Casting Deck

[Seadoomanls]

Hey guys! I am the proud owner of a completely out right owned 1974 Mako 20' Center Console. It is powered by a 1994 Yamaha 115 outboard that has served me well, with a few headaches of course. The purpose of this boat is 75% fishing, usually with myself and a buddy or two, and 25% pleasure cruise to an island where the very attractive misses would like to lay out in a bikini. Insert the problem here... The boat currently lacks a deck suitable for a 5'4'' person to lay out and get all the free sun rays available. I am attempting to attach pictures, and you can see in the front of the boat the deck goes up about 8" and is a 68"x49" deck. My idea here is to make the deck even with the top of the boat. This would make a great platform for me to cast net, fish from and attach the yeti for sight fishing. Also, it would double as a sun deck for the lady . Hopefully my idea came out correctly.

My plan would be to frame the area using fiberglass covered 2x4's and a sheet of plywood up top. I am comfortable with fiberglass and gelcoat work, I would just need guidance on the BEST fiberglass cloth and resin to use for maximum durability. Also, I don't think it would add a bunch of weight, but maybe somewhere in the 100 lb area. I also attached a picture of a poling platform (37"x42") being sold locally for $200. My thought was to purchase it, cut the aluminum legs even, and use in as a removable casting deck on the existing front deck of the boat. This would suit my needs for fishing, but wouldn't help with the sun deck idea.

I would really like to bring the deck up even to the top of the boat, as this would be my ideal situation so long as it doesn't cause a rot issue or a weight issue. Also, I have all the free wood I can get my hands on, so it would only cost fiberglass materials. My time is valued very high, but I give it to myself for free .

Thanks!

 

[redfury]

Well, I think 2x4's would be overkill, especially if you are going to fiberglass them. You could simply create the platform and fiberglass support pieces underneath it that would attach to the deck in whatever fashion you would design. Personally, I'd keep the platform about 3 inches below the lip, and then make a nice big old comfy cushion for your lady friend to rest on. Not only would the lip of the front of the boat help keep the pad in place, but while you are fishing, nothing could roll off the boat, beit inadvertently kicked, etc. Think of how strong a fiberglass tonneau cover is on a truck bed.

 

[Seadoomanls]

The less material, the better. What do you mean by fiberglass supports? Where would I do that?

 

[Seadoomanls]

My idea with the 2x4's is to create almost like "stringers" that the new deck would be sitting on.

Also, for the deck, should I use 1/2" or 3/4" plywood? And any particular kind. I have read a lot about this topic, but still seem to be confused.

 

[jigngrub]

Take a look at Sleeper6s build thread and you'll get a good idea on how to build with plywood and fiberglass:

http://forums.iboats.com/forum/boat...o-fishing-machine?t=507523&highlight=sleeper6

 

[hadaveha]

I agree sleeper6 is no joke, you can get a lot of ideas from his build

 

[Woodonglass]

What's the width of the beam where the deck will end? AD HD's idea for keeping a 3" lip is a good one, IMHO. Cushions seem good to. Could be stowed below deck when not in use. Depending on the width of the beam and the type of substructure you build will dictated the thickness of plywood you'll need. I'd recommend Polyester Resin and 1708 Biaxial Fabric for the build.

 

[Seadoomanls]

The width at the widest point will be 68". I have been reading a lot and have decided by first step will be to purchase the 2"x4"s used to create the framing. My stepdad owns a local prop shop and in the past I have ordered the West System 105 resin and hardener kit. Am I correct in saying that is a poly resin? I'm not sure if it has wax or not. I want to use no wax because I will be painting in the end. (Possibly gel coat, but I think my floor now is painted and I want to mimic it).

When I get my 2x4s tomorrow... Where do I start. My plan is to coat all the wood in the resin. Allow to dry approximately 30 min (I'm in FL in 75-80 degree weather) then put two layers of CSM followed by one layer of the woven mat that creates a smooth finish. I have read the thread and found the proper ratios for all that. Just wanted to make sure my fiberglass plan for the 2x4 is up to par. If I am doing overkill, or there is an easier method (such as 1708) please help!! Also, should I frame and screw all the wood together first, and glasss over the hardware, or glass all the wood independently and then screw it together? Or should I not screw anything and use fiberglass tabbing?.

 

[DAHoyle]

I am in agreement with the previous posts. Forget about the 2X4's. They are meant for vertical framing in a wall, not a support member across a span. a 1X6 properly attached would be more stiff, and lighter. For that matter, you could use foam board for stringers, or hell, just laminate several pieces of foam together to form a 6" thick slab, and glass a piece of 3/8 plywood on top of it and you would think you were standing on concrete. Would weigh nothing and add several hundred lbs of flotation. Mind you, I am not recommending either approach, just pointing out that there are several ways to skin a cat.

Bottom line, is that there are as many ways to go about it as there are people you ask.

There are some great ideas out there if you search a little, or even wait a little bit and let even more people chime in. Don't mean to be harsh, but I think you are jumping the gun and beginning the process without having a good plan. You can do it successfully that way, but you can do much better with a detailed plan that includes the pros and cons of various approaches, and you will stand a better chance of completing it without a number of mis-steps and re-works.

The single advantage I see to the 2X4's mentioned, is that you said they are free. That would not be a good enough reason for me to use them. They are a poor compromise in strength, and weight and every other attribute I can think of.

