Swim platform for my 26S

[Stickinthemud57]

For a while I have been wanting to add a swim platform, but was stymied by the need to allow the motor to tilt up and to be able to lift the rudder. After much thought, I decided I could make the following compromises:

1 - Not allow for motor tilt-up
2 - Not allow for full raising of the rudder
3 - Place the platform more above water level than I necessarily would prefer

I reason that it is not strictly necessary to lift the motor from the water, but instead put it in neutral and let the prop free-wheel. Performance will take a hit, but I am not looking to set speed records if we are going out for a leisurely afternoon.

Setting the platform above the rudder puts the top of the platform about 12 inches above the water. This still allows the rudder to kick up in shallow water, though perhaps not enough for beaching.

I plan to add a pull-out ladder on the motor side of the platform.

The frame will be 2x4 pine, with adequate cross-bracing to support the 1/4" HDPE platform. I plan to apply an anti-skid surface. The frame will be supported at the transom by 3 4x3 aluminum brackets and by Dyneema rope. Not shown in the drawing are retaining pins to prevent it falling out, doubling of the Dyneema rope, and turnbuckles to provide for adjustment.

I have considered sealing and painting the wood frame, but I hesitate. I'm not sure it is possible to seal a wood frame that is going to flex and fear that attempting to do so will only trap moisture that finds its way in. My plan for now is to paint the outside for appearance' sake and leave the other surfaces unsealed so they can dry out. If this doesn't work, I can consider other frame materials, such as aluminum rectangular tube (which would be much more costly).

The platform will be removed and stored in a protected area between sails.

I think I have this figured out, but would welcome any input my fellow sailors have to offer.

[dlandersson]

Suggestion,

Have your swim platform on either side, away from the outboard.

Use a 4 step hook ladder, then some floating foam cushion at the bottom.

For a while I have been wanting to add a swim platform, but was stymied by the need to allow the motor to tilt up and to be able to lift the rudder. After much thought, I decided I could make the following compromises:

1 - Not allow for motor tilt-up
2 - Not allow for full raising of the rudder
3 - Place the platform more above water level than I necessarily would prefer

I reason that it is not strictly necessary to lift the motor from the water, but instead put it in neutral and let the prop free-wheel. Performance will take a hit, but I am not looking to set speed records if we are going out for a leisurely afternoon.

Setting the platform above the rudder puts the top of the platform about 12 inches above the water. This still allows the rudder to kick up in shallow water, though perhaps not enough for beaching.

I plan to add a pull-out ladder on the motor side of the platform.

The frame will be 2x4 pine, with adequate cross-bracing to support the 1/4" HDPE platform. I plan to apply an anti-skid surface. The frame will be supported at the transom by 3 4x3 aluminum brackets and by Dyneema rope. Not shown in the drawing are retaining pins to prevent it falling out, doubling of the Dyneema rope, and turnbuckles to provide for adjustment.

I have considered sealing and painting the wood frame, but I hesitate. I'm not sure it is possible to seal a wood frame that is going to flex and fear that attempting to do so will only trap moisture that finds its way in. My plan for now is to paint the outside for appearance' sake and leave the other surfaces unsealed so they can dry out. If this doesn't work, I can consider other frame materials, such as aluminum rectangular tube (which would be much more costly).

The platform will be removed and stored in a protected area between sails.

I think I have this figured out, but would welcome any input my fellow sailors have to offer.

[Stickinthemud57]

D,

I have considered a floating cushion, but I am wanting something more solid.

The ideal goal is to have something beyond just a one-person perch for getting in and out of the water. I envision a relatively stable diving/lounging platform. Having made the frame, I am not quite sure the weight and bulk will be manageable. I realize a rigid platform of this size may be overly ambitious, but I figure it is worth a try. I can always cut it down in size. Going to a half-platform is my Plan B.

I like the idea of a hook-on ladder. Is there a particular one you might point me to? Most of the ones I have seen need some kind of support point either at the transom or side hull. I have tried ladders with only an upper support point, but without something lower to keep it from swinging inward, it's far too difficult to climb.

Progress report:

Frame is made and very sturdy. Platform is rough-cut and ready for rounding, motor slot and rudder rope slot. I found out the transom is not flat, so I will have to shim out the brackets. No show-stoppers thus far.

I knew all along the stock ladder solution would not be compatible. I have plans to remedy that.

[dlandersson]

[https://www.ebay.com/itm/262084773949?c ... gLOnfD_BwE

[Stickinthemud57]

Thanks for the link.

