Attaching plywood to van floor?

GreyDawg · 10-20-2009, 01:36 PM

Hi --

Looking for suggestions for attaching 3/8" plywood directly to the steel van floor.

SMB secures 1/2" plywood using Liquid Nails over the gas tank, and everywhere else drywall screws (fine thread, 6 x 1 1/4"). I reckon that this means about 1/2" of drywall screw is poking through the bottom of the floor (assuming the van floor is 1/4 thick...I wonder how thick it really is?)

Any other suggestions? Is there a reason NOT to use Liquid Nails for the entire floor?

Thanks!

jage · 10-20-2009, 09:07 PM

It kills?

I know it says non-toxic right there on the tube, but in highschool my brother did the classic "mouse in a maze" for a science fair project. After the sixth trip to the petstore to replace mice that died after one or two shots in the maze he changed his project to the discovery that a small amount of exposure to liquid nails, albiet supposedly safe, is enough to have your mice wake up dead the next day.

I'm sorry to say, I do not have a better suggestion to replace liquid nails over the gas tank.

GreyDawg · 10-20-2009, 09:15 PM

Hmmm. Definitely something to consider.

Meanwhile, any more suggestions for securing the floor? Terry Jones used 1/2" ply secured with construction adhesive (didn't state the brand) and "about 250 1"x6 sheet metal screws." That seems a bit overkill.

saabman · 10-21-2009, 01:01 AM

FYI my floor is "floating", let me explain:

The floor is butted up to the sides of the van and the seat runners are trough parts of the center of the floor. This stops any lateral movement. Then the sides are under the wall panel which maintains a pressure from above thus stopping the floor from jumping up.

Here in Europe many people building camper conversion either fit floating or glue with sikaflex...

I don't like the idea of screws though the floor as it can create rust traps and humidity entry points... not so good under the floor...

Good luck with your floors

**BroncoHauler** · 10-21-2009, 05:52 AM

Saabman,

How do you maintain the dimensional stability of the floor, so it doesn't warp? If the floor is just locked in place at a few points, it seems like it could warp.

Herb

saabman · 10-21-2009, 06:19 AM

The floor will warp no more than the body shell does... but to be honest it doesn't move at all at least not what the naked eye can see. Its like locked into place... from all sides...

GreyDawg · 10-21-2009, 07:28 AM

Thanks for the responses. Yes, WVvan we seem to be at about the same place in our builds! (Actually, you're 4 days ahead as I plan to purchase my plywood tomorrow.)

The thought of a floating plywood floor is attractive but without seat rails to serve as "locking points" (well illustrated in Saabman's photos), I still have the issue of fore/aft movement. Side-to-side movement would be limited by the walls, except at the sidedoorway. Up/down movement would be limited by the lip of the sidewall material, except again at the doorway. And next year (yes, this will be a build in stages) I may remove my "furniture" and replace the plastic sidewalls, putting insulation behind, so new sidewalls would have to have the same anchoring properties.

On the other hand, I will be utilizing six of the seat bracket holes with 12mm bolts to anchor furniture, so the bolts, passing through the floor, will hold the floor (at least, some of the plywood panels) in place.

I think that I now need to find an adhesive that is more forgiving than Liquid Nails (perhaps Sikaflex), which will hold the floor over the tank if it is dabbed in just a few spots, but which can be "broken" with a good crowbar if I ever need to remove the floor. Elsewhere use screws sparingly, mostly at seams of plywood sheets to ensure smooth level seams, and rely on the bolts through the floor for 99% of the securing of the floor.

Does that make sense?

saabman · 10-21-2009, 07:35 AM

One other thought:

If you use a huge piece of wood or two... the rear wheel arches will also stop for n' aft movement as the wood will (I suppose) wrap round them...

I my build the slats under the initial panels also hold all the panel together as one whole...

Looking forward to more pics of your build

GreyDawg · 10-21-2009, 08:00 AM

Quote:

Originally Posted by saabman

One other thought:

If you use a huge piece of wood or two... the rear wheel arches will also stop for n' aft movement as the wood will (I suppose) wrap round them...

I my build the slats under the initial panels also hold all the panel together as one whole...

Looking forward to more pics of your build

Yes, slats would be nice for creating a "one piece" floor. But alas, I have no way to recess them as you did.

My current plan is to use four pieces of plywood:
1. 4' wide by 6' long (rough cut) laid crosswise behind the driver/passenger seat, thus running from the driver side wall to the door opening.
2. 4 wide by 6' long (rough cut) laid crosswise, immediately aft of the first piece, and thus spanning the space between the wheelwells.
3. The remaining two panels, each 2'x4', to cover the rear space floor:

(the grey dashed lines simply mark off 2'x4' panels, but I would rather keep the sheets large for integrity.)

Perhaps I should play with re-orienting the large sheets to run fore/aft rather than crosswise.

bluedog225 · 10-23-2009, 06:43 PM

3m 4200 would be a great adhesive. It is removable.

3m 5200 if you are absolutely certain you will never, never, want to take it out without lots of cursing and blood.

Run a piece of wire/rope/strong line starting on left rear and running along the edge of the van, behind the front seats, and back to the right rear. Leave some extra. If you ever need to remove the plywood, attach a dowel to each end of the rope and pull/saw through the adhesive.

Just a thought.

Test the 4200. I think it will serve well.

I suspect the liquid nails would be non toxic after the carrier/solvent dried. Much like epoxy is inert when cured.

Tom