fiberglass fabricating ?'s

Discussion in 'The Garage' started by lucky_strike, Apr 9, 2007.

  1. the_gr8t_waldo

    the_gr8t_waldo Long timer

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    for foam use the std blue or pink foam that you see in homiedepo or lowe's(you'll probably have to serch a bit just to find 1/2" thick). this useing the epoxie. just fiberglass each side of the sheet and then cut the individual pecies out. assemble them useing pins to hold position. round off the outside edges( maybe 2"radius ) and glass 'em useing fiberglass tape( two layers...first 3", second 4-5") inside mix sawdust, micro spers, flocked cotton fiber, or cab-o-sil - and fillet the inside corners ( about 1.24 radius..when that's almost hardened, apply 3" fiberglass tape to the inside corners. as for a fairing that's got a lot more work involved, and your probably better off trying the more involved mold making. for this use the same type of foam. and finished with plaster or something like it, sand to PERFECTIO once it's done a few coats of paint to fill in the pourus plaster and coat with mold release. then fiberglass away untill it's been built up enought ( insert a few braces too.and two "strong backs" so that once finished you can turn it over and sit it on the strong backs.) then you can fiberglass the final part, if you're lucky enought try to use the vacume bagging technique.
    #21
  2. the_gr8t_waldo

    the_gr8t_waldo Long timer

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    bty i've found that most plastics supply places are WAY over priced! i use aircraft spruce & specialty co. for my needs
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  3. the_gr8t_waldo

    the_gr8t_waldo Long timer

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    oh yeah, i nearly forgot.........plywood core matl( in the flat sided projects) only need the outside fiberglassed and corners taped,( and only the inside corners filleted and tape) and if done properly will be a LOT stronger than foam cored.. on the other hand foam cuts and shapes a LOT easyer and will have to be finished inside.
    #23
  4. GreaseMonkey

    GreaseMonkey Preshrunk & Cottony

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    Foam will work fine if all you want to do is have it look pretty in your garage, but if you want it to do any work at all or get slapped by branches while riding it should have a bit more impact resistance than a foam core. To make a box out of foam and glass that can survive a tipover, for example, is going to be heavier than a similar plywood box that has been glassed over. Additionally, in addition to being stronger the plywood box will have more interior room with an identical outside dimension.

    If you are certain your bike will never be on roads with bushes and trees on the shoulders, or you are positive you'll never park it anywhere the ground can get soft during the night and have the bike fall over, possibly with all the weight resting on one of your boxes, then a lighter construction can be called for but to have a pannier fail when you need to rely on it to be doing work could turn into a major pita.

    Now you could weld up a steel skeleton and foam over/around that, but I didn't see any reference to welding so I am guessing you weren't planning on doing that.
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  5. blewgrass

    blewgrass Been here awhile

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    these are a good way to get larger pieces of foam without having to build them up from smaller pieces. We use these on our docks at work. Kinda pricey if you only need a smaller piece.

    //http://www.buoyancyfoam.com/

    I've also learned, but have never tried, that acetone will eat/dissolve that blue or pink foam. That being said, a mold can be made, glassed over entirely, drill a hole and pour in acetone, dump out the swill that occurs.

    On some of the designs that i've seen in this link, i noticed some sharp corners. Although they aren't impossible, they tend to be trickier to mold with glass, particularly if using thicker woven cloths. The glass just doesn't like to bend around/into them. A lightweight, non-woven matt is better for taking those corners.

    As someone else already stated, there are many different additives and types of epoxys/resins. Most of my experience is with west system and polyester resins. Although west is less stinky and backed up with myriads of additives it can be much more expensive than polyester.
    As someone has already stated west system creates its own amine blush to aid in its curing. this blush is a wax that protectst the product while it comes to a full cure. If additional layers of glass are to be added to a fully cured west project, this blush must be removed entirely to ensure proper adhesion of the new layers. Polyesters can come either waxed or not and the wax can be added to those that don't have it. Unwaxed resins will not cure fully because of the absence of that wax, so subsequent layers can be added without the fear of a blush. your final layer of glass should be of the waxed persuasion to cure fully.

    just trying to provide a little more info on this topic, this is not everything you need to know to conquer glass on your first go-around, but it will definitely help. Others in the know please correct any oversights you might (and probably will) see. good luck!
    #25
  6. blewgrass

    blewgrass Been here awhile

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    #26