Inlay 24K Gold into Palladium?

[davidshe]

Wondering if anyone has had experience engraving and inlaying 24K gold into a Palladium wedding band? I see on the Mohs scale of hardness that Palladium is about the same hardness as steel but not sure it would act the same. There is also a Palladium alloyed with silver which likely is not as hard and perhaps someone has tried working with that? Thanks for any input. ~David

 

[phil]

Gold 24 k will melt at 1053 deg C. Palladium at 1555. You will be able to melt the gold in directly to the inlay cavity.

 

[Brian Marshall]

I've done it, but I cannot remember which alloy I was sent to do it on? Was years ago.

It surely was not as hard as steel... I would remember something like that.

It was 24K wire and a small piece of sheet.


I can ask the company I did it for later on this week, but I dunno if they would remember the piece either?

Been a lot of changes among the guys who worked the counter since then.


Brian

 

[Brian Marshall]

Phil,


I would think that the surface tension of liquid 24K would prevent it from flowing far enough into a dovetail to securely lock the inlay in place.

Unless the palladium expands enough on heating and then shrinks back sufficiently onto the 24K "inlay"?


Never tried this specific combination, but have tried melting lower temp metals into cavities in higher temp metals over the years without much success...

This was done with torches as the source of heat. Modern day, inert atmosphere welders might possibly give better results?


Have you made it work yourself? What were the parameters?


Brian

 

[GTJC460]

I've done 24k into 950 platinum and red gold in to 950 platinum. Also did 24k into sterling.

The 24k was very simple and straight forward. The red gold was a real problem. The 24k into sterling wasn't easy, but I got the job done. The biggest problem was the softness of the silver.

I would think the palladium will respond very similar to the way the 24k/950pt worked. Although the palladium isn't as hard. You shouldn't have a problem. I certainly wouldn't turn the job down.

 

[davidshe]

Phil - along with melting the gold into the cavity of the palladium, have you also tried pounding gold wire into Palladium? If so, does the melting process work better for you than the typical gold wire inlay that is hammered in? If so, like Brian asked, what kind of dovetail or hooks did you use in the cavities and do you heat both the platinum and the gold to the same temp until the gold melts? Or?

Bert, were you indicating in your post that you inlaid the gold into the platinum by pounding in the wire or by the melting process that Phil mentioned?

Thanks to all for your input.

 

[Jan Hendrik]

I have also melted 24kt gold into cavities made in 950 platinum. You don't need any hooks or even a dovetail for that matter. Because the gold melts into the cavity it effectively becomes a solder that bonds with the platinum on a molecular level. The problem that may arise using this method is the formation of surface oxides during heating or carbon deposits accumulating on the surface that may prevent the gold from sticking to the metal surface. I suggest you heat the ring from the inside to try and prevent this from happening as far as possible. Also do short lengths at a time and pickle the metal between melts then ultrasonic clean before doing the next section. Let us know what happens.

 

[GTJC460]

I did all my inlays the same way you would do inlay/overlay on steel. I cut channel, undercut, AND raise small teeth in the channels.

24k into pt or pd is no prob. The 24k is like butter. It flows into the undercuts and teeth like grease.

 

[GTJC460]

Pd has a tendency to get black when heated. I would avoid trying to melt the gold into the cavity. If you flux it, you will then have issues with the flux.

You best bet is to inlay using mechanical methods. It's pretty straight forward. You can make the dovetail undercut pretty easily by just making a very simple "chisel" point. This will displace the edge slightly. Then when you hammer in the gold that edge will compress down on the gold to a certain degree acting like a "prong or channel" edge locking the gold in place.

I've done fairly complex designs using this method. I had one customer that wanted an inlaid Celtic knot style design all the way around the band. It was very time consuming, but worked very well.

 

[davidshe]

Thanks Jan and Bert for your valuable input. Very helpful and I appreciate you taking the time to respond. I will let you know later how this turns out.

