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gardener_boy

Armature questions

21 years ago

Hi,

Attempting something a bit too challenging perhaps, but gotta do what ya gotta do.

Trying to make a table entirely of tufa to carve into faux wood. Built a framework with the plasterer's wire mesh. The wire for the legs is about 1 1/2 inch in diameter which I formed by bending it around a broomstick. I was only able to complete a portion of the legs the first day as the tufa would only go up so far before it would sluff off below. Came back today and as I was continuing, the slight jiggling of the armature caused cracking in the hardened tufa from yesterday.

Got it all completed today, but when I go to turn it over in a few days to do the top, I'm convinced that it is going to crack all over, especially at the joints.

What is you advice on this project? Anyone built a table like this?

How can I make the legs more stable yet still have them bending in a curve as a branch would do? Would fibers help?

Disaster Dave

Comments (49)

  • 21 years ago

    What a project! I am wondering if anyone has ever covered a real table with tufa. I have a round table destined for the landfill and am very willing to cover it with tufa. I am planning to cover it in hardware cloth first, then covering it with tufa, Will this work? Is this a better thing to do then what disaster dave is doing? I just can't imagine, disaster dave. You are brave!

    Jo

  • 21 years ago

    This is new to me but could you wrap a real branch in wire to make a sturdier armature that has the shape you want?

  • 21 years ago

    Mudmaker-Sometimes the simplest ideas are the best ideas! You're a clever puss! Why didn't I think of that? Now I need to escape the City and go branch hunting.
    Still would like any feedback on how I might improve on my technique, as I'm sure is possible.
    David

  • 21 years ago

    Hi David

    try rebar, you can twist it, still can put wire mesh around it to hold the tufa. The branch might break under the weight. The iron-bar in the concrete makes it much more stronger, it is a chemical reaction, not only the strength of the iron.

    Andrea

  • 21 years ago

    Disaster Dave and Jo, in the Cortez post (wherever that is) there is a link to a site with a table wrapped in hardware cloth and the finished product. They used one of those cheap tables that you see at many functions. I had the link & lost it.

    Kay

  • 21 years ago

    Andrea,
    Are there diffenrent grades of rebar that are more bendable than the ones I am thinking of? That would be great. David

  • 21 years ago

    David, yes, there are. I used the thinner for my landscape. It is not too easy to bend , start with a longer piece, bend it around a tree or pole, anything strong.After you got all the curves, angles, cut off the rest. For side branches /if you need any/ you can use wires twisted together, steel or iron only, no aluminium, no coated.

    Have fun! Andrea

  • 21 years ago

    Hi David,
    Your project sounds Awesome!! Rebar is easy to bend, you can bend it around just about anything (1/4")....i use it for just about everything now lol! In fact, I'm getting ready to start another armature....A tall 'candle tree' for outdoors.

    The branch idea is good also, but for table legs I think you might be better off using rebar, or pvc, and like Andrea said for more detail (like branches) you could just wrap hardware mesh and hook onto your project and cover.....I can't wait to see pics....Oh, Hybridtufa also has a table on his site. Anela

    Here is a link that might be useful: Anela's Album

  • 21 years ago

    GB...furniture and such really needs the strength of rebar. You can get by with fairly small diameter if you bundle it up and tie or weld it together. I weld all my frameworks 'cause it's easier & quicker for me...also adds quite a bit more strength. Also, a device called a "Hickey" can be had for a few bucks that makes pretty light work of shaping anything up to 1/2" rebar. You do need to use a rust treatment on the steel if you want it to last, though. Rusting rebar is the #1 cause of death for concrete. Take a look at the albums on the link below...there are frames and tools aplenty. Great looking work, by the way. I've been away for a while, but I'm glad to see someone else here into faux bois. Go for it.

    Here is a link that might be useful: Armatures & Frames & Stuff, Oh my!

  • 21 years ago

    Hello David,

    Here's a link that may be useful to you. Hope it's what you're looking for. Good Luck!

    Sandy

    Here is a link that might be useful: faux bois table link

  • 21 years ago

    Sandy! Thanks for posting that link! I remember seeing it a long time ago, and was searching for it to post for David.
    It is now safely tucked away in my bookmarks.

    Tango88, what method do you use to weld your rebar? Welding is one skill I'd sure like to learn. Gotta start by getting a 'Hickey', I think that could be very useful.
    Your work is great - it gives me something to aspire to! Thanks for the link.

