Model Railroader – October 2019

October 2019 21

By Steven Otte

wheel contour standards, or whether
they’re too big. If the flanges are over-
sized (what modelers call “pizza cut-
ters”), look into replacing the wheels
with ones that conform to the NMRA
Recommended Practice RP-25 contour.
Or does it happen on only one turn-
out? Then it’s probably something about
that particular turnout. Perhaps you’ve
installed it at a point where the track
grade begins or ends, and the turnout’s
elevation is uneven, causing a “hump” at
the frog. Remove the turnout and check
for a hump in the middle of the roadbed.
Rasp it flat and reinstall the turnout.
Good luck tracking down your problem.

Q I have several Mantua “Big Six”
0-6-0 locomotives that I built in the
1970s. I put can motors in them 20
years later. They don’t run very well
now, and I tracked down the problem
to the driver wheels. I tried to clean the
axles along with the brass bushings
and the cavity in the frame, but they
still have poor electrical contact. Is
there any trick to cleaning the axles,
bushings, and frame to get a good
electrical connection?
Joe O’Neill, via e-mail

A As old as those locomotives are, their
zinc-alloy frames might be suffering
from corrosion that interferes with elec-
trical conduction. There’s no way to
reverse that short of replacing the frame.
Instead, I would bypass the frame. Insu-
late the motor from the frame with tape,
solder wire leads onto its pads, and
install phosphor-bronze wipers to pick
up current directly from the wheels and
carry it to the motor.

Q I’ve seen “paint stands” for steam
engines that make the wheels spin while
the locomotive is being painted so the
side rods don’t block the paint from the
drivers. I’d like to put one of these in my
paint booth, but my locomotives are all
Digital Command Control. Do I need to
have an expensive DCC power source,
or can I temporarily run the locomotive
using an old direct current power pack?
Ray Mlecko, Phoenix

A Most DCC decoders made in the past
decade are “dual mode,” meaning they
will run under direct current as well as
DCC. Unless your decoders are old, they
should work on DC. Check the manual
that came with the engine or decoder.

Q What’s the secret to getting a good

masking job when painting models?

I’ve used tan masking tape, blue

painter’s tape, green frog tape, and

yellow frog tape, and I always get

bleed through. I’ve been using spray

paint from the hobby shop; would an

airbrush be better?

Doug Coates, Brooks, Calif.

A I learned this trick from Group Tech-

nical Editor Cody Grivno. First, paint

the entire object the color you’re going to

mask off (the stripe on a locomotive

shell, for instance). Secondly, mask off

your stripe, and then – here’s the trick –

spray the object with the same color

again. This second coat will seal the

edges of the masking tape, but any paint

that seeps under the edge will be the

right color. Finally, paint the body color

one or two coats, and after it’s dry, care-

fully remove the masking tape. Since the

second coat of paint sealed the masking

tape, you should get a crisp edge.

Q I’m thinking of superelevating the

track on my N scale layout. My internet

search reveals plenty of discussion on

the subject. What’s most often recom-

mended is lifting the track, typically by

layers of masking tape, plastic strips, or

gentle wedging. Wouldn’t it be

proto typically more correct to super-

elevate the entire cork roadbed? I’m

thinking of lifting the outer edge of the

cork, using^1 ⁄ 16 " strips of basswood.

Wood wedges would fill the inside

space between the support surface and

the cork bedding. All would be sanded

down to create a smooth surface and

also to adjust the super elevation at the

spiral section.

Eberhard Jaeckh, Portland, Ore.

A Your method of shimming under the

cork roadbed would work as well as

shimming the track on top of the road-

bed. It would be wrong to call either

method “prototypically more correct,”

though, since the prototype doesn’t use

anything like cork roadbed, just ballast

on top of dirt. Go ahead and use whatever

method of superelevation works better

for you. I personally prefer masking tape

on top of the cork, since masking tape

can be flexed around curves and built up

gradually in thin layers.

Sometimes you have to move a benchwork joist after it’s been installed. For

example, it might interfere with the installation of a switch motor or a signal

mast. If the joist is installed using screws from above, tracks or scenery may

cover the screw head. Adding a flange on top of each joist before installation

allows attachment from underneath, but that’s a lot of work and takes up ver-

tical space you may need if there’s staging underneath that deck.

My solution is to use a pocket screw jig to make pockets for attaching the

joists to the tabletop from under the layout. If a joist needs to be moved, sim-

ply undo the screws in the pockets and move the joist. All of this is done under

the benchwork, so nothing above is affected. – Steve Ascolese

READER TIP

Steve Ascolese uses a pocket jig to drill screw pockets into his benchwork joists,

making them easier to remove in case a joist has to be moved to clear a switch

motor or other under-benchwork item. Steve Ascolese photo