Custom bending and forming bolsters from Starboard and PVC board and inside corner wraps can be the coolest part of an upholstery job. We are often confronted with difficult corner pieces that require a special formed piece to give that full custom appearance. Usually I start with 6 mil poly (plastic) and lay it over the area to be covered. If you have straight bolsters in front or behind, it is always best to fabricate them first. Install your plastic behind the ends so that when the bolsters are in place you can make a continuance of the bolster you are about to build. Double-face tape on the back makes it easy to get the proper curvature.
Trace the new bolster with a marker. Installation location can be done on the plastic at this time. Decide which type of fastener you are going to use before starting.
Take the pattern to the cutting table and lay your board out and trace around the plastic. Mark the mounting locations. Adding foam can be touchy because the curvature will change the edge distance, especially on outside corners, and you might have to add an inch or two to be trimmed later when fitting in place before you make the upholstery pattern. When final cutting is done, allow a ¼-inch overhang of foam to ensure compression of the foam and to get a nice, tight fit.
I like to use a little firmer foam because the fabric must be pulled tight, and using a soft foam will make doing so difficult. On seat backs, I use 50# firmness. If a bolster needs a softer finish, I will add a ¼-inch of sew foam behind the fabric to create a nice, soft feel.
Always allow a little extra curvature to the bolster because once you pull the fabric tight, it will want to bend a little differently. To ensure the proper cutting angle of the foam, I always install the bolster with the foam tacked in place. If you cut too much, you can always add a thin layer of foam to the ends to get it back to the right size.
Preparing the plastic board requires a little carpentry skill. I cut with a band saw or a jig saw. After cutting, sand the edges with 220 grit paper to get a smooth edge, especially on the hard corners. If using ½-inch PVC, a router can be used.
Heating the board can be done over an oven with some leather gloves, or you can use a good quality heat gun with even heating across the board.
PVC board bends at 200 to 250 degrees in about two minutes. Make sure you cut your vent holes after you bend it because cutting them before will not allow the plastic to distort. A router can be used to round off the edges.
Heating plastic board can be a new experience, and once you try it you will come up with new ideas for applications. I have fabricated other items like drink holders (Photos 1 and 2) and brackets for other installations.
PVC board is not a structural product, so cracking can occur when spanning large open areas, such as seat bottoms, if the customer has a tendency to jump in the boat from the dock, for example. If that’s the case, it’s best to reinforce from the bottom with fiberglass stringers, or use Starboard.
We found that fiberglassing the PVC board is also handy. I made a shell out of ½-inch PVC and formed it inside a 1923 T-Bucket interior. The top edge was to overlay the body edge, and when the fiberglass was installed it made it very solid (Photo 3).
All of the upholstered pieces are removable in one big piece (see photo at top of article). Installation with clips made it easy (Photo 4).
When preparing the surface to be fiberglassed, I recommend sanding the PVC area with #80 grit paper to secure the resin and cloth.
Experiment and practice on a few pieces of plastic and PVC before doing it on your customer’s project. Keep in mind the extra cost for the products and your time. You can create some unique projects that make your customers say, “wow!”
I hope this information gets your creative juices flowing. It has endless possibilities. Just have fun with it.
Don Racine is co-owner of Racine Design in Jacksonville, Fla.