    -GC

  • 21 years ago

    The Home Depots here carry the Rebar Hickey (under $20 bucks, as I recall), so you might check yours. As for welding, I use a little 110v, wire fed mig. They are much better & cheaper now than when I bought mine (10+ years ago)...you can pick one up thesedays for around $300 bucks and they are a breeze to learn & use. Makes it easy to branch out into metal sculpture too. Another handy tool for shaping rebar is an old fashioned 2-pound Cross Peen Hammer. With a slab of heavy plate steel or an anvil to beat on, you can quickly make curly-ques, spirals or just about any curve you want. Just don't try to heat the rebar (as with a torch), it will crytalize if you give it too much heat and can shatter like glass when you strike or bend it. Another reason why the mig-welding is preferred...it doesn't tend to overheat the metal. Hope the mistakes I've learned from are a help to you.

  • 21 years ago

    Wow! Your work is amazing.
    Thanks for sharing the great info on welding. That is something I'll have to learn.

  • 21 years ago

    Hey thanks for the great links and wonderful pics.
    Tango and Hands, both of your faux bois work is nicely done. I noticed that Tango wrapped the lathe very tightly around the rebar, where as Hands's was not. Is one way easier than the other in getting the tufa to adhere. My big problem as I was building up the legs, was that the lower tufa kept plopping off in places. Do you use a dryer or wetter consistency? Seems like drier might work better?
    Do you use fibers as well?
    I have to go check out the different type of rebar. Is the smaller diameter the one you can bundle up together without the hickey?
    I'll have more questions in the morning, but I'm too tired to think. Good night.
    David

  • 21 years ago

    GB...I like to wrap the first layer of stucco lath as tightly as possible. It secures the bond of the concrete to the rebar and prevents voids that can seriously weaken the finished piece. To that I apply a course "scratch coat" of concrete, then build up from there with more wire or lath as needed to give the piece the form I want. A lot more labor, but I "guarantee" all my work and have never had cracking affect a finished piece. Structural fractures can never really be patched, and starting over on work that has a couple of hundred hours in it is not a position I want to be in. As for mix...use as little water as humanly possible. It yields the strongest concrete and is the least prone to fractures during the initial set & cure. Never more than 25%, and with some practice and water reducing additives, you can get down around 12-14%. I also add fibers of the type used in commercial casting (shorter than most) which also helps prevent early hairline cracks. These, however, only go into my form building concrete layers, as my finish layers are pure, neat Portland Cement with no sand or aggregate. Very, very tricky to work with, but highly sculptable.
    As for rebar, there's a wide range of sizes and types available (including fiberglass). The smallest and easiest steel to shape is 1/4" "smooth rod" which does not have the "cleats" (bumps & ridges) on the surface that regular rebar does (hence the "smooth"). I work mostly with 3/8" & 1/2" and occasionally 5/8", but use the smooth when size or tight curls demand it. Smooth rod is maleable enough that it can be formed with large pliers or channel locks. A cheapo Chop Saw will also make your life easier...but always, always wear eye protection. Take it from someone who had to perform emergency self-surgery with an Exacto knife to save their own eye. Talk about learning something the "hard way".

  • 21 years ago

    Gasp! Tango I now have so much to learn! And of course, more questions: Where do you buy the fibers? How many layers of tufa do you use and do you have a favorite recipe for the under layers? Is all the rebar you mention available at HD or Lowes or should I check into the building supply stores too? How and how long do you cure the pieces between layers. I just draped it in wet rags. But does that conflict with your as little water as possible approach?
    Thanks, really, really for your answers to there and future queries.
    Your eye mis-hap sounds like an eye opener to always remember safety first. I work as a ski patrol in the winter and they always teach to make sure the scene is safe. Goes for the tufa hut as well.
    David

  • 21 years ago

    GC & David,
    You're both welcome.

    David,
    I didn't create that faux bois table. I came across that thread with that link when I was looking for I think it was Cindy's stain glass dragonfly bench, which I couldn't find. Anyway I had saved it when I saw that faux bois table (about 3/4 of the way down). Glad I was able to post it here for you. Please share your pictures when you're done with yours, would love to see them.

