I really Dumb Question But
 

Ok i want to make a mold of my hull out of plaster of paris. I want to take this mold and make some fiberglass hull's out of it. Is this possible? And if so. How would I go about it and what supply's would i need? Besides the plaster of paris.:D:D:D:D

RE: I really Dumb Question But
 

I have not heard of making large hulls in PoP. It would probably weigh a couple hundred pounds when finished and be prone to cracking/breaking. I think a more common way to do it is to use silicone to make a mold.

Thread on silicone hull mold

RE: I really Dumb Question But
 

you may want to check this thread out and ask Dreamin how he made his mold.

http://www.rcuniverse.com/forum/m_7912646/tm.htm

Dan.

RE: I really Dumb Question But
 

on myth busters.. they made a mold fro a 57"large RC deep V hull to test a theary on. They wanted to see if you turn your boat into a pole in the water at 35mhp would it going into the hull half way in?? they made a silicon mold to make four hulls to test.. but if you do make it out off plaster.. after you make the mold you need to paint the inside where your going to lay the glass up on.after you paint it let it dryout for two day then use a wax/reless agent on it first then layout your fiberglass cloth..after the cloth drysout then it should pop out of that mold.

RE: I really Dumb Question But
 

Know which episode that was msshydro. I can watch it on this one site i go to alot to watch tv shows and such. :)

RE: I really Dumb Question But
 

Hmm, I woulden't consider plaster a good material for such large parts like a boat. Small parts it would be ideal. I did use plaster for a few molds years ago making cowls and wheel pants for my scratch planes. You start building large molds from plaster you would definately have to internally reinforce the structure with wire or other materials, similar to how concrete is strengthened. Lots of extra weight on top an already incredibly heavy mold.

Composite molds made from fiberglass mat, or layers of mat and balsa sheet with carbon fiber are ideal, however just fiberglass would work very well and would last a LONG time. Good luck not chipping a piece of mold out while pulling out a hull on a mold made from plaster. It could be done the way you are thinking, however in my experiences the negatives outweigh the positives. Perhaps Dana from DaVette Boats could chime in a little on this topic.

-Scott

RE: I really Dumb Question But
 

Here's a how-to, the original is in French ........ [link=http://pagesperso-orange.fr/xavier.cardinale/Dossiers/Construction/Moulage_ceramique.html]Ceramic moulds[/link] but you can translate it through [link=http://se.babelfish.yahoo.com/translate_url]Babel fish[/link]

RE: I really Dumb Question But
 

Hey Miss do you know which show it was.
l
Let me know. Tx.

RE: I really Dumb Question But
 

Well Misshydro i fount the mythbuster's you said to look for. Here are the Link's :)
Click on where it says click here to access your movie link. It will take you to the show part. :)
Part 1
http://www.flickpeek.com/show_link.p...&data=NzcwNTQ=

Part 2
http://www.flickpeek.com/show_link.p...&data=NzcwNTU=

Part 3
http://www.flickpeek.com/show_link.p...&data=NzcwNTY=

Part 4
http://www.flickpeek.com/show_link.p...&data=NzcwNTc=

Now for the fun part where would i get the silcone for the mold.

RE: I really Dumb Question But
 

I personally wouldn't use silicon, glass for me. Silicon will not hold the shape well enough for a good straight hull that will perform well. For the boats that they used on Mythbusters where they were never going to be put on water, a silicon would be fine as it doesn't matter if the keel is hooked or the chines aren't dead straight.

RE: I really Dumb Question But
 

Am thinking of going ahead and do the plaster mold. Do one side then the other. Once i got both pieces i will use clamps to hold it together. once i got my new hull done just release the mold.

RE: I really Dumb Question But
 

I have been working with a friend of mine who is a professional in the R/C boat industry and all his moulds are made with polyester resin and boards for strength. If you are wanting to build a quality mould that is going to last a long time you should look into this. A person said on another thread that every flaw in the mould will be in every boat pulled from that mould. Do it right the first time. It will take longer but you will be happier with the finished product. Dennis