The graceful scrollwork of this iron gazebo evokes images of New Orleans' French Quarter. Imagine creating this charming structure to serve as the focal point of a garden wedding ceremony. Afterward, the gazebo could enclose a hot tub of generous dimensions, since it measures 10' (32.8 m) across the octagon. Definitely not for the inexperienced welder (nor the faint of heart!), this project requires skill and patience. When completed, the gazebo will weigh 850-900 lbs (385-408 kg) and will have consumed ¼ mile (0.40 km) of steel tubing. Tips for the successful completion of this project include: order the material well in advance; and decide at the outset whether or not the structure will be "hot dip" galvanized-if so, ¼" (6 mm) holes will have to be drilled in each piece of the material before it is welded together. The designer recommends using a MIG wire welder with approximately 225 amp capability, like Lincoln's Power MIG® 255XT, and ER70S-6 .030" welding wire such as Lincoln's SuperArc® L-56. Unless otherwise noted, all welds should be ground flush, and filed. Here are the basic steps to follow.
1. Constructing the Dome's Frame
The octagonal frames which tie the bottom of the dome to the base of the gazebo call for 16 pieces of 1" (25 mm) square steel tubing cut to a length of 48" (1200 mm). The angle of the equilateral octagon is 135 degrees; therefore, each of the 48" lengths must be cut to an angle of 67.5 degrees. The ends of all the pieces of tubing must then be deburred so that the metal will lie flat on the welding table when it is being tacked in place.
To begin assembly of the frame, clamp one segment of tubing to the welding table, and using a protractor set to a 135 degree angle, set the next piece of tubing correctly. Clamp and tack weld at both ends of the joint, using a heat range setting of 3, heat control setting of 5, and a wire feed setting of 5. Recheck the angle and adjust if necessary, then finish weld all the way around the joint using the same settings as above. Continue until you have four two-piece sections, then weld the two-piece sections together to form the first octagon.
To build the second octagon, make the two-piece sections as in the first instance, then place the four two-piece sections on top of the first octagon, and clamp in place. Tack weld all four sections together at the outside corners and make any minor adjustments before finish-welding, so that the two octagons are identical in shape.
The two octagons are then joined together using 5" (125 mm) spacers made of the same 1" (25 mm) square tubing placed 4" (100 mm) from each corner (see Photo 1). Follow a procedure of:
Cutting each spacer to the same length
Drilling 1/4" (6 mm) holes on the ends
Tacking the spacer in place
Rechecking for square on all sides
Finish butt welding only on the front and back sides using a heat range of 3, heat control of 4 and a wire feed of 4-5
Set the dome frame aside until later in the project.
2. Fabricating the Base Panels
Each of the base panels is made of 1" (25 mm) steel tubing, .083" (2 mm) wall, and consists of two 81" (2 m) lengths for the vertical columns (16 pieces total) and two 36" (900 mm) lengths (12 pieces total) for the cross members of each of the six base panels. (Note: only the six base panels will be welded at this time; the remaining two sides of the gazebo are gate assemblies, which will be explained later). All of these pieces must be cut exactly to measure so the frame will be square when it is welded together. As with all joints, deburr the edges. Use a large carpenter's square to align panels. Complete one joint at a time, following these steps"
Align the marks; check for square
Clamp the pieces using 4 clamps, one on each side of the joint and one on each side of the piece which is about to be joined
Tack the joint
Recheck for square
Finish butt welding only the front side of the joints (heat range 3, heat control 5, wire feed 5)
When the top half of a panel is completely finished, turn the panel over and finish butt welding on the back. Once all the joints are welded, grind flush and file the edges.
There will be a total of eight arches, each made of the same 1" steel tubing as above, cut to a length of 86" (2.2 m). The heavy duty pyramid rolls used to bend the tubing tend to distort it at each end, so the material must be cut longer than the actual arc length. Bend it until the arc has a radius of 22" (560 mm), as shown in Photo 3, then trim the inside radius of the arches to a length of 43" (1100 mm).
