Need Advice on Bow Platform/Deck Design

[minuteman62-64]

Next project on my aluminum Bayrunner: install a deck/platform extending from the where the existing bow seat is to the stem (see attached photo). It will have a hatch for access to storage below. Probably too tippy to be a casting platform, but will be stepped on during launching and retrieval. Will also be a space for stowing gear.

I have a couple of basic, conceptual questions before I start. Appreciate any input.

1. I've looked at a number of Bayrunners and similar craft with the type of platform I envision. I've seen three approaches. One, leave the existing bow seat plywood in place, and support the aft portion of the platform on the forward 1-2 inches of the bow seat. Two, leave the existing bow seat plywood in place, and basically cover it with the aft portion of the platform. Three, remove the existing bow seat plywood, and run new plywood for the platform from the seat framing to the stem.

Any pros and cons of these options?

2. I've looked at the framing of factory bow platform installations on Bayrunners and similar craft. Its pretty simple - sometimes just some aluminum brackets along the sides of the hull and at the stem. I've also looked at the framing some of you guys have used for similar installations - in some cases look sufficient to support an aircraft carrier. Sometimes lumber and sometimes structural aluminum.

Any thoughts on how robust the framing should be for my application (I do want to avoid putting too much weight in the bow)? For a tinney, lumber or structural aluminum framing? Boat use is strictly salt water - if I go aluminum would I need to locate some 5052 angles?

 

[oops!]

Re: Need Advice on Bow Platform/Deck Design

well.....its a deep hull small craft.

tippy will be a problem....

i would suggest before you do any major changes. that you throw a chunk of ply up where you intend on putting the deck....then stand on it, see how stable the craft is before you make permanent changes.

other wise, you might end up doing all that work for a unusable platform

 

[jasoutside]

Re: Need Advice on Bow Platform/Deck Design

Hey minuteman!

I can't tell what size boat you have there so 12/14/16? Bigger the better as far as stability is concerned obviously.

I installed a casting deck on my Jet Star and it's really comfortable up there. Click on the link in my signature and check it out, it might be helpful for brainstorming and such. The bow deck install is kinda spread out some otherwise I'd point out a post # for ya, sorry.

 

[minuteman62-64]

Re: Need Advice on Bow Platform/Deck Design

Went out this morning and stood on the bow seat w/boat on trailer. Confirmed that it will not be a casting platform (at 71 I can barely stand up in my kitchen, let alone on a platform on a rocking boat with no side rails to grasp). So, use of platform will be as a step when launching/retrieving, cover for the storage under and a place to stow stuff to keep it out of the way.

Boat is 15'6" long with a beam at 66" at transom gunnels (tapering in to water line) which spells "tippy."

I'll check out the Jet Star platform postings - thanks. Maybe back w/more questions.

 

[minuteman62-64]

Re: Need Advice on Bow Platform/Deck Design

Thanks, jasoutside. Your Jet Star bow platform is very similar to what I envision (I read all the way through about Post #70 ). Major differences: Instead of an aft bulkhead I will be using the framing for the existing bow seat; and, my access hatch will be on top (necessary because of the existing bow seat framing).

A few questions. First, it looks like you used 3/4" plywood that was supported only by the aft bulkhead and the aluminum brackets on the sides of the hull. When you put the boat in use did you find that the bow platform was sturdy/stable enough with that framing?

Second, were your aluminum brackets on the sides of the hull structural (angle) aluminum sections or did you fabricate them from sheet material?

Finally, did you fasten the platform plywood to the aluminum side brackets, and, if so, how?

(I'll PM you these questions in case you don't come across this post)

 

[jasoutside]

Re: Need Advice on Bow Platform/Deck Design

Yah, now that I think of it, since you are using the existing seat for framing my set up may not be very helpful. I'll see if I can grab your questions though...

First, it looks like you used 3/4" plywood that was supported only by the aft bulkhead and the aluminum brackets on the sides of the hull. When you put the boat in use did you find that the bow platform was sturdy/stable enough with that framing?

Yup, that's what I did. Yes, the platform was very solid and casting off of that platform the boat was plenty stable, not tippy at all.

Second, were your aluminum brackets on the sides of the hull structural (angle) aluminum sections or did you fabricate them from sheet material?

Yup, alum angle. I cut just a couple of "relief" cuts in em so they would bend to the curvature of the hull. Then riveted in (staggered for increased strength/rigidity).

Finally, did you fasten the platform plywood to the aluminum side brackets, and, if so, how?

Yup, I first laid down a fat bead of PL Adhesive then riveted them into the angle.

I was quite happy with how that whole set up turned out.

Cheers!

 

[jigngrub]

Re: Need Advice on Bow Platform/Deck Design

I personally would remove the existing plywood and frame with 1 1/2" x 1/16" aluminum angle and frame in the hatch opening. Use closed end blind rivets for fasteners.

Cover with a single piece of 3/4" plywood from the stem to the aft of the seat for a nice clean looking job.

I was just looking at hatch covers at Cabelas earlier and they have some on sale.

 

[minuteman62-64]

Re: Need Advice on Bow Platform/Deck Design

Yah, now that I think of it, since you are using the existing seat for framing my set up may not be very helpful. I'll see if I can grab your questions though...

Actually, your project was spot-on w/regard to my biggest issue - how to frame/construct. In my case the existing seat framing will take the place of your bulkhead and I'll have to do some additional framing to support the hatch in the deck. Relatively minor differences. Unfortunately, I won't be able to match your craftsmanship

 

[jasoutside]

Re: Need Advice on Bow Platform/Deck Design

Bah, I'm just a big doofis, ask any of these guys. They'll be happy to tell ya!

You got it