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  1. #1
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    Using fiberglass for trailer?

    I have put together the frame for a trailer from a few old bedframe metal I had. Haven't as yet figured out a good way to attach it to my Evox, but I have been wondering if a person could make up the walls of the trailer and fenders from fiberglass (make it look kinda like a mini 'step side' box of a pick up truck.

    Would glass be strong enough (have not used it before and am reading up on its use etc) for the walls of the trailer? I thought that it would be at least lighter than making the box out of wood (and easier to make smooth shapes etc). Also part of my idea is to make a cover for the cargo area of this trailer out of glass as well, again like those on a pick up, that are hinged at the front and latch at back.

    Just wondering about the weight and strength of glass for a project of this nature?

  2. #2
    Uber Goober StephenH's Avatar
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    I think it's not done due to easier alternatives. One of those being the big Rubbermaid boxes that you put on a flat trailer. Or you could use a car-top carrier as a trailer.
    "be careful this rando stuff is addictive and dan's the 'pusher'."

  3. #3
    Administrator Allen's Avatar
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    Quote Originally Posted by StephenH View Post
    I think it's not done due to easier alternatives. One of those being the big Rubbermaid boxes that you put on a flat trailer. Or you could use a car-top carrier as a trailer.
    This is true.
    To form the glass you would need a mold and use vacuum bagging techniques, or use glass over foam. Both are labor intensive, using molds is material intensive.

    Pre-made boxes would be much easier, quicker, and less expensive.

  4. #4
    Humvee of bikes =Worksman Nightshade's Avatar
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    Quote Originally Posted by Evox_Rider View Post
    I have put together the frame for a trailer from a few old bedframe metal I had. Haven't as yet figured out a good way to attach it to my Evox, but I have been wondering if a person could make up the walls of the trailer and fenders from fiberglass (make it look kinda like a mini 'step side' box of a pick up truck.

    Would glass be strong enough (have not used it before and am reading up on its use etc) for the walls of the trailer? I thought that it would be at least lighter than making the box out of wood (and easier to make smooth shapes etc). Also part of my idea is to make a cover for the cargo area of this trailer out of glass as well, again like those on a pick up, that are hinged at the front and latch at back.

    Just wondering about the weight and strength of glass for a project of this nature?
    I agree that pre-made plastic tubs/trunks would be a better solution. Ya don't wanna
    build a 'lead sled' that weighs a ton do ya?
    My preferred bicycle brand is.......WORKSMAN CYCLES
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    Steel: nearly a thousand years of metallurgical development
    Aluminum: barely a hundred, which one would you rather have under your butt at 30mph?

  5. #5
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    I wouldn't, and some of my first shop memories are of being scolded for playing with the fiberglass.

    The standard fiberglass composite is fiberglass combined with epoxy resin. It is a ******* to form nicely. You can have exciting durability issues where it is joined to metal. The metal can end up corroding faster at the join, or the composite can get stress fatigue. If the composite is formed properly, it will be stronger than a plain plastic. It will *not* be lighter unless you have extensive experience in getting composites to do what you want (and that often takes spiffy equipment).

    There are circumstances where a composite material is a good idea. But because they do behave very differently from standard materials and have very high costs compared to standard materials, they're rarely a good idea in home use. (and you've now had basically the same lecture *I* got as a teenager when I wanted to build a trailer out of carbon fiber composite *g* after all, carbon composite is so much lighter than Al, and it makes just as good engine mounts! so why not make the trailer out of carbon composite instead of Al and get a much lighter trailer?)

    Composites can work very well in mass produced applications with good engineering backup. Just be very sure that you really need and want the properties they give you.

  6. #6
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    I had read some about the nifty applications that they used glass for and thought it would make a really cool looking trailer...all smooth curves etc, but I guess you guys have mentioned all the big reasons why there isn't more "really cool looking trailers" out there. Thanks for giving me some solid answers guys...I will just stay with the KISS method of bike trailer.

