We have a couple of mountain streams/rivers on the layout. Since they will noticeably be going downhill, we’re leaning towards stippled plaster with a gloss varni***opcoat. I suspect other materials would settle to much towards being a flat puddle at the bottom.
What is a realistic looking ‘grade’ for the water before we should break it up with a waterfall or tumble of boulders to drop it down some more height?
We might have to go up to Vermont this spring when the water is really running down the White River and the Winooski and do some surveying [8)]
Any grade, Maureen. Water can go from a backed-up, deep and smooth beaver pond to a torrent on a cascade of rocks. If I were you, I’d consider what you intend to place on both sides of your stream/river, and let that dicate the speed of the water flow. Greater speed means greater grade, and if you have an eroded, deep cut that the current has been gouging for only 500 years, it will be steeper than a wider valley with a planar floor on which the now- slowed river has worked for 10,000 years.
On your layout, I would guess that you’d want a younger, faster torrent in a 20-50’ gorge or re-entrant, so the average grade would be near 2%, with a series of cascades or a single water fall making it about 8-12%
Really fast water will dig its way down to rock in a hurry, so sandy, muddy or swampy banks are out if you plan to model white water. Also, if the grade is extreme and there isn’t a forest or a snow field at the top, it will be down to a trickle or less as soon as the rain stops hitting its watershed. Then, when it does rain again (possibly miles away, but upstream) a wall of water will roar down the watercourse, taking everything in its path on a quick ride to oblivion.
That is why people are told to stay out of dry washes, and why we have to bury the ones who don’t.
We’re setting our foliage season in early spring, consequently the waters will be at a pretty constant high level with snow melt-off and seasonal rains.
mountain streams are typically step/riffle/pool. All of the elevation change occurs in the steps and riffles, while the pools are essentially flat. Much, much research has been done on stream restoration and stream characteristics. i have surveyed several moutain streams of this type, and slopes were around 1.5-3 (rise/run) over BOTH the pools and the riffles. In one example, riffles and steps should account for about 30-50% of the total length.
It has been discussed many many times ad nasum. As a rule real water don’t work, causes corrosion, dissolves scenry, has too much surface tension, leaves lime stains, causes humity, is always empty due to evaporation, and pump noise. It’s great in the garden layout, horrible inside. Fred
Real water doesn’t scale. That full-scale rain ruvulet that is trying to simulate the white water of a challenging kayak run will still look like a rain ruvulet. To make it look like white water, you will have to model white water with something that looks right in the scale being modeled.
I have seen lakes and oceanfront modeled with real water, including one that had ships floating in it. The water wasn’t moving much, and those big golden whales (koi) didn’t add to the realism.
during flood stage (spring), a river/stream will tend to scower the stream bed down to it’s bedrock sending all that dirt and rocks you see far downstream.
as the force of the water begins to subside, the larger boulders will begin to settle, and smaller ones on top of that, then sand, then silt.
these sections of a stream tend to look relatively flat. the grades mentioned above are probably accurate. larger streams seem to be flatter, smaller ones steeper (depending where on the mountain you are).
waterfalls are the result of a rock outcropping that resists erosion; therefore you will have a dropoff instead of a steep gully.
rapids/whitewater is almost always in conjunction with a side canyon meeting the main stream. it is the result of the debris from that side canyon piling up and trying to clog the mainstream. the downside of this pile can be rather steep and churny.
the headwaters of a mountain stream is usually a meadow. before the beaver was killed off, their dams could be found at the bottom of that meadow.
if this tells you all you need to know, then fine, go to vermont and look for what i have been talking about. if you need to know more; consult a geography 101 textbook, and a book on whitewater rafting. john wesley powells diary of his first trip through the colorado is a good read.
life is a beach, then you wrap (an old whitewater saying),
-rrick
If you want a Creek, larger than a mountain stream but smaller than a River, then you want a 1.5-2.5% grade on average. Don’t forget lots of standstone looking rocks. If you do a creek setting then you would have lots of trees on both sides. I have modeled real water and I didn’t have a problem on my HO scale layout. One important rule is make sure the water is moving most of the time and you can add chemicals to the water to prevent alge, lime, and calcium. I hope this helps.
I would counsel against real water in HO – the surface tension of real water does not scale down, so even if the problems of humidity and evaporation can be licked, the tendency of real water to bead up cannot be.
One thing not mentioned so far is that white water often is caused not by the grade of the fall but by its channeling – if a wide river suddenly becomes compacted into a smaller chute, the force of all that water backing up tends to accelerate the water in the narrows, and when that water encounters solid objects (like rocks) and cannot dislodge them, rapids develop. Grade will accentuate this but does not cause it.
It would be the scale speed that would put me off. Real water on a 2% slope on a layout would travel down that slope at a scale speed of over 40 mph, hardly realistic. The surface tension would certainly add to the “goofiness”.
I saw a product for making white water at the show at Macclesfield Staffs. (England) a couple of weeks ago… also a product for plain water that you can re-use if you don’t like the first result.
Amway makes a product that reduces surface tension of water to almost nothing but I can’t remember the name. Live water worked just fine on my HO layout years ago, just use some epoxy or somthing like it to coat the bottom and sides of the river/stream bed.
Tiggr
Any body remember that story about the N scale live steam, where they had to scale down the water by chopping it up?[:D]
On a serious note if the surface tension is so bad, why not add some sort of wetting agent? I have never seen any real water on anything smaller than O scale.