Now it is time to weld six of the eight arches in place. See "Front View" blueprint drawing for placement, and tack and finish weld on the top, bottom and inside radius of the arc, with a heat range of 3, heat control of 5 and wire feed of 5.
Next, cut the 32 brackets which will be welded on the top of all 16 columns to connect the base with the dome frame. Weld two pieces of 3/16" x 1" (5 x 25 mm), 3" (76 mm) in length, extending 1" above the top of each column. Weld these brackets on the front and back of the panel with a 1/16" (1.6 mm) spacer sandwiched between the column and the bracket to allow room for the coat of zinc and paint when the gazebo is finished. Run two 2" (50 mm) welds on either side of the bracket (heat range 3, heat control 5, wire feed 5).
The frames that will hold the decorative scrollwork inside each panel will be made next. The frames, made of ½" (13 mm) square tubing, 0.065" (1.65 mm) wall, each require two 32" (800 mm) horizontal pieces and two 26" (660 mm) vertical pieces, with all corners cut at a 45 degree angle. Weld the tubing using the following settings: heat range 3, heat control 4, and wire feed 4.
3. Making the Scrolls
The void between the top of the arches and the dome's frame is filled with two "S" style scrolls (refer to Photo 2) made of 3/16" (5 mm) by 1" (25 mm) band iron with a milled edge, cut to a length of 13" (330 mm). Trace the scroll design you would like to use full scale on a sheet of paper, then make the four jigs that will be used to bend the scrolls. Since these scrolls will be bent hot, they will conform exactly to the jig; therefore, the jig must be 3/16" smaller than th actual scroll. To shape the jig, a diacro bender is very helpful.
Once the arch scrolls are bent, weld them in place at the top of the arches (see "Front View" blueprint drawing for placement) using a ¼" (6 mm) weld on both sides, anywhere the scroll touches the arch or the column. The settings should be: heat range 3, heat control 5, and wire feed 5.
The next set of scrolls will be placed in the square frames. These are made of the same band iron material as those above, but this time there will be three different types of scrolls (see "Front View" blueprint drawing for style and placement). Make the eight jigs needed to bend these scrolls. Unlike the previous set of scrolls, these will be bent cold. Therefore, it is important to allow a ¼" (6 mm) gap between the desired scroll shape and the jig.
To mass-produce each set of scrolls:
Cut the material
Round the corners
Bend all of the lengths of metal in one jig before using another jig
Make any minor adjustments needed to make each scroll of a particular shape identical to the other scrolls of that shape
4. Welding the Scrollwork to the Frames, and the Frames to the Base Panels
Now, it's time to weld the scrolls in place, inside each frame. Measure precisely to center the scroll design within each panel. Weld the scrolls as shown in Photo 3 (heat range 3, heat control 5, wire feed 5), then grind and file all welds flush. Once all the scrolls have been welded in, the frames can be welded onto the side panels. First weld 2" (50 mm) spacers made of ½" (13 mm) square steel tubing onto the frames. De burr all 32 pieces. Weld the front and the back of the spacers with a heat range of 3, heat control of 4, and a wire feed of 4. Then grind and file all welds.
At this point, six of the frames will be welded to six of the base panels (two will be used to create the gates, described next). To make sure that the frames are lying in center of the panels, the frames should be shimmied up ¼" (6 mm) from the welding table using scrap ¼" band iron. Weld the spacers on the front and back using the settings above.
5. Constructing the Gates and Latches
First, cut four pieces of 1" (25 mm) square steel tubing to a length of 35-3/8" (900 mm). This length will allow a 5/16" (8 mm) gap on either side of each gate so they will swing freely. Next cut four 18 gauge by 1" by 1" pieces of sheet metal to gap the ends of each piece of tubing. Drill ¾" (19 mm) holes in the 1" tubing to allow the ½" (13 mm) tubing to be placed inside (see drawings in Plan 2 for placement). These pieces will accommodate a ½" hinge bolt and should be welded using a heat range of 3, a heat control 4 and a wire feed of 4. The weld must not be permitted to drip into the ½" tubing, or the gate may not close well. Grind flush and file all welds. Weld the two pieces of 1" tubing to the frame with the 2" spacers prepared earlier.
