Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Yachts and Sail => Topic started by: wet willy on May 11, 2010, 03:40:49 pm

Title: Pulling a mould off a plug
Post by: wet willy on May 11, 2010, 03:40:49 pm

Hi Folks,  I am in the middle of doing a plug, for a yacht mould. The keel is part & parcel of it, & having not worked with grp before, I can't help but think, it may be a task & a half pulling it off once cured.
I understand the need for relentless polishing & waxing, but not knowing the limitations of grp, should I be building the mould in two halves, as I think the finished hull will have to be built that way.

                                                                                          Many thanks.

Title: Re: Pulling a mould off a plug
Post by: tony23 on May 11, 2010, 05:26:23 pm

Hi,
     Your right in being cautious and personally I dont think you will get the hull out of the plug with a keel on it. Nearly all IOM yachts are built in two halves then the deck is fixed into place after reason being they are constructed with only 2 layers of cloth so are very fragil to pull out the mould. If your constructing the hull from fibraglass and it's quite thick you may get away with it and as you say polish the mould to a mirror like finish and use a releasing agent have a look on theses links they may be of some interest.
http://www.anderswallin.net/2009/12/shine-mould-shine/
http://www.anderswallin.net/category/iom-building/

Title: Re: Pulling a mould off a plug
Post by: wet willy on May 13, 2010, 03:58:26 pm

Hi Thanks for the links, think I need to do a bit more research.

Title: Re: Pulling a mould off a plug
Post by: Circlip on May 13, 2010, 04:19:19 pm

As a personal reply, I would split the mold vertically, but you can do no better from a Forum point by "Pinging"  "Bluebird" He's had a lifetime of full size practice.

  Regards  Ian.

Title: Re: Pulling a mould off a plug
Post by: wet willy on May 16, 2010, 09:20:04 am

As a mere rookie, you understand,  ----- wot's pinging ???  :embarrassed:

Title: Re: Pulling a mould off a plug
Post by: Circlip on May 16, 2010, 10:59:47 am

Send him a PM via the site. Gave BarryM the name of a book on Fibreglass molding techniques, can't remember what it's called, All zimmers again. Perhaps Martin can put a sticky on the building techniques posting to add Books??

   Regards  Ian.

Title: Re: Pulling a mould off a plug
Post by: wet willy on May 16, 2010, 11:18:47 am

Cheers  :-))

Title: Re: Pulling a mould off a plug
Post by: vintagent on May 16, 2010, 12:50:27 pm

On the fuul size in the car world we used to poor water down the gap between first released bit of moulding and mould.  We also shot air into the gap through special nozzles, but that might be a bit tight on a model boat. 
Release agent is the real key.  Vertical mould split line is foolproof.

Regards,
Vintagent

Title: Re: Pulling a mould off a plug
Post by: Circlip on May 16, 2010, 06:13:03 pm

Try this thread WW :- http://www.modelboatmayhem.co.uk/forum/index.php?topic=7768.0

  Regards  Ian.

Title: Re: Pulling a mould off a plug
Post by: wet willy on May 22, 2010, 08:27:34 am

Thanks !, Located said book, & will place order. Good to have a recommendation, as there are books & there are books.