Plywood swim platform?

I knew that would get some folks attention I am going to build a new swim platform for my boat and my thoughts were to build it out of plywood. 3/4"for the first layer with an epoxy laminated second layer of 1/2" turned perpendicular to the first. Next I was going to soak the whole thing in three coats of CPES and then paint using non-skid on top. Any reason this wouldn't be fast, strong, cheap and easy?*

Even "marine" plywood like Brunzeel and its costly kin SUCK if emerged very much.

Loads of epoxy on the edges will be required.

Starboard? Foam core glass?

Daddyo wrote:
I knew that would get some folks attention

I am going to build a new swim platform for my boat and my thoughts were to build it out of plywood. 3/4"for the first layer with an epoxy laminated second layer of 1/2" turned perpendicular to the first. Next I was going to soak the whole thing in three coats of CPES and then paint using non-skid on top. Any reason this wouldn't be fast, strong, cheap and easy?*

Click to expand...

*You could have one fabricated out of aluminum for about the same money, with ten times the resistance to the elements.

Daddyo, only thing you could have said to get more attention is to mention the word bayliner, except their swim platforms are not made of plywood.

I'd get one fabricated from a welding shop that doesn't know "marine" means you should pay 2x's the regular rate.

Yeah Plywood won't last a year. To hard to get it sealed up right.

One little bump that cracks the covering and you've got water intrusion. Even with marine ply you will get delamination with a plywood core.

Trust me I built my back deck that way and just winter summer temperature differences causes cracks where you made a mistake and not gotten enough glass and resin on the hard to reach places.

*Aluminum, all fiberglass or all wood. (teak strips or the like.) Remember it sticks out like a sore toe easy to bang it on a slip rail or another boat.

SD*


-- Edited by skipperdude on Thursday 19th of January 2012 03:36:19 PM

Non Skid pattern Starboard.

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Mike

Palm Coast Fl

Our second boat growing up was a 31' Trojan which Dad bought new in '67. It had a plywood swim step, covered with a rubberized non-skid material. It was still intact when he sold the boat in '76. We had covered moorage, so I am guessing the lack of fresh water hitting it helped keep it from rotting.

Before having my bow pulpit fabricated from 316L stainless, I made a prototype of 3/4" Baltic Birch from Home Depot. I glued it up 3 sheets thick with epoxy and cut a slot for the anchor. Shortly after that I decided to go with stainless and left it (prototype) outside with no paint or coating for three years to see what would happen. No delamination at all. I live in Southeastern CT.

YMMV

Rob

37' Sedan


-- Edited by Datenight on Monday 23rd of January 2012 08:56:32 PM

Daddyo wrote:
Any reason this wouldn't be fast, strong, cheap and easy?*

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*As we say in our business, you can have it good, fast, and cheap.* Pick any two.

I have no doubt plywood would work for awhile.* Soaking it in CPES before painting it would make it last a longer while.* Making it out of plywood and then fiberglassing the whole thing would make it last*an even longer while.* Making it out of teak will make it last a real long while--- ours is 39 years old and still going.* You could make one out of the right kind of metal and it will last damn near forever.

In the end you'll get what you pay for in terms of time, materials, effort, and money.

So the answer to your quesiton is easy:* how much do you value 1) strength, 2) longevity, 3) ease of fabrication, 4) aesthetics,*5) cost, 6)safety,*and 7) resale value?

Assign a value of 1 to 5 to each item, 5 being the most valuable, and whichever attributes are closest to 5 will tell you how to build your swimstep.

How you gonna mount it.

You can get a piece of UHMW or Starboard walla you got it.

I've had one made for years. Just trying to figgure out the best way to mount it.

Hate drilling holes in the transom to bolt it on.

Sd

skipperdude wrote:

Hate drilling holes in the transom to bolt it on.

*

Click to expand...

*It's what all the boat manufacturers do.* So if it's no big deal to Fleming, Grand Banks, and Nordic Tug I wouldn't think it should be a big deal to anyone else

Marin wrote:skipperdude wrote:

Hate drilling holes in the transom to bolt it on.

*

Click to expand...

*It's what all the boat manufacturers do.* So if it's no big deal to Fleming, Grand Banks, and Nordic Tug I wouldn't think it should be a big deal to anyone else

*I know. It's like take a deep breath hold it and then pull the trigger.

Any time I do something to the hull it's like that.

Apprehension, remorse. It's my boat we are talking about here.*

SD*

I'm closing in on completion of repairs to my swim platform. I think I might have posted a pic back after Hurricane Irene bit a chunk out of it when the marina cleat pulled out of the dock. Our floating docks are constructed with "ipe" also spelled epi by some. It's supposed to be harder and more durable than teak. After the storm I was able to salvage some stock and rebuild the platform. I don't know how ipe costs relate to teak, but it's apparently a whole lot less:

http://www.advantagelumber.com/decking2.htm

*

A couple of pics below of work in progress.* Yep, I had to give up and paint it. The two different materials, plus a few spots that are glassed over, made it the only alternative.* The top coat of paint has a non-skid in it.

Not too hard to mimic the original construction. Below the pic of my extension of 13" to my swimgrid. the inside 5 slats and 5 spacers are added. A teak plank 2"x6" made all the 14' long slats. Another 1.5"x4" made the spacers. Object of the exercise was to look like it came that way from the builder.

Keith it looks great. As a matter of interest what coating do you use on it? I've tried Marine Teak Oil repeatedly but it very rapidly loses its newly coated appearance.

