"Front" refers to the side with lettering or engraving that does not burn all the way through the carrier sheet. Before removing a part from the carrier, examine the back of the carrier sheet, and if the laser has not completely burned through, use a knife to finish cutting out the pieces. (To prevent 'overburn', the laser is set to the minimum setting to cut through the wood. Sometimes small differences in the wood or even the glues in the 1/64 plywood will cause the laser to not completely burn through the material.
My railroad paints coal cars an oxide red color. I used "Anita's All Purpose Craft Paint #11025 Rust Red" with a bit of dark gray added to tone down the color. Another good color is a medium-dark grey, such as "Apple Barrel #20580 Pewter Gray". For commercial artist colors, you can use Neutral Gray #3, or take Neutral Gray #5 and darken it a bit. Or you can use Floquil/Polly-S "Weathered Black" and lighten it a bit. There are 2 reasons to lighten the Weathered Black color: (1) so you can then weather the car with a darker coal dust color and have some contrast between the underlying paint and the coal dust. (2) if you want to paint the 'metal' pieces Weathered Black, they will show up as slightly different than the color of the more heavily weathered wood color. My railroad paints the metal parts, but the paint wears off more easily, so the metal parts are part paint/part rust :-) So I'm using Floquil "Rail Brown" for the metalwork braces, and Floquil Weathered Black for the tension rods, brakestaff and brake wheel.
Painting Tips:
Stain the front side of hopper slopes & bottom B5, 2xB6, 2xB7, -back
side- of hopper sides 2xB1, 2xB2. I used Minwax English Chestnut.
The insides of hoppers were not painted, as the paint wouldn't survive
the abuse of loading & unloading coal.
Punch out the"thick" pieces A1, A2, 2xA3, A4a, A4b and A6. (Also 2xA5 if you want. I don't bother with the brakes, they're not very visible...)
Assemble frame A1/A2 before painting . Here I use yellow carpenter's glue, thinned to the consistency of cream. Make sure A1 is on top, and the hole for brake staff aligns on both pieces. Looking at A1 from the brake end, the hole for the brakestaff should be on the left side of the car. Double-check the A1/A2 assembly before you glue them together. After the glue has dried, sand the ends so that the part line between the two pieces does not show.
Paint A1..A6, back sides of hopper slopes and bottom B5, 2xB6, 2xB7. Front side of hopper sides 2xB1, 2xB2, both sides of Brake Platform B8. Keep your brush dry and use 2 coats if necessary, to prevent the paint from bleeding through the laser-cut lines and discoloring the stained wood on the other side. Punch these pieces out (leaving 4xB3 in the carrier sheets. I used a felt-tipped marker ('Sharpie fine') to color the hings on the hopper bottom, B5.
Paint the metal rod weathered black or rail brown. Again I use Floquil paints on the metal rod. (Also, I substituted a piece of .015 for the brake staff and hopper release, as I think it looks a bit better.) Particularly on these metal pieces, it's always good to let Floquil dry thoroughly. Also paint the NBW castings at this time.
Punch out the pieces between the rungs on the brake wheels on the Bristol Board sheet. Paint Pedestals (4xB3) and the front side of the Bristol Board pieces an appropriate weathered/painted metal color. Also paint the back side of brake wheels and the truck braces (longer rectangles) on the Bristol Board sheet. I used Floquil Rail Brown. The bristol board doesn't take water-based paint very well, you might want to prime it with spray paint or an airbrush, but be very careful to not clog the scribings with paint.
Flip the A1/A2 assembly upside-down (the coupler pockets should show). Mark the centerline of the opening, then go 1/4" to either side. Draw lines that mark either side of the hopper bottom. Then glue the hopper bottom B5 onto A2, making sure that the engraving on the hopper bottom points up. I used thinned carpenter's glue and then added some superglue when everything was in alignment.
Using a square needle file, clean out the holes in the A1/A2 assembly for the A4a/A4b ends. You do not want to have to force these into the square cut holes (they're fragile until the car is assembled.
It's easiest to drill holes for the couplers on the A1/A2 assembly now, before adding anything else. I'm using Micro-Trains N-Scale 1015-1 couplers (as recommended by the Alkem instructions.) These couplers will couple to the scale size Kadee HO couplers. These couplers do sit lower than NMRA standards. (These cars were traditionally run as early 'unit trains' so you normally don't worry much about working couplers on them.) The prototype used hooks and chains, and might have moved to link-and-pin couplers near the end of their service life. Anyway, I'm using a #63 drill bit and Small parts 00-90 x 5/32 screws to hold the couplers in place. Position the coupler on the A1/A2 frame (you can tack it in place with some carpenter glue) and drill the pilot hole for the screws. If you accidentally break through the frame, this is no problem as you can touch up the paint later to hide the damage. I paint the coupler head and 'airhose' Floquil Rail Brown
Glue the pedestals 4xB3 to the sides 2xA3. Put a small glob of tacky glue (carpenter glue or Aileen's Quick Tack glue) in the hole and then insert the Delrin bearing. The bearing should 'snap' into position, but the glob of tacky glue makes sure the bearing stays put when you insert the wheelsets while assembling the car.
Test-fit the sides 2xA3 to the frame A1/A2 assembly. Sand lightly to get a tight fit. Be sure to sand both sides of A3 to keep the wheels aligned, and make sure to preserve the small shoulder on A3.
