Pennsylvania F22 30' Flat in N-scale

[cbroughton67]

After scratch-building a Pennsy F22 flat car in styrene, I needed to find a way to build a heavier version, closer to NMRA RP recommendations. So, I thought I'd try making a master, a mold, and casting one in pewter. Well, the pewter idea was swell and all, but that didn't go so well. So, I tried mixing tungsten powder with resin, and that worked out much better. If pictures are worth a thousand words, then I'll let them tell the story...


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The master compared to the styrene version I built:
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The master before pouring RTV silicone:
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The resulting mold:
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Potion of resin and tungsten (about 50/50 mixture):
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It worked! Here's the casting:
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After adding all the wire details...
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Test-fit of the coupler in the build-in coupler box:
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[cbroughton67]

Continued...


Best reason for an integrated coupler box - correct ride height and coupler height:
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After paint and decals, and wood deck stained, weathered, and ready to apply:
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...and the finished product!
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The car weighs about 0.5oz. Still a little light by NMRA standards, but a decent amount of heft for a 30' N-scale flat car. The decals are by Mount Vernon Shops, paint is True Color PRR freight car brown, Atlas 50-ton trucks w/ FVM metal wheels, and Micro-Trains 1015 couplers. Testors Dullcote seals everything.


Now, to make a couple more...


Chris

[peteski]

Looks to be a great model, but for some reason the photos you posted are not much bigger than thumbnails, so I can't see much detail.
The tungsten powder in the resin sounds liek  great idea too.

[robert3985]

Looks to be a great model, but for some reason the photos you posted are not much bigger than thumbnails, so I can't see much detail.
The tungsten powder in the resin sounds liek  great idea too.

What he said...

I wanna see 'em better.

Cheerio!
Bob Gilmoe

[cbroughton67]

@robert3985 @peteski Better?

[bbussey]

Much!

[Angus Shops]

Very nice work. Adding the tungsten powder to the resin was an inspired idea. I fully plan to use this idea in the future.

I mixed Woodlands Scenics ballast, which is very light, into the resin I used to make some coal loads for some hopper cars to make the loads lighter than a big chunk of resin would have been. It's amazing how much ballast you can mix in and still have a pourable mixture.

If  I may make a suggestion, it appears from your photos that you poured your resin into the mold, and after the resin was hard, you must have had to sand the upper surface flat before adding the wood deck. However, if you have second flat surfaced silicon piece you can avoid the sanding step:
   1.    Fill your mold as you you did,
   2.    Place the second silicon piece flat side down on top of your filled mold,
   3.    Press down and add weight to squeeze out the excess resin.

You should end up with a casting that only requires a little flash removal and has a nice flat top surface.
Geoff

[peteski]

Ah, much better now. Your photos now show how nice the model is!  Excellent job Chris. Do to its lower ride height, it look better than the similar N Scale Architect car.

I also echo the recommendation of using a piece of RTV rubber to cover the open mold after pour.  That will result in a smooth top surface, with just some flash around the perimeter to be removed.

I made RTV sheets by creating a rectangular dam on a piece of glass, making sure it sits level, and pouring a layer (about 1/8") onto the glass.  When hardened, I pulled the rubber out and trimmed into few different size pieces to be used to cover open molds.

[cbroughton67]

@Angus Shops @peteski Great idea regarding the flat silicone - I'll absolutely do this before my next pour.


Thanks!!!
Chris

[peteski]

@Angus Shops @peteski Great idea regarding the flat silicone - I'll absolutely do this before my next pour.


Thanks!!!
Chris

No problem!  I should have also mentioned that I  made those cover sheets using translucent RTV to be able to see the resin under them. But any RTV will do the job.

[GaryHinshaw]

Very nice build!  Any reason you decided not to use Tru-scale couplers with this one?  (Looks like the original used them.)

[cbroughton67]

@GaryHinshaw The original styrene car did use TSC's mainly for aesthetics, since it was my first attempt at scratch-building a car. I may retrofit them with 1015's, so I can use the car on my layout. TSC's look nice, but they're DOA as far as I'm concerned, since I like switching and ops, and this is one area where they don't work well. Friends like to bring their own equipment to run on my layout on "train night," so the lack of compatibility was another deal-breaker. For me, they're great as a replacement for Unimates between F and E locomotives or unit trains that are never broken-up, for example, but that's it. I went with 1015's for the cast car, since they work and work well.

If someone would combine the size, aesthetics, and the no-slinky effect of the TSC with the operability of the 1015, I would literally throw money at them.

Very nice build!  Any reason you decided not to use Tru-scale couplers with this one?  (Looks like the original used them.)

[chicken45]

These are great!

[JoeD]

@Angus Shops @peteski Great idea regarding the flat silicone - I'll absolutely do this before my next pour.

You can use the back sides of older molds as well.  I use them here at MTL as a matter of course and economy.

Joe


Thanks!!!
Chris

[wazzou]

I usually just spray some mold release on a flat square/rectangle of 3/16" ABS plastic and place it on top of the mold with some weight.