 

[Seadoomanls]

I am all ears and want to do is as light as possible. I am not good at using any kind of computer rendering software, so I can't really show you the idea in my head, but if there is a smarter way (not using the foam laminated together) then I am open. I spend about an hour a night on iboats and I have searched and searched. My idea also leaves under the new deck accessible from the main deck of the boat so that towels and other items may be stowed away and be dry and free from the elements.

As far as my stringers go, I suppose I could use some of the 1/2" ply and run them from the existing deck up to the new deck. Confusing without a rendering I'm sure.

 

[DAHoyle]

I am all ears and want to do is as light as possible. I am not good at using any kind of computer rendering software, so I can't really show you the idea in my head, but if there is a smarter way (not using the foam laminated together) then I am open. I spend about an hour a night on iboats and I have searched and searched. My idea also leaves under the new deck accessible from the main deck of the boat so that towels and other items may be stowed away and be dry and free from the elements.

As far as my stringers go, I suppose I could use some of the 1/2" ply and run them from the existing deck up to the new deck. Confusing without a rendering I'm sure.

The firs thing I would consider if it was me, would be to incorporate the storage you already have on the bow into the design. Maybe extend that area up to the new deck height, and use that structure as part of the support. Without actual dimensions, it is pretty hard to describe. Would use that as a starting point, which would give you some additional storage, and add stringers out at the edges. Glass that all up, with a pair of hatches to allow access underneath, and it would be well supported, and offer the extra storage you are looking for.

 

[Seadoomanls]

The only problem with that, is it would make that storage hatch about 3' deep. The storage only stores two deep cycle marine batteries for the trolling motor. I hate storing anything else in there because the door is so gosh darn heavy. What about making a base for the new deck out of 1"x1" square tubing. I could fasten it to the side of the gun wales about 3" down from the lip. Then use 1/2" ply, glass properly, and tab onto the gunwale using glass?

The aluminum 1"x1" in an 8' section weighs 1.3lbs. If I used 4 pieces, that is only 5.2lbs, then add the weight of wood and I am ahead of the game.

The deck dimensions are:
At the furthest point toward the bow- 40" from port to starboard inside gunwale
At the rear most point of existing deck- 68" from port to starboard inside gunwale
From rear most point of existing deck to the furthest point forward- 49" inside gunwale


And yes, I am an experienced aluminum welder if that helps. I know there are 1000 ways to skin this cat. I have yet to find a thread similar to mine. I'm not replacing the deck, so much as adding to it. Just want it to be the lightest way possible. Whether it cost 3 bucks or 300 is something I'll worry about later.

 

[Woodonglass]

Ok with your beam being 68" Here's a rough drawing and description of how I would do it using wood. This could all be done for less than $150 and under 75# in weight. 2x2' kerfed in order to make the bend and then toggled bolted to the sides to make a ledge for the outer edge of the deck to sit on. 2x4 on edge Port to starboard with center brace top to bottom. 3/4" Plywood deck. I'd configure this to set 3" below the top edge of the gunwales and then you could make 3" thick cushions if desired, All wood to be coated with 2-3 coats of epoxy, top and bottom and then painted with 2-3 coats of Rustoleum Pro Oil Based paint with hardener. This could be done in a weekend. 2 tops!!

 

[64osby]

With the platform in place do you need / want access to the existing hatch?

I like your Aluminum square tube idea and would build a removable platform with it. The thickness of the ply depends on the span between the supports.

 

[Seadoomanls]

Woodonglass, thank you for the rendering. I like it. And the only things under the hatch are trolling motor batteries. I just need to be able to put an extension cord in the for my charger. Easily done even with the deck

 

[Seadoomanls]

How can I know if the fiberglass I buy has wax in it or not? Also, I am using my idea of 2x4s (I will post pics...) when I'm covering with resin, do I need any CSM or Woven cloth on the 2x4s? On the actual deck I will use 2 layers of CSM and one layer of cloth. Unless I come across 1708 locally.

 

[Mikeopsycho]

I'm told you should be able to see the wax floating on top. If you don't want to open the containers, contact the manufacturer. This is what I did, and I found out the first stuff I bought was waxed, as is all their retail resins. I returned it and bought unwaxed from another supplier.

 

[jbcurt00]

I'm told you should be able to see the wax floating on top. If you don't want to open the containers, contact the manufacturer. This is what I did, and I found out the first stuff I bought was waxed, as is all their retail resins. I returned it and bought unwaxed from another supplier.

most off the shelf resin from big box stores, wally world, auto parts places and etc has wax in it. That's just 1 reason to avoid it, there are several. Old stock, and a random blend of components are 2 more reasons to avoid it.

 

[Seadoomanls]

Ok, thanks for the info! We have a local marine shop that has all the stuff you can't buy at the big box place. I will go there. Any word on whether or not to use CSM in addition to the resin for the supports under my deck?

 

[jbcurt00]

Poly resin IS NEVER used w/ out cloth or are you using Epoxy? My wax comment was for Poly not epoxy, but unless you buy non-blush epoxy, it does need to be used all in 1 layup or epoxy needs to be cleaned and scuffed between layups done after the previous layup cures.

So Poly or Epoxy?

If poly, yes wrap the 2X w/ resin and CSM twice, for waterproofing

If epoxy, it doesn't require it for waterproofing, but you can add cloth or epoxy compatible CSM. CSM won't add much strength to epoxy, IMO, but some do use it.