PVC Cemetery Sign Arch

After building an arch and PVC lighting/stage trussing for Halloween 2022 I decided to build another smaller arch for the cemetery entrance in my home haunt. This instructible will allow you to build a trus arch of any size as the methods are the same but, the length and radius may be larger or smaller for your needs.

For a 5 foot arch:

4 10' sections 1" SCH40 PVC pipes

2 10' sections 1/2" SCHD40 PVC pipes

8 45 degree 1" PVC elbows

12 1" PVC slip joint T's

38 1/2" PVC 90 degree elbows

32 1/4" X 3 1/2" hex head bolts

6 1/4" X 4" hex head bolts

38 1/4" hex head nylex nuts

1 8 oz can regular PVC clear cement

Propane weed burner torch and propane

1/4" drill bit and drill

7/16" hex head socket and ratchet or impact driver

channel lock pliers

PVC cutter or miter saw

1 4' X 8' sheet 1/2" plywood or osb

1 box exterior 1 5/8 #8 construction screws

1 8' long closet hanger wood dowel (1 1/4"diameter)

First and foremost figure out and measure the length that the arch will need to be to span your gate opening, For this particular arch I decided on 5 feet wide between the uprights for this arch. I built a larger arch last year that measured 16 feet Measure 5' from one edge and draw a 90 degree line from the bottom edge 18" long. This is the end s of the arch. For an arch larger than 8 feet you will need 2 or more sheets of plywood. Next, draw a 45 degree line from the bottom edge of the corner and at the 5' mark to the center of the arch. This line is used to line up the arch using the 45 degree elbows to attach the arch to the pillars or posts. Next mark another 45 degree mark on each side 6 inches above the bottom lines along the bottom of the plywood. These arches drawn on the plywood will be used to bend the PVC later. Mark a center line between the edge and the 5 foot line from the bottom to the top along the 4' width of the plywood and decide how short or tall you want the bottom of the arch to be. Set the plywood on the ground and line up the center line on the plywood with a point away from the bottom edge to make a center point to scribe the arch make a compass using a long piece of wood or string and line up the marks on the plywood then draw the arch on the plywood with a marker for the bottom arch. Measure 6" above the arch and draw a second arch above the first arch.

Cut the 1 1/4" dowel into 3" long pieces and drill a small pilot hole into the center of each piece of dowel. Measure a line 5/8" from the inside of each arch, spaced about 10" apart and drill a small pilot hole at each mark. Screw a dowel to the back side of the plywood through each hole. These will hold the pipe along the arch. Use a 1" PVC T and set against the dowel along the inside of the arch and mark a line on the plywood. Measure 5/8" from the edge line of the PVC T and drill a pilot hole on the mark, repeat for remaining marks spaced 10" apart along the outside of the arch line. Stagger these just off the first dowels to help the PVC hold its shape without kinking the pipe when heated and bent around the arch. Repeat this for the second arch as well. this will be the arch form.

Start by placing the form on a large table or 2 saw horses to elevate the form to make it easier to manage the pvc pipes. You can set it up on the ground if you don't mind bending over and standing back up several times during the forming process. You will need the 4 10' lengths of 1" diameter pvc, propane weed burner and propane. Its also a good idea to have a shop towel and a bucket of cold water to cool the pipe and set the curved arches,

Lay 1 10' 1" diameter pipe on the ground and light the weed burner. Be sure there is nothing to catch fire within 3 feet of the area along the length of the pipe. You want to use a lower propane adjustment to melt the pvc without burning the pipe. Higher flame heat will burn the pipe immediately without melting and softening the pipe. Gently walk the weed burner flame up and down the pipe and keep the flame moving. After 4 passes, turn the pipe over and heat the pipe some more with 4 passes. Keep turning and heating the pipe until it is very soft and flexible along the whole length of pipe. You may want to wear cotton or leather gloves as the pipe will be very warm to hot when handling the softened pipe.

Lay the pipe into the small inside arch gently pressing and guiding the pipe into the curved form. Start on the edge of the plywood and work around the arch until you have reached the end mark near the center of the plywood. Cool the pvc arch with the water soaked towel and let set in the form for about 5 minutes until the pipe has cooled and hardened enough to hold its shape. with a permanent marker mark the end of the arch in the form. Remove the formed pvc and repeat with one more pipe for the inside arch then, do the same for the outer arch. you should have 2 smaller diameter and 2 larger diameter pieces. Cut each arch where the arch ends at the marks made on the pvc.

