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The following article was written by the late George E. Adamy, describing the processes he used and the products he developed.  In 1991 I was introduced to the POLYADAM Concrete System.  It enabled me to develop my artwork in a whole new direction.  Through years of using Adamy’s products, I have made some adaptations in his procedures to compliment my style of sculpture.  I added footnotes, [  ], to sections of Mr. Adamy’s writing and included my notes at the end of this article.

I hope the combination of our information will be helpful to you and your creative work.  SWH 


For Sculptors, Craftspeople, Restorers, Architects, Curators, and Teachers 

By George Adamy

When an acrylic polymer emulsion is mixed with Portland cement and sand and reinforced with Glass Scrim, a mechanically superior, permanent and relatively light weight outdoor object can be produced quickly.  This is the POLADAM Concrete System*. Plaster and gypsum (Hydrocal) can be substituted for the Portland to make superior indoor objects.

The POLYADAM Concrete System consists of space age materials and materials proven over the centuries, plus new and traditional fabrication techniques.  The materials used are POLYADAM II, Portland cement (Type1), play sand (silica) and Glass Scrim.


1.  POLYADAMII or P-IIis an acrylic polymer emulsion, non-toxic, non-hydrocarbon, non-flammable, water-based, air-cured, low odor, adhesive, and white when an emulsion, but clear when dry.  It contains expensive acrylic solids specifically formulated to make the highest quality objects.  Cheap commercial emulsions containing mostly water and Rhoplex paint medium are totally unsuited for the fine art, permanent craft, and restoration projects under consideration here.  In addition, Rhoplex contains a toxic component, formaldehyde.

2.  Portland cement is industry's major construction material.  Ancient Roman structures made of concrete are still standing.  Portland, either white or regular grey, is cheap and available everywhere from building supply dealers, as are aggregates including play sand and mineral oxide pigments.

Very high cost "cast stone", "man-made stone", "synthetic stone", "Vatican Stone", etc. are essentially cement, gypsum and silica.  There is no reason to use them.  Simply add 10-20% Hydrocal to the Portland.

3.  Glass Scrim is a new material that is different than ordinary fiberglass used with resins.  The latter is destroyed by the alkali in Portland.  Glass Scrim is alkali-resistant, treated and constructed to be compatible with cement and all other products.  This material replaces traditional rusting steel wire armatures (hardware cloth, etc.) and reinforcements (burlap, etc.) in castings, laminations, Ferroc ement, etc. because it is physically superior, much easier and quicker to fabricate and won't cut fingers or tear clothes.  Unlike metal, it dissipates energy from impact blows.

4.  For heroic size or thin areas such as outstretched arms or fingers, armature reinforcement with rebar or steel wire is necessary.  They are available from building supply dealers.



POLYADAM Concrete or POLYADAM Plaster-Hydrocal can be directly applied to many kinds of substrates (armatures); cast, slushed, sprayed and tamped into molds; laminated; made into molds; used in the Ferro cement technique; modeled; and carved. 

The POLYADAM Concrete System is an attractive alternative for "fiberglass" which is actually polyester or epoxy resin with fiberglass embedded in it.  These hydrocarbon resins are highly toxic, cause illness, often smell, are difficult to use, are expensive, and all of them do not weather well. 


All of the methods of fabrication of POLYADAM Concrete, (or plaster) begin with a Neat Mix which is:

1. 1 part P-II

2. ¼ part water but never more, now or later.  Water initiates the chemical reaction.

    Optional - pigment or liquid colorant

    Optional - Defoamer if casting, slushing, or molding.

3.  3 parts Portland Cement, Type 1, or 2 ½ parts plaster or Hydrocal.


To make a Basic Mix add to the above:

4.  Up to 4 parts Sand (silica) such as play or masonry or marble sand.



The Neat and Basic Mix ingredients are pre-measured by volume using spoons, cups or pails.  The colorants are first mixed into the P-II and water and then the Portland is gradually added while continually mixing (2 minutes with a moderate speed Jiffy Mixer or 3-4 minutes by hand). Do not eyeball amounts or dump the powder into the liquid.  Add the sand, or other aggregate, gradually while continually mixing.  This method will put more cement and sand into a given batch thereby making the end product stronger.  Keep records so that later additions will be similar in strength, texture and color. 

