# Buttressed tree, my way



## Kalle (May 14, 2010)

Thought I would do a quick write up on how I've made my fake buttressed tree for my 340 gallon tank. 

I decided early I wanted a big buttressed tree trunk in the corner of my viv. I spent hours and hours just browsing pictures of buttress roots from all over the world. One day it kind of hit me. The trunks and roots had a very draped fabric look to them. Like the bark and outer trunk consisted out of a loose draped fabric. The wrinkled bark where it twisted. The cross section of the trunk looking like a heavy curtain. And then I knew how I would try and construct my fake tree. Fabric! 










This technique is not new but I haven't seen it applied to fake trees before. You basically drench a piece of fabric in a cement, concrete or hypertufa mix and hang it up to dry. Fabric formed concrete is also used when casting to get organic soft shapes. Google "fabric formed concrete" and you'll see some cool things! 

First I did some rough of the tree's cross section up where it will meet the top of the viv. I wanted some form of rigid shape to hang the fabric from that would give it its initial shape. I used some rope and thick aluminum wire for this. Looking back I don't really know why I used the rope, you certainly don't need it. 



















I also did some small scale experiments using a piece of fleece blanket that I drenched in a runny cement mix. They dried super hard and very light. 

















Next step was to make a stand from where I could hang the fabric to dry. I had a few styrofoam sheets that I put together for this. I needed to be able to lower the fabric down into the cement mix and then pull it up and secure it so I made a series of holes through the top and tied string to the "armature" and attached fabric. 



























I made a mix of pure portland cement and water. Had a very runny consistency. I put in the fabric and made sure it was soaked through everywhere before pulling it up and hanging it. It was very heavy at this point but draped beautifully in the shape I wanted. 



















I let this harden for about 24 hours before moving on to the next step, the actual buttress roots. At this point all I had was the trunk. 

I decided to use some aquarium water hose to make the shape and support for the roots. The hose bends very nicely in soft bends that looks very natural. I used wooden skewers to hold the hose in place to the styrofoam and screwed the hose to the trunk together with some hot glue. 










Then it was just a matter of fitting and cutting out pieces of fabric to drape over the hose. 



















Then I drenched those pieces and hung them over the hose. Tried to straighten out some wrinkles I didn't like. The blanket I used wasn't very stretchy so it wrinkled very easily when you forced it into some shapes. If I'd do this again I would try and find a more stretch fabric. 










After hardening it looked like this. It was very hard and stiff but surprisingly light. 

















I continued the same process for the last two roots.














































After it had hardened I cut it down to the final height using a hacksaw blade. You can see how thin the wall is. 









At this point it didn't really have a nice and natural texture to it. I decided to try and give it a coat of cement mixed with coco peat. Cement to peat ratio 50/50. Mixed it to a milkshake consistency and applied it with a normal paintbrush. Brushing and stippling. Using an old fork to add some more details. 














































Finally just for the fun of it I positioned some of the wood I have to see what it would look like. 





























There's where it is at the moment. What about sealing? Well, the only real problem with portland cement is the very high alkalinity that you have to bring down somehow. It will do so naturally from the CO2 in the air (carbonatation) but it can take some time. An engineer friend I talked to said that usually it takes concrete 25 years to get carbonated (right word?) 10mm below the surface. His guess was that pure cement like I used will reach that in just a few weeks. 
I think I'll attack that issue by sealing the backside of the tree with sodium silicate (water glass) and apply a acid wash to the front. Then attaching a support to the inside using thin pvc pipes and just spraying them into place with pu-foam. So even if the acid will weaken it some it will be supported and not collapse.


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## Woodswalker (Dec 26, 2014)

This is really fantastic. I'm planning a large tank (several years down the road, mind you), and this has completely changed my outlook on buttress roots. I had previously written them off as impractical and requiring too much floor space, but this method is less bulky, and gives much more control to the design, while still allowing it to appear natural. I admire your brilliance.


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## Kalle (May 14, 2010)

Woodswalker said:


> This is really fantastic. I'm planning a large tank (several years down the road, mind you), and this has completely changed my outlook on buttress roots. I had previously written them off as impractical and requiring too much floor space, but this method is less bulky, and gives much more control to the design, while still allowing it to appear natural. I admire your brilliance.


That's too kind! 

I've always looked on buttress roots as something iconic I wanted in my big show tank but I've never really seen any nice fake ones and I wasn't sure for a long time I could pull it off. But it feels like I've kind of cracked the initial code at least. I'm sure it can be further refined and improved. I kind of want this to be covered in moss and liverworts eventually so the actual texture of the "bark" is not super important but if I would do it again I would experiment more on how to achieve a more natural bark texture. For instance, I have seen people use latex mixed with peat to create backgrounds. Latex shrinks a lot when it dries and creates a nice bark like appearance with cracks. I wouldn't use latex because it's toxic to amphibians but if there's another material with similar properties that is frog safe that could be really interesting!