You can make the arch as wide or tall as you wish and will vary with the diameter of the arches and may increase the amount of Pvc used. The list I have provided is for this particular arch set with the dimensions here. You will need to cut 6 pieces of 1" pipe 4" long and 40 pieces of 1/2" pipe 4" long. You will also need to cut 4 pieces of 1" pipe 8" long.

Now comes the fun part of assembly after all of the forming has been completed. Begin by separating the 1/2" parts into two separate piles. For each trussing section, you will need 19 1/2" 90 degree elbows and 18 4" long 1/2" pipe pieces.

For one of two truss sections: Begin by gluing one elbow to a piece of 4" long pipe then glue a second piece of pipe to the other side of the elbow. You should have 2 pieces of pipe in one elbow. Repeat 8 times so that you have 9 elbows with 2 pieces of 1/2" pipe in each elbow. Next, on a flat surface, glue one elbow into one of the pipes of a 2 pipe section. Be sure the elbow is flat against the surface to continue the trussing in a straight line as if the trussing is a single piece of pipe laying flat along the surface. You should end up with the section with each end of the trussing on the same side. Glue one elbow to end the trussing just like the 4th photo. Repeat with the second truss section.

Shape the Truss to the Arch: Lay one section of trussing on the ground with one of the smaller diameter arches. Keep the arch 3 feet from the trussing. Gently heat the trussing pipes with the weed burner, avoiding the elbows. Turn the trussing over and heat the back side until flexible and form the trussing around the outside edge of the arch with the end elbows against the arched pipe. You can cool with the water soaked towel or just let is sit on the ground for 10 to 15 minutes to cool. Repeat with the second trussing.section.

Glue the 8 45 degree elbows to each of the 8 " pieces of 1" pipe. Lay the arches on the ground and glue one 45 degree elbow and 8" pipe section onto each end of each arch so that the elbows and arch lie on the ground in a straight line against the surface as if it was a single piece of pipe that is not cut.

Glue two 1" T's onto one piece of 4" long pipe so that the T's line up in the same direction when lied on a flat surface. Next, find the center of all 4 arches and mark this point on each arch. You can do this by measuring with a measuring tape from each end, dividing in half and measuring that point or,( not as accurate) use a piece of string and follow the curve from one end to the opposite end and fold in half then mark the center point.

Separate the arches so that the same sized arches are matched into 2 pairs. Cut one arch in half on the mark and glue a T section into the cut section making sure the T section is set 90 degrees perpendicular to the arch on a flat surface. On one end of the arch, measure 3/4" from the 45 degree elbow on the arch end set 90 degrees perpendicular to the arch on a flat surface. Glue another T section next to the elbow then, glue the arch to the second end of the T. Repeat on the second end. Flip the assembled arch over so that the T's are on the flat surface. Cut the second arch in half at the center mark and glue the arch to the T so that the two same sized arches line up. Cut one end 3/4" from the 45 degree elbow and glue the t to the end of the arch then glue the arch to the T. Repeat with the opposite end. Now you should have 2 of the same sized arches attached together with 3/4" long, 1" Pvc pipes with 2 T's. See the last photo of what the assembly should look like. Repeat with the second set of same sized arches.

Apologies for the lack of photos here. I got into putting the arch together and forgot to take the photos but, this step is pretty simple. Up on a table, place one shaped truss section on the table then the smaller arches on the inside of the truss section. Measure from the center of the elbow on one end of the trussing to the edge of the 45 degree elbow on the arch. Measure the opposite end in the same manner and adjust until measurements on each end are the same. Mark on both the center of the elbow to the pipe in a single line and drill a 1/4" hole through the arch to the center of the elbow. Push a 1/4" X 3 1/2" hex head bolt through the hole of the pipe through the elbow. Put a nylex nut onto the end of the bolt until tight and the bolt just comes through the end of the nut to be sure the nut is locked. Repeat with every elbow there it touches the arch until all elbow joints are bolted to the arch. Use a 4" bolt if the elbow rests on a T.

Now, place the larger arch section on the table and secure the trussing to the inside of the radius of the arch in the same way as the first section just assembled. You should have the larger assembly trussing and smaller assembly so that when set together you have a rectangular shaped, curved arch. Begin attaching the 2 assemblies together by bolting each assembly together in the center then on the ends. Once you have the center and ends attached along one section where the assemblies are joined then attach the second side in the same manner to secure as one piece. Continue until all elbows are bolted together.

Paint, especially spray paint does not stick to pvc and scratches very easily. To resolve this problem I sand all the pvc with 180 grit mesh sanding media or a sanding sponge to roughen the surface. Sanding the pipe really helps the paint stick and stay on the pvc. Now, you can color it any color you wish or, just leave it white.