making mold from plastic? for boat part

[Zackthrills]

Hey everyone I was wondering as I am New to ask the body world, how can I make a mold from a plastic part them use that mold to make a carbon fiber part? Doing the carbon fiber I understand to some degree , I am just lost when it comes to making a mold of something that it will be hard so not to flex or lose shape of original plastic part? Then I will try to duplicate it from the mold using carbon fiber or a mixture of carbon fiber and kevlar weave. Any help and help on where to get products to make mold would be great thank you so much everyone.

[grsboats]

Could you please post a pic of this part?Depending on its shape it can be a hard task as plastic parts are released from molds in different ways. Gill

[Zackthrills]

Ok this is what I'm doing. I am going to take a current hull that I have with capsule and I want to copy the shape and then use the reverse side to make another hull out of either carbon fiber or a two part of Kevlar and Carbon fiber weave. Max length of the hull is 56". I also thought about making a 2 peice carbon fiber or both Kevlar n carbon fiber weave rigger either 26" or bigger not sure yet. What do you think Gsr?

[grsboats]

Before anything I would go to http://www.acpsales.com/home.html and see what you can do with cf or c.f/kvlar. 56" boat means a big set of molds so I would start with small pieces before go up that lenght. 26" is a good size boat to learn the tips and tricks of the molding world.Gill

[Zackthrills]

Yes that's true. Your right start asks then if I me up its not so bad. Do you know of any good reads on doing kind of what I'm looking to do? That would be great. Thanks so much.

[grsboats]

This is a good start point.check this out: http://www.wikihow.com/Make-a-Fiberglass-Molding Gill

[Zackthrills]

Ya that is a good start I Find where v to ny ask materials and will start with maybe the hatch first

[lonewolf]

There is a lot that goes into making molds and plugs. Then there is vacume bagging which adds another level of quality..I would definitely do a lot of research. And try a few smaller projects.....something the size of 56 inches is pretty big. With that size warpage can become an issue.......depending on what you are trying to make a mold from. There are many ways to accomplish this. I have used bon do a few times but bon do can get pretty hot and warp ur plastic part. You will also need mold release....another issue is part removal...think of forming over a mushroom. Once cooled you cannot remove over the head of mushroom. So undercuts can be a problem....I'll chime in more as youprogress . There are many good threads at this site the guys have put many hours into...there are also many links here also. You tube is another great place to get info. Good luck!!!!

[grsboats]

this pic shows the set of molds of my big block C.F rigger. solid molds made of epoxy for high production. Gill

[Zackthrills]

See that's what I want that's exactly what I want to do?

[Zackthrills]

How many have you made from it and what kind of cost are we talking about to make inner boat or rigger?

[Zackthrills]

Are you injection modeling with plastic? Or what are you using to make them out of?

[grsboats]

Not sure but some dozens were relesead from these molds....all hand laid up. I can also use vacum bagging depending on the desired strenght and thickness.This a costly process ...don't remember how much I spent with them but maybe 3K with products now a days.Believe me start playing with tiny parts like cowls to experience your own limitations .I've been working with all sort of molds for 30 years and still learning! You can see similar molds on my thread GRX saw rigger here .Gill

[grsboats]

RTM (resin transfer molding) use similar molds with an injection pump but I don't think they are Worth the extra Money involved to produce our hulls.Gill

[Zackthrills]

That's awesome... I want to make a bad a$$ tiger