I've tried a lot of ways to fit the wheels, and here's what I've settled on. Get a piece of scrap wood or styrene. Using a file or razor saw, cut two grooves to hold the axles. The grooves should be 3/4" apart. Then tape the wheelsets to this jig. This keeps the wheelsets aligned. Now bend out the two sides A3. Lay the wheel jig on the car frame. The wheels need to dip into the slot on the frame between the hopper bottom and the sides. Bend the sides A3 back in, making sure the axles align with the Delrin bearings. (Don't glue the A3 pieces to the frame yet.)
Turn the car back over and add the ends A4a and A4b. Make sure the slot on A4b for the brakestaff platform is on the same side as the brakestaff hole, and to the left side of the car as you look at that end. Glue (I use ACC here) the ends A4a and A4b to the sides A3. Peel the tape off the wheelset axles, and slide out the jig. Finally, glue A3 to the A1/A2 frame, and glue A4a/A4b to the A1/A2 frame. At this point, everything should be square and sturdy.
Attach the Side Walls 2xB1. I use a bit of tacky glue to hold them into position, and then apply ACC. Make sure you center the slot in B1 with the matching slot on A3, and the top of B1 is flush with A1. Then attach the end walls 2xB2, making sure the top of B2 is flush with A4a/A4b.
I do the hopper end slope sheets 2xB7 first. Position one so that it lines up on the line on the hopper bottom (glued to the A1/A2 frame). Glue into place. Repeat for the other end sheet. Then apply the side sheets 2xB6. Fill any gaps with thickened ACC. It's best to test-fit these 4 pieces before doing any gluing, to make sure you are comfortable with how they go into position. You may need to lightly sand the side sheets B6 to fit.
Next cut out the "metal" pieces from the cardstock laser-cut panel. The most frustrating pieces are the upper corner brackets. Cut them out, and if you want color the white edges. The trick to accurately bending these pieces is to place an X-Acto knife edge along the back of the fold line, and fold the piece over the knife edge. Do both sides, pinching them to get them as square as you can. Put a small puddle of superglue on the top, side and end where the corner bracket goes, and then apply the piece. When you have all 4 corner brackets in place and glued down square, run a thin bead of ACC over the outside of the bracket, particularly where the bend exposes an edge of the bracket. This keeps the cardstock from delaminating.
Cut out the lower corner brackets. Paint the edges (I actually run a small felt-tip pen along the edges.) Fold each in half so that the angle is slightly sharper than right angles. Apply a small puddle of ACC to the end and side, and glue the bracket in place.
The long skinny cardboard pieces complete the 4-wheel truck assembly. Cut them out and paint the edges. Locate the fold line and fold this back into a reverse L shape. Place a small puddle of ACC on the end of the car frame, and locate the cardboard piece to the end frame. When that glue is dry, fold the cardboard piece over the truck, holding tight with a pin/needle and glue.
I made a jig to drill the end tension rods from scrap styrene. These are located about .025 to either side of the end vertical supports. The drill bit should run just in front of the end panels. I used a piece of scrap end panel to mark its thickness on my jig. If you're building more than 1 or 2 of these cars, the jig will easily pay for the time it takes to make it. Insert a (pre-painted) .010 metal rod into an end tension rod hole. Align it to touch the end panel and make sure it's parallel to the end vertical support. Glue in place (ACC), and trim so that about .010 sticks up above the end. This will simulate an NBW. (I tried to cut these flush and then add NBW castings on top of the rod. That was a recipe in frustration, but of course you can do that, too.) The side tension rod holes are already cut in the side support pieces. Insert the rod, glue and trim.
The NBW castings are easy. Clean out all the pre-drilled holes with a #77 drill, and drill the holes through the lower end brackets into the wood frame. (The NBW shafts actually fit a #78 drill, but they go in easier if the hole is drilled a bit oversize.) Cut an NBW off the sprue, dip into ACC, and stick it into the hole.
I weather the insides of the car with dark gray pastels, which I sand on a wallboard sanding screen to make 'dust'. Drill a #75 hole in the top brace, take care to keep this hole perpendicular to the bottom of the brace. Glue the brace to the top of the car. Then cut a piece of metal rod about .85 long. (I use .016 rod for the brake staff and the hopper release.) Bend the top at an angle, as shown in the instructions. Thread the rod through the brace and into the hole on the hopper floor. Glue in place, trim the rod beneath the hopper floor if necessary, and touch up the paint.
Drill out the hole in the brake platform with a #75 drill (if you use .016 rod, or a #78 if you're using .010 rod). Glue the brake platform on the end, centered between the (left) end of the car and the (leftmost) center end brace. The brake platform has a long and a short indent. The short indent goes into the notch cut into the center end brace. (Note: I've hd problems with the fit of the brake platform and the alignment of the brake staff, and have reported them back to Alkem.)
Touch up the paint as necessary. Dry transfer numbering is a bit
easier to weather off a model, I have not added any
numbering/lettering to my cars. Then apply a final weathering with
pastels, Alcohol & Ink washes, etc. You can seal the weathering and
lettering with Dullcoat or similar sealers. Cut a mask to from scrap
paper to cover the wheelsets when spraying the sides of the car.