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## Socratic Monologue (Apr 7, 2018)

That looks awesome! Great write up. 

I don't know that this will have much of an effect on your finished product, but there might be better choices than aluminum wire in a concrete construction; aluminum reacts with chemical bases (like the high pH concrete), gets degraded, and can fail. This is why aluminum utensils get damaged in the dishwasher -- dishwasher detergent is mostly calcium carbonate. Steel (or in a humid viv, stainless steel) wire would avoid this issue.

Looking forward to seeing this build progressing!


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## Kalle (May 14, 2010)

Socratic Monologue said:


> That looks awesome! Great write up.
> 
> I don't know that this will have much of an effect on your finished product, but there might be better choices than aluminum wire in a concrete construction; aluminum reacts with chemical bases (like the high pH concrete), gets degraded, and can fail. This is why aluminum utensils get damaged in the dishwasher -- dishwasher detergent is mostly calcium carbonate. Steel (or in a humid viv, stainless steel) wire would avoid this issue.
> 
> Looking forward to seeing this build progressing!


I agree with the aluminum. And it was cut away from the tree when I cut it to size. I'm not even 100% it was aluminum to be honest. 

There are a few galvanized steel screws hidden inside it now, that's all. 

And thanks for the appreciation!


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## Tijl (Feb 28, 2019)

Best Buttress root build I've seen to this day!


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## jgragg (Nov 23, 2009)

> Google "fabric formed concrete" and you'll see some cool things! ... This technique is not new but I haven't seen it applied to fake trees before.


Yeah man, me either. Holy shit. Awesome. Just _awesome_. Today, I have seen something new to me. Thank you very, very much. My craft jones is firing up something fierce. Gotta start a new build!!!

Best


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## Kalle (May 14, 2010)

Tijl said:


> Best Buttress root build I've seen to this day!


Many thanks! 



jgragg said:


> Yeah man, me either. Holy shit. Awesome. Just _awesome_. Today, I have seen something new to me. Thank you very, very much. My craft jones is firing up something fierce. Gotta start a new build!!!
> 
> Best


Thank you very much and I'm happy to have caused some inspiration!


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## Zippy (Dec 30, 2015)

That is hands down an awesome job!


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## Silent Running (Jan 27, 2019)

That looks absolutely fantastic! Looking forward to seeing it covered in moss! Great job!!!


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## genem1948 (Dec 8, 2013)

I'm Inspired


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## Dr. Manhattan (Oct 28, 2016)

Wow, just wow ! That


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## Kalle (May 14, 2010)

Zippy said:


> That is hands down an awesome job!





Silent Running said:


> That looks absolutely fantastic! Looking forward to seeing it covered in moss! Great job!!!





genem1948 said:


> I'm Inspired





Dr. Manhattan said:


> Wow, just wow ! That


Thank you all! 

Going to do some finishing work this weekend and next week.


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## bosco500 (Sep 12, 2018)

Wow nice job!


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## Mmkco (Dec 3, 2018)

Unbelievable! Thank you for sharing this project. Incredibly innovative and educational. You have done an incredible job on this and I just can't wait to see how you progress with it. It's gonna be something very special. Just WOW!!


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## jgragg (Nov 23, 2009)

Kalle - on another build, I wonder if you could use the same techniques and materials, except swap in epoxy resin for the concrete. That would save weight and eliminate the alkalinity issues. After the first "dunk" and partial cure, subsequent layers could just be brushed on. Emboss some texture into the final coat, then (quickly) apply dry pigments or acrylic paints for tinting. 

Do you have any insights into how well or poorly this might work? I really hate the weight of concrete in builds. Adding enough water to make concrete super-soupy invariably results in weak, weak concrete. And finally, concrete curing & efflorescence are not especially simple or trivial technical issues. My experiences anyway - I'm trying to square my earned dislike of concrete in vivaria, with the aesthetic appeal of the flowing, "drapey" look you get from the fabric.

Happy crafting this weekend!!!


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## Kalle (May 14, 2010)

Mmkco said:


> Unbelievable! Thank you for sharing this project. Incredibly innovative and educational. You have done an incredible job on this and I just can't wait to see how you progress with it. It's gonna be something very special. Just WOW!!


Thank you so much! 



jgragg said:


> Kalle - on another build, I wonder if you could use the same techniques and materials, except swap in epoxy resin for the concrete. That would save weight and eliminate the alkalinity issues. After the first "dunk" and partial cure, subsequent layers could just be brushed on. Emboss some texture into the final coat, then (quickly) apply dry pigments or acrylic paints for tinting.
> 
> Do you have any insights into how well or poorly this might work? I really hate the weight of concrete in builds. Adding enough water to make concrete super-soupy invariably results in weak, weak concrete. And finally, concrete curing & efflorescence are not especially simple or trivial technical issues. My experiences anyway - I'm trying to square my earned dislike of concrete in vivaria, with the aesthetic appeal of the flowing, "drapey" look you get from the fabric.
> 
> Happy crafting this weekend!!!


Honestly, without having looked on any numbers, I think using epoxy instead of cement would result in comparable weight. Now when this is dry it's not that heavy actually. Remember that it's only about maybe 1/4" thick. Epoxy isn't exactly a light weight material either. 

Of course epoxy could be used but for a considerable extra cost. I think it would result in a lot of excess epoxy having to be thrown away if you don't come up with a super efficient way of thoroughly wetting the fabric. This technique doesn't use a mold where you can brush on the epoxy on dry fabric like in boat builds or something. It relies on hanging wet fabric and letting it drape naturally. Just some spontaneous thoughts on using epoxy. One other material that could work pretty good and wouldn't be as expensive is some form of outdoor wooden white glue. Watered down to make it a bit runnier. I've tried it on rope to see how stiff it would become. I mixed water and wood glue 50/50 and wetted the piece of rope in it, squeesed out the excess and let it dry. It became very hard and stiff after drying. If I would do any further experiments I think I would go down that path. To add strength all you need to do is adding some extra layers to the fabric or use heavier fabrics. Thick old bathroom towels or something maybe? 

Finally, yes runny cement mix without any ballast results in a very weak "concrete" if you even can call it that. But the reinforcing fabric changes all that. Steel rebar reinforcement has nothing on fabric when it comes to adding strength. They build super thin and light weight bridges from this stuff that can never be achieved with traditional reinforcement. Polyester fibreglass resin is very brittle in itself, it's the combination with the fibres that gives it its strength. And in this case there is no real force acting on this except it's own weight. It's going to have good support from below and the vertical sides foamed/siliconed to the sides of the vivarium. So I don't think strength is an issue. 

I chose cement because it's very cheap and convenient and I think that it will work just fine. But I'm sure there are plenty of other materials that can be used as well and some even better. Choosing the right type of fabric is also something that can be improved upon.


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## jgragg (Nov 23, 2009)

OK, thanks a ton for the reply! I usually have some leftover epoxy lying around, and its shelf life is really only a year or two, so I'm often looking for something to play around with and consume those leftovers. But right now all I have is putty, not liquid, so exploring with fabrics will have to wait a bit. Probably until my next plywood-hull, big-viv build.



> I think it would result in a lot of excess epoxy having to be thrown away if you don't come up with a super efficient way of thoroughly wetting the fabric.


Possibly, yes. Wetting can be a challenge. Reducing viscosity can help but there can be big tradeoffs too. I find the reference materials at West to be helpful, e.g., https://www.epoxyworks.com/index.php/thinning-west-system-epoxy/
Heating the fabric to about 110F in e.g. a dry oven looks like a good way to go. That, and having a "dunking basin" of dimensions that balance a desire for minimal fabric folding, with a desire for small surface area. Give the fabric one good soaking dunk, then pull it out and hang it. Preferably right over the same basin. A polyethylene tub, or something, so you can pop out the cured epoxy waste.

This is something I'd also pondered - seems highly credible:


> One other material that could work pretty good and wouldn't be as expensive is some form of outdoor wooden white glue.


I haven't worked much with wood glue, except to, um, glue wood. Ha ha. But really. I am not accustomed to seeing the glue when the job is done! Do you know if it accepts multiple coats very well? How about tinting, painitng, etc?

I hope you got some good crafting in. I spent part of my weekend re-arranging my garage, trying to make room for my wife's new crafting-hobby (stained glass). Some day soon here I will be able to dive into a new project.


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## Kalle (May 14, 2010)

If you do some experimenting I'd be happy to har about your findings! 



jgragg said:


> I haven't worked much with wood glue, except to, um, glue wood. Ha ha. But really. I am not accustomed to seeing the glue when the job is done! Do you know if it accepts multiple coats very well? How about tinting, painitng, etc?
> .


Not sure about any of your questions, I haven't a big experience either. I just know some use it for backgrounds, wood glue mixed with peat. I'm sure you could add pigments to it or even some acrylic paints. I would paint it afterwards though to be able to use washes of different colors and lightness to bring some natural coloring to it. Otherwise I think it could come out very flat. 

