How-To Aricles
The following How-To articles were submitted by contributors:
Trestle Span
Tree Construction
Amfleet II Coach
Using RTV Molds
The Art Of Applying Decals
How To Apply Ballast
Trestle Span
by John Kraker
Recently, I decided to add a new canyon to my N-scale layout. The plan was to build three separate trestle spans across my new canyon, after I build my new canyon of course! This was my opportunity to create a steel sub-girder trestle 280 feet long and 75 feet tall, plus two main line trestle spans, 200 feet long and 50 feet tall! Not to mention the possibility of some deep-water scenery and maybe a chance to model a boat.
I purchased a supply of 'Micro Engineering' forty and eighty-foot steel sub girders and their "Tall Steel Viaduct" trestle kit. The sub-girders support the long sweeping curve as trains rumble over the canyon. The model looks great and can be built to support trains for any curve, and length. I decided on an arrangement of forty and eighty foot girder spans. It would make an interesting focal point to what was, dull scenery. I know trains are fascinating to watch, even more so when they cross bridges and trestles or appear from and disappear into tunnels.
My N-scale layout, is a tabletop on steroids. It is 800 by 400 feet (2½' x 5') scale. I planned it as a display to run transition era freight trains, rather than operate as a railroad. I have two levels, ten switches and four trestles on the layout, not to mention eighteen power blocks and two throttles. The switches are all hand laid and make the layout possible. I formed the scenery base with polyfoam and fiberglass screen, because of its strength, and lightweight. By design, this layout is subject to moving and whatever related stresses that may bring. The idea was to model detailed rock formations, and water scenes, rather than wooded, timber areas. Enough about my railroad, back to the curved trestles.
To start with, I made a tracing of the track to be spanned. I used freezer paper, shiny side down, and taped it to the track at each end of the span. Next, I traced the top of the rails to be supported by the trestle with a lead pencil and secured that tracing to a wood base with masking tape. This template will be used to shape the curve of the trestle.
I decided on the girder sequence and assembled the girders into modular trestles. When I was done, I had three forty foot spans complete with cross braces and two sets of eighty-foot spans without braces. Two of these eighty-foot girders are shortened to introduce a curve to the trestle. Remember the template is a top view and to build the trestle as you look down on it.
Eventually I wound up with three modules; two four leg, A-frame, steel support towers, and a module of five sub girders that follow the curve of the track. I finished cross bracing the span and painted the hard to reach places in the support towers before cementing them into a module. Once the trestle was completed, I finished painting and weathering details. Now I had to remove my canyon from rolling scenery. I say scenery, but it is basic. No color, everything is white resin cast plastic rocks or tan colored poly foam shell. At first glance, it looks like I modeled snow!
I laid out the canyon area with a felt tip pen, and proceeded to cut the line with a sharp razor knife. The polyfoam was hot glued to the bench work and can be removed easily with a sharp box knife. A characteristic of the polyfoam is how clean and easy it cuts with a sharp blade. With the polyfoam removed, the bench work is exposed. I marked all the braces on the bench work supporting the road, and began the process of removing and designing the new bench work. In this case I was looking at a roadbed, wires, switch motors, bench work and three bare tracks spanning an open hole. I could no longer run trains!
I rebuilt the bench work, and formed the shape of the canyon with polyfoam. I added cast resin rocks in the canyon walls and floor to make it a rugged and dangerous place to be. When finished, these huge rocks will be surrounded by water, and concrete pyramid footings will support the steel towers on the rocks.
Now, with basic scenery complete, I needed to fit the trestle into the canyon. I assembled the support towers right out of the kit. The length of each individual tower support leg would need to be determined allowing it to land on a concrete footing and square up to support the trestle. This is easier than it sounds. I used a 3:1 mixture of sculptamold and lightweight hydrocal to cast eight rectangular blocks ¾" x ¾"x 1 ¾".
When they cured, I used a bench mounted disc sander to shape them into a blunt pyramid. I drilled a 3/16" cavity 1" deep into the blunt end to accept the tower legs. This cavity allows for an adjustment while fitting the trestle into the canyon. Cut the bottom of the tower legs about ½" inch shorter than needed to reach the ground. Next, slip the tower leg into the cavity of the pyramid footing. After checking the fit to the rock, use a file to fit the pyramid base to the rock. I repeated the process with each tower leg.
