Filling the cooler hole in the compartment floor

[txav8r]

I am mounting a subwoofer enclosure in my starboard cockpit compartment and wanted to fill the floor recess yamaha designed to hold that rolling cooler. I don't use that cooler in the boat and hate that the floor is recessed for it. Even before I decided to locate the enclosure over that hole, I had storage containers that would fall into the hole and wanted it filled in some way. I have been trying to decide how to remedy the hole. I can fabricate a corner post for the enclosure made of HDPE and be done with the bracing, but the hole is still there and now things may fall into it and get wedged under the woofer enclosure...so it has to go.

I have decided to make a false floor out of 1/2" PVC sheet material. It is the same material that the backing board for the cushions is made of. I intend to make several legs to support the false floor and cover it with the same carpeting that the compartment is lined in. Then when I add my subwoofer enclosure to the compartment wall, I will add a more solid stack of HDPE directly under that corner that is under the false floor and then a piece that is about 1/4" thick between the floor and the bottom corner of the enclosure. It will add the rigidity and support I require to prevent the enclosure from torquing against its mounting wall.

The PVC sheet goods is readily available from plastics suppliers. Regal Plastics in Irving Texas sells it, HDPE, acrylics, and more. King Starboard, marine grade sheet material is an outdoor HDPE. Anything not in UV light doesn't have to have those inhibitors, and the plain old run of the mill HDPE that a cutting board is made of will work for many projects. I bought the full sheet of PVC to build my shelves in the head compartment with. It is lightweight and easy to machine. But being plastic, it is hard to glue or build with unless you use mechanical fasteners (screws). Pictures to follow on the floor mod.

 

[txav8r]

My challenge, fill this hole in the floor like it isn't there.

So I can support this box suspended over it in the corner...

edited spelling

 

[Julian]

How about just cutting a piece of plywood....lay it in the hole, and go out and find some more grey carpet and lay it over the top of the whole storage area and staple/glue it down?

 

[txav8r]

The recess slopes, and is about 2.5" deep. So support runners have to be cut to support the plywood. I have cut runners as well as the top out of PVC plywood I didn't want wood in the floor without sealing it. The subwoofer and enclosure already add 34 pounds so I didn't want to continue to add more weight. I have the carpet to match as well.

I took a piece of cardboard about 25" long and set it on edge cut to fit the length of the recess. I traced a line level with the floor onto the cardboard to have an accurate taper on the template. I did this for the outboard and inboard sides of the recess as that recess isn't the same on either side or front to back. Then I deducted the thickness of the carpet,the filler floor piece, and the cushion tape, so I could get the thickness of the runners. I cut these runners with a taper jig on the table saw to save time, but could have just as easily just followed the new line accounting for the thickness of the other components. Once the runners were cut, I test fit and trimmed the ends to in the recess as all edges slope inward as well. A little sanding was needed to adjust them but the cushion tape on the bottom of the runners will take care of most irregularities in the floor of this recess. The runners don't have to come completely to the ends. One mistake I made along the way was the trimming of the ends. My template was a gauge made showing the exact relationship of the slope and depth. But when I trimmed the ends off to get it to fit, it lowered the deeper end just a fraction of an inch too much. Rather than cut the runners again, I shimmed the deep end with some 1/4" stainless washers I had on hand, between the floor piece and the runners.

The top or floor was pretty easy. I measured from the widest points, the width and length of the opening, cut my floor, and took it out to see. The inward slope of the edges required me to trim all 4 sides to get a good fit. Don't forget to allow for the thickness of the carpet too. I then took it back out along with a couple of lids off cans and jars to gauge the radius of the rounded ends. They are not the same on all 4 but this wasn't needing to be perfect so I just wanted an idea, so I eyeballed the radius and then after test fitting 4 or 5 times, and sanding the radius down, I had them pretty close. The PVC plywood (not wood at all) is easy to sand and cut.

Once the pieces were cut and test fit, including some scrap cushion tape, I brought it in and marked where my runners went on both sides of the floor piece. I then clamped them once at a time to the floor and drilled pilot holes through the floor piece and into the runners. You don't really need to drill pilot holes, this material is soft. I did this for two reasons. When the screw goes into this material, it mushrooms and that will keep the pieces from fitting together flush and weaken the joint...and also change the thickness of the finished piece. The other reason I drilled it, was to have the holes in the runners to set my washers I needed for the extra 1/16th" of thickness my runners ended up being thin by. Then I installed the screws. PVC plywood or sheet material as it is referred to, won't take glues easily, so screwing pieces together is the only way to successfully bond them. I used stainless steel screws of adequate length and diameter to assemble two 1/2" boards perpendicular to each other... #10 screws 3/4" long.

