Inflatable Boat Floorboard & Seat

Uncle Tony was moving and had an old Coast Guard inflatable boat that he didn't want anymore and so he asked me if I wanted it - OF COURSE I DO!!! LOL

So the first time I tried the boat in the water, it was less than ideal - the floor doesn't inflate and I guess these boats were designed for a floor board system that I didn't have which made the boat unstable and fold in on itself a little bit.

I figured in order to be able to use this boat, it would need some kind of floor installed and set out to build one and chronicle my process so that others might be able to do the same.

Materials Used For This Project:

1 Piece of "Scrap" Plywood measuring 36"x96"

1 Piece of Geotextile Fabric for Backing

1 Piece of Indoor / Outdoor Carpet ( *Bought 7 yards and used half for this project )

3 Pieces of 3/4" x 6' Pipe Insulation

1 Bag of 7" Zip Ties (40 pcs)

1 Piece of 2" x 2" x 8' Pine

8 Carriage Bolts ( 1/4"x3" ) with Washers and Lock Washers

2 Brass Door Hinges (For Seat Lid)

1 Can of 3M Super 77 Spray Adhesive

Miscellaneous - Screws, Brad Nails, Wood Glue.

BONUS - Links Provided for 3D Printed Parts in Accessories Section

I measured the length and width of the inner seams of the bottom side of boat's floor.

I took my measurement's from the previous step for the rough dimensions and placed my markings on the plywood.

Then to get the size of the corners on the back and the bow, I just measured the floor from the start of the corner to the end in both directions and placed those marks on the plywood and then cut out both halves using a jigsaw. Then I sanded off all corners and edges with a palm sander.

TIP: Measure Twice Cut Once and Remember to use all appropriate safety equipment to protect yourself from injury.

I used a Geotextile fabric as the backer for the floor since I had some available and it is generally used below the ground so I think will work just fine if it gets considerably wet.

I cut out the rough shape of both floor halves and used a 3M spray adhesive first on the plywood in a thick even coat, and then a light spray on the fabric as well. Let it sit for a minute or less so that the adhesive gets tacky.

Then I used the cap of the spray can to smooth out the fabric from the center to the outside to avoid any wrinkles.

Once the adhesive has had some time to adhere, I used a pair of scissors to trim off the excess fabric.

As with the previous step, for the carpet, I cut out pieces to the rough size of the halves of the floorboard.

I placed the pieces of carpet onto the floor boards, and using the same spray adhesive, first a heavier spray on the plywood and a light spray on the carpet and smoothed from the center outward again using the cap of the spray can.

Again, once the carpet is adhered I trimmed off the excess carpet using a pair of scissors and a box knife.

I used 3/4" foam Pipe Insulation as a padding for the edge of the board so that it doesn't rub against the walls of the inflatable to prevent any tears or punctures.

I started by placing the pipe insulation around the edges of the plywood, and at drilled holes in the wood at spacing of about 6 inches (precision here isn't very important) run the zip tie through the hole and around the pipe insulation, then tighten as much as possible.

Note: I learned the hard way that you should only remove the yellow adhesive backing on the pipe insulation when you are ready to place it around the floor because it will stick to itself and separating it is not fun and I had to tear it a little.

Once I got around to the bow of the boat, I had to make a cut in the foam to get around the sharp curve - so I made a miter cut of sorts with a utility knife and it fit nicely.

Since the scrap piece of plywood was in two pieces, I figured that I would need to brace the floor for strength and to minimize floor movement on the water.

I used a piece of 2" x 2" pine cut into half for two 4 Foot lengths.

First I spray painted the wood to prevent premature rotting, then I removed the floor from the boat to make working on it easier.

I measured for the best placement - far enough to keep it from rubbing the walls, but also enough apart to get the seat and maybe even a cooler ;) between them and marked my holes to drill for the bolts.

To drill the holes, I started with a smaller diameter bit and then to the 3/16" bit to leave enough wiggle room for the 1/4" bolts.

I thought about using folding camping chairs to sit on, but the more I thought about paddling or using a trolling motor would be awkward so my solution was to make a box seat with storage for a trolling motor battery.

I used the leftover pieces of plywood to form the sides and the seat of the bench, and used some pallet boards to make up the front and back of the box.

Since the pieces of plywood were not quite big enough, I used a piece of pallet wood to join them with wood glue and brad nails.

Then I cut the pallet wood to length and then attached a pallet wood corner piece with wood glue and brad nails.

I joined together the pallet front/ back with the plywood sides into an L-shape with clamps, wood glue and brad nails.

I then joined the two L-pieces together in the same manner with clamps, wood glue and brad nails.

I drilled a 2-1/4" hole in the back of the box to let any future motor wires run into the battery storage area.

I did not put a bottom in the box on purpose for a couple of reasons - a) to save the weight, and b) I didn't think it was necessary because of the carpet on the floor.

I attached the brass hinges to the back of the outside of the box first and then to the underside of the lid and marked the holes, pilot drilled and screws added. They were a little long so I used a rotary tool to cut them off and grind them down.

Using the leftover pieces of carpet from the floor board, I covered the box with it as well.

I started the largest piece of carpet in the center and ran around the corner, as opposed to having the edges of the carpet on the corner of the box which, I think, would make it easier for the carpet to peel.

I did use some staples to help keep the carpet secure, I am a little concerned about staples around an inflatable boat, but I am confident that the staples will not damage the boat.

Once finished with the back, I cut the carpet in the hole in an 'X' and trimmed off the excess.

I wanted to add a few items that would make using this boat easier and more FUN!

So I added tie-downs and rope cleats to the floor braces in front and back for attaching a small anchor.

I also wanted to clean up the hole in the seat for wires, so I added a 3D Printed Grommet with Cover, this is an awesome little piece - Thanks to the designer, download the file here - https://www.thingiverse.com/thing:2131350

One last accessory, a 3D Printed Fishing Rod Holder attached to the seat top that can be removed for transport. Again, thanks to the designer and download it here - https://www.thingiverse.com/thing:686326

Now that the floor board and seat is finished, it's time to head to the pond.

To set it up, I partially inflate the boat, then insert the bolts into the floor board sections and place them down into the boat, then I put the white support rails down and tighten the nuts and then fully inflate the boat.

Then all you have to do is plop the seat down and push off in the pond and cast a line.

Have Fun if you build this Project and please vote for me in the "Water" Contest.

Thanks Uncle Tony!!