NOTE: BE SURE THE WELDER IS UNPLUGGED BEFORE ATTEMPTING ANY 
REPAIR OR MODIFICATION. LETHAL CURRENT EXISTS ANYTIME WELDER 
IS PLUGGED IN. BE AWARE THAT ANY MODIFICATION WILL VOID THE 
WARRANTY.

The small made-in-Italy MIG welder sold under the Clarke or Craftsman label work quite 
well for sheetmetal or light angle-iron welding, except that the machine tends to run 
hot and may overheat. 

A little experimenting showed that the cooling fan was mostly circulating air inside the 
cabinet, but not effectively exhausting the air out of the cabinet.
Further tests showed that if the fan were ducted, it would move a lot of air out of the 
cabinet.

The fan is in a tight spot just above the transformer and right behind the rectifier heat 
sink(see picture migb4.jpg) , so I decided to build a duct in two pieces that can be 
installed without disassembling the welder.

I modeled the duct with 110-pound card stock and then transferred the card stock patterns 
to aluminum 'coil stock'- the stuff that siding contractors use for windows and 
eaves trim. The card stock and coil stock have the nearly the same bending properties- 
close enough for this job.
There are three pieces- upper half, lower half, and a clamp that ties the two halves 
together.

The pictures migfan.jpg and migfsd.jpg show the duct installed.

The fan now does a superb job of moving air out of the cabinet.

Carl Byrns

carl.byrns@verizon.net
December 2005