Dennis Storzek wrote:

This is the reason that plywood is so stiff.

Exactly. Think of bending a stack of LOOSE sheets of the plywood plies.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

This is the reason that plywood is so stiff. We normally think of
plywood as a flat sheet, but sometimes it is used to make curved
objects by building it and letting the glue cure on a curved form..
Curved veneer passenger car headlinings, round veneer drum tables, old
time skis, and the original skateboards all kept their shape because
they were assembled from multiple plies of veneer on curved forms.

Dennis

Jim Betz wrote:

I'd be worried that any paper/wood product would absorb moisture from the air over time and 'deform itself' . . .

Paper and wood doesn't "deform itself" at all (though of course wood may continue to dry and shrink over years). 500-year old paper is still flat. The real point is:

. . . attempt to get the shape of the form and the shape of the resultant roof as nearly perfect as possible . . . so that you don't 'store' stresses in the roof that can be 'released' by moisture in the air or weaknesses in the walls of the model.

This is the real point, and well stated. But any composite (such as a multi-layer part) which is glued will be VERY rigid because each layer is prevented from moving or bending by the adjoining layer which cannot slide. In fact, something like Denny's three layers of paper can be much more rigid than a thicker solid piece of the same material. The same applies to "deforming itself."

Anthony Thompson
Dept. of Materials Science & Engineering
University of California, Berkeley
thompsonmarytony@...

In 1951 Rock Island received 2,000 PS-1 boxcars from Pullman with the "100 Years of Progress" logo. Were the trucks black or car body color?

Thanks,

George Hollwedel


Prototype N Scale Models
by George Hollwedel
proto.nscale@...
310 Loma Verde Street
Buda, TX 78610-9785
512-796-6883

---------------------------------
Don't let your dream ride pass you by. Make it a reality with Yahoo! Autos.

Denny,

I'd be worried that any paper/wood product would absorb moisture from the
air over time and 'deform itself' - especially the single sheet of thick paper
that is not impregnated with white glue. I'm not certain that even a
sanding sealer and paint will keep enough moisture out to provide the
longevity you probably want/need. If it has some form of white glue in it
then my experience is that that product line will not absorb water from
the atmosphere and soften once it is fully dry (a day or more depending upon
how much glue and how much it is exposed to the air). White glue -does- go
soft if it is truly wet ... but moisture from the air should not be a problem.
(You do live in a part of the world that gets significant humidity after all.)
As you discovered, white glue will penetrate paper/wood and make it extremely
rigid.

If at all possible you should attempt to get the shape of the form and the
shape of the resultant roof as nearly perfect as possible rather than using
the flexibility of the roof as a way to 'make it fit' - so that you don't
'store' stresses in the roof that can be 'released' by moisture in the air
or weaknesses in the walls of the model. If you go around the house and
look for things round you will almost always find something that is the
correct dimension. Superficially it would seem that when you are forming
a roof you would want it to end up being 'squeezed' slightly to form the
final shape - to make it easier to fit it to the body/walls.

One possible way to prevent any stored stresses from deforming the final
roof over time -might- be to coat the underside with a thin layer of epoxy -
this will make the roof considerably rigid and may make it impossible to
change its shape enough to 'make it fit' so experiment first. If you have
never tried this trick try thinning epoxy with isopropyl - be careful of
the quantities because the IPA will tend to accelerate the cure of the
epoxy ... but it -is- possible to get epoxy to flow like water and give
a very thin but very air tight coating. Use a fairly slow drying epoxy
such as the 1 hour stuff the model airplane guys use.

Your testing procedure seems very good - if you are using dry heat I'd
use more heat than you can get using hot water inside a glass ... and I
think I'd use significantly longer drying times than you used - such as 24
hours more after it first seems dry - before I removed it from the mold.

- Jim in San Jose

I submitted the original question on this
subject, and I have been most interested in the
many posts, both on and off line, relating all
of the methods that have worked over the years.
Although I asked about styrene, the fundamental
need was to fashion a radial car roof out of
whatever material might work the best for me.

With this in mind over this past week I tried
some quick and dirty experiments of my own, the
fundamental tools being a cylindrical glass
tumbler, a bunch of broad rubber bands, and 180º
F. water dispensed by a standard hot water
dispenser on the kitchen sink.

1) My first effort was to cold mold the roof out
of three layers of c. .008" Strathmore paper (a
brand of Bristol board- a very dense
high-rag-content paper). Such molding requires
slow-setting glues, and in this regard ordinary
white glue was perfect. I laminated the layers
with the white glue laid on with a small brush,
applied it around the glass before the glue could
set up, and kept it there with rubber bands. I
filled the glass with the hot water to provide
some dry heat, and an hour later I removed the
rubber bands and the molding.

