Now for Doc's Diversion #2 - modelling gum trees for the layout.
First off some limitations.
Most modules have a 200mm high aluminium frame under the baseboard and the track level is approximately 100mm above baseboard. We decided to have a 600mm maximum height for all modules apart from the Incline and Incline top modules (those two top out at 1 metre). This means that any trees on these modules can be no more than about 250mm above baseboard to prevent damage in transit. Now 250mm in 1/43 scale is about a 40' high gum tree. This is a "tiddler". Most gum trees on the Illawarra escarpment now have well over 60 years growth on them and are now well over 100' tall and are probably closer to 150' tall as shown in the first photo of the previous post.
For gum trees we decided to use the "Autumn Joy" variant of sedums, which look like this in the ground
These have been used both here and overseas as the basis for larger model trees. Back in 2012 I attended a modelling clinic by Aussie modeller Dan Pickard on using these to make larger gum trees (up to 3' tall). We decided to use a modified version of Dan's techniques to make smaller gum trees.
The trick is to let the flower heads and leaves die off until fully brown, then harvest the flowerheads to ground level. These are further died over a period of several weeks in a protected sunny spot to evaporate almost all moisture content. This gives a starting point like the brown ones shown in the right of the next photo
These can be a little fragile, but anything that snaps off during handling is either:
(A) - turned into a smaller scrubby tree
(B) - put through a blender to make a base ground cover layer
The green trees at the left of the previous photo are already at Stage 2. You can either use the cheapest spray cans or use an airbrush for then next painting stages
Stage 1 is to waft cheap white acrylic paint up from under the flower canopy
The aim here is to an uneven cover to break up the brown and give a lighter undersurface to the "leaves".
Stage 2 is to spray various greens to the top of the canopy. Again the aim is for variation rather than an even green over the whole of the model tree canopy. You can even use different greens.
If using an airbrush, don't bother cleaning it between greens. The residual colour will help add to the "variation" Also don't worry about any green overspray to the upper "branches". Most gum have a green tinge to the bark just below the leaf canopy.
Here's what Stage 2 looks like when done
The paint also tends to keep the smaller parts of the flowerheads attached. If you are not making gum trees you could be finished here if you wish.
There are some optional stuff you can do here. A light dry brush of either red or yellow across the top of parts of the canopy can give a different variety of gum or a gum tree that is under distress (not growing all that well)
Stage 3 is to represent the seeping gum resin seen on the main branches and trunk of most gum trees. This done with small dobs of burnt umber oil paints around the top of the main branches, then swiped with a turps-landed down the trunk to give the "bleeding" type stain.
Dan's technique also involved making the buttress root on the lower trunk before painting and modelling the and bark shedding around the lower trunk. Because of the lower height we wanted and also because the lower part of the trunks were planned to be hidden by other "scrubby stuff", we reckoned we could get away with a not modelling this part of the gum trees. This enabled us to get a large quantity of gum trees "done" very quickly.
Some of these were stored for anything up to 2 years before the layout got far along enough for them to be planted out on the layout
This completes the gum tree tutorial, Come back for Doc's Diversion #3 when we tackle the "scrubby stuff"