Site Prep

The scene was almost ready for water, but there were a few additional tasks to be done.

To help impart some apparent depth to the future stream, I airbrushed some Floquil Railroad Tie Brown into the creek bed.  I did this while painting some nearby flex track.  Darker colors can give the appearance of deeper water when viewed from above.  It's important to avoid hard edges so an airbrush is ideal.

Also, the creek bed slopes somewhat, and the intended water material tends to flow downhill if not restrained.  Adding "dams" at the location of future rapids helps to hold the "water" so it doesn't migrate too far downstream before setting.  I've tried several ways to do this, but here I used some clear caulk (this was Powergrab clear adhesive caulk; other types should work, although I'm not sure I'd trust pure silicone since later materials may not stick to it well).  Acrylic gel medium is one alternative, but is pretty much like acrylic caulk to work with in this application, and is much more expensive.

Note that so far I've kept most of the vegetation away from the future stream banks until after the water has been added.  The reason for that will become obvious later.

First Pour

For water, I used tried 'n' true epoxy resin.  I've tried several brands which all work interchangeably, including Enviro Tex, Crystal Sheen and this one, "Amazing Clear Cast."  It was the brand available at Hobby Lobby where I had 40% off coupons handy.

One thing I've done for ensuring epoxy resin sets up is to make sure you use a bit more (like 1/2% more) "part b" / hardener than "part a" / resin.  All the instructions seem to say to mix 50/50, but if you look at the containers you'll probably see more in the part b - I'm assuming this isn't an accident.  I've never had a batch fail to set properly with extra hardener.  Try for a precise 50/50 mix and you may find yourself with something that won't set up, I know I did when learning to use this stuff.  If temperatures are warm enough (see the directions) and you use extra hardener, every batch should set up perfectly within a couple days.  *CAUTION - SEE NOTE BELOW*

For mixing, I used the rigid plastic containers from some Hillshire Farms lunch meat, cleaned in the dishwasher first.  Any disposable plastic container should work provided it's tough enough not to melt from heat as the resin left in it starts to set.  There's just enough heat to affect flimsy plastic.

Here's the first resin pour.  Since I wanted the creek to look greenish and somewhat muddy, I added some Testors olive drab enamel military paint.  A few drops are plenty.  Clear resin is rarely realistic, so look at prototype photos for examples of color.  Other Testors paints of use include Dark Tan and Dark Green, and Floquil Pullman Green works great for other parts of my region.

The track was taped as a precaution.  Resin that drips into the ground elsewhere can be covered up readily, but I didn't want any stray drops ruining the track weathering or ballast.  Also note the newspapers on the floor to protect the carpet.  Resin will find a way to leak through any available hole in your scenery, so take care to cover everything below it.  Fortunately I had no leaks.

This is the opposite end of the scene.  I taped off the ends of the water course, then backed up the tape with some Homasote scraps clamped in place.  Homasote is soft enough to deform over irregularities in the fascia and prevent stray resin from going anywhere.

If you get resin on the carpet or your clothes, Goo Gone will take it out as long as the resin hasn't cured.

*NOTE* As per later posts from Alan ("LK&O"), who is a subject matter expert on the chemistry of such products due to his training and job experience, we can't automatically assume extra hardener should be used due to the chemical processes involved in manufacture.  Alan suggests only adding more hardener if a trial batch fails to set when mixed per manufacturer recommendations.

Second Pour

I allowed the initial batch of resin to set up for about three days before applying the next.  I mixed both batches the same, including color.  Preventing too much color in the first batch keeps the finished creek from getting too opaque later, as the opacity builds up.  The first layer was about 1/8" deep, and the second came out somewhat less.

Here's the upstream end of the second pour.  After the first one set up, I noted a few places where I could anticipate the next one flowing too much over some elevation changes, so I built up some taller dams with the caulk as needed first.  I let the caulk dry for a full day before pouring more resin.

Compare to the previous photos for how much more intense the color looks with the additional thickness of resin.