I was ready to unitize the trestle. Using (extra thick 10-25 sec.) cyanoacrylate glue, I filled the pyramid footing cavity ¼" from the top. Only one footing block should be attached at a time. I positioned the trestle into the canyon; and used tape to secure it to the track that spans the canyon. When you are satisfied the trestle is in the correct position and level, verify the location of the footing and let the glue set up. Repeat this until all eight footings are attached to the support tower legs.
Finally, I used a hobby saw to remove the original track. Micro Engineering Bridge Flex track, was used to replace the standard track across the trestle. The ties are wider and spaced closer and look true to scale 1:160. The trestle kit, model #75-518, comes with guardrails, water barrels and platforms. I am sure this kit is available in HO scale. Use cyanoacrylate glue sparingly to attach the trestle to the bottom of the ties when you finally finish the scenery.
Just two more two hundred-foot spans and I can run trains!
Tree Construction
by Lynn Goblin
Materials
A Tree Trunk Armature
Use anything that looks like a miniature tree of the scale, height, and species you want to model. I prefer sage brush twigs for larger deciduous trees like mature oaks and cottonwoods. For birches and smaller deciduous trees, I use pieces from a decorative broom I bought at a Ben Franklin craft store. You can, of course, use anything that looks like a tree, from yarrow and goldenrod weeds; to herb and tree roots; to manufactured cast metal and plastic armatures.
Ground Foam
Ground foam represents the leaves of the tree. You can certainly use Woodland Scenics ground foam, but I prefer AMSI. (Your favorite hobby store can order AMSI ground foam from Walthers.) I think AMSI ground foam is lighter and fluffier than Woodland Scenics. And, in my opinion, AMSI ground foam colors are more muted and more realistic than Woodland Scenics. For any tree, mix different colors and textures of ground foam. Remember, not all the leaves on a tree (or the sides of an individual leaf) are all exactly the same size and color. I've included a chart of the colors and texture mixes I use.
Woodland Scenics Polyfiber
Used to build up the volume of the tree's foliage.
Fast Drying Clear Spray Enamel or Lacquer
Stiffens the Polyfiber foliage, readying it to accept the ground foam leaves.
Hair Spray
This is the world's cheapest spray adhesive, and is used to glue the ground foam to the Polyfiber. I suppose you could use some other brand, but I prefer Aqua Net Unscented Super Extra Hold in the pretty lavender can. (Can anyone explain why an "unscented" hair spray includes fragrance in its list of ingredients?)
Ground Foam Color and Texture Mixtures
Species | Parts | AMSI Ground Foam Color/Texture | AMSI Catalog Number |
Oak | 1 1 1/4 |
Olive Medium Grass Green Medium Olive Fine |
432 442 431 |
Silver Maple | 1 1/4 1/16 |
Grass Green Medium Grass Green Fine Spruce Fine |
442 441 551 |
Elm | 1 1/4 |
Medium Tree Texture Grass Green Fine |
207 441 |
Ash | 1 1/4 1/8 |
Grass Green Medium Grass Green Fine Yellow Green Fine |
442 441 411 |
Cottonwood | 1 1/2 1/4 |
Olive Medium Eucalyptus Medium Olive Fine |
432 562 431 |
Sycamore | 1 1/2 1/4 |
Gray Green Medium Olive Medium Olive Fine |
472 432 431 |
Poplar | 1 1 |
Spruce Fine Grass Green Fine |
551 441 |
Aspen | 3 1 1 |
Grass Green Fine Spruce Fine Timber Products Meadow Green Course, #102-12 |
441 551 - |
Birch | 1 1 1/2 |
Medium Tree Texture Grass Green Fine Olive Fine |
207 441 431 |
Assembly Instructions
- Prepare the tree trunk armature by trimming it to size. Optionally (but preferably for larger trunks), "peg" the bottom of the trunk with a small wooden dowel or a nail so you have something to stick and glue your tree into your layout.
