Welder's Close-Quarters Wire Brush Handle

Prior to welding aluminum, it is necessary to remove the oxide layer that normally forms on the surface of the bare metal.  This oxide layer melts at a much higher temperature than the underlying material, so it must be removed to get a good result.  Typically, the removal is done using a stainless steel wire brush.   Don't use carbon steel! (that can cause corrosion).

Often, the length of the brush handle will impede access to the surface needing to be cleaned for welding.   In my case, I was having trouble getting the brush in between the longitudinal stringers of my boat build project.  I created this handle to solve the problem.

It is used with a Lincoln Electric KH581 stainless wire brush that is commonly available at Lowe's and other vendors.  The handle should be cut off such that the remaining length of the brush is between 80mm-82mm, then it is simply pressed in place.  Once the brush is worn out, there is a slot at one end where a small screwdriver may be inserted, to pry out the old brush so that it may be replaced.

I printed this out of Polymaker ABS on my Voron 2.4 using a 0.6mm nozzle at 0.3mm layer height.  Since wire brushes are not made to the tightest of tolerances, you may find it necessary to either scale when slicing, or to sand the brush handle slightly to achieve a good fit.  High strength is not required for this part, but if you don't skimp on material it should last a long time.

Edit to add…. Yeah, the brushes are not exactly made to a consistent size.  The latest bunch of KH581 brushes I purchased are a little wider than what I measured when designing this, so they didn't fit.  Scaling up 5% in the slicer seems to have solved this, and I have added a pre-scaled version of the STL to save you some time.  Leaving the original here, but personally I would just print the bigger one, and if you run into some narrower brush handles, add a few layers of tape to make up the difference.