Need Advise on Floorboard Installation

[minuteman62-64]

I have a 15.5 ft. Bayrunner, welded aluminum hull. I'm going to install a platform in the bow, extending from over the bow seat to the bow. This will make climbing in when launching easier, provide covered storage and maybe a casting platform.

I've looked at a number of similar boats that have platforms, so I know how I want to construct that part of the project. However, I also want to install a floorboard under the platform to provide a flat floor for storage. That's the part I'm not sure about.

The floorboard would cover the deep "V" portion of the bow (see photos), and be about 12 inches below the top of the bow seat (just about where the chine would be if there were an actual chine). Items stored would be the anchor/chain/anchor line (in the blue "tuff" container at the left of the second photo), some extra lines, cushons and some other light stuff.

In the aft portions of the boat, where the existing floorboards are located, there are longitudal stringers welded to the hull to support those floorboards. However, none in the bow.

So, my current thinking is a piece of 5/8" plywood for the floorboard, supported by three 5/8" plywood supports, perpenduclar to the floorboard, scribed to fit the curvature of the bow section. All epoxied together and coated with epoxy.

My concern would be creating a "hard spot" in the bow that would lead to stresses/cracks/problems. Anyone see problems with this? Other suggestions?

 

[oops!]

Re: Need Advise on Floorboard Installation

no problems.......go ahead....dont worry about hard joints in a tinny......especially in the bow area

 

[CaptainKickback]

Re: Need Advise on Floorboard Installation

You used the term "epoxy" several times but did mention any fiberglass. I hope you intend to fiberglass, not just resin the wood.

 

[Decker83]

Re: Need Advise on Floorboard Installation

Welcome to iboats.

You DO NOT want to use Pressure Treated WOOD on a tinny. This can cause a corrosion that will eat the aluminum.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

You used the term "epoxy" several times but did mention any fiberglass. I hope you intend to fiberglass, not just resin the wood.

I'll be assembling the floorboard and bottom supports using epoxy fillets reinforced w/fibreglass tape, like you'd do if you were building a stich-n-glue boat. I will probably fibreglass the top surface of the floorboard for abrasion resistance. Were you thinking of any other fibreglass applications?

Yes, I will not be using PT plywood. Just some AB-X that I have left over from when I rebuilt one of the seats and the rear hatch covers.

 

[CaptainKickback]

Re: Need Advise on Floorboard Installation

Bare wood in the elements is not a good idea. If you want your hard work to last very long, the wood needs to be encapsulted in FG (both sides and edges).

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

Here's where I am. Made the cross-ship frames of 5/8 inch A-B-X ply, scribed to fit hull. Fore-aft braces of 1/2 inch A-B-X ply. Lots of air circulation holes since I am now parinoid about dry-rot. All glued together w/West epoxy. Note: not PT ply

Next steps: (1) a little sanding to fine tune the fit to the hull (I removed the frames for the glue-up so got a slight bit of mis-alignment that showed up when I inserted the completed assembly into the hull); (2) make template, cut out and fit the actual floor (decided to use 1/2 inch ply since the loads will be light); (3) glue floor to frame; and, (4) reinforce w/thickened epoxy fillets and fibreglass tape.

 

[lilpig]

Re: Need Advise on Floorboard Installation

Thanks for posting so much info. I'm about to install a floor in my 14' and this helps.

It seems you have a floor in the rest of your boat. Did you make simular stringers to support the plywood?

 

[jigngrub]

Re: Need Advise on Floorboard Installation

OMG! Looks like the name of this thread should be fiberglass guy marries a tin boat! It should be an interesting thread.

Your "lumber" framing looks great!... but we tinny guys don't frame with lumber, we use aluminum angles and tubes and we fasten them with rivets. This way we don't have to worry about our framing rotting like the stringers in those nasty glass boats do.

We do not encapsulate anything!... and anything made out of fiberglass be it woven, strand, mat, cloth, or buttwipe weave isn't allowed within a 5 mile radius while we're doing a resto... I don't even like for an old Corvette to drive down my street when I'm working on my tinny!

We do know that we can use pressure treated plywood, but that it has to be kiln dried CCA pressure treated plywood... and that you can't buy this stuff just anywhere.

We seal the top side only of our decking with 4 coats of epoxy and then apply our chosen deck covering being sure to wrap the edges. We then install our decking on our aluminum framing using either rivets or screws through our deck covering so we can remove it at a later date without destroying our finished deck covering. We do this in case we have to fix those doggone leaky rivets, dents, or holes with sharp edges than can cut the fire out of you and make you lose a pint of blood!

