Instruction Manual

7
.7 Reducing Dross for Clean Cuts
Dross (slag) is the excess material that spaers and builds up on the underside of the work-piece as you
cut. Dross occurs when the operang procedure and technique is less than opmal. It will require pracce
and experience to obtain cuts without dross. Although less than opmal cuts will contain dross, it is
relavely easy to remove by breaking it o using pliers or chipping o with a chisel or scraping or grinding
the nished cut as needed and is generally only a minor inconvenience.
A combinaon of factors contributes to the build-up of dross. They include; material type, material
thickness , amperage used for the cut, speed of the torch across the work-piece, condion of the torch p,
input line voltage, air pressure, etc. Generally there is an inversely proporonal relaonship between
output current and speed of cut. Do not use more output current than is necessary and adjust speed of cut
toward minimizing
dross build-up on underside of cut. Experiment with adjusng current and speed to
minimize dross.
When dross is present on carbon steel, it is commonly referred to as either ‘high speed’, ‘low speed’, or
‘top dross’.
‘Top dross’ is present on top of the plate and is normally caused by too great a torch to plate distance or
too fast travel speed. It is normally very easy to remove and can oen be wiped o with a welding glove.
‘Low speed dross’ is norma
lly present on the boom edge of the plate. It can vary from a light to heavy
bead, but does not adhere ghtly to the cut edge, and can be easily scraped o.
‘High speed dross’ usually forms a narrow bead along the boom of the cut edge and is very dicult to
remove. Usually it will need to be removed by grinding. When cung troublesome steel, it is somemes
useful to reduce the cung speed to produce ‘low speed dross’. Any resultant clean up can then b
e
accomplished by scraping, not grinding.
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