Denny,
My success has come from tying the styrene around an object of a
slightly tighter radius object and running hot water over it. If that doesn't seem
to work for you. you might try placing said wrapped styrene in the back window
of your car. Keep a CLOSE eye on it!!
Good luck,
Chuck Hladik
Rutland Railroad
Virginia Division



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Friends, I am attempting to permanently bend some .030" styrene sheet to form a radial car roof. I want the permanent bend not only to avoid any unrelieved stresses, but also to be able to remove the roof on occasion. I have never done this before, and so far I have had no progress (using hot water poured over the sheet tied around a drinking glass, etc.).

How have others done this, and if so, how?

Denny
--
Denny S. Anspach, MD
Sacramento

I've done this on occasion. You need a circular "form" which is smaller than
the intended final diameter because of spring back of the styrene. A section
of PVC pipe of the appropriate diameter might give you the size you need.
Cut the styrene larger than needed to larger cut off and discard the sides
which don't curl evenly. I'd use rubber bands to hold it to the foam. Then
dunk everything in VERY (nearly boiling) hot water and leave it in the water
for the styrene to soften before removing it. You might need to experiment
with the water temperature. You might want to build the roof up from 2 or
more thinner pieces if the .030" doesn't curl evenly. Plan on making
carlines from .040" styrene to hold the final desired shape.

Good luck...

Jack Burgess
www.yosemitevalleyrr.com

Hi Denny,

My old friend Bob Hayden has an article in the September/October issue of
the "Narrow Gauge and Short Line Gazette" on modeling a 2-foot-gauge
excursion car with a radial roof shaped from .030" styrene. See page 20 in
that issue. He also shows how to lay out carlines to hold the roof in shape,
as Jack Burgess suggested. Bob is an experienced builder and I'd have
confidence in any method he recommends.

Good luck,

Andy

Andy Sperandeo
Executive Editor
Model Railroader magazine
asperandeo@...
262-796-8776, ext. 461
FAX 262-796-1142

Personally, I'd make braces of the correct radius (minus roof thickness) and
glue the sheet to the braces. This probably works better with .020 or .010 thick
sheet. You can always glue .005 or .010 to the underside to build up the
thickness after the form is set.

Tim

The current technique I am exploring is laminating three pieces of
styrene with the expectation
that the two bond joints will preserve the shape; I'm not done
building the car but the roof has held together for a month now


Roger Hinman

Dr. Anspach,



I have a freind that has successfully used his dishwasher (top rack) to do this, much like steaming wood. He needed to do this to correct his ECW 4-4-2 roof, which had the "warp" issue. It was of course ws a bit thicker, but the heat in the dishwasher was a longer duration but not as hot as the boiling water trick. I would experiment with all the suggestions you receive.



Greg Martin

The technique I'm exploring is to bond three pieces of styrene togehter over a car line shape. The two bond lines and the car lines hold the shape. Car's not done yet but the roof has held up for a month now

Roger Hinman

I've used two sheets of scribed stryene in a small
test. Place first over form and glue second to it,
secure both to form and let dry. The test has kicked
around my work bench for a couple of years and is
still holding its form.

Bill Vaughn


--- Denny Anspach <danspach@...> wrote:

Friends, I am attempting to permanently bend some
.030" styrene sheet
to form a radial car roof. I want the permanent
bend not only to
avoid any unrelieved stresses, but also to be able
to remove the roof
on occasion. I have never done this before, and so
far I have had no
progress (using hot water poured over the sheet tied
around a
drinking glass, etc.).

How have others done this, and if so, how?

Denny
--
Denny S. Anspach, MD
Sacramento

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Although you report good luck, in my experience, scribed styrene will warp
over time if not really braced. Walls aren't a problem but overhanging eaves
and such warp. I used some scribed styrene for the roof of a caboose and it
is still okay after several years but I used fairly beefy longitudinal
braces in addition to the carlines.

