Undervan Storage Box continued:
The box is now supported at each corner by long bolts.
Next step will be to seal the top ledge against the bottom of the van so no water or dust gets in. There are two problem areas. Above the front ledge of the box are the corrugations of the van floor. What I call the "hills" and the "flats".
Along the passenger side of the box the van floor is bowed down. You can see it in the upper left of this picture.
Before I get to the sealing have to take care of the bowed floor. To do that I'll need to lower the box.
True Story. I'm walking through Lowe's about three weeks ago and pass through the hardware section. I see a 3' section of 5/16" threaded rod and think to myself that one of those might come in handy sometime. So I bought it. Had no definite plans for it. Just that I might need it one day.
Jump back to now. I'm standing at the back of the van trying to think up some way to lower the box to the ground. Didn't want to use the floor jack again. Inclined plane? Lever? Block and tackle? Then I remembered the threaded rod. Here's what I came up with.
Take a scrap 2x4 and cut it so it will just fit width wise inside the box. Drill a hole through the center. slide one end of the threaded rod through the hole. Attach two nuts, a washer and a lock washer to one end of the rod.
Get a second scrap 2x4 long enough to span the floor opening front to back. Drill a hole through the middle of this 2x4. Install the two 2x4s and threaded rod into the van. Add a washer and 5/16" nut to the rod just above the second 2x4. Attach a drill to the top end of the threaded rod. The threaded rod fit just fine into the drill chuck. Tighten the chuck.
Remove the bolts at each corner. Now the box is supported by the two 2x4s and threaded rod. I'm standing on a 1/2" wrench that's used to prevent the nut above the second 2x4 from spinning. Run the drill in forward. As the rod spins it causes the 2x4 inside the box to lower away from the top 2x4. This works as long as I keep that top nut from spinning. As the 2x4 lowers so does the box.
The drill and threaded rod worked like a champ. In about 20 seconds the box was sitting on the ground. I used the sawzall to trim the rod once the box was down. Will make the box "elevator" a bit easier to use.
Fix the bowed floor first. Using a 2x4 as a straight edge you can see the bow.
A few well placed blows and it's much better. The bow is all gone.
"Screw" the box back into place and check the fit. It's A-OK now. Lower it down again.
Next up is the seal between the box and the floor. From what I read butyl rubber would be a good choice for this type of an application. Never had any experience with using it before. Headed on down to the my local NAPA. I asked the guy behind the counter what he had in the way of butyl. He said that this 3/8" x 15' Auto Glass Replacement Kit ($21.29) was the only thing he carried. I went ahead and bought it.
It might have been all he carried but as it turned out it was exactly
what I needed.
With the box on the ground get ready to apply a bead of the butyl along the top edge. This stuff is real sticky so I wore gloves.
Application was straight forward. Just stick it down as you slowly unroll it. Leave the paper tape in place.
Problem came when I tried to cut it. It would stick to the utility blade then s-t-r-e-t-c-h like Silly Putty when I tried to pull it way.
I unrolled a bead completely around the top edge of the box. For the driver's side ledge and rear of the box ledge this would be enough since where they mated to the bottom of the van floor it was on a "flat". This isn't the case for the front and passenger sides. The "hills" in the floor raise between 1/4 to 3/8" from the flat so a single bead won't be enough to close the gap.
Since the roll is 15' long I still have extra left over. Remove the top tape and run another bead on top of the first one. Do this just on the front and passenger side's box ledges.
Slowly raise the box. Make sure that the butyl doesn't contact anything on the way up. Raise the box with the "elevator" just until the long corner bolts I used before will reach. On the way up remove the tape from the top of the butyl bead. Attach the four corner bolts and remove the 2x4s and threaded rod.
This is the edge along the back side. You can see I wasn't careful enough while raising the box. A small section of the butyl was snagged and pulled away.
Not to worry since I still had a little left over. I'm getting the hang of the butyl. Cut down through the paper tape onto a piece of wood. Doesn't stick and stretch that way.
After that I just started tightening up the corner bolts in an alternating manner to slowly raise the box keeping it level while completing the seal. Once I got the box high enough I started adding 1" long 5/16" bolts with washers.
Replace the long corner bolts with 1" bolts and continue to raise and seal the box. In this picture you see that the butyl has filled in the gap under the floor "hills".
I didn't have any 5/16" lock washers on hand while doing this tightening. I'll add them later.
Once I felt I had the box in place I tested it by add a lot of weight. Over 200lbs worth.
Jumped up and down a few times and it felt pretty sturdy.
One bit of cleanup. The butyl got squeezed into the threads of the long bolts.
Some work with mineral spirits got them cleaned up. Had to do the same with my hands.