Hello All-
I just discovered this group, looks like I'll be spending a lot of time
here...
I have one question regarding plaster casting. I am scratchbuilding my
HO structures and have made latex molds for brick but does anyone know
of any commercially available brick molds? I am more or less satisfied
with the results but there isn't much depth to the Plastruct sheets I
used as a master. My thought is that a mold made specifically for
plaster might have more relief to it. Any thoughts?
Thanks in advance,
Pat Shanahan
Chicago
Pat Shanahan spake thus:
This is an area where I've been experimenting, albeit fitfully, for
several years. I haven't come up with a good solution either, but here's
what I've discovered along the way.
Most brick sheets are extremely disappointing, either in terms of brick
size, depth, as you've pointed out, or just overall realism. Some of the
worst is the ubiquitous Holgate & Reynolds stuff, which is much too
small, and also is some weird plastic that's tough to glue.
The best brick sheets I've found so far come from the British Plasticard
company. About a decade or more ago, I sent away for a sample pack of
their stuff, and a few of the sheets were outstanding. I don't know
exactly which ones they were, but you might try contacting them (some of
the UK folks here should be able to help). They're scale sized and
pretty realistic.
It's too bad that one can't get brick sheets which look like the brick
walls on some of the plastic model lines, like DPM and even Walthers,
which are incredibly realistic by comparison.
The last thing I tried, out of desperation, was making my own mold
masters. Yes, this is truly an act of obsession, but you know what? it's
actually doable, given enough patience. I cast a large flat slab of
plaster, using the shallow plastic cover for a box of stationery
supplies. I then cheated, by printing a brick pattern on my laser
printer (from a Corel Draw illustration), then transferring it to the
plaster by putting the face of the print against it and wetting the
paper with acetone, which dissolved the toner and let enough of it
transfer to the plaster to be visible. I then used the guidelines to
position a metal ruler, guiding my scribe tool (a sharpened metal
point). The long horizontal lines are easy, of course: it's the brick
lines that are a pain in the ass.
The small sample I made actually made some pretty nice looking brick
casts. I used the blue RTV stuff for the mold, then just cast plaster.
(Suggestion: to eliminate the inevitable bubbles, wet the mold with
rubbing alcohol first.)
Anyhow, I'd be interested to hear if anyone has come up with any other
solutions to this problem.
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Welcome to the group, Pat! You might find something at Linka World:
formatting link
Bill
Bill's Railroad Empire
N Scale Model Railroad:
Thanks for the replies Bill & David. The Linka molds look clunky on the
product pages but the gallery images look very good, I think I'll give
them a try.
I've tried making my own molds twice this past weekend with poor
results. Brush applied latex is too flexible and pourable plastic
(Smooth-On) is too rigis. In addition, the plastic really heated up and
warped the styrene I was using as a master. AARRGH!
Thanks for the help, I'll post my results if (and when) I get this
right.
Pat Shanahan
Chicago
Pat Shanahan spake thus:
For molds, you really ought to try the RTV (room-temperature
vulcanizing) stuff. Once it sets, it's pretty impervious to just about
anything, soft & flexible yet plenty rigid enough to cast large
sections. Tap Plastics has it (probably several in Chicagoland).
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