differences in plat casting quality at different jewelers?

[ragtop]

hi all-

i''ve read a ton of great posts here (thanks everyone!), and it sounds like a lot of people get custom settings made, but i haven''t seen much discussion on this particular issue.

background: i want a platinum solitaire setting that is a custom design at one of my local jewelers (in the sf south bay)...it''s a very simple piece, just extremely unusual in the sense that amongst the thousands of designs i''ve looked at, it''s very rare to see something that even resembles it...this particular jeweler''s in-house work looks beautiful, but there''s only one smith and the lead time estimates range from 6wks to ??, and although the setting is heavy, they are also on the pricy side...soooo, i''ve been asking around at other jewelers about their lead times and getting rough ballpark prices based on a description of what i want. timewise, i''ve heard 2wks, 3-4, and 6 at other stores, and pricewise, anywhere from ~900''s, 1100/1200, & 1300/1400 (the original runs 1600), so i know that i can get it done faster and a fair amount cheaper elsewhere.

what i''m wondering is, are there different methods of producing the metal setting that will affect appearance and wear later on that i should be questioning the jewelers about when i''m doing my comparison? i thought i understood the process (communicate your design to the jeweler, who creates a wax for you to try on and tweak before they cast it, make sure it''s 950plat, etc.) but i heard from joe escobar diamonds in campbell that they send their designs to a third party to cast because the pieces come out less porous - got the impression this was a factory of some sort that''s capable of a more heavy-duty process. now, this is the first time i''ve heard anything like this after visiting stores like derco, willow glen jewelers, ida''s, etc., so i''m wondering if pieces done at any of these other places will be less durable/strong if in fact the casting is done on-site? or was this just a sales pitch? does anyone else have any other tips on what to consider when choosing a jeweler for a custom project?

thanks for any input!
-ragtop

 

[strmrdr]

There is some differences in the finished products depending on which machines were used to cast them given the same alloy.

The biggest difference between the $5000 and the $20000+ casting machines is how well they control the temperature, how much metal they hold in the flask and how much centrifugal force they inject the metal with.

Bottom line:
more precise temperature, more metal (weight) behind it and the greater the force its injected with the denser the final result is.

My designer despite having a couple of the low end machines ($5000) in his shop farms all his final casting out to a big firm with the better machines.

To give you an idea of how much metal is involved the place he uses guarantees that the flask has at least 3lbs of gold in it for every cast.
We didnt talk about casting plat. but it should be similar.

 

[sciencegeek]

I would recommend going to a local jeweler where you can see many samples of work done in house. My ring is also custom, and it was made by Whiteflash. We went with WF based on all the rave reviews they get on this site and because it was $300-500 cheaper than estimates we got from SF Bay Area jewelers.

However, when we received my ring, we were not satisfied with the quality of the workmanship and ended up sending the ring back to be remade. From the looks of things the new ring is much nicer, but I don''t have it yet so I''ll reserve judgment. My fiance and I have two main thoughts on custom rings now:

1. The lowest bidder isn''t necessarily the right choice. Even with a relatively simple design like mine, I would hope that the extra $$ goes into extra attention to detail in the casting and care when polishing the platinum. My admittedly high expectations (I inspect under magnification) were not met the first time around, and we''ll see how I feel about the new ring once I receive it. Can''t help but wonder if paying the extra money at a highly recommended local jeweler would have prevented this and I would be wearing my ring right now instead of having to give it up for 3 weeks.

2. If you have specific ideas about what you want, getting the ring made may be an iterative process- you tell the jeweler what you''re looking for, he makes sketches, you modify them, he makes the cast, you comment, etc. This is easier if you can actually sit down together to go over things. When there were problems with my ring, conveying them over the phone was difficult and pictures often don''t capture what you want them to.

Pictures of my old and new rings are here

Hope this helps and good luck with your ring!

 

[ragtop]

sciencegeek-

i haven''t even seriously entertained the idea of having any of the online vendors to the setting, because i agree, i think it would be too hard to do long-distance even though it is a simple design. i''m still toying with the idea that i might just have to bite the bullet and wait for the original shop to do the minor tweaking i want, at the higher price, just to be sure it''s exactly right...

sorry to hear of your woes...hope the new ring is just right!

-ragtop

 

[ragtop]

steve-

wouldn''t greater porosity in the cast platinum mean that it''s more likely to pit later on? or am i confused about the importance of this?

i''ve also read some posts about platinum being soft if not properly hardened: is there any way to check for this when you accept your finished product, or is this one of those things where you just have to trust in your jeweler''s good reputation?

thanks!
-ragtop

 

[PhillipSchmidt]

Hi,

All super-heated platinum is soft (annealed). It is hardened when it has been worked on. This relates to hand-forged and cast metals, as hand-forged platinum will have been heated to solder the setting head. Cast metal needs more ''work'' to harden it after casting.
Working a metal, refers to the forging process, where you roll the metal through heavy-duty rollers, beat it with a hammer, draw it through draw plates etc. All this puts a grain on the metal and increases density. It will always polish better then cast metal of the same calibre of alloy.

Hand-forged plat is a different alloy. Casting alloys in plat are designed to run better in the cast. I have never seen porosity in bought stock. (Gold melted in the crucible can be porous, but rolling out the stock makes it dense and if the metal was rich, and the flame or furnace, ok, it will always roll out perfectly) I have seen disastrous porosity in platinum casting. I only use those with the expensive machines, but I don''t have a casting machine anyway. Gold will come out fine, if everything is timed and weighted right. You may struggle with detail on centrifugal machines, depending on the alloy.

Platinum casting is a specialists job.

Hand-forged metal is better for many reasons, but not always noticeably. I for one will cast platinum on any design that doesn''t lend itself to forging. I prefer to cast a whole plat ring and avoid soldering. I don''t like plat solder. It isn''t 950.

950 is not as good as 900/100 iridium, as I am led to believe. The iridium alloy has more platinum by volume them 950/50 cobalt, by far. It will polish better and have a better colour. The same cant be said of 950/50 iridium which is too soft.
You could ask for a platinum alloy without cobalt. See how you go. (Cobalt is rarely porus, but it is just not that nice a metal. 90% of platinum is a cast cobalt alloy). For me in Melbourne, there is no other casting alloy available without supplying my own. Pitty for us...

I would go with the first guy. 6 weeks lead-time, may suggest he is busy and for a reason. Price is neither here nor there. The same thing can always be produced in half the time. It is not as simple as you might think and the jeweller knows how far to go before he will be satisfied with the result.

Hardening the setting etc is a matter for the setter. It depends on what tools he uses and is comfortable with. Some settings need a bit of help in the strength department. Planishing the setting helps.

Plannishing is where the metal is beaten. You need a small hammer or other planing devices to planish a ring, but there are many burnishing methods that work as well (that is where you rub the metal, with steel). Jewellers who use a hammer attachment on their drill when setting don''t have a problem with soft (annealed) platinum, but this is a crude tool and not highly regarded (especially amongst those who mainly work with gold). It is very helpful in platinum cast rings as you will get a polish akin to forged metal. I would notice, you might not.

Last of all, porosity will mostly likely show up after the ring has first been polished. When it is nice and clear you shouldn''t expect it to arise at a later date.

I hope this helps or at least you are not more confused then you started,

Phillip

 

[ragtop]

thanks so much, everyone!

phillip, your info is tremendously helpful...i have a much better idea what goes on behind the scenes, so to speak, and i''ll be sure to ask about iridium rather than cobalt...thank you!

never ceases to amaze me how much fantastic info is available in this forum...

-ragtop