2) My second effort was with a roof made of .031"
(1/32") thick scribed Northeastern wood siding.
In the same glass, filled anew with hot water,
the wood was soaked for about ten minutes. The
wood was removed, the water decanted, and the
wood was then wrapped on the surface of the glass
with rubber bands in the same manner as above,
scribed side down. The glass was then refilled
with the hot water to continue a (dry) direct
heat source. This was left for about three hours
so that the wood could thoroughly dry.

3) My third effort was with a roof made of .016"
single layer Strathmore paper applied to the hot
glass in the same manner, but thoroughly soaked
beforehand for several minutes in 180º water.
This piece was dry in about an hour, after which
it could be removed.

4) The last effort was with a roof made of .030
sheet styrene applied cold to the hot glass
tumbler. It was removed after about one hour.

Results:

1) Glued-up paper: Remarkable! The resulting
molded radial roof almost exactly mirrors the
radius of the glass tumbler, and is so stiff, one
can almost physically stand on it before there is
any deformation. The down side of this is that
unless the radius is almost right on from the
git-go, getting an accurate fit without a
force-fit will result in a lot of unrelieved
stress that is going to be difficult to deal with
(the radius of the tumbler, and thus the molded
roof as well, are both tighter than the desired
roof radius). Finishing such a roof would be
easy inasmuch as Strathmore is one of the easier
materials to fill and paint to a smooth finish.
In most installations, presuming the fit was
good, no carlines at all may be required.

2) Wood: By far the very easiest. Bending wood
with hot water/steam is a time honored process,
and as expected here, it worked well to a "T". As
stiff as the laminated paper turned out to be (as above), the bent wood turned out just the
opposite- sufficiently flexible to readily adapt
to a variety of radii. The bent wood by itself
will maintain the bend for posterity if left
alone, but in this regard it will need to be
protected by thorough sealing on both sides with
a good filler/sanding sealer. This will also be
required to gain a good finishing surface. If a
roof of this type is to be removable, carlines
will be required. If mounted permanently, either
a very few carlines, or none at all would be
required, depending upon roof size and existing
supports.

3) Paper, single layer alone: Very simple. After
a thorough pre-soaking in hot water, this also
worked quite well, and a nicely curved roof
resulted that was not stiff, and adapted well to
a variety of radii. The thickness is not as
great, and in this regard, supporting structure
(including carlines) and fasciae would probably
have to fabricated (not hard to do with either
styrene or strip wood).

4) .030" sheet Styrene: It worked, but not very
successfully (good solid bend, but way too much
"spring back"). Richard White's serendipitous
and very good post on this same subject today
points to the reason: The water I use is not hot
enough and/or the glass wall of the tumbler I use
does not transfer heat well enough. Using a
suitable metal can (excellent heat transfer)
instead of the glass would seem to be a key here.
Whether one would get his results with only 180º
F. water (v. 212º F) or not, would have to await
trial. Also, what the results might be with .020"
or .010" sheet styrene under identical
circumstances are as yet unknown to me, but I
would expect they might be much better.

Conclusions:

All of these methods used in the creation of a
curved HO car roof have something to recommend
them, as well each has some detractions. I have
yet to decide which one I will elect; much
depending upon how easily I determine it will be
to trim to size, detail, fit and finish these
roofs "non-destructively"- i.e. can I get from
here to there without ruining things!

As in most instances, what works best for one
person does not in fact work the same for
another- reflecting common individual differences
in both skills and familiarities working with
different materials over the years. Styrene is
the current lingua franca of model scratch
building, but both paper and wood as
model-building materials have long played a
distinguished role in fine model building and
should not be summarily dismissed. Each has their
own place. It is certainly not an "either/or", it
is "both", and any or all of these materials can
be used quite well with each other.

This has been an interesting exercise, and like
others I will be collecting all of the posts into
an edited compendium in WORD.

Denny


--
Denny S. Anspach, MD
Sacramento

Are those Universal brake booster castings available separately Ted?

Rob Kirkham

Hello: I remember in the mid 50's seeing many 40' box cars of wheat at the
East Boston yard of the NYC (ex-B&A) consigned for export to Russia. I recall
that this was in response to an appeal for help during one of their frequent
famines at that time. I also recall seeing the empties with grain doors made
with corrugated cardboard and light boards. Probably 1x3 light pine. However,
I have no idea what roads and numbers they were. Funny how what you focus on
changes over the years. Regards, Al Campbell



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In a message dated 10/6/2007 1:28:00 A.M. Eastern Daylight Time,
rdkirkham@... writes:

Does anyone have one of their models who might be able to
answer whether the F&C kit includes parts for the K brake rig (beyond the
usual Tichy K brake sprue and some wire bits.)