Jack Burgess
www.yosemitevalleyrr.com

Denny-
I'd be inclined to build up the roof from laminations of thinner material over carline formers as Jack suggested.... the compound curve of a passenger car roof needs to
be reproduced and held and short of making a wood form to the correct inner shape and practically melting the sheet over it I think the other methods mentioned so far
will not prove to be satisfactory for your project.
MR had an article on building an O Scale Passenger car a couple of years ago that may have some useful techniques in it for your car.
Charlie Vlk

Hello Denny,
I have enjoyed reading some of the responses to your question and would
like to throw another method into the mix for you to try. I have used a
dry method for making radiused roof sections for milk cars, freight
cars, passenger cars in ON2, and DL&W depot roofs. I model in O Scale
to give my remarks some perspective as to size. I have found the
easiest for me has been to laminate two or more thinner layers together
using a product known in industry as splicing tape. I tape the first
layer down over a curved form of appropriate radius allowing for a bit
of 'spring back' when finally removed. Then I apply a layer of tape and
apply the next layer of styrene to the tape. The bond is permanent. The
method can also be used for applying styrene to different substrates
such as brass, vinyl, or wood.
Let me explain a bit about splicing tape. It is so called because it is
often used to join lengths of wide process goods that are made on a
continuous basis such as paper. There are a number of variations of
splicing tape, but the two basic types are ones that either have
a 'carrier' or not. A carrier has adhesive coating on both sides of a
plastic film. I prefer the type without the carrier because it is by
nature thinner. It is made by speading a thin layer of aggressive
adhesive onto a release sheet that is usually silicon coated paper, and
then wound into a roll and slit to various widths for application. I
prefer 2" wide material for my uses. To use it, unwind the tape and
apply it sticky side down onto the styrene. You can at that point peel
away the backing, exposing the other side of the adhesive. I have
learned not to do this because there is simply too much adhesive area
and it is difficult to put the second layer down without adhering where
you don't want it to. Rather I start the peeling process by pulling the
backing away on one end just enough to expose enough adhesive to anchor
the end before pulling the rest of the backing out progressively as I
press down the second styrene layer. If you have ever done or seen
laminating performed with contact adhesive you know that when contact
is made, the bond is almost instant and the alignment had better be
correct. In the case of styrene, as others have suggested, make the
part oversize when laminating and trim when the bonding is done. If you
model in HO, I would suggest trying 1" wide tape. It also helps if
you 'roll' the second layer onto the first so that the bonding becomes
a controlled progressive line contact. I learned this technique back in
the 60's when I worked for a company that made splicing tape and I was
able to experiment with its properties. Then in the 90's I worked for
another firm and stocked up prior to my retirement. I believe 3M makes
some product that is available through distributors for individual
modelers. My last project was a DL&W depot roof that has a flat peak
section and curved eaves. By starting with the eaves and working toward
the peak, I first taped the eave section to a large diameter pipe and
laminated that portion before moving to taping the rest on a flat
benchtop.
I wish you well with your own projects.
Ben Brown

The Bron Killer Red tape that I described in the July 2007 issue of RMC is
the same as the "splicing tape" that Ben describes. As mentioned in that
article, you can purchase individual rolls of this tape from TAP Plastics
(http://www.tapplastics.com/shop/product.php?pid=411&d) but only in the 1/2"
width. Having worked with this tape, Ben's approach would work if you can
avoid contacting the tape prematurely. However, I don't see much benefit
over styrene cement in this case. But this is still very cool tape with a
lot of uses....

Jack Burgess
www.yosemitevalleyrr.com

Denny:

I have built a number of radial roofs using a laminated technique.

The first step is to develop a form for the carline either concave or
convex. I typically use wood including things like baseboard or casement
molding.

Next, use some double-sided tape like Scotch Brand. Use the thin type. It
doesn't cause "bumps" in the final product. Just lay three strips along
the form with one being in the center.

Cut a sheet of 0.010" styrene sheet to slightly larger than the desired
length and width. Place that on the mold making contact with the tape.

Cut the additional sheets of styrene at this time.

Carefully spread slow-curing CA glue on the surface of the first sheet.
Carefully press the second sheet down. Use a dowel or Exacto knife handle
to "roll out" the lamination. This will ensure that there aren't any voids
in the lamination. Add the last sheet and let it cure. I would let a
sit overnight then you can pry the part off of the form and trim to size.




