Plumb Platinum Solders

The physical strength of this solder is very high.  Plumb solder works well on all common platinum alloys. That includes Iridium, ruthenium, palladium, cobalt and copper. I want to point out that all high temp solders have a potential problem with some platinum alloys-Simply based on the relatively low melt temperature.    A common frustration with repair platinum solder is the tendency to polish out and leave a seam. Plumb solder more closely matches the rest of the item.

PT-E   is 90% Pt, and 10% alloy, and flows in the  1300C range-Our easy flow solder. As the name implies this is our easy flow solder that is plumb (same content as the intended jewelry) to all the 90%Pt/10% Ir or Ru or whatever. Its color is closest to 90/10 of course.

PT-M is 92.5% platinum. The way to increase the flow temperature was to increase the platinum. This material flows in the 1400C range. This is our medium flow solder. Its color works with any kind of platinum jewelry, but is only truly plumb to 90/10 jewelry.

PT-H is 95% platinum. The highest flow among the new solders, it flows at 1500C or a bit less. We call it the hard flow solder, despite the fact that its flow temperature is hundreds below the flow of ordinary casting platinum. It is plumb or better to all platinum jewelry.

A few rhetorical questions

What is really in silver solder?   Silver of course in varying amounts but lots of silver.

What is really in lead solder? Lead of course, even though we use it on copper pipe most often!

What is really in gold solder? Gold, and most often in the same percentage as the rest of the jewelry.

What is really in Platinum solders? A different story. 

In what should be called platinum repair solders, a necessary lack of Platinum causes the addition of substitute metals intended to pull down he flow temp while providing color and strength. All of us in the platinum solder trade use substitute metals for flow and or color. Bench jewelers must be very careful about what brand of solder they use so as to avoid problems. One gets accustomed to a particular brand of solder, and any change requires adjustments along the way. All of these shortcomings help the new laser solder machines look good. In addition to keeping the heat close to the work, a laser welded joint matches color perfectly. The cost however is still in excess of $20,000 for each machine. Many jewelers tell me of how they learned to weld rather than solder platinum due to quality concerns. They want the best finished result they can get.

Lets examine the metals we commonly substitute for platinum to make repair  solders.

1. Nickel-Remember all the trouble cause by Nickel in white gold? We usually work to keep nickel out of jewelry where it is practical to do so. Europe prefers no nickel at all.

2. Silver-This is hardly a metal commonly associated with platinum jewelry, but it provides important properties to conventional platinum solders.

3. Palladium-Too high a melt temperature to help much at all, but it is the very common element found in higher temperature solders. In recent months cost has become a big factor with this important element.

4. Gold-Wrong color and too high a temperature to solve the flow.

These repair solders do have shortcomings

Poor color, porosity and some very visible seams just to name a few. This is often fixed with rhodium plating, but that is another unneeded expense, and rhodium will wear off with time, which can disappoint the buying public.  Due to the unique nature of platinum, we always had to compromise the platinum content of the solders.

Sometimes in the higher temps we find some Platinum but only rarely below 1500C. In these solders we do not find platinum content even closely approaching the content in the jewelry. I must point out that all of the above applies to the solders made by PMWest, just like anyone else making solder for use on platinum.

At 1500C there is typically from 10% to as little as 0% platinum content.

Platinum solder rarely really deserves the title platinum. As shown before we usually name a solder by its main ingredient rather than its use. Ever heard of  copper solder?’ Of course not plumbers and electricians use lead solder for that. I do not mean to imply any deception was ever intended. Platinum, as we well know from bench work and casting is a very different animal than gold. Astronomic temperatures cause all kinds of difficulties, many of which are best solved by solutions published by PGI! I refer to all those books from previous platinum days.


Please note all prices are estimates per penneyweight aka dwt. There are 20 dwt to the Troy ounce and convert to grams at 1.55gm per dwt. The above pricing reflects credit card payment. Discounts do apply for immediate payment via wire transfer or check.

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