Pontoon boat rebuild HELP

Discussion in 'Boat Design' started by tymonty44, Apr 3, 2016.

  1. tymonty44
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    tymonty44 Junior Member

    I'm about to do a rebuild on this old tri toon. I might be getting ahead of myself but one of my concerns is keeping the boat balanced when I put on the new furniture. It is going to be arranged so it is a family fishing boat. I will have two fishing chairs up front and two in back. The sitting area and console will be in the middle. There will be 3-4 batteries on the boat as well to power the trolling motor, engine, and electronics. Does anyone have any tips or advice for weight distribution (more forward, more backwards, or right in the middle). I think I can keep it balanced left and right just my keeping weight of furniture and batteries somewhat even, right? Here are some pics of the boat and a very tentative/early design plan.
     

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  2. PAR
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    PAR Yacht Designer/Builder

    The real trick, particularly with the average pontoon boat is weight. Keep it as light as practical, so this means don't make furniture out of 3/4" plywood, when 1/4" will do.

    I rebuilt a Honda 50 for a fellow last week and he put a small cabin on the back of his 20' 'toon. It was built of 2x4's, with a 3/4" plywood skin and roof. Instead of replacing the floor, he skinned it with more 3/4" plywood, right over the bad stuff. The furnature was also 3/4" plywood boxes and seating. The scum line on the 'toons was just a few inches below being fully submerged in the stern and about 3/4's submerged at the bow. The 50 HP outboard barely pushed it to 10 MPH, probably beating the water to a froth behind it, as it tried it's best. I tried to explain things to him, but I suspect he'll continue operating it until it does what I suggested it will and capsizes. I'll read about him in the paper, before summer's end, I just hope no one gets seriously hurt.

    Keep it light. If the 'toons are sinking anywhere close to half way submerged, you're as heavy as you can go, so don't put anything else aboard. Ideally, the aft part of the 'toon, should be close to half way under, with the bow portions a few to several inches above this.
     
  3. tymonty44
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    tymonty44 Junior Member

    Thanks for the advice. While on the topic of weight, have you or anyone tried an aluminum boat deck? I was reading about AridDek aluminum decking online. Going to call tomorrow for a quote but can't imagine it being cheaper than wood.
     
  4. messabout
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    messabout Senior Member

    An aluminum deck is going to be uncomfortably hot in summer. An aluminum deck that is thick enough to resist excessive deflection is going to be heavier than plywood of sufficient thickness to resist that excessive deflection.
     
  5. PAR
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    PAR Yacht Designer/Builder

    An aluminum deck, even some extruded or pultruded, thing will cost several times more than plywood as well. From what I know about AridDek aluminum decking, it's an interlocking (click and screw) extrusion and if applied perpendicular to the 'toons, might be stiff enough, though with all those interlocking pieces, I'll bet it'll permit the 'toons to flex like crazy in a rough chop. Get a quote for the square footage you need and I'm sure the price, will make you run quickly in the opposite direction.
     
  6. tymonty44
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    tymonty44 Junior Member

    I called AridDek and got a quote. It was $1650 for a 22' boat. I think you might be right about the flexing because the boards run parallel to the toons and they are 6" wide (I think that is what the guy said). Advantage to aluminum is you don't have to put floor over it so when I did the numbers it was only about $400 more than wood with vinyl flooring. Not too over priced in my opinion but think I would like wood more.
     
  7. PAR
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    PAR Yacht Designer/Builder

    The aluminum decking should run athwartship, not fore and aft for best result (strength and stiffness).

    Plywood is 6 sheets of 3/4" for a 22' boat. Using exterior grade from Lowe's, I can't see how it would comes remotely close to $1200. PS1-09 (3/4") is about $20 a sheet.
     
  8. tymonty44
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    tymonty44 Junior Member

    Just going based off what the ariddek guy told me. My wood estimate is based on pontoonstuff.com. The Marine grade plywood is $105 each and then vinyl floor. That comes out to around $1200. I don't know about pressure treated plywood. From what I have read Marine grade is better. If I was just doing seats or furniture I might use pressure treated but the deck will be constantly exposed to water on both sides so I was going with marine.
     
  9. PAR
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    PAR Yacht Designer/Builder

    No pontoon decking that I've ever seen was built with anything more than PS1-09 (exterior grade plywood), though some use PT, most don't. Even if you buy the extra long 8.5' stuff at $105 per sheet from PontoonStuff, it's still six sheets, which is $630. BTW, you're paying full up retail at PontoonStuff.com.