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    Quote Originally Posted by Evox_Rider View Post
    I have put together the frame for a trailer from a few old bedframe metal I had. Haven't as yet figured out a good way to attach it to my Evox, but I have been wondering if a person could make up the walls of the trailer and fenders from fiberglass (make it look kinda like a mini 'step side' box of a pick up truck.
    It could work well, but you would need a vacuum at the least and would be a LOT more work than just using a plastic bin. Also if the fiberglass got cracked, repairing it well can be very difficult.

    I've seen fair vacuum pumps available online for $40, so it's not like it can't be done cheaply--but working with composites is very messy, you don't realize how bad it is until you try. You would need a space you can work over a few days, where you could leave stuff set up overnight.
    ~

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    Repairing a straight up crack on a fiberglass/epoxy composite isn't difficult. Just heavy and ugly. You end up manually forming new composite on the outer and inner surface, then let it cure. I would expect this sort of patch to hold up under moderate forces (based on original design spec). This gives you a form of butt joint, which isn't the strongest thing going but can do decently if it's not loaded to original max.

    If the problem is micro-cracks, I would not attempt a repair. That means you're exceeding design spec forces in "normal" use, or that the item should have failed out in inspection because it doesn't meet spec. Micro-cracks mean the composite is failing utterly. (the only time I've seen this was with a batch of model airplane propellers that shouldn't have passed inspection... was a definite eugh moment, since we *just* missed experiencing in air failure)

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    Quote Originally Posted by Torrilin View Post
    Repairing a straight up crack on a fiberglass/epoxy composite isn't difficult. Just heavy and ugly. ....
    I seem to remember that somebody around here said they wanted to take a fiberglass cartop carrier (the coffin-type) and bolt wheels and a towbar right to it.
    ~

  10. #10
    Senior Member hotbike's Avatar
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    I'd like to chime in , if I may.
    I had a lot of success with fiberglass. My Daughter designed this "Fiberglass Ladies Bicycle", and it was the number one Google result for "ladies bicycle" for most of 2005 and 2006.

    I also consider this bike a success because it cost $270 to build, and when I sold it, I got $1,215.00; a 450% profit.
    The fiberglass is ten layers thick, and is heavily wrapped around the steel tubes of the original bike frame.

    After Type 9 was sold, I built a Type 10:

    This time I used only seven layers of epoxy/fiberglass, over a foam core. I should mention a trick was used; the foam core was grooved with a round file at the edges, to mate with the bike's aluminum tubes, and was 'sandwiched' with seven layers of epoxy/fiberglass, running four to six inches up the sides of the foam core. It was aligned and allowed to cure. Another six layers of epoxy/fiberglass was wrapped around the aluminum tubes, and up the sides of the 'glass structure.

    It worked for me.

    The fiberglass is extremely strong, and I have demonstrated this strength by banging on it with a hammer.

    I would say , since you are a beginner , to err on the side of caution, and make the fiberglass a bit overweight. The first one weighed 55 pounds, and the yellow one weighs 40 pounds.

    Vacuum bagging was not used. I really soaked the 'glass with resin to make sure there were no air bubbles.
    http://www.flickr.com/photos/11629987@N02/sets/72157639939606343/

  11. #11
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    You would probably require a fair amount of space for a project like a trailer...I am in townhouse and would therefore have to work in backyard...be too much to be completely tidying up after each session. Maybe something for if ever get a place with a garage.

  12. #12
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    Fiberglassing is fun, but my experience with fiberglassing is small projects.

    But, why not take something and mold the fiberglass around it?

    This is my idea, take your bathtub and wrap it with aluminum foil (fiberglass resin doesnt stick to Al foil). Then you can make a layer or two of fiberglass and resin. Take the fiberglass tub out and keep adding layers untill you feel it's strong enough. Then you can just drill and bolt on a axle and hitch.

    Though I wouldnt do this project indoors inside the bathroom (you'll die), but if you have a spare bathtub, or a swimming pool, or even refrigerator box then one should be able to mold a trailer from it.

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