... but hey, this is your boat and you can do it any way you want. And by the looks of your initial wood framing (it really does look good), it looks like you'll do a fine job on the bastardization of a tin boat.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

Thanks for posting so much info. I'm about to install a floor in my 14' and this helps.

It seems you have a floor in the rest of your boat. Did you make simular stringers to support the plywood?

The floor in the rest of the boat is supported on aluminum stringers that run across the bottom of the hull. As the photos show, presumably because of the steep "V", no such stringers were installed in the bow section.

As I fitted the 1/2 inch ply floor piece I realized I've probably done some over-kill. The geometry of the hull would allow using only the floor piece (omitting the sub-floor framing) together with a couple of clips to hold it in place. Oh well, its almost done, not too heavy and I kind of like it - so I'll go ahead and complete it. It will distribute the load a little more evenly than just the floor piece alone.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

OMG! Looks like the name of this thread should be fiberglass guy marries a tin boat! It should be an interesting thread.

Your "lumber" framing looks great!... but we tinny guys don't frame with lumber, we use aluminum angles and tubes and we fasten them with rivets. This way we don't have to worry about our framing rotting like the stringers in those nasty glass boats do.

We do not encapsulate anything!... and anything made out of fiberglass be it woven, strand, mat, cloth, or buttwipe weave isn't allowed within a 5 mile radius while we're doing a resto... I don't even like for an old Corvette to drive down my street when I'm working on my tinny!

We do know that we can use pressure treated plywood, but that it has to be kiln dried CCA pressure treated plywood... and that you can't buy this stuff just anywhere.

We seal the top side only of our decking with 4 coats of epoxy and then apply our chosen deck covering being sure to wrap the edges. We then install our decking on our aluminum framing using either rivets or screws through our deck covering so we can remove it at a later date without destroying our finished deck covering. We do this in case we have to fix those doggone leaky rivets, dents, or holes with sharp edges than can cut the fire out of you and make you lose a pint of blood!

... but hey, this is your boat and you can do it any way you want. And by the looks of your initial wood framing (it really does look good), it looks like you'll do a fine job on the bastardization of a tin boat.

Sorry, I didn't realize I was violating the sacred creed of the tinny owner. I don't think anybody ever administered the oath

I was thinking, that with ply transom, floor boards and seat tops, a little more ply would be socially acceptable.

There seem to be two schools of thought on epoxy barrier coating. One is do it to keep the moisture out. The other is don't do it since there is already moisture in the wood and it needs to breathe. I've had good luck with the use of a barrier coating in the past, so I'll go ahead with it on this project. The way it's constructed it is easily removable for inspection/maintenance.

 

[Decker83]

Re: Need Advise on Floorboard Installation

Your craftmanship looks great and would fit in any tiny.

 

[PlayD0h]

Re: Need Advise on Floorboard Installation

thanks for the laugh jigngrub

minuteman62-64 - looks great

 

[jigngrub]

Re: Need Advise on Floorboard Installation

Sorry, I didn't realize I was violating the sacred creed of the tinny owner. I don't think anybody ever administered the oath

I was thinking, that with ply transom, floor boards and seat tops, a little more ply would be socially acceptable.

There seem to be two schools of thought on epoxy barrier coating. One is do it to keep the moisture out. The other is don't do it since there is already moisture in the wood and it needs to breathe. I've had good luck with the use of a barrier coating in the past, so I'll go ahead with it on this project. The way it's constructed it is easily removable for inspection/maintenance.

Seriously, I also agree with the epoxy barrier coating... but on the top side only. The bottom side of your decking will see very little moisture if your boat is maintained and stored properly. The uncoated bottom side of the decking will let the plywood breathe while the coated top side will protect it from water/moisture intrusion.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

Moving on, although slowly , here's the fabricated component with joints filleted and taped, coated w/epoxy and wet sanded to provide a little "tooth" for the paint.

Next steps, paint & install.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

Whoops, wrong photo. That was after the initial epoxy application. Here's the "ready for paint" version.

 

[minuteman62-64]

Re: Need Advise on Floorboard Installation

And, here's the final product, painted and installed. Second photo shows Dri-Deck that will be fitted - just haven't decided yet on how much to trim off.

Next project will be to make a deck, with hatch, over this area. I'll be back with plenty of questions