- Prepare your ground foam mixture, and put a cupful in a shaker container with 1/4" holes.
- With your fingers, tease out a golfball-sized chunk of Polyfiber into a thin sheet.
- Cut out a postage stamp-sized (or smaller) piece of the Polyfiber sheet. With two tweezers, tease out this piece of Polyfiber until it is as thin, as wispy, and as lacy as you can possibly make it.
- Using the tweezers, pull the Polyfiber piece onto an individual branch of the tree. If you are using an armature of a natural material like sage brush, you won't need to glue the Polyfiber to the armature. Natural materials have enough surface texture to grab and hold the Polyfiber in place. Manufactured armatures, however, like those made from cast metal or plastic, might be too slippery, and sometimes need just a touch of some sort of adhesive to hold the Polyfiber.
- Repeat steps 4 and 5 until all of your branches are covered with the Polyfiber. Remember that when you look up through the branches of a real tree you see mostly blue sky. So on your model tree, leave plenty of empty space, and maybe a "dead" branch or two.
- Fast path alternative: Instead of cutting, teasing, and pulling small pieces of Polyfiber onto your tree armature, take the sheet of Polyfiber from step 3 and drape it over the entire tree. Tease the Polyfiber around the branches.
- Please use a spray booth or an appropriately rated mask or respirator during this step! (I use both.) Spray the Polyfiber foliage base with clear enamel or lacquer. Set aside and let dry for at least 15 minutes. This will ensure that the Polyfiber sticks to the armature. The enamel or lacquer also stiffens the Polyfiber, thus preparing the fiber to receive the ground foam.
- Liberally spray the Polyfiber foliage base with hair spray, avoiding, if possible, those parts of the trunk and branches you don't want covered with ground foam. Immediately go to the next step!
- Turn your tree upside down and sprinkle the ground foam mixture onto the still-wet-with-hair-spray Polyfiber. Cover the bottom side of the foliage base on each branch. Then, turn your tree right-side up and finish sprinkling the foam mixture onto the tree. Stop sprinkling the ground foam just as the Polyfiber starts to "disappear."
- Suggestion: Sprinkle the ground foam over a grocery bag or some newspaper. The "over sprinkle" can be reused on other trees.
- Tap off the extra ground foam and lightly spray with hair spray. Let dry for at least 15 minutes.
- Using your scissors, trim off any stray Polyfiber strands.
- Lightly spray one last time with hair spray.
- Plant, and stand back and marvel at your creation!
Tips
- I can't stress enough how important it is to tease out the Polyfiber as much as you possibly can. Your goal should be to build a tree that you can see through.
- Vary the color and texture of your ground foam mixtures, certainly from species to species, but also from tree to tree.
- Expect to spend a lot of time with each tree. Although relatively simple to do, this technique can require up to an hour per tree. Putting the Polyfiber on the armature is time consuming and, frankly, boring. But sprinkling on the ground foam is quick, fun, and rewarding! That's when your tree really takes on life!
- If you're making a bunch of trees all at once, try building them all one step at a time. For example, prepare all the trunks, then fiber all the armatures, and so on.
- And one last reminder: please use a spray booth or a respirator when using spray enamel or lacquer!
Amfleet II Coach
by Tommy Bates
The ends of the Walthers cars come out. They're stuck with a little glue, just snap 'em out on one end only; doesn't matter which.
Next, carefully start cutting with pliers. Because the shell is a little flimsy, I found that an X-acto knife did not work well. On the sides, the edge of the vestibule door is like your cutting guide, but only use the pliers to cut away the large parts.
Once you get close, use an assortment of files and X-acto knives to finish and have a straight cut. The end piece that you removed should fit back together, although it was necessary in addition to gluing it, to use body putty to fill in the edges where you cut.
As for the underframe , cut it into two and then make another cut to remove enough of the under frame so that it will reassemble to the modified and shortened body. In addition to gluing the under frame together, a car weight also helped splice the two pieces together and made it a little stronger, and then use body putty to fill the cracks if it bothers you.
