Custom Fiberglass Extended Swim Platform

[kcassells]

bondo spreader

Like Scott said and cut a couple so you can get into smaller cavities, angles, rounded areas. Keep them ready next to you.
Good luck!

 

[tpenfield]

Yup, thanks, I do have Bondo spreaders. Going to try the plastic sheeting as well.

I'm using the MCP hardener, so I get about 75 minutes working time for soaking and laying the piece up.

 

[kcassells]

Wow that's a LOOOOOONNGGGGGGGGG time. Awesome. Also some chip brushes cut to points to pop air bubbles, as well as flat to move out to sides.
In 75 minutes you'll have fallen asleep.

 

[tpenfield]

This is what I don't like about hand layup . . .
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Horizontal surfaces are fine, but vertical surfaces can be a challenge. These areas were completely wet out and rolled, but they developed air pockets during the cure.

Vacuum bagging / infusion is trickier in some regards, but the glass is tight to the mold when cured.

 

[kcassells]

Need to improve your skills!:embarassed:
That pointed chip brush will get you out of trouble a lot of times.

 

[tpenfield]

Need to improve your skills!:embarassed:
That pointed chip brush will get you out of trouble a lot of times.

I tend to have better luck when I cover the wetted glass with plastic wrap (Saran wrap or thin plastic drop cloth), but then I got to rough-up the surface for the next layer. So, I tried leaving it exposed to the air and it made bubbles while I was not looking. Maybe I'll try peel ply and plastic wrap

 

[froggy1150]

Why not use 4lb foam? It's more dense to begin with and from what I have read the cell wall is thicker and more resistant to water and breakdown....

 

[Scott Danforth]

hand layup and bag

 

[kcassells]

Why not use 4lb foam? It's more dense to begin with and from what I have read the cell wall is thicker and more resistant to water and breakdown....

Froggy that's a good point. 4# foam is considered structural vs just flotation. You wont need a lot of foam you may want to consider upping it even from 4#
UScomp web descript;

16# foam;

[SIZE=-2]Product Information: Free Rise Density: 16.0 lbs per cubic ft. Expansion Rate: Approx. 4x Liquid Volume Buoyancy (flotation): 46 LBs per Cubic Ft.[/SIZE]

[SIZE=-2]*Physical Properties: Parallel Compressive Strength: 580 psi Tensile Strength: 450 psi Shear Strength: 230 psi Flexural Strength: 750 psi[/SIZE]

2# foam

[SIZE=-2]Product Information: Free Rise Density: 2.0 lbs per cubic ft. Expansion Rate: Approx. 25-30x Liquid Volume Buoyancy (flotation): 60 LBs per Cubic Ft.[/SIZE]

[SIZE=-2]*Physical Properties: Parallel Compressive Strength: 40 psi Tensile Strength: 30 psi Shear Strength: 30 psi Flexural Strength: 50 psi[/SIZE]

 

[tpenfield]

I think the foam that I have is 2#. I don't need 30X expansion, so by cooling it the end result may be around 15X or essentially 4# density.

I'm not too concerned about structural strength for filling voids around the perimeter, since the foam sheets that make up the core are 8# density.

 

[tpenfield]

Progress update . . .

I have the core laid down and glassed in. I've tried a few techniques with wetting out the 1708 cloth. It seems to be getting better.

Here are a few pictures . . . .


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I have the remaining 'embedded' hardware installed, just got to clean up around the studs a bit. So a total of 8 studs.


I hope the 'navtruss' core will work out well. It wasn't too difficult laying it down and getting it all glassed, once I got it organized. and the pieces sequenced and the glass weave all pre-cut.
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I've got to do a bit of clean-up on sharp edges, etc,

I did some re-thinking on the foam, which is still a work in progress.

Next steps are some 'bevel' pieces that go at the step that is shown in the picture above, then another layer (or 2) of glass.

 

[tpenfield]

Here are the bevel pieces, which will (hopefully) stiffen the area of the step-down. I plan on glassing them in with 24 oz WR.
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[Scott Danforth]

Looking good Ted

 

[tpenfield]

I like using 24 oz Woven Roving, because it is wicked strong and shapes well. The only problem with it is that when you cut pieces for small layup it easy frays around the perimeter.

I have a trick that I'll share . . . not sure if anyone else uses this sort of technique . I lightly spray the WR with 3M 77 adhesive and adhere some plastic drop cloth sheeting to one side of the WR.

Then I can cut the cloth without having it fall apart, like the piece you see below . . .



Here are all the bevel pieces glassed in.


I'm going to apply another layer to stiffen them up.

 

[kcassells]

That's neat Ted. Cool way to wet out WR. Amazed how it took to the corners! :yo:

 

[sphelps]

Starting to look really strong !
? Any reason you used individual blocks rather than a continuous piece ? I guess with the glass turned back in on the sides of the blocks that might just be a stronger application ..idk

 

[tpenfield]

Starting to look really strong !
? Any reason you used individual blocks rather than a continuous piece ? I guess with the glass turned back in on the sides of the blocks that might just be a stronger application ..idk

Yes, stronger.

 

[Scott Danforth]

Starting to look really strong !
? Any reason you used individual blocks rather than a continuous piece ? I guess with the glass turned back in on the sides of the blocks that might just be a stronger application ..idk

the individual blocks act as closed off gussets vs a single angled panel. about 50% stronger or more.

 

[tpenfield]

Speaking of stronger . . .

I decided to add a 'support' to the pylons to tie the side into the rest of the platform. This should also stiffen things up a bit ( I hope )

Here are the foam cores all cut and shaped.


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I glassed both sides using a vacuum bag. Once the resin cures, I'll be able to tab them in.

 

[tpenfield]

Update . . .

Here are the pylon supports after vacuum bagging the glass (1708) onto the surface. Still needs to be trimmed.
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Now I got to figure out some 'structure' to box in the rear edge, to better support the ladders and stiffen the platform overall.