The eight brackets used to create the hinges are made of 3/16" (5 mm) band iron cut 1-1/2" (38 mm) long. Drill a ½" (13 mm) hole in each of them to allow the ½" bolt to pass through (see "Hinge" blueprint drawing). Weld these brackets to two of the four 81" (2 m) remaining columns (4 brackets per column). Weld on all 4 sides using a heat range of 3, heat control of 5, and a wire feed of 5. Place the arches in the tops of the two gate panels, keeping the bottoms of the columns square with the rest of each panel. Install the gates using four ½" by 1-3/4" (44 mm) galvanized NC bolts with Teflon® locking nuts.
Make the two latches using six pieces of ¼" (6 mm) solid square stock cut 5" (127 mm) long (see "Gate Latch" blueprint drawing). Two pieces will be used to make the "U" shape; lay out two marks 1-1/16" (27 mm) from each other in the center of the material. Bend the material in a vise and shape on an anvil. The four latch hinges are made of 3/16" (5 mm) circular steel tubing cut ¼" long. Use a flux coated bronze brazing rod and an oxyacetylene torch to braze weld the hinges onto the ends of the 5" stock. Cut the length of the "U" shaped stock, after its bends, to 3/8" (10 mm). Weld the pieces in place 1-1/2" from the end opposite the hinge using a heat range of 3, heat control of 4, and wire feed of 4, keeping everything square. Grind and file all the welds. Mount the hinges on the ends of the gates by drilling two 3/16" (5 mm) holes 3-1/8" (89 mm) from the ends of the gates. With the addition of two 12-24 (?) by ¾" (19 mm) machine screws with Teflon® locking nuts, the gates are finished!
6. Constructing the Base Frame
Now, it's time to build the octagonal frame that will be used as a base plate to hold the panels in their final, upright position. It will made of eight pieces of 3/8" (10 mm) by 2" (50 mm) band iron, each cut to a length of 48-1/2" (1230 mm), and with the ends cut to an angle of 67-1/2 degrees. To allow proper weld penetration, grind a ¼" (6 mm) chamfer top and bottom on each end of each piece. Clamp the pieces of this third octagon on top of the dome's octagon, and tack weld all pieces in place. Finish weld with an arc welder set to 125-140 amp AC, and a 1/8" (3 mm) E6013 stick electrode (Lincoln Electric's Fleetweld® 37). Grind down all welds, then transfer marks from the dome frame to the base frame so they can be aligned later when the dome is placed on top of the base. Weld on the back side of the frame, and grind the welds flush.
7. Raising the Panels
Lay out the base, and to ensure proper placement of the panels, make marks 5" (127 mm) from each corner of the base frame and two marks ½" (13 mm) from either side of the width. Level the base. Keeping the first panel in position using either a brace or an assistant, use two tack welds to attach each leg of the panel to the base. Be sure the panel is level and plumb before welding. Continue raising the panels until all eight are tack welded in place. Now, place the dome's frame on top of the panels (see Photo 4). If it doesn't fit perfectly, break the tack welds and reposition the panels.
8. Connecting the Panels
Next, cut thirty-two 5" (127 mm) pieces of 1" (25 mm) square tubing to make the braces that will hold the panels together. Cut one end of each piece on an angle of 67-1/2 degrees, and cut the other end square. Make a jig to hold two pieces at the correct angle, clamp the pieces to the jig and weld them using a heat range of 3, heat control of 4, and a wire feed of 4. Grind down and file all welds.
Tack weld each brace into position using a heat range of 3, heat control of 5, and wire feed of 5. Recheck the square of all the braces. Now, weld the legs of the panels onto the base frame, welding all the way around each leg, using settings above. Now, finish weld the braces on the tops and sides of the panels, same settings. Finally, filet weld the tops of the joints between the vertical columns and the horizontal cross members on all the panels.