Cheers
Janis

Janis:

No coating on the top side, several coats of varnish on the bottom side, to keep it from going green. Last haulout, July 2011, the underside didn't yet need any attention, after 5 yrs. The top side is uniform in colour, now grey, good for traction when wet, needs no attention. In the picture, you can see the new boards are a slightly "newer " colour than the old, which had the green sanded off them. I flipped the original swimgrid over, which gave an unworn appearance to the old part.

I did a plywood swimstep for our 38 Tolly. two layers of 3/4 AC plywood epoxied together and cover with glass cloth put on with epoxy rather than polyester resin. Used 1" tubing flattened on the ends for the angle brackets ala Bayliner. Lasted several years while we had the boat, don't know how it is faring now.

Well it's done and not quite plywood. I used Ipe. Screwed together with stainless screws and epoxy. Just need to put the perpendicular ends on or I might just finish the edge with rub rail. The boards at the outside edge are a couple of days less in the sun. Added nearly a foot in width. Ipe is much, much stiffer and stronger then teak.

Wow, what a great looking swim grid.
I am sure you don't regret the extra work or cost, over your originally posted thought to use plywood.
That swimgrid will last as long as the boat, and look good the whole time.

Thanks! I just couldn't resist working in the material I know best, good old wood.

Daddyo, how did the ipe compare to teak on cost? I did some research on it and it looks to be a very good choice.

Other options

Good job i cheated bought one of a wrecked super Yacht cut it down to size.but used some additional pieces to incorprate a rub/crash Rail.

I've thought of building custom swimsteps as a side gig after retirement. I have a CNC router and am always looking at ways that it'll support me 'post workaday world'

Starboard would be an easy material to work with. A full sheet (54" x 96") is around $450 for 1" thickness. The beauty is the abilty to cut, shape and design it any way you wanted without regard to grain and direction.

Fun stuff to work with. If anyone can think of things they'd like to see cut in CNC, shoot me an email. I'm always looking for fun projects and ideas. I have less time than imagination, but do have a CNC router and a CNC laser in my garage shop.

I have a local Mega yacht/sport fishing boat builder about 2 blocks from my house and they use starboard for loads of stuff, Cabinets on the fishing deck, Instraments mounting, Cabin doors for the head, I had a hard frame top with Sunbrella on it, changed it to 3/4 inch starboard added a drip rail and shaped the front rounded it was fantastic, and you could stand on it, i was able to mount all my electronics on it with out worry of leaks or hard to service . Great idea

It's amazing stuff to work with too. Works easily, the machine runs through it single-pass at 2-3 inches per second and while more expensive than ply, will last forever.

It definitely has some applications that it exceeds wood, but lacks in others though. Another drawback is the ability to bond the stuff. NOTHING will stick to it.

I love working with the stuff, but come out covered in snow every evening when I run it on the machine.

Forkliftt said:

Daddyo, how did the ipe compare to teak on cost? I did some research on it and it looks to be a very good choice.

Click to expand...

It was about a third of the price and exponentially stronger. Couldn't even make the transom bend with the 1 1/4" laying horizontal so I had to turn it on edge showing the 1".

Did you finish this project Daddyo? Let's see some pics!

Really good looking result. Traction and feel must be great. Sure would appreciate you building me one for my Manatee. How many bucks for materials? Hours?

Daddy

If you used IPE it will last past generations. In my home town there is an old peer made of IPE in 1908. It is still used by a Gas Station and all kinds of boats tie in it…..
I really wish that I live as long as the first signal of rotten wood appears in your swimm platform. That will give me another 30 to 35 years to enjoy life, starting now.

Enjoy

Howdy - Not meaning to Hi-Jack this swim platform thread... but rather to continue on the theme for best materials regarding weight bearing, stand-upon boat areas, I post the following.

Marin’s post with listed build-out weights and measures for nearly any item is spot on i.e. - - > “...answer to your question is easy: How much do you value 1) strength, 2) longevity, 3) ease of fabrication/installation, 4) aesthetics, 5) cost, 6)safety, and 7) resale value? Assign a value of 1 to 5 to each item, 5 being the most valuable, and whichever attributes are closest to 5 will tell you how to build your...” – [whatever]

BTW – Many posts on this thread have shown/described great build-outs on your swim-steps and some good input on various materials and build methods were well discussed... Thanks!

Soooo this is my situation:

I recently acquired a lightly used, considerably good condition (needs thorough cleaning and engine reactivation after misting years ago; upholstery and gel coat are fine) 700 hour total use, 20’ 1990 Malibu Skier with 350 cid, 270 hp... on a good trailer. My only real problem is some areas of floor rot in the carpeted plywood; i.e. center of boat on both sides of engine hatch where skiers stood upon exiting water. 11 year grandson and I have removed all furniture etc to carpeted floor and we together will restore this Skier with some help in cleaning from his 9 year sister. Stringers are in great condition. I can either leave existing plywood in place (areas other than on sides of engine are still in sound condition) and simply cover it all with added 1/2” marine ply (or other material) and lay carpet or I can tear out entire floor and replace with 5/8” or 3/4”. Still making my decision for technique on floor repair in this instance on a 1990 Skier/party-boat in regard to the build-out weights and measures mentioned above.

The question I bring to you all with this post:

In this case of overlaying or completely replacing a carpeted ski-boat floor, instead of marine plywood, what suggestion for floor material might you provide? I was extremely interested to read the input on aluminum and will call my metal shop to get a fabrication bid on an aluminum overlay and aluminum for complete floor replacement. I’ve never used Star Board. This will be an interesting project with grandson... the boat just might become his in 5 or 6 years! Ya just never know...

Suggestions always appreciated – Thanks Art