Now, unless your satisfied with the windows, punch out the tinted insert. If your windows will be transparent, then go ahead and enlarge them. If not just leave them the way they are. The trick I used for creating enlarged windows was to cut out enough windows (I think 18 per car; 9 each side) out of photo negatives. The window size should be the same as a Superliner window.
To get photo negatives, you can have a photo company process the NEGATIVES ONLY of an unexposed roll of film to get light brown, transparent windows that you can see through. If you want more darker windows, pull all the film out of the canister as much you can and expose it to a source of light. When the film is processed, you will get very dark, glossy negatives, but they are dark enough that you cannot see through them.
I cut enough Superliner size windows from the negatives and applied them to the model in the appropriate manner. BTW: it is important to paint the shell first before applying the windows! I even decaled before adding the windows- it's best unless you want to do all that pain in the ass cutting to fit the decals around the windows.
Since the darker negatives are non-transparent, you dont have to worry about trimming anything (such as decals) for the original windows, just apply the decals right over the window opens, because the new, larger windows will cover the depression in the decal anyway. Let me know if any parts seemed unclear.
Using RTV Molds
by Tony Segro
RTV (Room Temperature Vulcanized) Rubber molds are simple to make and can allow you to cast several identical detail castings for your scratchbuilt models. RTV Rubber is a two-part mixture made by Dow-Corning. It comes in various styles. I find 3110 the easiest to use because it does not require an expensive vacuum pump to decompress air bubbles.
Take the detail you wish to copy, called a MASTER, and glue it into a cardboard or styrene box with dimensions about one inch longer than the master by one inch wider than the master. When placing the master in the box, you will have 1/2" on all sides. The height of the box should be a minimum 1/4" higher than the master (the master should be 1/4" below the top of the box.
To find out exactly how much RTV it will take to make the mold (I don't like to waste any RTV because it is a bit expensive), I fill the box to the top with salt, or some other granulated substance. I then pour the salt into a clear plastic cup, and level it off. With a black marker, I mark a line around the cup at the height of the salt. I then return the salt to its container.
In the cup, I slowly pour the liquid rubber until it's just about to the line. I then take some of the catalyst (it's in a tube with the liquid rubber mixture) on a popcicle stick. Read the directions on the tube for how much to use. It should be a 10:1 ratio of rubber to catalyst.
Slowly stir the catalyst into the rubber until the two are blended well (about 2 minutes). Air bubbles will surface as you stir. Trickle the rubber mixture into the box slowly, trying to fill the corners first. Then, slowly fill the box with the rubber. The master should be totally covered by the rubber. THE SLOWER YOU POUR, THE FEWER AIR BUBBLES THERE WILL BE.
After pouring, the box should be just about full. Gently tap the box on a flat surface for 3-5 minutes to get rid of air bubbles. Another way to eliminate the bubbles would be to use the warm air from a blow dryer. Any trapped air bubbles will ruin your mold as they will destroy the details.
Once the air bubbles stop surfacing, let the box sit on a flat surface for 24 hours. To check to see if it hardened after 24 hours, take a toothpick and gently rub it over the smooth, rubber surface. If it's still liquidy, let it sit another several hours, checking it from time to time.
Once the rubber is hardened, cut down the sides of the box and remove it slowly and carefully from the master detail, and powder it with baby powder.
The mold, if handled with care (cleaned with dish detergent, blow dried and powdered between each use), will last for an extremely long time without losing detail. You can use Alumilite (2 part liquid plastic) or a type of plaster or polyurethane to cast your copies.
The Art of Applying Decals
by Joe Czapiga
The art of applying thin film wet decals to models is one that only gets better with practice. If at first you don't succeed, try and try again. Patience and persistency will allow you to produce models that look as good, if not better than the models in all your favorite magazines. I am sure many people have many different methods of applying decals successfully. The methods I use were mostly developed by trial and error and lots of query at every hobby shop I've gone to.
As for the myth that you won't be able to produce a great looking model until you have 20 years of experience, forget it. I have always loved trains, but I have only been a modeler for about three years. It has only been about one year since I decided to try custom painting and decaling.