The Jiffy Mixer is chucked into an electric drill. It is constructed to minimize the bubbles in the mix.  The formula used varies with the particular fabrication method to be used.  Please see the individual sections that follow. 


One gallon of P-II used in a Basic Mix with one layer of Heavy Glass Scrim covers an area of about 25 square feet, ¼ inch thick and weighs about 58 lbs. 

The chemistry of Portland Cement is radically changed by the use of POLYADAM II.  Normally, when only water is used, the Portland requires a 5 day wet cure, but with P-II, a 24 hour cure is ample. 

If the POLYADAM Concrete dries out sooner, particularly in thin layers, it will crack unless it is covered with plastic film for 24 hours to regulate the rate of cure.  Therefore after each work session and upon completion of the object, or when making repairs, make sure that the POLYADAM Concrete: (A) is not dry and, if it is, wet it with P-II (never water), (B) is covered with plastic film, such as polyethylene, for 24 hours. 


Direct application of the POLYADAM Concrete System onto armatures (substrates) is the fastest and easiest way to make durable yet lightweight outdoor objects of any size.  Anything that will support the weight of the POLYADAM System can be used as an armature since it cures as an independent strong shape irrespective of the support.  So canvas and cardboard, clay and plaster, wood and steel, or foam, all work as substrates.  The fragile porous ones should first be stiffened and strengthened by brushing or spraying on P-II, P-89 or a mix of 1 part Portland or Plaster into 1 part P-II or P-89. P-89 is a thicker version of P-II and is used primarily to cast paper and to seal.  Glass Scrim can also be incorporated for additional strength.  It can be attached mechanically, using wire, twine, roofing nails, or a hot glue gun, directly to the substrate and then coated with the POLYADAM Concrete mix. 


Styrofoam makes an ideal armature because it's easily cut, carved, and shaped with serrated knives, saws and coarse files and glued with water based adhesives and P-89.  It is lightweight, weather resistant and readily available.  Appliance dealers daily throw out interesting shapes.  It can be bought in 2' x 8' slabs 1, 2, and 4 inches thick at building and marine supply dealers.  Cheap foam is available but it crumbles when being cut and shaped so consider using the higher quality closed cell foam from Dow or its equivalent.


Do not use hot wire cutters, or other hot tools to fabricate Styrofoam since excessive toxic gas is released.  Use the tools mentioned.  Work outdoors, if possible, or with proper ventilation indoors.  Wear a NIOSH approved vapor and dust mask and vacuum the area frequently.  Store foam in a well-ventilated area.  Once it is coated there is no longer any concern. 


A flexible foam, sometimes called "foam rubber", can be quickly formed into delicious, voluminous organic shapes of any size held in place by rubber bands, wire, or sewn with twine. Buy it from a catalog under "Toppers" or foam and upholsterer.  It is non-toxic (unless burned). 


Large armatures, and those with thin extensions, such as fingers, should be reinforced with steel wire, rebars or pipe. Make sure you have adequate support for the structural demands of your object. 

Polyurethane foam is lively, it moves when touched and your shape can be distorted in another area when you apply some POLYADAM Concrete and Scrim to a given area. Therefore, in addition to securely mounting the armature to a base board, use supports such as plastic bottles, cups, or wood covered with plastic film to keep the shape. Work only in small areas at a time applying the various layers, letting them harden for 24 hours and then move onto the next area.  Don't try to do too much in any work session, but think of what you are accomplishing at each stage of the work. Excessive neatness or desire to "finish" the work at each stage is frustrating and a waste of time. If you don't cover everything or have rough spots, leave it until it hardens, then smooth them or simply apply the next layer of POLYADAM Concrete. With polyurethane foam, screening, canvas and cardboard, have patience, work systematically, and go with the material. Don't fight it. As the layers are added, the substrate (armature) becomes stronger and will distort less. Remove the supports only after the reinforced object stands by itself, then finish the areas involved in the support.