    Sandy

    Here is a link that might be useful: Outdoor Mosaic Table (Large)

  • 21 years ago

    GB...Best places to find a variety of fibers are concrete specialty vendors. They are more common than you might imagine, you just have to find them. Check with anyone doing commercial concrete work locally. I use maybe a couple of hand fulls per mixer load (usually a 51# mix). Rebar is also much cheaper from a commercial supply house, but generally comes in 20' sticks. Some places will cut a load in half at no charge (much easier to get home), others charge a couple of bucks.
    As you know by now, curing is critical. Begin as soon as the initial set has taken place (time depends on temp, humidity, etc.). Once set, additional water has no impact on the mixtures formulation and you can't overdo it. In fact, a total water immersion cure is as good as it gets. Time again depends on environmental factors. I've applied additional layers prior to the initial set on some pieces and waited as long as a year on others. Note...once a piece has set and the surface is dry, you really need to use a Bonding Agent to make sure the next layer stays stuck to the first. "Scratching" the surface of under layers you will be adding to is also always advisable.
    As for formulas, I'm afraid I'm strictly a concrete & cement guy. Haven't done anything in 'Tufa to date, so I'll have to defer to the Pros like Peak on that one. Best of luck. Live large, stay curious & share what you learn.

  • 21 years ago

    At the web site potsplus.com, they talk about how they put together the faux bois pieces. One item they use is an epoxy paint to coat the re-bar. They state that it is for added durability. Do you think this is for strength or for rust protection? Anyone ever used epxoy paint on re-bar?
    Sold my faux bois table! I'll post a pic eventually.
    David

  • 21 years ago

    Hate to tell 'em, but epoxy paint really doesn't prevent rust on embedded rebar. All paints rely on surface adhesion which will not keep oxidation from migrating under it. Even if the entire surface is perfectly sealed, by the time you apply lath, wire reinforcement or even just concrete (very abasive stuff) it's likely that there is a flaw or scratch or a microscopic bit of remaining rust that will kick-start the oxidation process all over again...from there it grows like a cancer and paint does little to even slow it down. That said, there are some new "Rust Converters" that actually alter the surface of the metal and transform it into a rust-proof barrier. Unlike painted surfaces, rust cannot migrate or advance beyond any point of damage on "converted" metal. They are called "Converters"...and that is just what they do...convert the surface metallurgy into a stable black compound that simply does not rust. This is a problem area I've been researching for years and only in the last few have these products emerged and been successfully tested. Rusting rebar and reinforcing steel are the reason so much of our aging national infrastructure (bridges, dams, etc.)is crumbling. Finally, this category of products promises some hope for future construction (and art). Here is one of several makers websites. It really is alchemy...and it really does work.

    Here is a link that might be useful: Alchemy Whips Rust

  • 21 years ago

    So tango, do I understand correctly that the surface you apply the 'rust converter' has to be rusted already? If so, to what extent. Does this add an extra step to building armatures, in that you must let the piece rust, then 'convert' the rust, then you can proceed with applying concrete?

  • 21 years ago

    Wow! That is good info, especially if you would like your items to exsist 50 years from now. They are building a bridge nearby and I am watching carefully. They use standard rebar and just encase it in concrete with no coating whatsoever! You know they will be tearing that baby down in 50 years or less! That's how they make their $$$$.
    If building a retaining wall or some permanent structure, you will want it to last, or if you expect your item to end up at the Metro. Museum of Art someday, you better heed the warning or they will be doing some major restorations on your masterpiece. (who knows, could happen!)

    Jo

  • 21 years ago

    GardenChicken...Roger...the "Converter" only affects rust. However, I've yet to find any rebar that didn't come with plenty. Everthing elese I use is galvanized (lath) or stainless (wrapping wire).
    Jo...The rate at which spalling can destroy a piece of work depends on many environmental conditions. It can occur in a couple of years, or take 50+. Ya' just never know, my Little Rosannedan.

  • 21 years ago

    Tango, do you use these converters on your work?

  • 21 years ago

    GB...Yes...I do now. I've been running tests on a variety of rust controlling products for the last couple of years and I now use the "converter". I have a half-dozen pieces on which I have left the rebar either exposed or partly exposed and have even sprayed weekly with concentrated saltwater. They remain free of any rust so far. On some I intentionally scratched through the "converted" surface and exposed raw metal. In these areas, rust formed, but remained limited to only the small areas exposed. With paint, the rust quickly travels under the paints surface, seperating the bond with the metal and goes about it's work oxidizingthe metal. This appears to be the best solution to date for a major problem and it's not that expensive. I pay around $10 bucks for a quart and it covers a lot of rebar. And since most of my work consists of fairly large scale commissions, the impact on the finished price is nil.

