Thanks again for the links and ideas. It's clear I've got to try each of these suggestions on some test areas to see the effects and finished results. I really appreciate the help gentlemen!
Mister Kempinsky explained it in a book published by Kalmbach
He use CA gel with ballast to model the slag residue around cars and the one were the hot iron cars were emptied.
Some picture are shared in his book ( I beleive still available at Kalmbach about steel mills).
He hidlight some of the slag residue with wash of yellow and orange paint to simulate hot slag.
Here is a YouTube video showing one method:
https://youtu.be/K4a2unLQovA
I would do things a bit differently. For example I would use quite a few more LEDs but at a lower brightness (10,000 ohm resistors?). The LEDs could be spaced unevenly up and down the flow line so that it will glow from top to bottom. I would also try using so called 'straw hat' LEDs which are designed to disperse the light to the sides instead of having it project straight forward.
The video presenter asked about orange LEDs. These are the straw hat style:
https://www.ebay.ca/itm/50-pcs-5mm-Orange-Amber-Straw-hat-LED-Wide-Angle-Light-Lamp-New-Free-Shipping/170845631393?hash=item27c73173a1:g:zd8AAMXQQQZR0IRK
This might be another possibility:
https://www.ebay.ca/itm/LED-Glow-El-Wire-String-Lights-Strip-Rope-Car-Xmas-Party-3V-12V-USB-Controller/293197311907?var=592067246683&_trkparms=ispr%3D1&hash=item4443ebefa3:g:uvwAAOSwlWBdXmX2&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qXCsMOLh7pbYJnhM%2BzUOpsfyc7buJECAEtasbdMCSeVV2DHPgUy0xLil3NMMXmsowIG7JGIHccOpmorEVK3Erio0Qv7P1Y3wqioVac2NlejC2wpIW%2BsCVDjULrj2YRS7VKhYTCaTi2SK%2FWjgwdYfdhAkXKPennXeAFGvxyCwv5Oz0PxZdwb1n5BXt8etkZeFlboVLEDFqMeP4yN9jhzMJmu0I734UL7egjXISQsjf1uDOS0cEjRNlxkfNehNxfSpxKyfXGu2TOLf4pmYMhf6t8CP79FeEzr%2FVie1B2O8T9kNGrySljt28gef2zCt1KCsaXSDt5tylAD4FID3DxCriJlgMymP13jU0ezVk3L%2BW5RaAMsofn13oOYVgSRUjzNkJZXz54eNBbXbcReYCz%2Bom90RAVBGjzNy6ZtjZa1rIxUVh37E9jswV86I5xGOrpQo42DMtN528FEKmSR%2FHEU27Uy8eugHOnzc0Mya05iRcfnjKiJyt4rnSjtmyRGanlKbBn%2FUn0K6Vdseodkjr1u6u7Mp%2FYHcAYsEWpT8yYBsvbTfZNEFvKv6P%2FYiuKhYIY0%2FtTVmMlWPAwd%2FY0lZGmHTnpkTPdYzu567J%2BW%2F%2BJMHGXPiIoKNDcSgv%2FMIQ44N5W8p1GGYOlPbCBvx5D4zgF57YLrIZCC0RAqLNiGIuKd7bJVPR4l6z6rr%2BZ6cZW5vqU69mj%2BeVVwWdiDGrGiyO5rYmbSQmXEl1kzRKlPe11mDFLCTVAw3k72kY02Buqaa8Z5LaM%3D&checksum=293197311907a57389a4fb1141d1b4f0da94d6410834
I would not use the yellow paint to highlight the surface of the pours. Ideally they should be dark when cooled. Dry brushing with dark gray would accomplish that.
It would be neat to have the pours brightly lit when fresh and then have them fade slowly to the darker colour as they cool. I'm sure some electronic guru could explain how to do that.
Finally, without seeming to be too fussy, the slag pours did not match the spacing between the slag cars. Minor detail.
There was another 'how to' article withing the past couple of years that showed how to use paint alone to achieve the appearance of a hot pour. The results were excellent! I'll keep looking for it.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Hi Erie lackawana in georgia
If we are talking the really fine stuff around tracks perhaps chinchila dust mixed with some coarse brown ballast might work make sure its well glued down before painting.
regards John
If you go to Home Depot or Lowes, there are small pieces of broken concrte block as well as sand like pieces where the block has chipped. I asked and they let me take all of the cips and sand pieces that I wanted.
Broke it into ieces and it works fine for n scale, so if you are HO it would also work well.
Thanks for the suggestions! I'm finishing up my AP Cars with two of these - playing with a "hot" slab look with a load from State Tool and Die and thought a bed of slag would really finish off the appearance.
I also model HO and the N scale smaller texture sounds like the way to go!
I've been gathering various crushed stone materials, sometimes from suppliers that have gone out of business, so that really won't help.
Highball used to make a "taconite" material that was an excellent color and grade to use around a steel mill. It made good "dross" around the bottle cars and ingot molds, too.
There are several suppliers (Arizona Rock & Mineral being my present go-to source) that have dark gray blends that would make decent slag. You can always use powders to vary the color once applied. ARM has a "Yard Mix" that might suit a steel mill area. Some of their paving powders might suit your needs, too.
Scenic Express is another source.
I model in HO but I prefer the smaller sizes, #50 or N scale, which seem to look better than over-scale stuff.
Good Luck, Ed
Any suggestions on how to model slag - specifically powdered residue around the steel mill tracks, buildings and on mill cars? I'm finishing up scratchbuilding a few slab flat cars. I used code 100 rail pieces on the decks and would like to complete the weathering process with a heavy coating of built up slag on the decks between the support rails.