If you have never tried to apply thin film decals before, your first experience will probably be one of impatience and frustration. These decals are very delicate and can be ruined very easily. For your first project, I recommend practicing with simple decal jobs which do not require strict alignment in order to look good.
Usually, rolling stock such as box cars (smooth sided), covered hoppers, etc. have pretty simple paint schemes. Many are only one or two colors. Stay away from thin, long, longitudinal lines on the long hood of a locomotive such as the GATX units you see on the St. Lawrence & Atlantic. Even the most experienced modeler can have difficulties with these.
Applying decals also requires some special tools. What I mean by special tools is you probably have them in your hobby tool box but might not think they would be used to apply decals. Here is a list of tools & supplies I have within arms reach when I apply decals to a model:
- A shallow bowl filled about 1/2 way with luke warm water.
- Scissors (preferably small to medium size).
- Hobby knife.
- Two small detailing paint brushes.
- Solvaset (decal setting fluid).
- Bath tissue or Kleenex (NOT paper towels).
- Two No.2 pencils with an eraser.
- Cross locking tweezers.
- Decals.
- Prototype photos (if you have any).
After you have all these items together you're ready to apply decals. If by now you don't have a model to decal, it would probably be a good time to get one. Decals stick the easiest to glossy finishes. They will stick to dull finishes just as well but are much harder to work with on this type of surface. The decals don't slide into place as easily making it much more critical to place them almost exactly where they need to be with little or no adjustment. Because of this it may be more difficult to remove any air bubbles under the decal. First time decalers should choose something with a glossy finish. Glossy paint or clear gloss coat work equally well.
The first thing to do is to get all your tools listed above and your model and set them up on a clean flat surface with good lighting. Make sure you have plenty of room to spread out your tools so they can be easily reached if you need them quickly. Make sure you wash your hands thoroughly before you start.
Next, choose a decal you would like to apply. At this step it is a good idea to know what type of decal you are about to apply. I am familiar of two different types; Type One is printed on a plain old sheet of decal paper, and Type Two has each individual decal printed on decal film which is then applied to the paper backing.
With Type One you must trim as close as possible to the design of the decal you are going to apply, otherwise the excess may become visible when it dries on the model. Type Two decals can be cut as close or as far away from the design as you like. Whichever type you have, cut the selected decal from the sheet and place it on the model where you would like it to be. Lining things up and visualizing what you want to do before you put the decal in the water is very important. Once you put the decal in the water, things can get difficult.
Third, you will want to wet the area where the decal will sit with some of the warm water. Use your paintbrush for this. Wetting this area will help reduce air bubbles under the decal and help you maneuver the decal into place. When you become more experienced at applying decals, you may use the Solvaset to wet the area instead of water. There is an advantage and a disadvantage to using Solvaset instead of water.
Using water allows you unlimited time in adjusting and lining up your decal where you would like it, but does not eliminate air bubbles under the decal (it only helps to minimize). Using Solvaset eliminates air bubbles almost entirely, BUT, and I stress BUT, you only have about 20 seconds (maximum) before the Solvaset softens the decal making it almost impossible to maneuver.
Now you may take your decal and place it in the water. I usually hold the decal with cross-locking tweezers as I place it in the water. Sometimes it is difficult to retrieve a decal, especially if it is small, from the bowl of water if you just toss it in. After about 15-30 seconds you should be able to move the decal around on the paper backing. If not put it back in the water for about 10 seconds more.
Once you can move it, place the decal and paper backing (do not remove the decal from the backing yet) on your index finger. Remove the cross-lock tweezers, slide the decal just a tiny bit to the opposite side of the hand your tweezers are in, and re-apply the tweezers to the backing paper ONLY. Now you have the backing paper and a decal which is free to slide in any direction you would like.
Position the model so you can place the edge of the decal on the model. Then hold that edge to the model with your paintbrush and slide the decal paper backing away. Try to keep the decal as close to the model as possible while pulling the backing paper.
Once you have removed the backing paper, use your paintbrush to position the decal. Pushing on the edges of the decal is most effective. You may also use the eraser of a No.2 Pencil to move the decal around. Remember, if you used Solvaset instead of water to wet your surface, you must work fast.
