Trees, The search for the Holy Grail

I am old enough to remember when molded plastic trees were acceptable scenic detail on a model railroad layout.  Some adventurous artistic types would actually clip the molded- in flat base and “plant” the things into the scenery.  They still looked like plastic trees.

And then came Jack Work.  In an article in one of the leading model magazines Mr. Work showed how he created trees from balsa wood and sprigs of fern plant. I was deep into model airplanes at the time but sliding toward trains rapidly.  Jack Work’s trees all but convinced me that a layout could be built, elevating the hobby from toy like appearance, to something very artistic.  Balsa was something I understood and the process was simple.  And his trees were beautiful!

Desert Forests, Lawnmowers and a Plan

In the ensuing years much progress has been made in the variety and appearance of commercially available trees.   Still, there are some problems; among them are price and suitability.  I have no argument with the prices charged.  I am sure they are fair for the value received but when you need a thousand of them; things tend to get out of hand.

I model the desert southwest and there is very little available commercially that is suitable for that region. Contrary to popular belief the Sonora desert is not a vast wasteland; rather, it is filled with living things of all description including trees and an occasional forest. And I am always looking for raw materials to follow in Jack Work’s footsteps.

I think Mother Natures materials are the best when you are trying to duplicate Her.  When we lived in the high desert of Southern California and Tucson, Arizona we had Black Walnut trees growing in our yards and the neighborhood.  Nice trees with nuts that didn’t really taste very good. Then we moved too Oregon and lo’ and behold our new home has two prime examples in the side yard.  They must be a highly adaptive species.

Being so close to the ocean, the wind blows and snaps off smaller branches from the upper reaches of the trees.  If I don’t pick them up the lawnmower shoots them out the side at high velocity endangering small children and passing motorists. It didn’t take long for a plan to emerge from the wind blown detritus.

The Hoosegow

I know what you’re thinking, I don’t have a Black Walnut tree in my yard and if the neighbors catch me breaking branches off theirs I’ll get arrested and sent to jail.  I’ll grant you the thought but not the underlying premise of the article. KEEP YOUR EYES OPEN. The technique I’m about to show you might work on something else you have growing right under your feet.

Stuff You Need

Crafting this tree is going to require a supply of  twigs, 60 minute epoxy glue, brass or piano wire, a Zona saw, small diameter drill to match the wire/pin vise, CA adhesive, glass micro spheres, matte medium and a throw away mixing cup.  Maybe some acrylic paints if you are not careful.

The Artsy Part

Here’s where the art part comes in.  From your pile of twigs, pick out a likely looking candidate for your trunk. I was looking for a tree that was dead. I have a scene in mind and so I have a particular looking tree I want to fit there. Fortunately we don’t have to carve any bark into a balsa stick or even paint it (well, almost) it’s already been done for us by Mom Nature. After trunk selection start looking for twigs that will work as limbs or branches.  They should taper gently and have pleasing “branch-like” shapes.  When you are happy with your selections try fitting the branches to the trunk in a way that looks natural.  I find that odd numbers of branches usually look right to me. 3, 5, 7 and so on. Try to make sure that you don’t end up with a “flat” tree. Spread the added on branches and limbs evenly around the circumference of the trunk.

The trunk is second from the left.  The straight “branch” ended up in the discard pile.  The trunk is about 25 feet tall in “O” scale.

These Black Walnut twigs are hollow.  I let them dry for about 6 months. I don’t know if this is a critical step or not but I suspect so.  I don’t think they would bond very well while they are “damp.”  Mix up a small batch of 60 minute epoxy (30 minute will also work, but it won’t be as strong and you obviously don’t have as much time to work). After mixing add in a small amount of glass micro spheres to bring the mixture to the consistency of peanut butter. Cut the branch twigs to fit the contour of the trunk where you want it to go and drill a small hole in the trunk the diameter of the wire you have chosen to use as reinforcement.  I used .024 brass wire because I had it on hand.  That really isn’t big enough and should be at least .040 or thereabouts.  The wire serves as a locator primarily but also reinforcement. Cut off a short length of wire and make a very small bend in one end, small enough that it will fit into the hollow of the cut end of the branch.  The bend is just to make sure the wire won’t pull out of the branch.  Use a spatula or craft stick or similar and force the epoxy into the cut end of the branch until it is full.  Place the bent end of the wire into the epoxy you just put into the branch and then slop a little more onto the end.  Make sure the wire is sticking out of the end of the branch.

A Handy Little Trick

You should have pre-fitted the branch on the trunk to ensure a reasonably close fit so now all you need to do is insert the wire into the pre-drilled hole and allow a little of the epoxy slurry to squeeze out around the joint. It will not be self supporting at this stage so you will have to cradle it with one hand while you work the epoxy around the joint smoothing it out.  (You might be able to set the trunk on your bench and use another object to hold the branch in position while you work).  I have also used one of those fixtures that have alligator clips at the ends and are articulated.  The problem is, once set in position; it must be left until the epoxy has set before moving it again.  Here’s a trick though.  Use a drop of thin CA on the wet epoxy joint and it will set it almost instantly (At least the outer portion).  I think the CA is solidifying the glass spheres. I have found that the joint is still very weak but will give you some flexibility in handling the tree. You can use files to contour the hard set epoxy so don’t panic if you haven’t gotten it all smoothed out.  You want to leave the least amount of epoxy on the trunk that you can while still filling any gaps because you have to paint it.  The twigs are natures perfect colors, the epoxy is stark white.  Make it easy on yourself.  Keep repeating the above instructions until you have the shape and density of branch and limb structure you want. 