Hi Rob, I have one of their kits with the AB brake and it uses a Tichy
sprue, for what that may be worth. The F&C kit does not have a one piece body,
which is why I only have one. Also, the Sylvan kit seems to have a better level
of detail and a one piece body. Walt



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If it is the same mechanism as used on these Katy cars then it is a
Universal brake booster. I included some castings to make this in
the kits for these Katy versions.

Regards,
Ted Culotta

Speedwitch Media
645 Tanner Marsh Road, Guilford, CT 06437
info@...
www.speedwitch.com
(203) 747-0190

That's kind of amusing, Jim. I didn't know there were three models on the market. I think there may be an earlier 1920's era version of cars like these - have not studied the distinguishing points.

I built a Sylvan version of the 1929/30 car a couple of weeks ago (with AB brakes), then did this Kaslo car. I wonder whether I should do an F&C and fill out the roster with more variants..... That always seems like a recipe for reducing realism to me, as the differences in models should be explainable. At this point, they are subtle enough however that I'm not sure way one could pick a Kaslo from a Sylvan car unless they studied the two models closely.

I notice that the upper door stop on the Sylvan car is quite a bit more detailed than that on the Kaslo. Looking at the F&C page, even though they sell a K brake version, their photos do not show a built up model - and do not reveal whether their kit contains the parts to model this complex brake rig. Pity. Does anyone have one of their models who might be able to answer whether the F&C kit includes parts for the K brake rig (beyond the usual Tichy K brake sprue and some wire bits.)

Thanks

Rob Kirkham

Thanks again Dennis, the photos are a tremendous aid. I think I'll try to sketch out a plan version, and work from that. I suppose no one offers a separate detail part for this particular brake rig so will have to do something creative. Not sure what that will be yet.

Rob Kirkham

Chuck Hladik wrote:

The Sylvan sight is . . .

And quite a sight it is, too <g>.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Funaro & Camerlengo, http://www.fandckits.com <http://www.fandckits.com/> ,
also makes a model of this boxcar. They call it a 1924-25 boxcar on their
website and on the box but the included history starts out 'In the late
1920s.' and refers to orders from 1929 & 1930.



Jim Hayes

Portland Oregon

--- In STMFC@..., "proto48er" <atkott@...> wrote:

Many thanks for the photo, Dennis! I am getting ready to build
the "O" scale Sylvan Models kit of this car, and the info is timely.

The second image is now available at:

http://ph.groups.yahoo.com/group/STMFC/photos/browse/fbbf

It gives a little better perspective as to how the parts fit together.

AT, what car did Sylvan do? Could you give us a link to a web site or
at least an image?

Thanks,

Dennis

--- In STMFC@..., "Lynn Finch" <lmfin@...> wrote:

Does anyone have info on the dimensions and construction of grain

doors? Was there a standard? I have seen this reference to a 1938 -
AAR Standard Grain Door is approved for use nationwide but have been
unable to find this standard. Or was grain door construction
determined largely by the builder and materials available with the only
requirement to keep grain inside a box car. Lynn Finch


A few weeks back I gave references to two articles on grain doors in
the model RR press.
Jared Harper
Athens, GA

Dennis,
The Sylvan sight is _http://isp.ca/sylvan/_ (http://isp.ca/sylvan/) .
Chuck Hladik



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Many thanks for the photo, Dennis! I am getting ready to build
the "O" scale Sylvan Models kit of this car, and the info is timely.

Incidentally, the same 2:1 "power" handbrake arrangement was under M-
K-T #95500-95999 (MtVernon - 1925) and M-K-T #96000-96499 (M-K-T -
1926) also. In the car I was under, the rectangular rod on which the
chain-wrapped block slides was horizontal, not inclined like in your
photo or in the CN drawing referenced.

A.T. Kott

Has anyone heard anything about NEXT year's Naperville dates? We have been moving "forward" in days, away from Halloween, but Martin may or may not continue that next year.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Does anyone have info on the dimensions and construction of grain doors? Was there a standard? I have seen this reference to a 1938 - AAR Standard Grain Door is approved for use nationwide but have been unable to find this standard. Or was grain door construction determined largely by the builder and materials available with the only requirement to keep grain inside a box car. Lynn Finch