Position the decal where you would like it to be. Try to push out any air bubbles under the decal by rolling the bristles of the paintbrush to the outer edge of the decal. After all of the air bubbles have been removed, very gently brush on Solvaset sparingly while not moving the position of the decal. Be sure to cover the whole decal especially around the edges. The Solvaset usually works its way under the decal pretty good.
At this point you should put the model down and let this decal dry. If you are confident enough you may apply more decals, but remember the decal you just applied is very fragile. If you touch it before it dries you will probably ruin it.
Sometimes the Solvaset makes the decal appear as if it is wrinkling up. This is normal. The decal will set flat on the model when it dries. When the decal does wrinkle, keep an eye on it. If it appears the wrinkle is not coming out on its own you may have to get those wrinkles out. Before you attempt to move the decal, carefully brush on some warm water (no more than a 1/2 drop or so).Carefully use your paint brush to drag the decal from the outer edges away from the center of the wrinkled area. The decal's position on the model should not be compromised by this. You should only have to move part of the decal a distance equal to the thickness of the wrinkle.
After the decal dries, inspect it for air bubbles that you missed the first time. If there are any, make a tiny hole in the decal with a pin and brush on some Solvaset making sure it gets in the hole and under the decal. The Solvaset will soften the decal again and make it set to the surface of the model. Since the decal is soft and wet again you should allow it to dry. Drying times may vary. I recommend at least an hour or so. Usually I will let them dry about an hour before I apply another decal unless I know I can do it without disturbing the one I just applied.
Finally, I recommend a gloss or dull coat be applied by air brush or spray can to the model after all the decals have been applied and have dried. This will help "hide" the decal edges and make your model look realistic. After you have practiced these methods a few times and develop some of your own, you will be able to produce models of superior quality.
How To Apply Ballast
Basic Information
Many people ask me how to apply ballast even if they have done it before. They must not be satisfied how theirs turned out so the very best way will be presented here. I use several techniques and each one has an advantage over the other as the desired effects or the situations vary. A neat looking roadbed is a major accomplishment and very satisfying to look at when finished.
The best rule of thumb is to apply it slowly and carefully. Each step is very important to follow because "now", you will be in control of its finished appearance. It takes extra work to "fix" areas where the ballast is to thick and mounded up. This problem is going to happen in places where we didn't mean too anyway. I'll show you how to "re-groom" a disaster. Study all the techniques we have introduced in the text and then evaluate the various options presented.
Getting Started
Cut a corner off the package. Sprinkle it right from the package directly to the roadbed. The four mil Poly package is ridged and will not collapse when you work with it. Keep the opening about four inches or less from your work. Shake the bag back and fourth and parallel to the roadbed as you tip it. Apply only enough to cover the area. You can always add some more later and you will have to anyway because of random bare spots after wetting and gluing. If you get to much on the ties, (knuckle head), stop!
Grooming Around The Ties
Use a stiff brush to move the extra down the line. There will still be a few grains on the ties and rail flanges. Tap the rail tops with the brush handle to bounce these stubborn particles away. Your can then wipe the tie tops with your finger tip to remove the rest.
For Track Without Roadbed
This applies to all track without roadbed such as industrial sidings, yards or even mainlines. If you want the ballast to be perfectly flat beyond the ties, lift the package up a little higher while sprinkling. This will disperse the grains further and help eliminate mounds. A piece of paper can be used as a guard where the ballast line stops against other scenery.
Fixes
A big mound of ballast maybe to big too feather out so, just scoop it up with a spoon and remove it. Those little unwanted mounds occur in places where I don't want them. I use a small piece of news paper and drag it over the mound back and forth to feather it out. What ever you use, it will leave a mark. Your fingers will leave prints and a brush will leave furrows. The best way to erase these marks is by tapping the bench work from below with a hammer to flatten them out.
Ballasting With Roadbed
Split cork roadbed always has a rough burr that needs to be sanded smooth. Other roadbeds such as Homosote need to have the sharp edges sanded round. If the track is not centered on the roadbed, plan on using more ballast to make it even from side to side.