Coat the trunk/branch structure with matte medium to preserve it.

About those Micro Spheres

Glass micro spheres are standard boat and aircraft industry fillers for epoxy resin.  They are used to make sanding the hardened epoxy easy and are considered non structural.  The spheres are literally microscopic in size and act like a fluid when handled. I use them here to thicken the resin enough that it won’t just run away.  Sometimes the surrounding wood will literally starve the joint of resin because the content of resin in the mixture is so low and therefore you might want to pre-glue your joints with pure epoxy before you add the slurry to the joint.  I haven’t had a problem with starved joints in this application yet, I think because I’m using the CA in conjunction. But if you do, this might be the reason.

Glass micro spheres are available from Aircraft Spruce and Specialty in Corona, California.  Contact them at www.Aircraftspruce.com as well as many marine supply houses around the country.  It is usually sold by the pound and is very reasonable in price. A pound should last a forest worth.

My dead tree ready for placement. Should be a Raven up there scanning the landscape for road kill.

It's Alive!

Should you be looking for a live, leafy tree, there are many common techniques in use to fill out the basic armature.  Adding more and smaller limbs is the first step.  At some point you can no longer use the wire and epoxy idea and must go to just drilling holes large enough to fit the entire limb into the branches. I use epoxy to bond these joints because it will dry nearly clear and is easy to hide if you are careful.  In some cases it can look like tree sap. I might suggest that if you know you are after this kind of tree from the beginning you might consider taking each branch and building it up separately before attaching it to the trunk.

It would pain me to cover up all those beautiful branches and limbs with gauze and ground foam but that is one way to do it.  I don’t think I can get away with a layout full of dead trees so continued to look for natural answers to the foliage problem.  Jack Work had the right idea back all those years after all.  I spied a fern in the garden the other day that looked about right for green leaves. My wife asked if I was still making trees... as she picked up the potted plant and vanished.  I followed her into her studio and she introduced me to natural preserved flowers.  Actually I already knew about them but she had just gotten a new bunch and figured they might take my mind off the garden.  She was right.  I went right to the German Statice. Limbs with real leaves and a color selection.  The other good thing is they were already preserved and really pretty cheap.  She uses them for flower arrangements but she knew immediately, by the look on my face, she was going to have to hand some over to save the bounty in the garden.

This is German Statice.  It has to be separated from the as delivered state and then cut into appropriate lengths for the application. 

I began experimenting and discovered some things. Just sticking Statice into the branches wasn’t going to cut it.  I had to go out and look at some trees. Mostly, they seem to grow leaves on the outsides of the branches (wherever they can find sunlight) and limbs, and nothing is symmetrical. The problem is, if you want a fairly dense growth of foliage, there isn’t any way to do that without some symmetry in the placement. There simply isn’t room. Use different colors. While GREEN may seem like the thing to do with leaves, they come in virtually all shades of the color wheel. Sometimes on the same tree. 

Try to avoid a bottle brush appearance.  If you end up doing this, try trimming the Statice with scissors to get a better shape before tossing the whole branch out.  I glued the Statice in place with Elmers glue after drilling small holes in the branches.  I used .025 hole size but it depends on what size Statice you are trying to mount.  The Elmers worked fine and dried clear.  Much cheaper than epoxy. A branch assembly gets pretty delicate at about the half way point when you begin to run out of places to hold on while you drill holes.  Just be patient.  Sometimes it is best to put it down and allow the glue to dry and come back to it later. 

When you get the density of foliage you want and all the glue is dry, assemble the branches to the trunk. Don’t forget to foliate any branches on the trunk too.  Done, except for planting, but that’s probably fodder for another article.

The finished tree.  I thought about trimming the width a little but I’ve seen too many like this in the desert spreading out for every ounce of sunlight and drink of water.

This is Tucson, Arizona. 4000 feet elevation. I have no idea of the species of this tree.  I took the photo primarily for the drainage details and the detritus. This is the “model” for the following model tree however. I used acrylic paints to color the trunk and branches and assembled it in the manner described in the article.

And this is how the model turned out.  Not an exact replica but representative.  The next step is to “plant” it and with all that photo help it should gain realism in that process.  It is still possible to “trim” the tree at this point as well as air brushing the colors if you don’t like what you’ve got.  Don’t get too carried away because it can also get worse from here.  Be subtle.  You’ll note that this one has a 1/8” styrene post in the base as a mount pin.  You can glue it in or glue it into the layout base and then be able to remove the tree for “maintenance,” it’s up to you.

A Thousand of Them?

So, what would I do if I had to have a thousand of these trees?  I’d either write a check for a commercial one or model a forest fire!!  It takes me an afternoon to put one of these together but then I work slowly.  I suppose you could devise a production line of some sort but I like the artistic part of making these trees and that would take the fun out of it and probably lower the quality.  They are not, alas, the holy grail of model trees but if you need a few good ones, on the other hand, these are inexpensive and fun to make, and they keep me in good stead with the Chief Gardner around my house!