Brush on a thin layer of runny POLYADAM Concrete (or Plaster) Neat Mix. Use 1 Part P-II and 1 to 2 parts Portland. Add several layers of Basic Mix, using as much sand as you wish, alternating with layers of Glass Scrim, Medium- Light and Heavy. Pre--cut the Scrim to size, shape and notch. Use wire or string to hold the Scrim onto vertical surfaces of the urethane foam and wide head roofing nails for the Styrofoam. The Medium-Light Scrim is put on first and is wrapped around corners. The next layer of Heavy Scrim is merely butted up to both edges. The number of total layers of Basic Mix and Scrim is determined by the size and shape of your object.  

One layer each of POLYADAM Concrete Basic Mix plus medium-light Scrim for a small object, 3 layers of Basic Mix and 1 layer each of Medium-light and Heavy Scrim for a medium size object and 4 to 5 lavers of POLYADAM Concrete and both Scrims for heroic size are recommended. Total System thickness will be ¼ to ¾". 


Steel or aluminum wire screening make excellent large scale armatures.  Fiberglass screening, which is softer and less rigid, is fine for small objects.  All are easily cut and shaped and held together by sewing or with twisted wire.  Purchase them from hardware or building supply stores. 


After creating your 3D shape and mounting it on a board if small, begin the stiffening and space filling by

brushing or spraying on a Neat Mix of 1 part P-II. ¼ water and 1 to 2 parts Portland Cement. Let it dry. Next

add a heavier Neat layer containing 1 P-I!, ¼ water and 3 Portland which is applied with a brushed or spatula to achieve texture. If a smooth finish is desired, dip your tool into P-II and then smooth, followed by dry and wet sanding and/or tooling as previously described. Embedded objects can be added to the mix or stuck into the wet POLYADAM Cement. 

A small object with many close folds may now be finished and can be painted. Larger objects and those with

free form extensions will require additional layers of POLYADAM Concrete. and reinforcing Medium-Light or

Heavy Scrim and possibly rebars or steel rods for structural strength. Simply build one layer of POLYADAM

Concrete with Scrim at a time until the object will support the anticipated stresses it may be subjected to. A

large wall piece will require less support than a free standing sculpture that kids will climb on. 


Gutter guard is available in about 6" wide rolls in hardware stores and wire lath for plastering from building suppliers. Because they have a heavier metal construction they are easier than screening to shape into intricate detailed shapes. Gutter guard is excellent for jewelry..

Because of their larger mesh holes, they have to be covered with cloth or paper dipped into, or sprayed with P-II or POLYADAM 89. When dry, hand-made paper pulp or POLYADAM Hydrocal (or concrete) can be hand molded, or applied with a spatula or brushed and the results painted. 


Build your wire armature and securely mount it onto a board. See basic sculpture books on how to make armatures. Cardboard is scored, bent and assembled using drafting or cloth tape. Provide sufficient supports so it doesn't collapse when you put weight on it. Thoroughly wet any fabric, from pantyhose to rugs, by dipping it  into P-II, or preferably, the thicker P-89. Squeeze out the excess, and wrap the fabric around your armature.  Secure with wire or twine until the fabric dries. This ranges from minutes to days depending on how much P-II or P-89 was absorbed. 

An alternative to dipping and arranging is tying or sewing the fabric on dry and then spraying or brushing on several coats of P-II or P-89. 

Next add a POLYADAM Concrete or Hydrocal Neat Mix layer followed by a Basic Mix layer (see page 2 for formulas) and cover the objects for 24 hours to cure. Some objects are now complete except for any tooling or modifications you might make. The object can be colored. 

Larger, life-size, objects or those with structural concerns can have additional layers of POLYADAM Concrete or Hydrocal plus Glass Scrim added to give them greater strength and durability. 

The POLYADAM Concrete object can be permanently displayed out doors. The POLYADAM Hydrocal objects are for indoor display, and temporarily outdoors. P-89 or acrylic auto lacquers are the preferred final coat sealers. 



To make copies of an existing sculpture or object, your mold will either be a rigid plaster mold (including plaster waste molds) or a flexible RTV rubber-type, in one or more parts. The plaster molds have to be thoroughly dry and then sealed with several coats of brushed on P-89, POLYADAM II, or acrylic auto lacquer, (never shellac, varnish or polyurethanes), then waxed and buffed several times with Johnson’s or Butcher’s Paste Wax. All molds, including the plaster molds, have to have a release applied. We prefer Par Film Spray since it leaves no residue on the casting so it can be colored. