Model Boat Mayhem

Technical, Techniques, Hints, and Tips => GRP & Epoxy => Topic started by: U-33 on August 10, 2014, 02:34:51 pm

Title: Styrene to fibreglass...?
Post by: U-33 on August 10, 2014, 02:34:51 pm
I'm not sure if this is possible...but, here goes anyway.


Is it feasible to use a vac formed styrene hull/deck as a mould (plug?) for a fibreglass hull? I'll try and explain that better...I have a set of styrene mouldings, and if possible I'd like to have a set made from them in fibreglass. Does that make better sense?


Rich
(totallyconfusedbyallthis.com)
Title: Re: Styrene to fibreglass...?
Post by: mudway on August 11, 2014, 02:28:13 am
Yes, I've done it using plastic vac form hulls as a mould. Make sure you wax it thoroughly, pva it and do not put too much catalyst in otherwise the heat build up will destroy it.
I put one coat of gelcoat on, left it to cure, then a layer of glass tissue & 2 layers of 225 fibreglass mat. They went on a layer at a time and allowed to cure and cool off before the next lay up.
Hard work as I'm not very patient.
Remeber to lay up inside the vac formed hull not the outside, corners, curves etc are better defined on the inside of such hulls.
Title: Re: Styrene to fibreglass...?
Post by: U-33 on August 11, 2014, 06:51:19 am
That's grand...cheers for that sir,  much appreciated.


I'll have  my man commence work on it.


Rich
Title: Re: Styrene to fibreglass...?
Post by: Tug-Kenny RIP on August 11, 2014, 10:53:36 am
Hi Rich,

A series of photographs as this is being made would be of great benefit to us all.  (especially me  %) )    Pleeeeeze.

Cheers

Ken

Title: Re: Styrene to fibreglass...?
Post by: U-33 on August 11, 2014, 11:40:24 am
I'll ask my man nicely  Ken...it would benefit me as well.  %)


Rich
Title: Re: Styrene to fibreglass...?
Post by: Subculture on August 11, 2014, 02:35:10 pm
Make sure the styrene has a good barrier coat if you are using polyester resin, otherwise there will be tears before bedtime.

Polyester resin will melt styrene, resulting in a sticky mishapen mess. PVA and wax may be enough, but personally I would be inclined to give it a coat of two pack polyurethane paint or epoxy primer to be sure.

Alternatives are to make a cast in plaster (works fine if there are no undercuts), make a tool from epoxy, or cast in RTV rubber ().
Title: Re: Styrene to fibreglass...?
Post by: U-33 on August 11, 2014, 02:48:13 pm
That's grand, thanks for that advice, Andy...I'll pass your recommendations on to my man. (It's Nigel E, btw...)


Rich
Title: Re: Styrene to fibreglass...?
Post by: Subculture on August 11, 2014, 03:39:39 pm
Well he'll know what to do.
Title: Re: Styrene to fibreglass...?
Post by: U-33 on August 11, 2014, 03:43:37 pm
Well he'll know what to do.


I hope so...


Rich
Title: Re: Styrene to fibreglass...?
Post by: Plastic - RIP on August 11, 2014, 04:14:23 pm
I've not tried this myself, but friends of mine recommend using the thin brown parcel-tape as the barrier layer to stop the resins getting to the styrene.
I've seen it done with aluminium foil as well (it shows good detail when rubbed smooth). It's also a bit more 'definite' than a patchy wax coating.

They use this when they carve ordinary white polystyrene blocks and have to coat them in fibreglass to make a mould.
Title: Re: Styrene to fibreglass...?
Post by: U-33 on August 11, 2014, 05:49:00 pm
Just had a word with my man...yes, it won't be a problem to do it, but it won't be done until much later in the year due to Nigel having previous commitments. So, it's a case of waiting, I'm afraid.


Rich
Title: Re: Styrene to fibreglass...?
Post by: mudway on August 12, 2014, 01:43:48 am
I didn't have any problem with the plastic being attacked but I did put the pva on thicker than usual.