After some careful consideration, the thought of using one continuous piece of vinyl turned out to be less than desirable. While it would provide a nice, consistent surface, I just couldn’t figure out a way to install it reliably. The cove base adhesive, which does have some give and allows the vinyl to be repositioned a bit, is a pretty quick grab on the vinyl. So, I stepped back and questioned the approach. Going back to a suggestion from Joe Atkinson when we discussed the topic of backdrops a couple months ago, could I use the plywood as the primary backdrop and just put vinyl in the locations where it would serve a beneficial purpose?
To do this, I would need to seal and smooth the surface of the plywood. I’ve had good luck in the past, on other projects, with Rust-Oleum Filler Primer, including on the fascia boards. It’s a spray can, though, and the thought of spraying the entire 2′ x 16′ backdrop was not appealing, not to mention all the masking that would be needed to keep the overspray from going everywhere else in the room. After some research, I found a traditional primer in a can that claims easy sanding:
I figured I would give this Zinsser Bulls Eye 2 Multi-Purpose primer a try. But first, I would need to apply the vinyl in a few choice locations where it makes sense, namely across the gap between the plywood sheets and in the corner, coved to make a nice transition. The joint between sheets is a likely spot where movement will take place and simply filling it with joint compound is asking for future cracking. The coving of the corner just looks nice and will hide any movement between the backdrop and the room wall.
Before applying the vinyl, some prep worked was done on the plywood backdrop panels. First, the joint between panels was not perfectly flush. Some joint compound was applied, tooled smooth, allowed to dry, and then sanded to create a small ramp to smooth out the transition. Although this will be covered by vinyl, I wanted to make sure the vinyl had good adhesive contact and didn’t end up telegraphing the small misalignment to the front side.
The other thing done was to attach a small piece of trim to the end of the plywood to make the transition around the corner a bit nicer. The trim piece was slightly wider than the plywood, so again joint compound was used to smooth out the transition and fill/cover any small gaps between the trim and the plywood.
Once the joint compound dried, the entire backdrop was sanded with a 220 grid sanding screen. This smoothed the joint compound, but also took off the fuzz on the plywood surface. After the dust was cleaned, the next step was attaching the vinyl.
To begin applying the vinyl, the adhesive was spread with a small putty knife, then tooled into ridges using a 1/32″ notched trowel. I originally thought I could get away with using a straight taping knife to spread the adhesive in a thin layer. However, some experiments showed that this did not hold very well. The extra body you get from the 1/32 ridges helps immensely and increases the holding power on the vinyl.
The adhesive (Henry 440 Cove Base) was spread over the entire area where the vinyl will go and just past the edges. I premarked the edges using the cut vinyl sheet as a template. In this case I ran the ridges of adhesive horizontally so when smoothing the vinyl, any trapped air could exit on either side (or so goes the theory).
Next, the vinyl sheet was placed on the adhesive, starting at the bottom and moving up toward the top. A plastic scraper was then used to smooth the vinyl, starting in the middle and moving toward the outer edges. It is important to wipe away any adhesive that squeezes out the edge and gets on the scraper – if you don’t, you’ll deposit that squeeze out on the vinyl and have to clean it up (fortunately, as I learned, it cleans up with water if you get it before it dries). Several passes with the scraper and the vinyl was pretty flat. To make sure the edges were flush with the plywood surface, the scraper was then run vertically down the edge, slowly moving it toward the outside as it is moved down. This pressed the edge down, while keeping any adhesive squeeze out moving away from the vinyl.
Finally, a wet rag cleaned up the excess adhesive along the edges. Any adhesive that got on the vinyl can also be cleaned at this stage, too.
The cove in the corner was done in basically the same manner. In this case, though, since a finished wall was at one end, a 1/8″ sheet of plywood was first nailed to the wall. Fortunately a stud was available in just the right spot. The vinyl attaches to this sheet, preventing damage to the room wall from the adhesive.
Next step… transitioning the vinyl to the plywood surface, priming, and finally, painting!