Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Fresh solder generating more dross

Chrys

#14222

Fresh solder generating more dross | 16 September, 1998

Hi Folks, Need to draw upon the vast expertise in this forum... Whenever you fill a new wave solder machine with fresh bar solder, it seems to produce more than the normal amount of dross for a few weeks. I always understood this to be the solder "cleaning itself out" for lack of a better term. Even fresh bar solder comes with some dross included in it. Yesterday I was told (by a solder supplier)that the extra dross formation is due to the iron in the walls of the solder pot. Until the iron oxidizes from the heat of running, it catalyzes dross production in the tin/lead solder. This is a new one on me, but I'm a gear head, not a metallurgist. Can anyone confirm or deny this theory? Thanks.

reply »

Chrys

#14223

Re: Fresh solder generating more dross - C'mon, you guys! | 17 September, 1998

| Hi Folks, | Need to draw upon the vast expertise in this forum... | Whenever you fill a new wave solder machine with fresh bar solder, it seems to produce more than the normal amount of dross for a few weeks. I always understood this to be the solder "cleaning itself out" for lack of a better term. Even fresh bar solder comes with some dross included in it. | Yesterday I was told (by a solder supplier)that the extra dross formation is due to the iron in the walls of the solder pot. Until the iron oxidizes from the heat of running, it catalyzes dross production in the tin/lead solder. | This is a new one on me, but I'm a gear head, not a metallurgist. Can anyone confirm or deny this theory? | Thanks. **************************************************************** An entire day and no respone??? Come on, somebody's got to have some insight on this. Wayne, Moon Man - anybody home? Jusitn - you've got input on EVERYTHING; Steve, no wiseacre remarks with a big GRIN? I can't believe that something as simple as a solder question could stump THIS forum of experts... ;-)

reply »

Steve Gregory

#14224

Re: Fresh solder generating more dross - C'mon, you guys! | 17 September, 1998

| | Hi Folks, | | Need to draw upon the vast expertise in this forum... | | Whenever you fill a new wave solder machine with fresh bar solder, it seems to produce more than the normal amount of dross for a few weeks. I always understood this to be the solder "cleaning itself out" for lack of a better term. Even fresh bar solder comes with some dross included in it. | | Yesterday I was told (by a solder supplier)that the extra dross formation is due to the iron in the walls of the solder pot. Until the iron oxidizes from the heat of running, it catalyzes dross production in the tin/lead solder. | | This is a new one on me, but I'm a gear head, not a metallurgist. Can anyone confirm or deny this theory? | | Thanks. | **************************************************************** | An entire day and no respone??? Come on, somebody's got to have some insight on this. Wayne, Moon Man - anybody home? Jusitn - you've got input on EVERYTHING; Steve, no wiseacre remarks with a big GRIN? | I can't believe that something as simple as a solder question could stump THIS forum of experts... ;-) Hey Chrys!! Whaddya mean wiseacre? I'm as pure as the fresh driven snow! (..snicker..) I 'member reading something about that quite a while ago, but couldn't remember where. But after some careful contemplation, I 'membered! It was an article written by a VP of Kesters Research and Development. To wit: The Effect of Metallic Impurities on the Wetting Properties of Solder by: Dennis Bernier Vice President Research & Development Kester Solder Company Iron - Temperatures over 430�C will cause the solder to dissolve iron from the solder pot itself. An improperly alloyed solder using too much heat could contain excessive iron. A new solder pot -- whether cast iron, cold-rolled steel or stainless steel -- will have exposed iron available for dissolution into the solder. Excessive cleaning of the pot walls with a wire brush can also introduce iron into the solder. The problem associated with iron contamination is excessive drossing which usually clears up as the iron compounds are removed with the dross. Dross Inclusions Dross inclusions in the solder show up as visible particulate grit or hidden inside a bump or pimple in the otherwise shiny solder surface. Quite often the source of this problem is an unusual amount of iron in the solder. So, according to the info above, your observations of more dross being generated right after you add fresh solder, is basically correct. Because when is the most likely time you add solder? Right after you clean the pot, right? There's always some scraping and wire brushing going on then huh? See? No wisecracks...you should hang your head in shame for maligning my outstanding character, and my true desire to assist my fellow man.......excuse me for a sec'...... (HA!HA!HA!HA!HA!) Okay...I'm back now, had to compose myself. May you have a dross-free day... -Steve Gregory-

reply »

Chrys

#14225

Re: Fresh solder generating more dross - C'mon, you guys! | 18 September, 1998

| | | | Hi Folks, | | | Need to draw upon the vast expertise in this forum... | | | Whenever you fill a new wave solder machine with fresh bar solder, it seems to produce more than the normal amount of dross for a few weeks. I always understood this to be the solder "cleaning itself out" for lack of a better term. Even fresh bar solder comes with some dross included in it. | | | Yesterday I was told (by a solder supplier)that the extra dross formation is due to the iron in the walls of the solder pot. Until the iron oxidizes from the heat of running, it catalyzes dross production in the tin/lead solder. | | | This is a new one on me, but I'm a gear head, not a metallurgist. Can anyone confirm or deny this theory? | | | Thanks. | | **************************************************************** | | An entire day and no respone??? Come on, somebody's got to have some insight on this. Wayne, Moon Man - anybody home? Jusitn - you've got input on EVERYTHING; Steve, no wiseacre remarks with a big GRIN? | | I can't believe that something as simple as a solder question could stump THIS forum of experts... ;-) | Hey Chrys!! | Whaddya mean wiseacre? I'm as pure as the fresh driven snow! (..snicker..) I 'member reading something about that quite a while ago, but couldn't remember where. But after some careful contemplation, I 'membered! It was an article written by a VP of Kesters Research and Development. To wit: | The Effect of Metallic Impurities on the Wetting Properties of Solder | by: Dennis Bernier Vice President | Research & Development Kester Solder Company | Iron - Temperatures over 430�C will cause the solder to dissolve iron from the solder pot itself. An improperly alloyed solder using too much heat could contain excessive iron. A new solder pot -- whether cast iron, cold-rolled steel or stainless steel -- will have exposed iron available for dissolution into the solder. Excessive cleaning of the pot walls with a wire brush can also introduce iron into the solder. The problem associated with iron contamination is excessive drossing which usually clears up as the iron compounds are removed with the dross. | Dross Inclusions | Dross inclusions in the solder show up as visible particulate grit or hidden inside a bump or pimple in the otherwise shiny solder surface. Quite often the source of this problem is an unusual amount of iron in the solder. | So, according to the info above, your observations of more dross being generated right after you add fresh solder, is basically correct. Because when is the most likely time you add solder? Right after you clean the pot, right? There's always some scraping and wire brushing going on then huh? | See? No wisecracks...you should hang your head in shame for maligning my outstanding character, and my true desire to assist my fellow man.......excuse me for a sec'...... | (HA!HA!HA!HA!HA!) | Okay...I'm back now, had to compose myself. | May you have a dross-free day... | -Steve Gregory- HAHAHAHAHAHAHAHAHAHAHAHAHA Steve, My sincerest thanks. I will never, ever, impugn your sterling character again. (NOT!) Thanks. This forum really is cool. :-)

reply »

Hioki Flying Probe Tester

PCB Cleaning