Next, sketch a design for the eighty scrolls that will connect the panels (an example is shown in Photo 5). Bend the scrolls out of 36" (914 mm) lengths of ¾" (19 mm) by 3/16" (5 mm) band iron. Place one set of two scrolls between two columns, making sure that they fit snugly, and tack weld them together. This set will serve as a pattern for welding the other 78 scrolls together. Weld the sets of scrolls using the settings above, and grind the welds flush. Mount the scrolls between the panels and weld in place, using 3/8" (10 mm) welds on the inside of the panels, with the same settings. File the welds, and the base of the gazebo is complete!
9. Creating the Dome Frame
The octagon that tops the dome frame (see "Done's Frame" blueprint drawing) is made of 1" (25 mm), .085" (2 mm) wall square tubing cut to eight 10-1/2" (267 mm) long pieces, with both ends of each piece cut to an angle of 67-1/2 degrees. De burr the ends, and weld all the way around the tubing using a heat range of 3, heat control of 4, and wire feed of 4. Grind the welds flush and file them.
Now, turn to the dome frame that fabricated in Step 1. In both the small octagon and the top octagon of the dome frame, lay out the holes that the ½" (13 mm) square ribs will slip into (see "Done's Frame" blueprint drawing for placement). Drill the holes using a ¾" (19 mm) drill bit. Cut eight pieces of ½" square stock to an intial length of 240" (6 m). Create a 117" (3 m) circle on the floor. Using the floor diagram as a guide, pre-bend the eight arches (to a half-circle). Then cut each arch at the center, yielding two equal ribs. From this cut, measure down 79" (2 m) using a piece of string, and eliminate bent ends of the stock. Bend the ribs to their final shape using a diacro bender and the floor pattern as a guide.
By whatever means available, position the small octagon above the dome frame 66" (1676 mm) above the dome and center it. Insert the ribs in the holes that were drilled in each octagon, and tack weld them (heat range 3, heat control 5, wire feed 5). Make sure the ribs are plumb, and finish weld all the way around each rib-to-octagon connection, using the previous settings.
10. Fabricating and Welding the Dome Scrolls
Completing the dome requires the fabrication of 160 scrolls out of 3/16" (5 mm) by ½" (13 mm) band iron with a milled edge. As they continue up the ribs of the dome, the scrolls will have to become smaller and smaller (see "Top View" blueprint drawing). For each new set of scrolls there will have to be a full size set of plans so the size of the jigs and the length of the scroll can be calculated. To weld the scrolls between the dome's ribs:
Tack weld the sets of four "clover" shaped scrolls together on the top side (heat range 3, heat control 5, wire feed 5)
Tie two string lines directly over the area where the scrolls are to be set (see Photo 6)
Align the scrolls between the ribs of the dome and the string lines, and tack weld them to the dome's frame with the settings above
Bend the tack welds so the scrolls match the contours of the ribs
Fit the heart shaped scrolls between the ribs, adjusting for fit and contour
Tack weld the heart shaped scrolls to the clovers and then to the ribs, using the same settings
When all 160 scrolls have been tack welded in place, finish weld them on the outside first, then on the inside. As the position of the scrolls becomes more horizontal toward the top of the dome, they must be welded upside-down. (This presents the risk of the weld puddle dripping into the collate of the welder; to avoid this, hold the welder at the top part of the weld to keep the collate of the welder as horizontal as possible.) When finish welding is completed, grind flush all welds and remove weld splatter with a half round double cut file or a pneumatic die grinder. The dome is now complete.
Front View (PDF)
Gate Latch (PDF)
Dome's Frame (PDF)
Top View (PDF)
*This project has been published to show how individuals used their ingenuity for their own needs, convenience and enjoyment. Only limited details are available and the projects have NOT been engineered by the Lincoln Electric Company. Therefore, when you use the ideas for projects of your own, you must develop your own details and plans and the safety and performance of your work is your responsibility.