The Ship Model Forum

Hi all,
What is the best way to cut styrene sheet ?

While it’s very easy to cut it in a straight line , also with sheet thick from 2 to 4 mm or even more , the problem i am having is to cut curved line .

I first used a proxxon scroll saw , you can all imagine the mess I made , the plastic melted also if I set a slow speed .

I did search on the web for tip and also for videos that show the how/to but I didn’t find any useful.
Any advice is appreciated , Thanks

Daniele

how tight of a curve line as in a bow or as a circle?

Hi David
The shape is more of a bow kind
I just thought i can use a french ruler and do the cut and than snap it , probably that was the right way to do from the beginning .
I am not familiar with the material and i started with the proxxon and it was the worst things ever

i attached an example of the shape

For gentle curves like this, you should be able to score and snap. Although, when you get to 4mm and thicker, it becomes harder to do it neatly.

The key is to ensure a nice deep score line (2 or even 3 passes with a sharp #11 blade), then snap in small sections (maybe 3/4" long) and work your way around the curve. It can be helpful to use a pair of pliers to get in close to the score line to prevent bending the plastic on the inside that you want to keep flat.

Also, you don't have to snap it completely off with the first bend. Work your way around with partial bends and then repeat until it all comes off easily. Don't force it. I've done 1" diameter circles using this method on .020" thick styrene. A little cleaning of the edge and it works great!

If you have trouble, you can score and snap off angled sections, smaller and smaller around the curve, until you are close enough to sand it smooth.

Sawing will work, but you need a slow saw or be very fast. Plastic will melt, but it can be done.

_________________
Darren (Admiral Hawk)
In the not so tropical climate of the Great White North.

I would use a #16 blade instead of a #11 blade. http://www.xacto.com/products/cutting-s ... etail/X216
Daniele, on a piece like that, is it going ontop of the hull or between the hull top sides?

Thanks For the advice Admhawk , I will go ahead and post some result .

David the plan I posted is for a small LCS , I will stick this plan on a very thin styrene and than apply it on a thicker piece of wood the shape of the hull is almost square so it will work out.
The problem I had is for a different build , a Regia marina cruiser LIBIA 1/350 , were I will need to cut from 5 to 6 layers of styrene sheet to be able to shape the hull correctly .
I have both the #11 and #16 blade I will give a shot to both of them for sure .
Thank you guys for the advice .

Daniele

do you have a dremel tool? you are scratch building the cruiser's hull, correct?

David i have a variable speed dremel and yes i will try to scratch build the hull .

I presume waterline? leave the layers as rectangular shapes not trimmed to shape. have the top layer have the outline of the shape of the hull marked on it. sand all gluing surfaces with coarse sandpaper then glue together & let sit for a day or so. use the dremel tool at a low speed to grind the hull to shape. I'm doing the same thing for the torpedo bulges & rebuilt bows on my OBB(old battleships) using Revell's 1/429 scale Arizona.
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Yes waterline ( half ship
the only plan i find have only the waterline option .
thanks David for the advice , i didnt even think of using the dremel ,i have the small drum attachment and for sure it will help a lot .

Daniele

use a coarse drum for most of the grinding off before using the finer drums & hand sanding.

Carving and sanding a hull for a 1/350 scale ship out of styrene is a lot of work. You would be better off using pine or balsa and skinning it with 10thou sheet.

If it's waterline, you probably will have large flat areas on the sides. Build a box for these sections. Gentle curves can be done over frames. Only carve the extreme ends where the curves are hard to achieve with sheeting.

Depending on how 'curvy' the hull is, will dictate how far you can go with styrene plating. Do some tests and post some photos.

_________________
Darren (Admiral Hawk)
In the not so tropical climate of the Great White North.

Here are some photos to show what can be done.

I've been working on a 1/96 scale 5" gun. It's about 1.25" wide and 1" tall.
In front are 3 disks I cut out using the snap method above. All the pieces are snapped out of larger sheets.
The Tan item is a piece of butter board, a dense foam resin material used by sign makers and professional model builders.
It comes in a variety of densities and carves and sands great! I'm using it for the top section that has a very curvy surface.
On the bottom rear, there is a section of thicker styrene where a curve needs to be carved/sanded at the edge.
The lines and markings are mostly removable sticker paper by avery that I have printed a pattern onto for a cutting guide. It peels off when no longer needed leaving the styrene undamaged.

These are test pieces and still pretty rough, but it wouldn't take much to finish them nicely.
The outer skin is one piece gently bent around the support frame underneath.

_________________
Darren (Admiral Hawk)
In the not so tropical climate of the Great White North.

Thanks for the advice ADMHAWK ,
wow great job on this "turrets"

I guess there will be no problem to glue together wood and styrene Sheet ?
cyanoacrylate should work fine i think .

Daniele

Correct, instant glues work really well to glue plastic to wood. You can sand really smooth edges as well.

_________________
Darren (Admiral Hawk)
In the not so tropical climate of the Great White North.

I use testors tube glue to glue styrene to balsawood & these 1/144 scale warships are close to 35yrs old with no adhesion problems.

What is the source for the "butter board"?

Plastic wholesalers sell large sheets. But it's expensive.

Sign shops often have scraps left over.

Sometimes professional model building shops have leftovers as well.

You may find some in craft stores, not sure.

I got mine from a friend who bought a large piece from a wholesaler.

_________________
Darren (Admiral Hawk)
In the not so tropical climate of the Great White North.

Thanks for the reply!

Here in the great yellow North (it's Fall) just below the Arctic Circle. Our city's motto for Winter should be "Way Cool"...

T

I wanted to add a note in about scoring plastic sheets and then snapping the excess off. I agree with what Adam said and how he was able to get very good results. You have to snap a little at a time. One thing you can do to keep from tearing or stress the next sections is to score away at right angles from the curve a line that will let you flex the part into a smaller sections. So as you go around the hull you are snapping off 5 sections instead of one long continuous one.

This also works when you are trying to create pockets in a sheet that are not straight. For a case like this I score multi angled "X," patterns in the pocket that would form triangles. I work one or two triangles to snap out, then work my way around the inside hole.

I hope this makes sense. I could not send or attach a picture from my work computer. But,.......... Here is a link to see what I am talking about. Adam Savage (Myth-Busters). Did a video on his one day builds on how he scratch builds with plastic sheets. He shows a very similar process to what I described. Here is the link. https://www.youtube.com/watch?v=ZfvtGrhYk0I

I hope this helps.

Cheers,
Todd