Start ballasting from the bench work up to the top of the roadbed first. This allows the lower grains to become a foundation for the grains that pile up on top. If you ballast from the top down, the rocks pick up speed on the sloped roadbed and make a mess as they bounce all over. Now you can ballast around the ties as we mentioned before.
Grooming
Wherever the ballast is uneven along the sloped bank, drag a piece of news paper over it to grade it. You may even have to drag material from bottom to the top. Sprinkle more ballast only to even out your repair marks.
Ballasting With Two Or More Colors
Western railroads are notorious for re-ballasting with different colors over the years. You can see different color bands in the roadbed as a result of this. Begin by applying an earth product on the bench work up to both sides of the roadbed. Start applying the lowest color along the base of the roadbed and cover it up to the top edge of the slope. Apply the second color around the ties but don't let it spill down the slope and mix into the other ballast. Three colors can be done the same way, however a taller roadbed such as Homosote makes it easier.
etting
All dry scenery material should be wetted before bonding. We add a few drops of liquid dish soap to a quart of water as a dispersant. This helps the water flow thought the material evenly and thoroughly. The material needs to get wet right down to the base. The wetting operation prepares the material for accepting the bonding material.
Some modelers prefer to use rubbing alcohol or photo flow as a wetting agent because they are of a lower viscosity than water. This means that it's less likely to leave "pot holes" in the dry ballast.
How to wet
Eye Dropper Method.
It is very easy to disturb the ballast with even a drop of water.
- Start wetting the ballast by dropping water on the ties. The water will slowly run off them and into the ballast. You will see the water spread out into the dry ballast
- Now you can drop water where ever the ballast is already wet. Do about a foot of track until all the ballast is wet.
- Use a spray bottle that gives a fine mist. Hold the nozzle about a foot away and start spraying in a sweeping motion. The one foot distance allows the sprayer to disperse the water into a mist without blasting the dry ballast.
- Some nozzles will sputter water drops just as you pull the trigger. Start the spray action where the ballast is already wet and then move it over the dry ballast.
- Continue spraying until the ballast is soaked.
Before You Bond It
Take a good look at the wet ballast. If you are not satisfied with the neatness of it, stop! Allow it to dry out and then "fix it" while you can.
Bonding Materials
White Glue
One part white glue and three parts water is the most economical type of bonding agent. I mix up a batch in a pint bottle and use it for all scenery work. It sets up very hard and will even amplify the train wheel sounds to the bench work. Have you ever heard a quiet train? White glue can be softened by wetting the area with water. Now you can make any changes with the track work if necessary later on.
Matte Medium
Matte Medium can be purchased in art supply stores. It is more water resistant that white glue, however, the cost can be several times more. Some modelers use it because they want less "sound board" effect while running trains.
Granular Glue
Some modelers like to pre-mix dry glue into the ballast. All you have to do is spread it in place and then wet it. "Weldwood" powdered glue will cure "water proof". One disadvantage is that the ballast may leave depressions as the glue dissolves while wetting. The major problem is that once you "wet" it, you can't fix it anymore.
Bonding
The same bonding method is used for "white glue" or "matte medium". Wet ballast is fairly stable and is not disturbed like dry ballast during the bonding process. Spray bottles get glue on the rails and make clean up more difficult. I have found that an eye dropper is a safer tool to use for "N" & "HO" Fine ballast. Start out by dripping over the ties and then out to the edges of the roadbed. You can see the milky color from the glue seep into the wetted ballast. This is how you can tell where you need to apply more bonding agent.
HO Mainline and Large Scale ballast is bigger rock so you can apply the bonding agent faster. An eye dropper is still the safer tool to avoid making those "pot holes." You can use a 6 or 12 oz. bottle with a small extended tip and just stream the glue on between the ties. Now you can finish the sloped area the same way.
Touch Up
Once the ballast is wet, look at it for excessive mounds. They will still be there when it dries and hard to fix. Use your finger to pat it smooth and then leave it alone to dry. Hopefully this problem exist in only a few places at the most because you don't want the finished job appearing with a lot of finger prints. Let it dry and then lightly scrape away the loose grains sticking out and then re-ballast the area lightly and re-bond.