Halloween Project: The Great Pumpkin Arch Needs Elevation – Part 3

Thankfully Brad is taking care of the wild side of Intrigued while I try and recover from a mighty beat down. Not really up to going through my image catalog to find, process, upload, prep and then think of something clever to say about the creatures that are targeted for that sister site The images for this Halloween project were already ready to go, so I just need to give some narrative on the elements of the build …sooooo much easier (and these I can do from the couch with bags of ice on my legs ha). Just to bring everyone up to date, we’ve covered the following so far:

Pumpkin Creation (link here)
The Arch Support Structure (link here)

Now if you look at the revised sketch, you will notice that the plan includes two columns to support the pumpkin arch.

Admittedly, there was a quick thought of making the guests limbo under it, but Linda gave me the quick, hard, no uncertain term “No” response on that one. I let her think she swayed me, although there was a critical design consideration of having to get my UTF under it. This way she gets to tell the story to her friends that she kept them from having to get their butts dirty hehehehe. Anyway, I needed to build two columns and I basically used a lot of the same approach used in the Gargoyle platform (link here). That column turned out really nice and, therefore, no need to deviate too far at this point.

Hit the jump for a behind the scenes look at the columns supporting our new entrance to the Haunted Trail of Tears

Weight was actually important in this particular build. I didn’t want the arch to fall down and, if at all possible, wanted to keep it tether free. The PVC frame wasn’t overly heavy (I can lift it and move it around pretty easy), but once all the pumpkins were added it became quite a windfoil. Stayed with the 2×4 approach as the gargoyle platform is pretty heavy – to do that again I’d back down on the size of the wood used). Had an absolute shock when I went to pick up the wood. Bought 10 2x4x8 clear studs. Normally I have to pay 3 or so bucks more for the cleaner grade of wood which put me in the $6-$7 range. I hate dealing with crappy, warped wood. Went to pay and they were $12 and some change EACH. WTF – Thanks Brandon. Pretty pissed at that, but told myself I would simply nix any wood purchases the rest of the year.

Used the exact same layout as before. Made the risers 4 feet to maximize the height, while minimizing the waste. Made four halves exactly alike and then cut crossbars to put them together. Probably took me all of 45 minutes to crank out the inner frame.

I initially thought I needed a top – same as the gargoyle frame, so grabbed a couple of pieces of scrap plywood. Ended up needing 4 pieces to cover the two tops and screwed them in place. Later remembered the Gargoyle was really heavy resin the foam panels wouldn’t support – my plan was to have the weight supported by PVC pipes in the interior of the column. The tops got jettisoned a little later in the build.

Wanted to do a quick size check. Width wise they looked essentially perfect. Time I added in the foam facade and the planned column top, the bottom pumpkins should fit nicely.

Next, check the depth to make sure that looked good. Yes, I did a quick measurement before I started building the columns, but things have a way of ….let’s go with shifting during the course of a final build. The pumpkins would sit forward on the columns due to the arch frame in the back. This was a definite impact of changing the design in the arch phase as the PVC supports were originally meant to go through the middle of the pumpkins. No worries, I elongated the columns to help account for this.

Now happy with the frame, it was time to start “skinning” them. The haunter’s preferred facade material are 8×4 sheets of pink insulation foam panels. We use them for everything that even needs to come close to looking like walls as well as a primary staple for tombstones. They are surprisingly pricey (especially with the current economic catastrophe), but worth it – easy to cut, easy to carve, easy to paint and especially easy to carry. My foam cutter jig was covered in a previous post (link here). That jig has worked out incredibly well.

Grabbed the foam cutter jig, my hot knife, a measuring tape and a marker – oh, and, of course, my respirator. Always do this type of work outside and NEVER do this without a respirator. When this foam is burned it produces toxic gasses you do not want to be breathing in. Pretty short work to get the primary panels cut. Almost forgot. I use 1.5 inch thick foam panels – that gives you enough meat if you want to carve something in them (tombstone epitaphs etc.) and fits flush inside the top and bottom 2×4 crossbars (yes, 2x4s are really 1.5″ and not 2″ thick).

Changed it up a bit from the gargoyle column skinning – at least on the top. I wanted a more formal column look, so grabbed a piece of 2″ thick foam I had laying around to be the actual top and then put a 1.5″ piece below that cut at a 45 degree angle. Looked back at the examples of columns I had bookmarked on Pinterest and that was the look I liked best. An important note here, I made the bottom 1.5″ piece (the bottom of the 45 degree cut) an extra 3.5″ inches bigger than the dimensions of the top giving me an extra 1.75″ inches on every side. Will explain why in a couple of steps. The 2″ top piece was cut 1/4″ larger than the widest bevel dimensions of the 1.5″ plate it was going to sit on.

Here is what the top will look like once they are glued together.

Managed to get all the foam pieces measured and cut in about 4 hours. Once you get in a groove it is pretty easy to crank them out – especially since the dimensions matched on both columns. The pink foam boards are pre-slit to allow installers to snap to fit between wall frames. Great for the real use of these panels – not great for our use. Last thing we want is to spend all this time on the facade and have it snap in half. To help prevent that, each of those pre-slits are covered with Gorilla Construction Adhesive. Just a thin line to prevent any unwanted snaps. The foam connection system I developed is also detailed in a previous post (link here), so I’m going to skip over that. One note there though – I’ve switched from the spoked connectors to simple blades (think popsicle sticks). They are more forgiving and not as prone to breaking if you accidentally torque the panel when you are putting them on.

