending on
the ring. But so many rings are already worked on, I hate to chance
overheating for that reason as well. Hope we’ve all learned from
this thread. Thanks Dennis
I just retipped a 2carat round Friday. Kind of scary to do since we were discussing this. I used 14y medium solder, very soft heat [propane], cleaned the diamond for 4days in strong ultrasonic, steamed many times and then viewed the cleanliness thru the microscope of my laser welder. I coated the stone as we have be discussing with fresh alcohol and boric acid. I made sure that the table was perfectly coated.
Dennis why did you not use your laser to do the re-tipping? I don’t
have a laser but I had heard that this was one of the wonderful
things that you can do with one.
Just curious,
Jim
This comes under the heading of general curiosity, as I don’t do
repairs, but… Why does one retip with a diamond in place? If you’re
messing with the prongs anyway, why chance it-- why not just take it
out?
–Noel
Hi James, I didn’t use laser to do the retipping because of where
the break was. It was right at the culet of the stone. I suppose that
I could have cut the prong way back and lasered the prong there and
then reworked the bigger piece new prong. However, this stone is
mounted in a Belcher mounting. The prongs are more a part of the
ring than tiffany style prongs are. It would have meant a lot of
filing and forming. BUT the biggest issue with using the laser is
that you can get a cracked stone very easily. A laser is a beam of
light and IF it reflects off of the surface the metal, which it can,
you can bust a stone. I have seen a jeweler I know accidently destroy
an aquamarine, [not a cheap stone by any means], by a reflective
strike. There are all sorts of things that you can do to try and
prevent this. You can but mask over the stone, some folks use
toothpaste. But this is all messy and too risky for me. If you burn a
stone you can repolish, break it and it can be rubble.
Dennis
Noel, I ask the customer to consider replacing the mounting. It is a
Belcher 14k mounting. You can get them anywhere. this ring had had
every prong retipped at some point. You can just simply bend them
back and remove the stone. Who knows what will happen? Probably more
will break and the problem gets bigger. The customer declined to buy
a new ring. So… you do what you have to. I feel for the folks
who have to do shop repair work ,every job is an accident waiting to
happen. I don’t generally do repairs anymore. There were ‘office
politics’ involved with this repair. It was not a big deal, the man
is a nice guy and I fixed it up for him. I will probably get a nice
bottle of wine come the holidays!
Dennis
Jim,
I have to admit that I am also one of those who do not like to use
the laser for retipping, for several reasons. One is that I am very
skilled with my torch, and since diamonds can easily take the heat of
retipping, I prefer this method. The other reason is that I am still
very nervous about hitting the diamond with the laser beam. A diamond
can take the heat of the torch, but they do not react well to a laser
burst. If I cannot use a torch to retip a prong, and taking the stone
out is impractical or impossible, I will use the laser. My favorite
retipping tool is actually the Tack II welder…
I heard you were teaching a workshop on using the PUK welder. I
would love to sit in on THAT workshop. I have seen the machine
demonstrated, but it never seemed to do all that the salesman claimed
it could do. Yet I know that in the right hands, it can do a lot.
Since I am “retiring” and giving up my laser, I have been thinking
about the PUK. I know you like yours a lot.
Doug
Douglas Zaruba
33 N. Market St.
Frederick, MD 21701
301 695-1107
@Douglas_Zaruba
Jim,
I heard you were teaching a workshop on using the PUK welder. I would love to sit in on THAT workshop. I have seen the machine demonstrated, but it never seemed to do all that the salesman claimed it could do. Yet I know that in the right hands, it can do a lot. Since I am "retiring" and giving up my laser, I have been thinking about the PUK. I know you like yours a lot.
I also would be interested in a workshop on using the PUK welder. I
know we are both in the same part of the country. When are you
having it?
Janet
I also would be interested in a workshop on using the PUK welder. I know we are both in the same part of the country. When are you having it?
Yeah, count me in too. I’m going to buy one when I can get the bank
to loan me some money for it. How about the folks at PUK? Are they
doing this? I suspect ABI would help if their units were involved,
but so far, from what I’m seeing, PUK is a better product for less
money.
David L. Huffman
I have to admit that I am also one of those who do not like to use the laser for retipping, for several reasons. One is that I am very skilled with my torch, and since diamonds can easily take the heat of retipping, I prefer this method. The other reason is that I am still very nervous about hitting the diamond with the laser beam. A diamond can take the heat of the torch, but they do not react well to a laser burst. If I cannot use a torch to retip a prong, and taking the stone out is impractical or impossible, I will use the laser. My favorite retipping tool is actually the Tack II welder....
Thanks for this insight Doug
I heard you were teaching a workshop on using the PUK welder. I would love to sit in on THAT workshop. I have seen the machine demonstrated, but it never seemed to do all that the salesman claimed it could do. Yet I know that in the right hands, it can do a lot. Since I am "retiring" and giving up my laser, I have been thinking about the PUK. I know you like yours a lot.
There is a definite steep learning curve on the PUK 2. I now feel
fairly confident in my use of it but as you noted I have not seen
any salesmen demo it very well. I did see a German goldsmith at
MJSA Expo NY who was a true wizzard with it and picked up some very
useful tricks from him. Because I don’t own a laser it is hard for
me to give a balanced opinion but with that said I think you can do
most of the things that a laser can do with a PUK. I know there are
some things you cannot do with it but for a fabricator like
yourself I think it would be a great tool to add to your kit
I also would be interested in a workshop on using the PUK welder. I know we are both in the same part of the country. When are you having it?
Hi Janet,
It will be at the Revere Academy of Jewelry Arts next spring (April
22-23 2006). I am not sure when the catalog comes out but I know you
can get more from the folks at Revere (415-391-4179)
Hope to see you there.
Jim
Jim,
There is a definite steep learning curve on the PUK 2. I now feel fairly confident in my use of it but as you noted I have not seen any salesmen demo it very well. I did see a German goldsmith at MJSA Expo NY who was a true wizzard with it and picked up some very useful tricks from him.
So, OK. When are you teaching the workshop?
Doug
Douglas Zaruba
33 N. Market St.
Frederick, MD 21701
301 695-1107
@Douglas_Zaruba