 

[phil]

I was asked to inlay 24 k into platinum wedding bands. The project I had was to replicate a number of grand Prix circuits around the perimeter of these bands. Ie Monaco on one,Silverstone on another etc. This was before I was aware of any engraving techniques such as inlay and was therefore the only method I knew of. I excavated the cavity using a ball drill that was way undersized compared to the width of the line I wanted. This was so I could "tickle" open the line and refine it as needed. No undercuts are necessary as the gold is bonding to the receiving metal, the same way as solder does at a molecular level. I used .0.6 mmround gold wire and no flux at all. The ring was then heated with a microweld although a simple propane torch will work aslong as the flame is large enough. I then applied the wire the same as you would using wire solder. As long as the receiving ring is hot enough the wire melts and flows into it just as solder does. Excess metal does flow over the sides of the cavity, but of course once filed down to the original surface the clear delineated inlay is revealed.
It really was as easy as that and anybody with moderate jewellery skills etc will have no trouble at all. I was pleasantly surprised at just how well it worked. If I do those sort of jobs now I cut the cavity with gravers. I wasn't capable of that then. If you do have the odd pit hole then simply drill down over the porosity and push in some wire of the appropriate diameter and cut off about 2 mm above the surface of the metal. Go straight in with a savage flame and melt the excess into the hole( imagine oxy gas welding a platinum join).
As for inlaying engravers style then be careful of some palladium alloys as they are very soft indeed and although the 24 k will readily inlay you may find that the cavity width opens or distorts very slightly.
If I had to choose a method it would be to cut cavity using gravers. No undercuts. Heat ring and fuse wire into it. File surface. Cut ultra fine border along edge of inlay and blacken for contrast.
I hope this helps.

 

[Brian Marshall]

Platinum & palladium behave differently... and there are now dozens of new alloys.

Once upon a time, that wasn't the case. You never saw palladium jewelry.

Heads/crowns, yes, but not jewelry.

Back in the days before 50 kinds of gemstone "enhancements". Before the black, "coffee" & "tea" colored diamonds (formerly drill bit material) were flogged as "desirable".


Some platinum alloys can be flame welded/fused, some cannot. Some are "formulated" for the least amount of failures in the casting process...

I'd think it wise to find out what specifically you are working with. If possible test compatability with melting 24K inlay beforehand?

"Mechanical" inlay will almost always work. At least it has never yet failed for me?


Brian

 

[davidshe]

Phil - thanks again for the great info! Have you ever tried this technique with stainless/damascus rings or other metals?

Brian - thanks for your input. Can you recommend any particular precious metal suppliers that work nicely with a small volume engraver? Perhaps one that might even be willing to let you try out a sample piece of the metal you intend to buy?

 

[Brian Marshall]

Hah!

They will ALL send you samples... you just have to pay for them!


Most of the metals dealers and even refineries will now deal with small volume clients. (They lost most of their bigger clients during the crash)

You will however, have to fill out a 40 page form these days. You might be laundering money or aiding and abetting terrorists? Or hoarding?


No one can be trusted anymore... Try buying what were once common chemicals for depeletion gilding or patination - even more BS.


B.

 

[davidshe]

What I meant was before buying for example a platinum or palladium wedding band if it was possible to buy a small sample of the same material from a piece of sheet. But, probably not!

 

[phil]

www.cooksongold-magazine.com/articles/ISS4BULLION/bullion.pdf
This PDF contains the specific technical information and metallurgical composition for the platinum and palladium alloys that I have used and know work. You may be able to order them from your bullion dealers. As Brian says. There are a multitude of different alloys out there so if you are unsure then go for mechanical inlays.
I have only ever fused brass into steel, not precious metals.
I hope this helps. By the way. This bullion dealer will ship globally if you want the same alloy that I used.

 

[davidshe]

Thanks so much Phil, I will check this out.

Also, currently I only have small butane torches and I know that I will need to invest in a larger torch setup if I were to attempt this type of inlay process. I see some nice torch setups such as Smith Little and Meco but was wondering about using oxy/propane vs oxy/acetylene? Would like to buy just one torch setup that can do most everything related to jewelry engraving. My studio is in my attached garage. Input anyone? Thank you.

 

[phil]

Go for oxy propane over oxy acetylene. Its much cleaner. Oxy acetyylne is more likely to cause carbon embrittlement in platinum alloys. The little torch is a great setup and what I use. The sievert torches that use propane and draw the oxygen from the air are versatile but not hot enough for platinum work.

 

[Brian Marshall]

Meco... you can find or make tips to do practically anything with it. (The tips for all torches have gotten outrageously expensive - make 'em)

Although there is a Little Torch on one of the soldering stations here - I personally hate the thing.


Except maybe once every 10 years or so?... when I work on a platinum chain - which can be done better with a Hydrotorch anyway.


Brian

 

[Brian Marshall]

I agree with Phil - Oxy/propane.


B.