    The same is true for their flooring products. This is the West Marine of pontoon boats. Standard exterior carpet, is the usual choice and these run from about a $1 - $2 a square foot. Your boat, assuming a 8' 6" beam is about 190 square ft. This is the retail price. The textured vinyl stuff is usually about $3 a square foot. A bucket of mastic is about $25. A local Joann Fabrics store a few miles from me, sells gray, blue and black marine carpet for less than a buck a square foot.

    What I'm saying is if you shop at the application specific stores (pontons-are-us.cm, we'll-rob-u-marine, etc.), you're going to pay top dollar for whatever. On the other hand, with a little knowledge and looking around, you can buy the same stuff a whole lot cheaper.

    Simply put, I put a new deck on a pontoon boat several times a year (this is the pontoon boat capital of the world). I could use BS-1088 or 6566 marine grade, but customers are willing to accept these prices, so I use the same stuff the manufactures do, regular 'ol construction exterior grade. Typically 3/4", though a few wanting bullet proof have had two layers of 3/8" or 1/2" with staggered seams. My usual plywood bill is less than $150. Most insist on carpet again, so I know they'll be back when it rots out the refreshed plywood, but with some precautions (read more money) you can encapsulate the decking and get much long durability.
     
  10. tymonty44
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    tymonty44 Junior Member

    Thank you so much for the advice. I am not wanting to replace the flooring very often so I guess my question is, about how long will exterior grade last? What can I do to make it last longer? I am looking forward to this rebuild project and the things I will learn but when its done I anticipate wanting to spend more time on the water and not having to worry about having to redo the deck every couple of years. I would really like to use vinyl and I will start looking around my area to find a cheaper source. You said any type of mastic will work? I guess it is no different than putting tile up in a bathroom on cement board (which I know a little bit more about than pontoon rebuilds).

    P.S. I am very grateful I found this message board and for all the wonderful information provided, not just on this thread, but throughout all the others I have been reading.
     
  11. PAR
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    PAR Yacht Designer/Builder

    The mastic you'll use is specific for the type of covering. Vinyl flooring uses one type, carpet another.

    There are options to the exterior grade plywood choice, but the prices rise dramatically with them, which is why most just put plywood back down. If the boat is keep clean and dry, the plywood will last a long time (decades). This isn't the case with most pontoon boats and the weather has its way with it.

    Epoxy sealing the plywood will add a lot of durability and longevity to it, but (again) it's an added expense. You'll need 3 gallons to do 180 sq. ft. with enough film thickness to be effective. A 3 gallon kit will be in the $150 - $180 range.
     
  12. tymonty44
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    tymonty44 Junior Member

    Ok. So I have narrowed it down to exterior grade or marine grade plywood. Do I have to seal or treat either of those two products before installing and if so what would you recommend treating with. I am willing to spend more $ to make it last longer.
     
  13. PAR
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    PAR Yacht Designer/Builder

    No, you don't HAVE to treat plywood, but it's always a good idea. The manufactures don't treat it and this is one reason it needs to be replaced with regularity. Epoxy is the only real choice at sealing it. It gets applied neat, in three coats, especially the end grain and any holes or cutouts. Once cured, it gets painted to protect it from UV damage and you're done or ready to apply vinyl, carpet or whatever.

    Epoxyproducts.com (a forum member here), bateau.com and duckworksmagazine.com will have the cheapest varities of epoxy, that are suitable for your needs. Log onto my site and look over the Epoxy Tips & Tricks page for a brief overview of how to work this goo.
     
  14. Chase_B
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    Chase_B Junior Member

    Check the decking in air freight aircraft, it is honeycombed with aluminum skin on each side, very light and they load tanks on it,.. Very strong, i have a few small pieces, i aquired it from a recycler that bought out a business that liquidated, if I remember right 1/2" thick 4'x8' sheet weighs 4-5 lbs . I will ask the recycler next I see him the proper nomenclature for this stuff,
     

  15. PAR
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    PAR Yacht Designer/Builder

    There's lots of brand name for these honeycomb panels, as well as lots of facing and core materials available. In the aircraft industry these are referred to as ACP or ACM panels. A 4'x8' sheet of these type of products are typically about a $800 - $1,200 a piece, so do yourself a favor and wear a cup when getting a quote.
     
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