Gary S Wrote:DocWayne - Can durabond be found at the big box hardware stores? Need to find some and run some experiments.

Tom - Thanks for all the thoughts - keep 'em coming!

Gary, I have seen it at our local home depot.
Charlie

Gary,

I ended up using a 3 3/4" wide section of sheet plastic as the lining for my canal bottom. While I don't have the exact photo at hand, I initially wanted a canal that was similar to Lance Mindheim's East Rail layout. However, Lance used only 3/4" foam and I already had 2" glued down to wood. I ended up having to build up the canal bottom with wood sheets to get to the roughly 3/4" depth. Once completed, I used sheet plastic glued to the wood to finish off the canal bottom to obtain the smooth surface for either Envirotex or just a triple step varnish. I then angle cut the foam canal banks and used a drywall mud over that. Once hard, the foam banks and canal bottom base were sealed together. I'm not sure but the gloss varnish may attack exposed foam. Doctor Wayne would know for sure.

Larry

Durabond should be available in any home improvement store or well-stocked lumber yard. It's made here by Canada Gypsum and in the States by U.S. Gypsum, so should be available just about anywhere in North America. The name "Durabond" will be followed by a number, which represents the setting time in minutes. As far as I know, the fastest is Durabond 20, while I use Durabond 90 (I originally started using it to make my landforms, over window screen, and the longer setting time meant that more of it got used before it hardened in the mixing container ). It's available in small boxes, one or two pounds, I think, and also in 33lb. bags.
I mix mine in a plastic tub, meant for use as a cat's litter box, but anything flexible will work - for small amounts, a plastic margarine tub will do. When it starts to set, there's not much that you can do. I let it harden somewhat, then flex the tub to break it free. Broken up with a hammer, the bits make decent talus or riprap fill:

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Larry, I don't use foam on my layout (I may on the second level, though), but the water-based clear urethane should be safe on foam, with the added benefit that it won't yellow over time like most varnishes.

Wayne

Larry, thanks for the idea on how to do the bayou bottom. If I can't make the durabond work, I'll use your method. On that note, I probably should just use that method to start with, as it is simple and straightforward. But I want to experiment with the durabond just to expand my technique.

DocWayne, I'm heading to the HD in just a bit to get some of the dura-bond.

I still haven't figured the best way to do the bridge. Build the whole thing on the workbench and then set it into place, or build it into the layout from the get go.

Hey biL!

In another thread, you had mentioned using foam. I like it alot, especially for doing an area like Houston - basically flat but alot of terrain features that go down instead of up. It is simple enough to cut the terrain features into the foam. As for tools, I use various kitchen knives, a box cutter, and a sheetrock saw for roughing in the terrain, then a stiff wire brush and a sanding block with 60 grit sandpaper for finishing. I also used my table saw to cut the triangle pieces I used for fill at the big bridge. For glueing the foam togehter, I use PL300 glue which works well. Here's a pic of the tools at another bayou crossing I am working on. I've made a good start on the left side.

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The downfall of the foam is that it makes a huge mess. The little particles pile up quickly and are "staticky" in that they stick to everything. I'm going to have to do the major contouring on the entire layout before I do any actual scenery because the foam particles will get all over everything.

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This photo shows the left side 80% complete and alot left to do on the right side. Nothing hard about the technique, except keep a big shop vac handy and vacuum frequently.

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Here is a photo of the big bridge area - the basic foam terrain is completed.

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Just an FYI, the home improvement store probably has other products/brands other then Durabond that may work just as well for this application. You probably don't one that is premixed in a tub but rather a powder that sets up chemically. Simple plaster of paris may work just fine, but I would look for a product that is used for floor leveling.

Gary...That's coming along nicely. I like your foamwork..Nice and neat...

As to the bridge, I would advice you build it on the workbench and set it in place just before you do the urethane "water". It's a real PITA to do it "on site", and you'll probably wind up with quite a few "imperfections".

Kevin, I went to HD today and no Durabond was to be found. I'll have to check around, and check on other products. Any ideas?

Gus, I did a little mock-up to see what strip styrene I would need to do the bridge. When I was working on the foam, I had been using a 36" + leftover DIN rail (electrical component rail) as a mock bridge and measuring tool. It dawned on me that it may serve well as the bridge interior - for strength. The length I have is just right for the bridge. I took a shorter piece of the rail to build the little mock-up.

Some photos - first, the side of the real bridge.

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And the side of the mock-up. Paint and weathering was hastily thrown on just to see if it would do. I only have to model this side of the bridge because the other side is to the backdrop.

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Top of the real bridge.

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Top of mock-up. Not exact, but close enough. Need to add handrails.

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And an end shot showing how it was made. Will try to get by the LHS and get the appropriate styrene to do the whole thing. It is right at 3 feet long.

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Hey! That works! I like it, and think that method will do nicely. It sure will be STURDY too.

I think HD carries the DAP line. The stuff I have been using is called "webpatch 90" or something like that. It is a gypsum based floor leveler and hole filler. I think it is stronger than plaster of paris, and takes longer to set up. I bought it to fill holes in my plaster walls, and it works well for the layout, too. I have mixed it up pretty thin before (about like pancake batter), and it still sets up hard. The thinner you mix it, the longer it takes to set up. But, I suspect if you mix it too thin it will lose strength and be useless.

Your quick weathering looks quite nice!

Gary S Wrote:And the side of the mock-up. Paint and weathering was hastily thrown on just to see if it would do. I only have to model this side of the bridge because the other side is to the backdrop.

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"Hastily"??? Gee, I'd really hate to see how it would turn out if you really took your time...!

That is a fantastic piece of concrete simulation!

Andrew

Tom, I'll be heading back to the real bridge to make sure the measurements are in the ballpark. I guessed on the width and depth of the concrete structure. Also, I need to know the diameter of the support pipes and such. Hopefully have time to do that today.

Kevin, I also hope to get by HD today and look for the stuff you mention.

Andrew, JGl, appreciate the sentiments - I simply put one coat of light gray over the white styrene (it didn't cover completely), then I splashed some brown wash on it. I guess it turned out okay, but will be more precise on the actual bridge, probably use some powders too.

Gary...That mock-up is great..!! Using that rail as a "core" sure is going to make things easier, and it sure will be sturdy.
Guess you had one of those "Why Didn't I Think of That Before..!!" moments. Happens to me all the time...I guess my thinking is slowing down....

I'm a little late to the party here but if you could angle that waterway into the backdrop a little more, it will really help to extend the illusion as well as reduce the awkwardness of having a waterway butt right up against your backdrop.
Doc Wayne did that in this picture and you can see the difference it makes...

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