Downstream again.  Things are starting to look good and muddy.

One annoying characteristic of the resin is how it creeps around the edges.  It can get into surrounding scenery materials, and soak into something like sand for quite some distance.  You can see where it's oozed in these photos.  Not to worry, we take care of that next.

Rapids and Touch Up

Whenever water flows sharply downhill, or encounters an obstacle, the resulting turbulence can create a need fo modeling white water.  Cedar Creek has some rapids, but no large waterfalls.  The major rapids are just a build up of caulk and the resin that flowed over it, plus some paint.

Using a pile of prototype photos, I added whitewater as appropriate using acrylic paint.  Acrylic builds up in semi-translucent layers, which is just what we want.  Some areas get very little paint, almost as a wash, others get more and still more until the white covers everything.

Also at this stage, I dry brush rock and dirt colors onto any areas where the resin crept out of bounds.  As part of my normal scenery finishing, I already used such paint on the rocks anyway, so the new coat blended right in.  I eliminated shine around the banks, and also on large rocks emerging above the water surface in mid stream.

Farther down, the elevation changes are less abrupt so there's less white to add.

Catch Some Waves

As it sets up naturally, epoxy produces a glassy, smooth surface that doesn't represent moving water well.  I don't think it looks quite right for anything but truly stagnant places.  Trying to texture the resin as it sets is a losing proposition in most circumstances.  Fortunately, there are easier ways to handle it.

I like using gloss Mod Podge for ripples.  Acrylic gloss medium will also work, but it's less viscous and more prone to filling with bubbles as it's applied.  Whichever you like is probably fine.  A disposable acid brush works great as an applicator.

I cover nearly the entire surface of the resin with Mod Podge.  Ripple patterns can vary depending on stream flow, and brush marks look appropriate around rapids, so adapt the application technique as you go.

So how does all this turn out?  I'll have to keep you in suspense until I get some more done and photographed.

Modeling water

Just what I needed...

Threads like these really help to keep me involved and inspired.  My modeling motivation has been at an all time low lately and reading this thread has reminded me why I became hooked in the first place.  Besides the interest in trains, creating that ultra realistic scene!

Some great tips and pictures here and a great tutorial.

Thanks as always for the inspiration!

Looks Good

Looks good so far, Rob. I'm anxious to see how it looks like once the Mod Podge had dried.

Tom Patterson

Re: Tom

Me too!  I haven't checked since I took the final photo last night.

very nice job Rob!

Not only is it  coming out nicely, thanks for sharing the steps.  One of these times you should send it in as an article instead of posting, you could use the MRH article dollars for even more work to share

Steve

Excuse Me Master

Rob, I have said it before and I will say it again, I hold you and your modeling skills in the highest regard. I never thought I would see the day where I rebuke something you recommend. But alas, that day has arrived. For you have wandered into my area of expertise.

Changing the mixing ratio of any epoxy product is a bad idea. While I cannot explain the root reason for your experiences with epoxy that will not cure, I can definitively say that adding additional part B is not a good idea. There is sound chemistry for this.

Consumer epoxy products are the reaction of an epoxide with an amine in a balanced mixture. Once the polymerization completes (all epoxides reacted), any leftover amine will remain free in the epoxy. Unreacted amines cause yellowing.

As a proof statement of what I say try this. Mix epoxy in a wildly out of balance ratio, say 1:5. Once the epoxy is no longer tacky paint it with a thin coat of bright white paint. Watch what happens to the white over a period of a few days. You will see the white paint turn yellow. You are witnessing the yellowing power of amines. The amine was leftover in the epoxy because of the incorrect mixing ratio. It was free to migrate into the white paint because it was not part of the polymerized epoxy lattice. Once in the white paint the amine reacted with the pigment. Result - white paint turns yellow. Amines will yellow over time even without something else to react with. I suggest the white paint experiment because the results are quick.

Chemistry aside, I am liking the water pour on the 8th Sub.

Yep another fine example Rob...

Awesome tutorial ....

