Collaring

Collars

Collars are pieces of metal that wrap around two or more pieces to hold them together. They can also be used to hide a weld that is holding two pieces together. You may decorate the collars or keep them plain. It is a simple process if you make the correct tooling. The only special tool required for a collar is a sizing form.

Sizing Form

To make your sizing form you need two pieces the same size as the two pieces being wrapped by the collar. If you made your scrolls out of % by 1 than you will need a piece of 1/4 by 1 about 18 inches long. Make the form out of two pieces that match the two pieces being joined exactly. You can weld them together if they come from different size stock. The % by 1 is for the shelf bracket created in Mark Sperry's class.

The first step is to fold over the last two inches of the bar as if you where going to do a faggot weld. Be careful not to distort the size of the steel or your jig will not work appropriately.

Once the piece is folded, carefully taper the very end of the fold where it has expanded. The collar will slide off easier if the end is slightly smaller.

Measuring your collar

To find the length of your collar material you simply need to place the form on the end of the stock, 90 degrees to the bar, and carefully roll the form until you have made one full turn. Mark this with a scribe or sharpened soapstone.

This is the proper length of the collar that will butt ends together. If you choose to you may forge a taper on both ends of the collar piece so that they will overlap. Try both methods and find what works best for you. Once you have this mark you may measure it and mark the rest of the collars that you need. Cut them with a hacksaw or hardy.

Wrapping your collar

Heat up the collar to a high orange and make a 90-degree bend about 3A inch from either end. Place the form on the collar, 90 degrees to the collars length, tight to the bend and fold the tab onto the top of the form.

At this point you will probably need to reheat your steel. Place the hot collar back on the form and bend the other side up and fold the tab down on the top of the form to match the other side. If you have measured, marked, and cut correctly the ends of the collar should just meet. Make adjustments as needed for a nice tight fit. Slide the collar off of the form. This is why you need the slight taper on the end of the form.

Installing the collar on your work Heat the collar up and open it by forcing the sides apart. A pair of scrolling tongs work well for this. Insert the tip of the tongs into the closed collar. Open the tongs toward the short sides and the collar "mouth" should open. Only open it far enough to put it over the two pieces being joined.

Now heat up the open collar to a bright orange or yellow heat, it will cool very quickly. Place it on the two pieces and squeeze closed with the scrolling tongs. You will need to make some final adjustments for a tight fit by squeezing with the tongs or gentle hammer blows to flatten it out. Once the collar has cooled to a dull red do not fiddle with it. As it cools it will tighten up slightly. If you continue to adjust it the collar will actually loosen.

If the collar has cooled before you closed it completely you have several options to reheat it, the forge, oxy-acetylene, or kind words. The forge will heat the entire piece, which can lead to distortion of the piece and many kind words. Oxy-acetylene, while traditional to the 20th century, is the easiest way to reheat the collar. Map gas and even propane may work since the collar is so thin.

Practice Use two pieces of scrap to practice installing the collar. Also you should practice putting the collar on the actual pieces cold so that you get the technique and angle correct. This will save you precious time and heat when installing the collar.

Now you should be ready to assemble the shelf bracket. Remember you need a pair of shelf brackets or you just made a single sign bracket. I hope you enjoyed this review of traditional joinery. Please contact me with any questions or assistance to complete this project.

-- RebStaup - 11 Feb 2008