Thanks everyone for the feedback.
Maybe if you had a way to chuck it in a drill to spin everything heavy to the outside (bubbles to the inside)........ it might be worth a try.
I'd expect lots of hair and bubbles without a way to make them go (away), and separating the interior from the bottle might be a trick. Epoxy seems to be utterly incapable of sticking to certain things, unless you don't want it to.
Some kind of release agent may be a good idea, and you'll probably want a fan or a bowl of water to keep it cool as it cures. If it overheats the bottle, you'll probably have a mess.
Edit--If you do it, take pictures.
I doubt that bubbles would be much of a problem, like Kelly mentions below, this would be much like other things that are fabricated with a FG gel coat. With the slick surface of the water bottle I don't think that the epoxy would stick to it. I was planning on rotating it, but I don't know how I'd do it where it's getting more than a single direction roll. My friend in Hollywood worked on "Enemy Mine", and said that he was able to modify a disco light fixture to rotocast the Drax skulls seen in the movie, but that would be a bit of a problem to source.
more appropriate would be to carefully cut bottle in half,essentially making mold of each half. lay up fiberglass inside, then remove.
Depending on how stiff the bottle is u may need to support each half with something sturdy like foam.
Use glass strips along seam to put NC back together.
Just using chopped glass would be terribly brittle and would not work. Probably 2 layers of 6oz and another 2 of something much heavier. What about incorporating the shoulder?
Cutting the bottle in half would be a PITA to mold the inside, it's very flimsy once cut lengthwise. However, there is the idea that it could be a gel coat that would be reinforced from the inside later with sheets of FG. Would it be really brittle? I imagine it would be kind of like OSB chip board
As to the shoulder, I was thinking that if I can get it to be about 1/16" thick, then an ordinary coupler could be inserted in it, and epoxied in place..
I think heat during curing is the biggest issue. I honestly don't know how hot epoxy gets as it cures, but if it is hot enough to distort the bottle it would be a problem. If it gets hot enough could you instead make a plaster impression of the bottle and then pour the epoxy into the mold. Smash the mold when the epoxy is cured and you have your nose cone.
I don't think that heat would be a big issue, especially if I drill a vent, build it up in thin layers, and keep things rotating while it cures. If it's a thick coating, I can see it doing that, but not with a thin skin of it. The plaster idea however... I'm liking that.
I've fabricated lots of nose and tail cones and never had heat issues even when fabricating over a balloon for a 5" nosecone when wetting out single layers of glass. Using large amounts of epoxy for weight in a nosecone is a different story.
Phil
Thats COOL!!! I like the idea of the balloon. I might be able to use it for a different project. I made a PVC pipe and brush bristle "cactus" for the local Mexican restaurant, as an advertisement. Never could figure out how to top it off though. Hmmm...
This is essentially how many fiberglass items (boats, e.g.) are made, in a female mold - except using glass mat or cloth instead of chopped, and putting down a gelcoat first to get a good finish. Do you have more than one bottle, for trial and error? Cloth would probably be better, if you could get it to lay flat.
The bottles are readily available, so trial and error is a possibility. Getting FG to lay flat would be a major PITA, as the "mold" is so thin and flimsy. But after the chopped FG and gel coat layer cures, reinforcing from the inside would be possible. Perhaps creating a reinforcing jacket of plaster would be a in order.
Again, Thanks All for the ideas.
I think I'll give it a go if I can source some local epoxy. My BSI stuff is too valuable to try with this..
All The Best!