  • 21 years ago

    Tango, I noticed on your other post (enemy rust), the link to the company in Australia for the converter. Is there a more local, state-side source that you use?
    The Historic bench is so wonderful, especially the way the seat was made. Something for me to aspire to down the road. Hope the restoration is a total success!
    Enjoyed looking at all your pics again. Any chance you have more updated photos of your works in progress of the scratch coatings. Would love to see the finished products, as your armature work looks so interesting.
    In your tool pics, did you buy a particular cement mixer? I am thinking I really need to think about a major leap. All this hand mixing is starting to take a toll on my aching wrists. Now I know what a hicky is too! Is it unrealistic of me to build more furniture using re-bar as a frame and not to need a soddering iron?
    The faux bois is something I really want to pursue. Ever seen the incredible work at the Buttes Chaumont in Paris? An amazing display of steps, bannisters, furniture and landscapes. That and a million other reasons to go to Paris, right?
    Lastly, any books on the subject(faux bois, not Paris!) you or anyone else can recommend?
    David

  • 21 years ago

    Unrusted steel forms a special chemical bond with cement. Lynn Olsen goes into it in some detail in his book.

  • 21 years ago

    GB...I currently use the product I've been testing...it's called "Restore" by Quest Chemical in Houston, Texas. I have to agree. The bench & chair the Heritage Society has is remarkable in terms of workmanship and technique. It was very likely done by one of Carlos Cortes's forbearers (See the link for his amazing work).
    Don't have any completed pics to show. I've spent the whole year completing several works that I am going to retail as cast garden items. Just closed a deal with the largest Garden Center chain in Texas and I'm negotiating with the largest in California (keep your fingers crossed!). That and a major commision for the County Arboretum here has had me swamped and way behind on "retail" work, which is what most of the pics are of.
    Wish I could recommend a "how-to" book...but there doesn't seem to be any...that's my "other" project of the moment, trying to write one. I really don't want the medium to be entirely lost to time. The "old masters" of the trade were very protective & secretive of their techniques, so the learning curve can easily occupy a lifetime of research and experimentation. If I can just put together the basics I've acquired over the last 10 years, maybe it will help kickstart someone in that direction. Meanwhile...take a look at Carlos' work. He's a little secrective too, but a really nice guy who does some incredible work. See the link below if you haven't been there yet. All my best.

    Here is a link that might be useful: The Amazing Carlos Cortes

  • 21 years ago

    So glad you're willing to share your expertise with us as we learn. I've yet to attempt faux bois but love to read these informative threads. Keep us posted on your book progress and successes.

  • 21 years ago

    bump

  • 21 years ago

    Oh gosh! Thanks for the bump! So much good info in this posting that I had not visited for so long.
    Tango, did you ever get that deal with the Ca. chain? Any new pics to share?
    I found a local biz. Western Wire which has a whole bevy of different grades of wire/re-bar. Is there a significant difference between wire (un-galvanized) and re-bar when it comes to using it as an armature?
    David

  • 21 years ago

    GB...Having fits finding a reliable & qualified manufacturer in CA. The garden chain wants the goods, but I've gone through three makers so far with no luck. Looking better here in Texas. I may even form a partnership with a Mold/Casting company here. Can't show any pics 'til the deal is done (a couple of weeks ???), but will be glad to then.
    As for the "ungalvanized wire"...I'm not certain what they are referring to unless it is what is called Smooth Rod 'round these parts. 3/16 to 1/4 inch steel rod. Comes in long sections & sometimes rolled. Handy stuff, as it is very easy to shape & form and can be bundled to acheive greater strength. It is simply untreated, heavy guage steel wire, so they may be one in the same. Rebar usually starts out at 3/8 of an inch and goes up from there depending on the application. I've seen 1 1/2" and have heard of much larger being fabricated. Rebar also traditionally has "cleats" on the surface. Those are the raised bumps and ridges that help the concrete get a better grip onto the metal. I use both in my work, depending on what I need to accomplish, and thesedays I treat all of the reinforcing steel with a rust converter. Everything else is either galvanized (stucco lath) or stainless steel (wrapping wire).

  • 21 years ago

    Tango,
    That is what it must be, the smooth rod. Would some bundles and wrapped rod be good enough for leg support on a table?
    Is the converter product easy to find at a building supply?
    Look forward to the new pics, as I am an admirer of your work.
    David

  • 21 years ago

    Just consider the loads that will be involved and then overengineer the hell out of it...that's my formula anyway.
    (Will that big ol' boy from accross the road be tempted to sit on it?) Try to tie the legs to the top as best you can so the loads get transferred. Welded frames are hard to beat...they can be truly load bearing on their own. And you might consider bracing or connecting the legs together...that makes an enormous difference.
    As for the converter...here is a link to their company site. I just got off the phone discussing these products with master craftsman, Carlos Cortes and he said he thought that Lowes might be carrying it now, but he wasn't sure. Try contacting Quest company to find a supplier near you...a couple of other folks here have found it that way.