I used the red heavy duty 3M cushion tape. I had bought a roll of it for mounting several things such as my paper towel holder both in the boat and on my stainless steel prep table on my patio. The normal strength kept falling off on those projects but the heavy duty worked great. Thanks @Jim Robeson ! I fixed the tape to the length of one runner, leaving it overhanging one edge and flush with the other. I trimmed against the runners edge with a razor knife to remove the excess and used that on the other runner. Then I test fit it again.

I then cut carpet to size leaving enough to wrap around and under the lip of the floor piece. I sprayed my 3M 77 Super adhesive spray over the surfaces that the carpet would cover. I was generous with this. And then stretched the carpet into place by laying the new floor face down onto the carpet and pulling it tight from the edges up and over the back face. I trimmed the corners by cutting triangles out of each corner the way you would put a book cover on a school book.

I then took it out and test fit again. I was pleased enough to go with it. Since I needed to brace the corner of my subwoofer and enclosure, which weighs 34 pounds in the enclosure, I added another HDPE block under the floor support snug against the top to give me a sturdy place for the corner to be braced and screwed into. There is still a little less than a 1/4" of shim that will go between the carpeted floor and the corner of the enclosure cabinet to act as a foot. Two reasons for this. Wet carpet will wick moisture and transfer it to your enclosure cabinet, no matter how waterproof it is. So preventing this is important. Second, once the cabinet is secured to the wall and speaker, it is suspended off the floor of the compartment, and needs support. HDPE won't glue without heating and using epoxy plastic glue...too much trouble for this. So I just cut some bunk material I had from when I did UBB's on my MFI trailer. I cut out two pieces 1.5" thick to make a 4"x4" base block. Then I needed about 1/4" of remaining thickness also 4"x4". So I resawed that thickness off of a piece of the block and fashioned that thickness to the other block with the same screws used above. Once this 4"x4" block was fabricated, I used 3M 77 to hold it still until it set up long enough to turn the floor upside down with the block installed and I installed the new false floor in the compartment after removing the tape backing on the runners. The adhesive won't hold the block permanently, but my enclosure will get screwed down on that corner, through the false floor and into that block. The purpose is to brace the corner of the enclosure in rough conditions. The enclosure is actually secured to the speaker by sandwiching the wall. It won't go anywhere, but the weight of the cabinet needs bracing to keep it from torquing the wall...that is why I went to all this trouble. I hope this helps someone that faces the same issue and gives them some ideas on how to accomplish it. A simple brace under the corner of the speaker would have been good enough...but I didn't like this hole in the floor.

 

[txav8r]

My progress thus far...

 

[Suchawittygal]

@txav8r...Damn Mel, you're quite handy. Nice work.

 

[txav8r]

The carpet appeared a better match but it is close, and works. The runners fit good and the level is very good.


@Jim Robeson , notice some of that excellent heavy duty 3m double sided cushion tape! Carpet going on...another 3M product, 77 super spray adhesive!

 

[txav8r]

And installed...

 

[jcyamaharider]

Nicely Done Mel!!

 

[BigN8]

Pretty slick!

 

[txav8r]

Thanks guys. I also put an HDPE block under the section that will support the subwoofer enclosure, and the enclosure will get screwed down to that. All will be removable without any change to the boat, so that heaven forbid, I sold the boat, I could go back stock on the cooler...but I don't know what I would do about the 10" hole in the compartment wall for the subwoofer! lol

 

[albett3]

That is impressive!

 

[Murf'n'surf]

Nice work Mel! I assume that this recessed area has a drain? If not, I would drill a few holes so water is not laying in there for extended periods.

 

[GTBRMC]

Looks great, Mel!

 

[txav8r]

Yes @Murf'n'surf , that recess has a drain. All the components are waterproof as well. Should be good to go.

 

[Jim Robeson]

Very nice @txav8r !!!! And thanks!! I need all the help I can get to keep that 401K going!!!!

 

[BravoMike]

Very nice @txav8r! Wish I had your tools and know how to do these kind of mods.

 

[beachbum]

x2 what BravoMike said...

 

[txav8r]

Thanks for the compliments guys. I used a table saw, band saw, and a taper jig. Most guys would have a circular saw or even a jig saw and sander along with a cordless drill to do this project. I give it a 2 beer rating and you could even stretch it to 3 beers during test fitting and getting in and out of the boat. But it wasn't hard, just custom.

I thought I might describe how I did it to go along with the pictures, so I edited that post a little more to add more description.

 

[96Pirate]

Nice work Mel! My garage looked like yours until this past weekend when I had to get all the tools and lumber up against the wall so my wife can get her car in.