All holes burned into the foam panels, all inserts glued into place and the matching holes drilled into the wood structures. Next up was to construct the tops. Remember when I mentioned the 1.5″ top plate was cut 3.5″ beyond the dimensions of the top? Well, the reason for that was due to an improvement from the gargoyle top. In that first one, I made the top piece of foam fit exactly and then had to pin each of the four sides on. Seemed like extra work – why not just glue them onto the top and simply slip the foam cap over the top of the structures – less connectors, less time putting together. Three inches of the overage was to cover the 1.5″ pieces of foam on each side – then just to give myself some leeway, added an extra 1/4″ all the way around it. Simply glued the side panels onto the top and put wood skewers to add support and help hold them while drying.

Then just needed to center this inner top plate in the middle of the 2″ plates and you now have yourself a very nice looking top for your column that simply slips on and off the frame. Will probably go back and do this to the gargoyle facade during the off season.

The next phase takes a little bit of getting used to if you haven’t done this …or made tombstones before. Basically give your hard work a good beating! I use a foam rasp to scrap up every exposed edge of the foam – go ahead, get in there and let your inner frustrations on the economy get out. General rule – you can never scrape too much – they are supposed to be old worn columns that have been sitting in the elements for decades. Typically this causes cracks as well. Took out the pocketknife and started adding those to the sides – stick large blade slightly in and start wiggling as you pull it across the foam panels. Scrape the flat side of the blade down the crack you just made to pluck pieces out. Feel free to look at pictures of old cemeteries if you want ideas on what various crack formations look like and how they tend to start at corners and splinter as they meander down. Cracks tend to go downward. At the start and wherever it comes in contact with an edge, pluck larger pieces of foam out with your fingers – that is where larger chunks tend to fall out in the real world.

Have fun with it (and don’t think about all the hours you have put in getting those pristine foam pieces to fit just right. Once you have all the edges scraped and the cracks laid in, time to get the vacuum cleaner out and clean up the absolute mess you’ve made hehehe. Next, take them back outside (if you can) and grab your respirator again. I always hit the edges and cracks with a heat gun. That will firm up the edges while widening the cracks to a realistic feel. This goes quick and you should be careful not to get the gun too close to the foam – quick passes just down the edges and then down the paths of the crack.

As an example of the effect, the front column shows the crack after hitting it with the heat gun where the one behind it hasn’t been. Notice it is a bit wider and the jaggies have been burned off in the front one.

Just another perspective of the columns now completely gone over with the heat gun. Just noticed something I forgot to mention earlier. There are small, stonelike pellets embedded in the pink foam, Again, probably a benefit for its real use, but not for our use. The hot knife will hit those, heat them up and then drag them through the foam as it cuts through. This causes “worm holes” in the foam. Technically, you could just leave those to add to the weathered look. For wood it is probably okay. I think it looks odd in stone facades, so I fill those in with Gorilla construction glue as well. I used clear glue for a number of areas in this project, so it looks like they are still there in the pictures – you will notice they are gone after the paint goes on.

You may have noticed the gargoyle panels had grooves cut into them to look like brick mortar lines. Didn’t have time to do that to this pair. Instead, picked up some millwork appliques at Amazon to put on the front panels (link here). An easy way to dress up your facade – lightweight, paintable and easily adheres to the foam board.

Each crack is then given a black coating with an airbrush. You can paint this with a brush if you do not have an airbrush, but it is a LOT easier to get all the deep crevices and jaggies covered with the sprayer – DO NOT USE SPRAY PAINT. The propellant used in them will eat your foam. Instead, just use latex hobby paint.

The monster mud used to coat the pumpkins worked so well, thought I’d try it on the facade panels. Went back to the clearance racks at Lowes to see what they had – my lucky day, they had a gallon of greyish tint that looked similar to the color of grey stone. Same process – use drywall plaster for the base and then add in the latex exterior paint until it has the consistency of thick soup.

I applied the mud with a chip brush being careful to keep the brush level when going over the cracks so the paint didn’t get in them. Unlike the Drylok approach used on the previous column, this concoction covered the pink foam in one coat! What a huge time saver as Drylok took at least 2 to 3 coats until you couldn’t see the pink coming through. Granted the Drylok does have grit in it which adds texture to the panels, but in this case wanted more of a smooth stone look.

All the panels were dry now (it also dries faster than Drylok), started putting them back together to see how they looked.

Incredibly happy with how they turned out – did I mention how lucky I was finding that paint color!?!

Another perspective.

Thought there were shots taken while putting in the arch support pipes – apparently not, my bad. Not to difficult. Simply used U brackets to attach PVC pipe to the back of the column frame. This is when it hit me I didn’t really need the wood pieces that were cut for the top of the columns – chucked those so I didn’t have to cut a hole in them for the pipe. Note, this did push the tops down 1`/4″ having a positive impact of now adding overlap to help hold the tops of the side panels.

Still needed to cut holes in the top so the arch support legs could fit into them. I skipped over this, but if you look at the monster mud shot above, you will see two plastic inserts I designed and 3D printed to fit over the pipes. This allowed for some imperfections in the cuts through the foam top – painted them with the same mud and slipped them over the pipes giving a nicely finished look.

And there you have it, the two columns for our pumpkin arch. Nice and heavy too, so they might be able to support the arch without having any tethers!

Now time to put it all together – I’ll save that for the 4th and final part of this project series. Hope you enjoyed the behind scenes look at the column phase of our signature piece for this year’s Haunted Trail event.