Tango, that was an excellent description! I think if you just assemble your posts you'll find that your book is mostly done :) Do you tend to use different types of portland for different stages of the same project? Thanks again for all the help. Justin

Thank You Tango,

I was hoping you would jump in with something like this. Do you use one recipe for your faux bois or does the recipe change to suit the project? When your book is finished, I really want to know. I can hardly wait for a copy.
Thanks again.

Amy

Hi Guys --- Regarding recipes, yes. Base your formula on the task at hand. Unlike a monolithic casting, when you are "building up" a piece in layers, you have the opportunity to apply the mix that best suits the needs & demands of each. While every sculpted project will have different issues that guide their construction, if you begin by examining the desired design and form (think like an artist), and then try to think through and visualize the "how to" processes involved in putting it together (think like an engineer), the piece itself will help guide you to the best possible solutions, minimize failures and allow you to concentrate on the creative issues, rather than the mechanical, as you work. This is a case in which form determines function. Visualize making the entire piece and then ask yourself a lot of specific questions as you walk through it. Is an area going to be thick or thin? Does it need an internal support system like a armature or can it carry it's own weight? What will the medium do while it is curing...sag, slump or stay put? How will a given layer of material be "worked". Is it simply to build up mass or do I need to create fine detail in it? All of which leads to...how can I adjust a mix to achieve the end results I want? Areas of large mass that will be covered by ensuing layers can be formulated for bulk, economy and strength. That means you can use larger aggregate and a faster setting mix. Forming thin areas, on the other hand, requires smaller aggregate and the strongest possible mix. Poly fibers & a wide range of property specific admixtures will help acheive the best formulation for these areas, but you'll have to do some homework, as there are just too many to go into here at this time. And then there are the "finish" layers. Once again, let function designate form. What kind of surface do you want? Rough, smooth, colored, plain, course & rustic or controlled and highly detailed? How will a certain mixture respond to the tools required to produce the results I want? Visualize in advance and mix accordingly. Keep in mind that while strength is highly dependent on the use of a healthy mix of large and small aggregate...these same physical properties limit the degree of detail acheiveable. On the other hand, finer and finer aggregates permit finer and finer detail...but result in a mixture that is limited in strength. By building up well bonded layers that are matched to the design and tooling requirements of each, it is possible to produce a piece that is optimized throughout. Cementeous products offer incredible creative possibilities because they can be worked in all their states...fluid, plastic, semi-ridgid & hardened solid. But their unrelenting metamorphasis from one state to the other, requires planning, preparation and a series of constantly changing techniques to make the most of what it has to offer. With a little practice, experimentation and practical experience, the working processes become second nature and open the door to an amazing range of creative possibilities not possible with any other medium. Technically speaking...it's really neat stuff.

Tango, Thanks for all the good points! I finally feel a little more comfortable with my understanding of different recipes for the different stages of each project. However, I've noticed that some people use different types of portland for different stages of the same project. For example, the use of quick-setting cement for the detailed outer layers of faux pieces. Is this part of your strategy? I'm not sure if it's just a personal preference issue or a better way of getting good detail?

Thanks,
Justin

Justin --- Personal taste, experience & technique all contribute to material and tool selection. As for me, if I am trying to create a lot of detail, I add a retarder into my mix to give myself as much working time as possible before it reaches a fully hardened set. Once that occurs, you are simply more limited in the range of effects you can apply. Conversely, I like to use the "qwik-sets" for building up the interior and base layers...the tedious, but most spontaneous part. Please take note that I avoided using the word "boring", because this is the really when the form of the final work is determined. Of course, you can always take off a bump or lump later if you don't like it, but once it sets, it's a LOT more work. That reminds me...where the heck did I leave those blasting caps...

Tango,

That makes a lot of sense. I get too impatient during the ealry stages and often end up cracking projects in attempts at moving on to the next step. I think the fast-setting cement in the early step would really help me out. I'm really glad you mentioned that!

Thanks again. Justin

Justin ( and all )--- just met today with some concrete technology gurus and I am pursuing more data on some chemistry that really sounds interesting. A family of surface retarders and hydration retention solutions. Could be real problem solvers for sculptural applications. I will post more as I root it out.

Just wanted to note that, if you're using copper piping inside your sculpture (not sure what you're using for your water sculptures, Justin), watch out that you're not using concrete with a chloride ingredient, which can be present in accelerant admixtures. I'm not sure if there's any spalling involved here but there seems to be some problems. See link below.

Here is a link that might be useful: Nonferrous metals and concrete

HowieDoin, funny you mentioned that. I'm using plastic tubing, but I wasn't paying attention the other day and must have got a bunch of cement past in the water outlet. Needless to say, it totally clogged the pipes. I had to use some strong muriatic acid to dissolve it. Anyway, theres a small piece of copper tubing connecting the plastic tubes in my water reservoir. After adding my acrylic sealer I noticed a blue-green tint on many of the areas. That sounds like what your site was talking about, but I seemed to have accelerated the process a bit. It actually looks pretty cool.

Justin

As some of you may recall from earlier discussions on coloring compounds, Copperas, otherwise known as Copper Sulphate, is one of the compounds of choice for creating blue tones in cementious and many other materials. It's been used for this purpose since at least the time of the Babylonian Empire and was later considered so precious that the Papacy actually maintained a church controlled monopoly on it for centuries. Even today, VooDoo practicioners use it in the form of magic "Blue Stones" for purification rituals. So be careful how you use it. Because not only is it toxic, in high concentration, but you might wind up either really p -----g off some evil spirits, or having to pay royalties to the Vatican.

Well, that's interesting. And here I was only worried about using an acid that dissolves concrete!!! Nasty stuff but it sure cleaned out the cement residue I thought was a permanent part of my bathroom sink...just in time for the landlord inspection :)

Tango, would it or would it not be safe to use to stain concrete? Is it something that you don't handle after it is stained?

Ahhh, reminds me of my grade school days when one of my classmates suggested the "trick" of getting to miss a school day--suck on a penny! Said it would make you sick enough to get out of school for a day or two. I think I preferred the faking it method where at least you felt decent when you missed.

Tango, keep us posted on the new additives. I've been searching for the holy grail...tufa/concrete that sculpts like clay. I figure sculpting it wet will be much easier than carving it dry.

Has anyone ever tried adding dry clay powder to their tufa mix? I am wondering if it would make it more workable.

Jo

Jo, I've been thinking about trying that one of these days. What type of clay powder do you think would be the best bet?

A friend of mine is a potter. She says that we can just dry the earthenware clay she has and grind it up into a powder? She also mentioned albany slip. This is one ingrediant I have in mind for a tufa outdoor oven. I think that burning wood in the oven will fire the clay and make it strong. Imagine a faux bois fire pit? How cool would that be!

Jo

Ha, that does sound cool. You should be able to buy a lot of different types of clay in powder form. I think this is something I'll put on the back burner for now :)

Bump

I went to HD today and found a metal lathing covered with pvc. The company claim its not going to rust. The bloddy thing was pretty expensive but I'll give it a try.

too curious wondering if concrete will react like the galvanized one.

by the way tango did you ever pasted the recipe(s) you are using for the faux bois?

very nice explanation tango. your so good to us ;o)
eventually i'll reach your level :o)

I bet a long way to learn is infront of me ;o)

Tango, just read your info on the Faux Bois. Great description, you seem to really enjoy your craft!
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