Barnacles - Frame Fabrication

This post shows some of the steps involved in the fabrication of the framework that supports the spun steel pieces of Barnacles. Barnacles is composed of sixteen frames that are each about 5 feet wide. Each frame is unique.

Rear views of Barnacles

This shows a construction drawing and cut list for two of the sixteen sections of Barnacles.

Raw material: 1.5" square tube and .75 OD x .375 ID round DOM tube.

The first step in the fabrication of the frames is cutting the square tube to the correct lengths and angles. Most of the cuts are 90 degree cuts, but there is an occasional 45.

These are the cut to length parts for one of the sixteen 5' wide sections of frame that comprise Barnacles.

After all the pieces of a frame have been cut, I lay them out on the welding table and plot the location of all the holes and where the welds will be.

Next, drilling holes on the mill

Now that all the holes have been drilled, I'll begin the next step which is adding an internal spacer that will strengthen the square tube when the spun steel pieces are fastened to the frame.

To facilitate welding the spacers inside the square tube, a keyhole slot is milled.

The spacers are inserted into the square tube and held in registration with a brass pin. Then a small tack weld is made in the slot.

Welding spacers

View showing spacers that have been welded inside the square tube

Sometimes a hole falls on a mitered corner. In that circumstance, the spacer is welded into one side of the miter, and then the two mitered cuts are welded together.

Detail showing a spacer welded into half of a mitered cut

After the spacers have been welded inside the square tube, the bulk of the weld is removed on the belt sander.

Now that the bulk of the weld has been ground off on the belt sander, I'll finish this off with a different grinder.

The final grinding is done with a small right angle air grinder.

The weld that holds the spacer in place is ground out flat which still leaves just a little bit of weld obscuring the hole.

The last step with the spacers is cleaning out the hole with an end mill.

Now that the spacers have been completed, I'm ready to begin welding the frame together.

Generally a frame has many short pieces that are welded to longer pieces at 90 degree angles, so I begin by welding all the short pieces first.

And then I start welding together the smaller sections into larger sections.

And then those sections are assembled and welded into the final configuration.

After all the sections have been welded together, the welds are ground out flat.

The frame is about 80% done at this point. Next, we'll do a test fit of the spun steel pieces before the final structural elements are added, and it's sent to the powder coater.