Re: Alan

You raise some valid questions, which I'll attempt to address.  You know the chemistry of the materials, and I'm speaking but from experience.

It was merely as I noted earlier.  Batches measured precisely 50/50 that refused to cure.  Some worked, some didn't.  I noticed at the time (close to 30 years ago) that the product always came with a bit more part B, so I made sure to add just a bit more to every batch after a time, and haven't had one that has given me trouble since.  The problem wasn't bad product, as merely adding about 1/2% more part B worked with the same material that stayed tacky at 50/50.  Everyone in my work group has been mixing epoxy resin this same way for about the same time, and all of our many batches have set up since, with no evidence at all of yellowing over time.  We've quite literally used gallon upon gallon of the stuff on different layouts and modules, with predictable results. 

We're taking about a marginal change to the ratio, less than a percent.  Believe me, I respect the chemistry side of this, but after all these years if I noticed the slightest issue with the process I use I wouldn't still be doing it.  I just figured maybe the available product could be a bit touchy, as with many other consumer goods that don't quite work as intended every time.  I don't claim to really know for certain.

Now if this scene goes to crap with time, or is befallen by some catastrophe due to the epoxy, you have full permission to point and laugh.

Looks Great!

I always look forward to seeing posts from Rob! His layout is one of the nicest out there!

I promise I would never point and laugh

Rob, my concern was that with your recognized stature in the community a reader may interpret your message as whenever I use any epoxy I should add additional B component. That would be a disservice to the reader. I suspect the product(s) you have used are manufactured to less than exacting standards hence your experience. Perhaps better advice is to test the material first mixed per manufacturer's recommendation. If unsatisfactory drying is observed then vary the mixing ratio by 1/2% in second test. A quality epoxy product will cure properly at the recommended mixing ratio. We manufacture thousands of gallons of epoxy products yearly. Every batch is QC'ed per our mixing/application recommendations. They harden properly or the batch gets discarded. As you have noticed only a small change in the mixing ratio greatly affected the final product. Imagine someone using an epoxy that actually does work properly at 50/50. What happens when they add additional part B? Amines gone wild.

My response was meant to enlighten you to the possible ramifications of your mixing actions. You may solve one problem while unknowingly creating another.

Unlikely, but there is another possibility that would explain your experience and the different fill levels in the containers. Is it possible the product you are using is intended to be mixed by weight rather than volume? I know that sounds crazy for a consumer product but we do manufacture some specialized epoxy products where the mixing ratio is specified by weight. Another possibility that would explain your results but not the unequal fill levels might be the A and B components are not fully homogenous prior to mixing.

Glad to hear it works for you Rob. But for the other readers, don't automatically add more B component to your epoxy because you read it on a forum.

Precautions

Just to ensure everybody gets the word, I edited the initial post on mixing ratios to refer readers to Alan's comments.

Reflecting on the Progress

Given that I'm modeling the 70s, I was unsure if there wasn't another Love Canal situation brewing in the train room from all the chemical processes at work, so I re-entered to check on the Mod Podge only with great trepidation.

Last night I only completed Mod Podge as far as the bridge seen here.  I intentionally left the remainder of the surface as-is to illustrate the contrast.  The section with the ripples looks to me like moving water, while the rest just doesn't.  Also note how the glassy plain resin can reflect hard edges of room features, like the top of a backdrop, light fixtures, and so on.  The ripples diffuse such unrealistic reflections so they don't intrude on the scene.

You nailed it...

Thanks Jas

I'll see if I can finish up the rest tonight.  Shouldn't take more than a few minutes.

Fantastic!

What more can I say?

Very nice

Looks great, Rob- turned out extremely well! 

Tom Patterson

Thanks, Rob

Rob,

This post of yours is very nice, and that's saying something as all of your post are nice!  The "how to" with the accompanying pictures are very helpful.  I'm going to cut and paste this thread into a PDF and add it to my other very helpful docs.  Thanks and please keep it coming!

Nice job!

Rob,

Great article! Well done!

Thank you,

Jay