[OverEasy]

Hi StickInTheMud57!

Nice platform!
As you mentioned the 2x4 subframe is gonna weigh a few pounds.

Just a thought for an alternative approach….
Closed cell rigid epoxy compatible foam panels and fiberglass laminate construction.
Same shape, considerably less weight and 3 to 4 times stronger and more rigidly stable.
Possibly start with 4 Sheets of 1/2 thick rigid foam cut to shape.
Encapsulate the first foam sheet (Bottom layer) with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply second foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply third foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply fourth foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply two over wraps of biaxial fiberglass and epoxy resin to completely encapsulate the assembly.
Allow to cure then sand to remove sharp edges taking care no to sand through the fiberglass.
Paint with epoxy paint and apply tread safe granular to top surface while wet.
Allow paint to dry, brush off excess granules and apply second and third epoxy paint coats.
When cured the laminate structure will be incredibly strong and rigid.
Reinforce the SST eye bolts for the tension support lines with thick large diameter SST fender washers and use SST nylock nuts.
Apply water proof caulk to seal the bolt holes.

It won’t rot and the layered encapsulated construct minimizes or limits any water intrusion potential.

Just a suggestion is all.
Your boat, your rules.

Best Regards
Over Easy

[Jimmyt]

Looking good! Keep those progress pics (and discussion) coming.

[Stickinthemud57]

@overeasy,

Thanks for your input!

Although I have experience laying up fiberglass, it was many years ago and my design expertise is lacking. I may have to look into that approach if my wood frame proves unworkable.

Your comment regarding weight is accurate. Three 8' fir (not pine) 2x4's and a 27x48 slab of 1/4" HDPE have a combined weight approaching 50 lbs (Edit - this is not accurate. Actual weight is more like 36 lbs.). I can just wrangle my 66 lb. outboard, so I am definitely nearing the practical weight limit. Adding a telescoping ladder would be the straw that broke the skipper's back, so I am toying with two alternatives: One would be to devise a way to attach my existing stern ladder to the platform, since that ladder has to be removable anyway for this to work.The second would be to convert a three-rung section of a standard cheap aluminum extension ladder so it could hang on the edge of the platform. Since either would be removeable, the weight of the platform will not increase for handling purposes. I like the first solution because it would save me having to stow it elsewhere, and would be one less part to manage.

I am having a bit of a head-slap moment, inspired by your suggestion. Wondering how difficult it would be to incorporate one of these https://www.advantagechurchchairs.com/a ... b-2448-gg/ into the whole design scheme. One would have to overcome the structural compromise of having to cut out for the motor. Maybe it's back to the drawing board on this?

Stay tuned for our next episode...

[Stickinthemud57]

1 step back, 2 steps forward...

Well, the folding table idea did not work out as hoped. Bottom line, the table I tried (Cosco brand at Lowe's) is not designed for standing on (who knew, right?). I figured it would need some bracing, and not satisfied with the aluminum stock available at Lowe's, I sourced some locally. Unfortunately, I found that what was available and substantial enough would actually have created a heavier final product than my original design. On top of that, I was finding that if I laid the table down on a flat surface and started walking on it, some places would distort. Over the long term, I was convinced that this would end up lumpy and uneven, even with bracing added, and at least a tad on the flimsy side.

The total weight of the fir frame and HDPE platform is 36 lbs, and I have not yet cut out the motor opening or rudder rope slot. I think that will be a manageable weight. I have worked out a way to use the existing boarding ladder on the platform, but want to get a little further along before I tout that solution.

Like most mods, a process. I'm bummed that the table idea did not work, but it was worth the $45 to at least give it a go.

[OverEasy]

Hi StickInTheMud 57

Just read your post on the Costco table…. Ahhhh…. I think you answered your own question..
Sorry it didn’t work… but now you have a nice fiberglass work table!!!

(The Costco table is also hollow with a couple of holes which cold allow it to flood so raising it back up might be heavier yet! )

But a thought did come to mind… How about using a section of and aluminum ladder for the under frame instead of the 2x4s ???

Lighter, stronger, and pretty much corrosion resistant?

Just a thought….

Best Regards
Over Easy

[kurz]

Hi StickInTheMud57!

Nice platform!
As you mentioned the 2x4 subframe is gonna weigh a few pounds.