I have posted a couple of photos the process.



Gene Deimling

I have not tried shaping styrene but I have a suggestion for a source of
controllable heat that might work better than any posted so far ...

Go to your local R/C airplane store and pick up one of the heat guns that
they use for shrinking the covering on the wings and fuselage of their planes.
They are shaped like an 'industrial hair dryer' (ie. like a gun) and have
a switch in the handle. Push the switch once and you get heat (it builds up
for the first minute or so until it reaches temp), push the switch again and
it turns the heat off but leaves the fan running providing air that is
cooling down as time passes by, push the switch a third time it shuts off.
You will find that you can quickly develop the technique of getting just
about whatever temp air you want flowing over whatever surface you want.
Keep the gun moving at all times - it will build up a lot of heat in the
surface if you hold it still. I like to have the hand I'm holding the
work with just outside of the area I want heated ... and by using a
shimmy-shake action with the gun some of the air gets out to my hand and
lets me control how hot/cool the air flow is.
I know a few guys who use one of those commercial heat guns for doing
various tasks associated with modelling. I can't 'get it right' when I
use one of those ... it always seems to heat up whatever I'm pointing it
at too quickly. The one for the R/C planes is much more controllable
because the heat is sufficient but not over-powering. YMMV.

Among other uses - I use one of these for shrinking heat shrink tubing
when doing electrical projects - it is far superior to using the tip of a
soldering iron or any other method I've found. It also cleans off my work
bench of any little bits of stuff as a 'bonus'. The phrase "blown away"
might mean something slightly differently to me than the rest of you ... ;-)

- Jim in San Jose

Jim wrote:

Go to your local R/C airplane store and pick up one of the heat
guns that
they use for shrinking the covering on the wings and fuselage of
their planes.

I just bought a heat gun from Home Depot for around $40. It is a Milwaukee
Model 3300 and has 6 heat ranges from 250 degrees to 1350 degrees. I got
primarily for electrical shrink-wrap but it should also work as Jim
suggests.

Jack Burgess
www.yosemitevalleyrr.com

--- In STMFC@..., "Jack Burgess" <jack@...> wrote:

I just bought a heat gun from Home Depot for around $40. It is a

Milwaukee

Model 3300 and has 6 heat ranges from 250 degrees to 1350 degrees. I

got

primarily for electrical shrink-wrap but it should also work as Jim
suggests.

Jack, you'll find that the distance from the heat source has as much to
do with the temperature of the item being heated as does the setting.

Ed

True except that the fan volume is also a factor for some applications.

Jack

This topic is very interesting, though I do not have a current need
for this technique. I hope someone trying these techniques can find
a way to put their experiences into "print" either in a magazine or
more easily in an online modeling magazine like the B&O, Keystone or
ACL/SCL Modeler magazines. Just another biased request to preserve
and pass on information from this list.

Regards,
Bruce D. Griffin
Editor, B&O Modeler


--- In STMFC@..., "Jack Burgess" <jack@...> wrote:

True except that the fan volume is also a factor for some

applications.

Jack

-----Original Message-----
From: STMFC@... [mailto:STMFC@...]On

Behalf Of

ed_mines
Sent: Tuesday, October 02, 2007 10:18 AM
To: STMFC@...
Subject: [STMFC] Re: Shaping/bending styrene.


--- In STMFC@..., "Jack Burgess" <jack@> wrote:

I just bought a heat gun from Home Depot for around $40. It is

a

Milwaukee

Model 3300 and has 6 heat ranges from 250 degrees to 1350

degrees. I

got

primarily for electrical shrink-wrap but it should also work as

Jim

suggests.

Jack, you'll find that the distance from the heat source has as

much to

do with the temperature of the item being heated as does the

setting.

Ed




Yahoo! Groups Links

Years ago Wayne Wesolowski (Spelling?) wrote an article about solvent forming styrene. The basic concept was quickly dip styrene into solvent and then put it in a form to hold it's shape while it dried. The article was about building a window frame but perhaps it would work on larger surfaces also.

I am sure a quick look at the magazine search database should find the article.

Ned Carey