Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[andrewh]

Happy New Year the Mayhemmers!

Incredibly I have two vac-form styrene hulls, and want to make progress.
they are both about 30 inch long and quite thin - too floppy to use without either an internal framework or a way of stiffening the hull.

What I am thinking of is:  a layer of fibreglass/polyester resin (car body resin) on the inside (including a keelson) and planking the outside with (more or less) fake planks so that the overall appearance is planked.

Will polyester overheat the styrene as it cures?  has anyone done this?
what material and glue for the planks?
(  I am thinking along the lines of thin styrene bonded on with solvent, Iron-on veneer or a thick tape with good varnishing/painting to keep it in place)

hulls are a 30 inch Thames sailing barge from Midway Models and the Mobile marine models general purpose vac-form hull which will become an RN cutter like this

thanx in advance

andrew

[nhp651]

NO! NO! NO!......IT WILL MELT IT,,and if it is a thick hull and doesn't get round to melting, it WILL  distort it.

polystirene [ even HIPS...High intensity polystirene] and ployester resin just don't mix at all.

[nemesis]

Hello, I have done this a few times, I found that a slow cure, a one that does not generate a lot of heat did the trick for me. Why not do a test on various thicknesses of Styrene sheet & evaluate the results. Nemesis

[towboatjoe]

How about epoxy finishing resin instead

[andrewh]

Thanks everyone for the replies -

I was planning to try resin on bits of styrene of various thicknesses and see what happens

nhp651 - thanks - didn't know that polyester reacted with styrene.  I do know it does with foam PS!
towboatjoe:  I am scottish, and live by the tenet "if its free its essential"  I have about 10 gallons of polyester (given to me free) but only one gallon US of areopoxy (also free).  I'll use the epoxy if necessary; I know that will work and not react/overheat the styrene

Any views on the "planking" of the exterior?
It has just ocurred to me that instead of laboriously planking styrene with styrene I could gently scribe planking lines  - then I would NEED the interior reinforcement!
andrew

[dreadnought72]

... and the Mobile marine models general purpose vac-form hull which will become an RN cutter like this

<image>

She may not point too well with her topmast asunder and her sails so badly ripped, Andrew. 

  Andy

[Netleyned]

Thats the Royal Mail for you

Ned

[andrewh]

Andy,

is THAT the problem?  I just built it like the box-top

I'm not very good at masts and rigging - so I was considering a diorama "Trafalgar After the battle"
actually that leads to the thought of modeling "Trafalgar at the heat of the battle" no ships at all (apart from Pickle and a few frigates) - just a vast ball of grey cotton wool with a noisemaker in the middle.
andrew

[Circlip]

didn't know that polyester reacted with styrene.  I do know it does with foam PS!

  Polystyrene is unexpanded expanded polystyrene 

   Regards   Ian.

[andrewh]

Homework report

Well, following the theory, the practice

I catalysed three lots ot styrene to different extents so as to get three different cure rates and temperatures
and I can teport to the class that none of them had any effect on the bits of scrap styrene that I poured them over (I wanted to get a good thickness of resin on the styrene so that there would be high temperatures)

No damage to any of the styrene - at all
I would show you photos, but the last working camers has gone for a burton

So I am encouraged enough to do a further experiment with thinner styrene - similar to the hull thickness

andrew
more as it happens

[hdserv]

A bit late with my commet why not make a plaster mould of the hull

[andrewh]

hdserv

Because I have the hulls already, but want to

A) stiffen them enough for scale sailing with tall rigs and
B) make them of the "planked" appearance

oh, I forgot to mention-  the hull destined to become a naval cutter will get  a fairly deep "foot" or keel tapering from the gripe to its deepest at the rudder position.  This will allow me to get the lead low down and give it a bit of a grip on the water

andrew

[StarLocAdhesives/FiveStar]

polyester resin is a resin dissolved in styrene monomer to make it liquid, styrene monomer dissolves polystyrene

its a bad idea to use styrene on polystyrene sheet ( hips ) as it will cause problems , if you get away with it and it doesnt melt / distort ( if you are lucky ) it will still cause problems down the line with things like stress cracking , also the polystyrene can prevent the styrene from setting making a very low strength softer area where the two join

You are better off using a flexible superglue / flexy cyano adhesive