Just a thought for an alternative approach….
Closed cell rigid epoxy compatible foam panels and fiberglass laminate construction.
Same shape, considerably less weight and 3 to 4 times stronger and more rigidly stable.
Possibly start with 4 Sheets of 1/2 thick rigid foam cut to shape.
Encapsulate the first foam sheet (Bottom layer) with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply second foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply third foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply fourth foam sheet and encapsulate with biaxial fiberglass and epoxy resin.
Then while epoxy is still wet apply two over wraps of biaxial fiberglass and epoxy resin to completely encapsulate the assembly.
Allow to cure then sand to remove sharp edges taking care no to sand through the fiberglass.
Paint with epoxy paint and apply tread safe granular to top surface while wet.
Allow paint to dry, brush off excess granules and apply second and third epoxy paint coats.
When cured the laminate structure will be incredibly strong and rigid.
Reinforce the SST eye bolts for the tension support lines with thick large diameter SST fender washers and use SST nylock nuts.
Apply water proof caulk to seal the bolt holes.

It won’t rot and the layered encapsulated construct minimizes or limits any water intrusion potential.

Just a suggestion is all.
Your boat, your rules.

Best Regards
Over Easy

this is a nice idea also to form a swim platform for an like this:

Maybe you could simplifie it if you buy sandwich panels ready for use. Maybe one day I will go for it for the MacM, but as it would take sooo much time... there is some time...

[OverEasy]

Hi StickInTheMud57!

One thought on your design that might help make it more durable and distribute the loading stresses better…

The side cable stays…. Currently you have the cable stays at mid span of the side sections.. This puts the significant strain on the upper tie-off cleats (if that is your intended location that is)… When climbing out of the water or standing on the mid platform nearly all the downward load support is on the cable stays and their connection points… The hinge connections act as levered uplift force points at that loading.

If you were to move the cable stays to the aft corners you would then distribute more of the downward loading between the cable stays and the hinges. Yes on climbing out of the water most of the load is still on the cable stays but as one moves more toward the middle the load becomes more equalized between the fwd hinges and cables… there would be little to no uplifting forces on the hinges.

Why is it important you ask? Well if one maximizes the ability to distribute down force loads uniformity to the attach points one minimizes the stress at any one point. Loading reversals, like with the hinges when using the mid span cable stay locations tend to work the hinge interface more and can increase wear at those points while the majority of the work load is only done by the cable stays and their attach points.

Just a thought….

I think your concept of the swim platform will greatly improve the fun on the water for you and your family!

Best Regards
Over Easy

[OverEasy]

Hi Kurt!

Yes, that is a nice swim platform!
I may be mistaken but that particular design was an Aussie limit marketed product for the that seems to have disappeared.

The design has a lot going for it!
I wouldn’t mind figuring out how to mount it to our !

Best Regards
Over Easy

[Stickinthemud57]

I really appreciate all the great replies! Overeasy, I have to say I do have some apprehension regarding the lever-arm distance I am creating mounting the support rope as far inboard as I am thinking. While mounting the support brackets (see photos), I had a chance to examine the areas above the rub rail I am considering mounting the U-bolts, and am not exactly overwhelmed by their stalwart construction. Spreading that load out is going to be necessary, I think, and moving the support out the the corner of the swim platform may be a good move as well.

While drilling the holes for the brackets on the port side, just under the motor mount, I was dismayed to find that area is waterlogged. I will try to figure out how the moisture got in and how best to drain that area in hopes of avoiding rot in whatever is sandwiched between the fiberglass in that area. Wood of some kind, judging from the drill tailings.

Today was a big step forward. Unable to find exactly what I wanted by way of mounting brackets, I fashioned 4 support brackets from a piece of aluminum 4x4 square tube with 1/8" walls. Lots of cutting, grinding, and filing. I realized early on that the transom was not flat (sticks out about an inch further in the middle than at the sides), so I fashioned some shims from spare pieces of plastic/wood composite decking material, cut with a 2.5-degree bevel (thank you, internet triangle calculator!) to bring them out as needed. The lower part of the bracket extends further than the top so I can rest the platform on the lower tabs before pulling it up into place.

Here is a photo of the starboard bracket and shim:


Each bracket is backed by a large piece of plexiglass:


The platform in place, supported at the transom by 4 brackets:


I have been confident all along that I could come up with something worthwhile and viable, but it is exciting to see it coming together. Envisioning idyllic scenes on the lake with family and friends!

[Jimmyt]

Coming along nicely!