    Here is a link that might be useful: Link for Rust Converter

  • 21 years ago

    good information

  • 21 years ago

    Dave, did you ever get the faux bois table finished? So much good information came out of this post.

  • 21 years ago

    Yes the table was finished and it turned out quite nice. I had it at a show and alot of people were tempted but no takers at $300. Still have it at the wine shop in the garden. Someone may eventually drink enough and just have to have it! I will eventually make some other furniture, but it is a lot of work and time consuming!
    Gb

  • 20 years ago

    Bump

  • 20 years ago

    Tango,
    Just wondering if you still use the "restore" product? I finally found a place to get it from but it was a lot more than $10 a quart.
    thanks
    dian

  • 20 years ago

    dian --- Yep. And there does seem to be a wide range of markup depending on the retailer, so shop around. I contacted the manufacturer and they gave me a list of retailers in the area. I then called around to check prices. Still $10 bucks so far.

    Happy hunting & good luck --- Tango

  • 20 years ago

    thanks Tango
    Only one in my area. the rest are about 100 or so miles away. Ashamed to say, I paid $30 plus shipping for a quart.Damn!
    May have to call the company again and get more numbers even of the places are further. wonder what it costs to ship from Texas to PA?
    thanks

  • 20 years ago

    Yeow!!! We're in the wrong business! That's way too much markup even for greedy people. I can't imagine shipping adding that much for a quart bottle. Good thing is it goes a long ways if you brush it on and aren't too messy. Another note. Use disposable gloves as once it hits the metal it starts reacting and will stain your hands.

    Good luck with your hunt. There's gotta' be a better alternative out there.

    All my best --- Tango

  • 20 years ago

    well, the product arrived. Opened the box and it is called rustech corrosion control for rusted metal. NOw when I called this company (number from quest) they assured me they carrieds it. Received this product and immedialtely called. They said,1st, we just put our name on their bottle.Then when questiond some more, they said that they make their own product. and it is better than restore. Well, of course they would say that. I sadi well , I though you were a distributor of the quest product. Thay are but (surprise) do not carry this one. Told him other people are paying $10 for bottle and he found that unbelievable. Can return this if I so desire.
    What is the consensus on this. Should I try it. I mean I already have it, or should I return it and try and fins someplace else.
    I will not have time to search until next week
    thanks
    dian

    I do feel as though I was misled initially.They should have told me they were selling me their product. Gona give quest another call

    tango, do you think The place in Texas will ship to PA
    this place was not too far from me.

  • 20 years ago

    Dian --- What a hassle. Sounds like "bait & switch" to me which is very illegal in just about every state I know of. You should definitely let Quset know what they are up to. Since I know nothing at all about the other product, I can't comment on it.

    Meanwhile, I will make a call tomorrow (local for me) and see what I can find out about their shipping direct. Need to restock myself, so I'll be glad to let you know what I find out. You can email me the retailers name if you like, I'm sure Quest won't be too thrilled with their tactics.

    All my best --- Tango

  • 20 years ago

    Hmm maybe I will call this co. and see if I can just return it by driving out there . It is not too far. That would save me shipping costs and I will get my full price back.

    thanks Tango

  • 20 years ago

    well, called the compaNY BACK and asked for a return tag. No problem said UPS would be here to pick it up. then proceeded to tell me I would have to pay for return shipping. I said why? why would I have to pay for shipping, that is why I am calling for a return tag. He said, well, you bought the product. I told him excuse me, but this is NOT the product I called and ordered from you. They will now pay for shipping. I just hope that I get a full refund or else I will end up having to dispute with the credit card company.

  • 20 years ago

    dian2 --- Spoke with a field rep today who said the price is now about$11.50 a quart because of the price of oil. Good luck with the retailer. I still don't have an asnwer as to whether they even sell the Quest products or not. The manufacturer was supposed to call back but I haven't heard anything yet. Will try again tomorrow.

    Tango

  • 20 years ago

    Ok Tango, thanks

    11.50 sure beats $30. total bill was $40.32 which I got from the credit card co.so that means almost $10 in shipping. Not much of an arguement from the company so I guess they knew they did a bad, bad, thing.
    Did you get my e-mail??

  • 18 years ago

    Hi. Please allow a question from another newbie to working w concrete. I've been thinking about creating a different cover for the well than a faux rock. I would like to make a big mushroom. Question is whether it would be necessary to use rebar for armature or could I get by with a hardware cloth form only? Thanks so much.

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