Bimini made from PVC pipes + Fiberglass/polyester resin

Discussion in 'Boat Design' started by mariobrothers88, Oct 18, 2020.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

    Or better still, think of vaulting poles !
  2. waikikin
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    waikikin Senior Member

    It would be worth the exercise to manufacture a similar length say 1.8m of 1" pvc tube laminated with poly & cloth(the light cloth that will wet & wrap easy will be exxy to build thickness) at a & then let it fight it out with similar staino & alu tube. The beauty of metals is that the glue sets very quickly so the job progresses well. If you wanted a composite targa bar with integrated davits & hard top the composite might go ok but would take some time & surface finishing.
    For solar panels - & I'm not that up on the frame sizing now, but back in the 90s I did a series of aluminium solar targas for some cats, some 2" box section closely matched the frame thickness of the Solarex panels back then & made them very easy to integrate. They're still out there somewhere still doing the job 25 years later, The sections with radiused corners came out the neatest and kindest to rope, sails & humans. The surface finishing of aluminium is "optional" but a degrease with caustic soda, & really well rinsed off and wet & dry then etch primer followed with some polyurethane is pretty quick & easy.
  3. missinginaction
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    missinginaction Senior Member

    Seems like a lot of work but it could be done. It might be challenging to get a professional looking finish. I've used PVC outside (in non load bearing applications) with good results but it needs to be painted. PVC gets brittle with exposure to UV and epoxy doesn't like the sun either. I don't use poly so I don't know about that. I painted a section of pipe about a decade ago with Interlux Perfection and it looks as good today as the day it was painted.

    One thing I don't see mentioned is the strength of the pipe and it's ability to take stress before it fails. It seems that even up here in New York (a relatively tranquil part of the world), we're getting increasing numbers of high wind events over the past few years. Just last year we had an unexpected storm damage numerous boats and topple large trees at our club. The forecast was for good weather so this unexpected event played havoc with a lot of canvas that wasn't stowed. I noticed that even my relatively small, very well anchored upper top had a slight bend in a section of the stainless steel frame. This was easily fixed but I wonder what would happen to a hard top with solar on top of it. Stainless steel or aluminum will bend before it kinks. PVC and fiberglass cloth is going to shatter I'd think. I've seen people try to make storage frames out of PVC with poor results. In fairness these frames aren't reinforced with fiberglass.

    Just some thoughts.....

  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Where I am, just about all PVC pipes are resistant to UV, and will survive the sun without it, but do hold paint well.
  5. Blueknarr
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    Blueknarr Senior Member

    Tube cutters are less than $10 at any diy center.
    Conduit benders less than $30.
    Get a length of conduit to practice with.

    A commercial election could do it for you in an hour or two.

    Not the cheapest, but West Marine will have or can get the tubing and fittings.
  6. clmanges
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    clmanges Senior Member

    I think you're overestimating how strong PVC pipe is. It's not intended for structural uses, and the fiberglass won't help that. You could bolt together pieces of aluminum angle or box channel if you want something that's easy to build with.
  7. Rumars
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    Rumars Senior Member

    If you want fiberglass tube make some, but PVC would only be useful as a mold. Leaving PVC tubes in does not make sense, they only make the FRP tube heavier.
    If you want stainless without bending and welding you can have it, the plumbing industry is full of 316L pipe and fittings. Looks "industrial", but strenght will not be a problem. I recommend having the plumbing supply shop cut the pipe to size and threading it.
  8. Charlyipad
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    Charlyipad Senior Member

    Online metals sells schedule 40 aluminum 6016 aluminum tubing. Zoro sells elbow, tee, etc Hollander fittings to fit (look for "speed rail"). Easy, cheap, strong, quick.

  9. mariobrothers88
    Joined: Sep 2020
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    mariobrothers88 Junior Member

    Thank you so much!!
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