DROSS in Wave

Best dross remover is to not produce dross. Search the fine SMYnet Archives for previous discussions

Dross will not increase signicantly * Another story, that lead-free solders will generate a greater volume of dross than conventional materials, is also known to be incorrect. Cookson Electronic's laboratory work confirms that lead-free solder dross generation is not statistically different from lead solders. However, there are significant issues to be confronted, and manufacturers will find that lead-free processing is somewhat more demanding overall than conventional tin/lead solder production. [Clarifying Issues in the Transition to Lead-Free Assembly; Krista Fabian; Cookson Electronics] * Dross and Lead Free - Controlling Cost and Process [Lead Free Wave Soldering; Marquez, U; 10/18/03, Vitronics Soltec] � Dross formation of SnPb = Lead Free � Use of Nitrogen reduces dross formation � Cost analysis nitrogen vs amount of dross No increase of the dross formation is recognized: ||Air kg dross||Nitrogen kg dross SnAgCu 260*C||2.00||1.27 SnAgCu 270*C||1.90||1.37 SnPb 250*C||1.92||

There will roughly be twice as much dross generated with lead-free alloys. SnCu will dross slightly more than SnAgCu. Nitrogen blanketing of the solder pot will reduce dross dramatically. [Kester]

Although some reports indicate that the generation of dross will not be increased, more trustworthy research indicates that five to seven times as much dross may occur when operating in air. As 90 percent of the cost of bar solder derives directly from metal cost, the higher metal cost will be felt immediately. More dross also means more maintenance. [New Avenues for Wave Soldering and Lead-Free Conversion; Martin Theriault, M & Rahn, A; Circuits Assembly, April 2002, p.34]

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To answer your question specifically: http://www.pkaymetal.com/dross.php4

NOW, I can not reccomend for or against this!!! Do your homework, call PK, talk to thier technical people. this product absolutely works in some applications. Primarily high volume 24/7 applications. It is also a bit partial to the machine you may have.

I like the suggestion of "produce less dross". The simplest most uncommon solution to this, is: run the wave less!! Batch your boards, run in standby mode.

What machine are you running, what diind of volume, what hours?

Bill.

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