fiberglassing a trunk lid

ive seen plenty people fiberglassing trunk lids, but my question is how are they mounted and not crack from taking a beating when the trunk lid gets slammed shut. i know FG is pretty strong as i have made a small sub enclosure in the corner of my trunk and i know it can withstand the beating of the bass, but wit the fiberglass hanging from the trunk when its closed and gettin slammed shut would that have anything to do with it having the possibility of cracking off the trunk lid and laying on the trunk floor? but most importantly how would you mount it to the trunk lid? ive seen most of them with out looking like they are screwed into the lid. i would like to make one that i can mold to the trun klid and then take it off to paint, then mount it, but i really dont want to leave and holes in the enclosure if i have to screw it in and most trunk lids that ive seen fiberglassed dont have any holes

ok im done rambling on now. hopefully someone can make sense of my post and reply to it :)

depends on how far the trunk swings back past the center of gravity, like, if you lift it, you will get to a point where the lid is basically straight up and down where it can kinda stand there on its own...if you can open the lid more where gravity opens it more, then your set.

Iv never been good at explinations

At my shop we did that for our geo storm, , the gas lift supports couldn't hold our cheep wing, , i think that monster was made of steel haha.    We used a child pool stick haha, , , just put sum pool balls in the trunk and people think its a theam.

Hey CarAudioHelp,

   Would you mind drawing a picture of some kind to show me what you mean by screw points. Ive been wondering about seamless mounting for some time, but don't quite see what you mean here.

Speak slow to the slow kid

Thanks,  if you have a a sec i'd appreciate it.

   Ryan

CarAudioHelp wrote:

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Then pieces of wood are bonded to the trunk lid (not screwed for obvious reasons).

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What kind of epoxy would you use to bind wood to metal? I won't mind putting some 6.5s in the trunk jsut to have some mids and highs durring tail gates and such.

PATPJRICK wrote:

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i was planing on just adding a design on the trunk instead of speakers

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Here's two ways I could see you making it work:

1) since it's just a fiberglass piece to look good (ie. not too heavy): Find some places in the inside layer of the metal (re-enforcement part) to drill small holes, and glass in some of those plastic things used to hold interior panels in place. This would be nice, because you can easily take it off should you ever need to.

2) make your trunk lid in more than one piece: The fiberglass design piece, with holes around the perimeter to screw it in, and one or more trim pieces that can snap in as described above. The trim pieces would be small (and lightweight) and will cover the holes. HINT, HINT: cover them in carpet or vinyl to match whatever's in your trunk!

that would add a nice touch, tie your trunk together, and no worries about scratching/chipping the edges of the fiberglass piece!!!

If you're gonna put something heavy in it, an idea:

the wood block idea sounds good - or you can wrap the wood block with foil, lay glass over the sides - and make fiberglass struts. Eliminate bonding separate materials. (keep in mind, you'll want these to be heavy duty though, so make them thick)

PATPJRICK wrote:

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....would the trunk lid just fall down due to being too heavy each time i had it opened

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I am not sure what kind of Car/Year/Trunk Design you are working with, but I recommend or suggest you do something similar to what the gurus over at www.hzemall.com example...

https://www.hzemall.com/Regal_folder/tim_regal_the_trunk.htm

This is particularly what I am talking about (click on link above for info on exactly what your're looking at)
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https://www.hzemall.com/images/regal/P1010020.JPG
https://www.hzemall.com/images/regal/P10100215.JPG
https://www.hzemall.com/images/regal/P10100225.JPG

So, if you do not have that exact setup, you get the basic idea behind it; using powerful gas lifters or some kind of hydralic device to support the weight.  I think if you balance and configure it right you can even have the lid rise up automatically the moment the truck is opened (I believe it will require powerful lifters)