I managed to do some work this weekend but I couldn't find all the supplies needed so it's a bit delayed as usual. But I stained the cement yesterday with some iron sulphate. Came out a nice splotchy uneven brown/reddish color that's a nice start for further coloring. Going to start sealing it with waterglass tonight and after that continue with painting using acrylics.


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## Kalle (May 14, 2010)

Did a little more work. 

Prepped some holes for two drip lines on each side. It's 1" ribbed hose that will come up from the bottom behind the tree and out on each side. 

Also made a hole for the fogger line that will exit through a 1" mesh covered hole.






































I also started sealing the cement but before I did that I decided to try and stain the cement with iron sulphate. I know it's used to kill moss in lawns but I figure it'll be ok once I seal the cement on top. After sealing I'll add some more acrylic washes to it.

Before pic:

















After staining:

























I then applied the first coating of waterglass. Tomorrow I'll apply the next and I think that'll be enough.


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## Fahad (Aug 25, 2019)

Looks fantastic, Kalle. So it's the sealant issue that has me questioning how I might do something similar; also why I've been skeptical about epoxy for my own preferences. Is water going to bead off the sealed surface?

I'm wondering if I'd prefer to use concrete or similar and neutralize it rather than seal it. I'm going to have to get on it sooner or later because I've been speculating for months and think I'll have to dive in.


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## byrnstar (Jul 8, 2019)

_It's going to have good support from below and the vertical sides *foamed*/siliconed to the sides of the vivarium. So I don't think strength is an issue._

Hey now, there’s another idea. Use Great Stuff foam to build and carve the shape you want, and then use it as a form to drape the concreted fabric over. Takes care of both the support and void space issues.

And I bet this would be a fun way to experiment with making mini waterfalls or ponds!


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## Kalle (May 14, 2010)

Fahad said:


> Looks fantastic, Kalle. So it's the sealant issue that has me questioning how I might do something similar; also why I've been skeptical about epoxy for my own preferences. Is water going to bead off the sealed surface?
> 
> I'm wondering if I'd prefer to use concrete or similar and neutralize it rather than seal it. I'm going to have to get on it sooner or later because I've been speculating for months and think I'll have to dive in.


After treating it with waterglass twice with drying in between it reached a slightly glossy surface where water beads on top of it.



byrnstar said:


> _It's going to have good support from below and the vertical sides *foamed*/siliconed to the sides of the vivarium. So I don't think strength is an issue._
> 
> Hey now, there’s another idea. Use Great Stuff foam to build and carve the shape you want, and then use it as a form to drape the concreted fabric over. Takes care of both the support and void space issues.
> 
> And I bet this would be a fun way to experiment with making mini waterfalls or ponds!


Could definitely work but you won't get the natural draping shapes from the fabric which was what I was after. To me the voids aren't really an issue.


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## Kalle (May 14, 2010)

Finally got done for some painting and I'm quite happy with the end results even if I probably would make a better job if I had to start over. You've learned the tricks by the time you've finished as usual. 

Did some dark washes with blacks and browns



























After that I started painting on some lichen and I should have practiced this a lot more than I did before starting. It's hard finding the right shape and right shape but it improved along the way. Main trick is to not make a lot of small islands but to connect them up into larger patches. And to use a smaller brush to make crisp roundish edges.



















Continued on with some dark washes on the lichen to give them some depth and to take off the brightness and soften them up a bit.


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## Tijl (Feb 28, 2019)

Please make me a tree when you finished this one 😄


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## eyeviper (May 23, 2006)

Very very cool idea. Best buttress root I’ve seen. I’ve been planning a big viv with a buttress but have never settled on the best way to build it until now, thanks to your technique. If it’s cool I’m using it on the next one. Fantastic idea. 


Sent from my iPhone using Tapatalk


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## nightowl (Dec 13, 2010)

Amazing work....


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## Hedge (Jan 14, 2011)

It's been a while since I worked on the viv I'm making and I've always wanted to do buttress roots because well, you're right they're iconic. Anyway, thought I'd have a wee look at the forum see what people have been using for textures and coatings recently.

I'm absolutely blown away by this. You have captured it so perfectly, and you've got one hell of an artists eye to spot the way they look like draped fabric. 

Deffo don't have the skills or materials to do this myself, but I'm feeling inspired now to test things out.


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## athiker04 (Nov 15, 2013)

Any updates on the build?


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## DigitalChromosome (Jun 25, 2020)

Epic and simply brilliant!


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## Bannef (10 mo ago)

Kalle said:


> Finally got done for some painting and I'm quite happy with the end results even if I probably would make a better job if I had to start over. You've learned the tricks by the time you've finished as usual.
> 
> Did some dark washes with blacks and browns
> 
> ...


Did you ever get this in a tank? I can't imagine, it looks amazing.


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