A Jig What?

When you see cargo vans like our Promaster on the road, you probably think they're just big rectangular breadboxes inside.  Unfortunately, they are not.  The walls curve, support beams stick out, walls meet at odd angles.  All this asymmetry causes the van's floor to have several odd cut outs, curves, and angled joints.  This makes building a floor no easy task, but a perfect job for a jig saw.

 Tracing the shopping bag jig saw template onto the plywood.

Tracing the shopping bag jig saw template onto the plywood.

If everything goes to plan, the floor is the only work requiring a jig saw. So, I found a local tool rental shop to pick one up for $11 per day.  When I called to reserve it earlier in the week, the guy said they rarely rent those so I didn’t need a reservation, just stop by for it whenever.  He was quite right.  Of the three people manning the rental counter, 2 didn’t know they stocked jig saws and the third didn’t even know what one was.  After a little digging around we found it on a shelf under a pile of other power tools. 

There are many steps to building the floor, but I was most worried about getting the jig saw cuts right.  I've never used one before and with Andrea out of town I had nobody to double check my measurements.  I used a few Wholefoods bags to cut templates to trace onto the plywood as a cutting guide.  There was only one cut (the rear corner between the door and the wheel well) that required several tries.

Once the plywood had all the right angles and curves, I turned to my next new tool: the miter saw.  We are using 1/2 inch riser beams under the plywood to create space for insulation.  I cut the riser beams to size and started drilling holes to screw them to the bottom of the plywood.  I also applied a line of Liquid Nails on the beam-to-plywood connection to keep them from squeaking. 

The pace slowed down a lot as I figured out how to get all the pieces aligned for drilling so I only got about 1/3 of the way done the first day.  I eventually figured out a system for aligning the holes and drilling a countersink so the screw heads would be level with the floor.

 Using the new miter saw to cut risers for under the floor.

Using the new miter saw to cut risers for under the floor.

After much debate, we decided to seal the entire subfloor to protect it from water and moisture.  We used Waterlox Original Marine Sealer because the guy at the local woodworking shop recommended it and promised it wouldn't be toxic.  We are trying to be careful with building materials to limit the impact of chemicals in such a confined living space.  

 Applying sealant to subfloor. Also, Andrea using the fancy speedlight and soft box she rented.

Applying sealant to subfloor. Also, Andrea using the fancy speedlight and soft box she rented.

After applying the sealant, we left it to dry for a few days.  In the meantime we worked on insulating the floor, as described here.

QUICK FACTS
Time Spent: 18 hrs
Dollars Spent: $225
Products Used: 
    * Exterior grade plywood
    * Redwood 0.5 by 1.5 inch boards
    * Liquid Nails
    * Waterlox Original Marine Sealer
Tools Required: jig saw, miter saw, drill, caulk gun
Frustration Factor: moderate

 Finally, after several days of work we were ready to install the floor.  The van came with 8 floor tie-down bolts and we reused these holes to attach the floor.  Unfortunately, this set off a long and unsuccessful search for the proper bolts.  Since the new floor adds about an inch of thickness, the original tie-down bolts wouldn't fit any more. The van uses all metric bolts because it's really a re-badged Fiat.  Metrics bolt assortment is pretty limited in the US.  We tried 2 home improvement shops and 3 auto parts stores but never found the nice, low profile, rounded heads we wanted.  Instead we had to settle for standard hex bolts which stick up more than desired.

I had several hours in DIY-Hell as I tried to get holes drilled into the floor in exactly the right place to match up with the tie-down locations.  My original plan was to lay the floor down and then drill small starter holes through the tie-down points from underneath the van.  But it turns out 7 of the 8 tie-down locations are inaccessible from underneath.  I attempted to measure the proper locations but ended up off by a few millimeters, leading to a long process of gradually widening the holes in the floor.  Anyway, I eventually got them aligned and we bolted the floor in.  All done!

 Nothing left but a little clean up.

Nothing left but a little clean up.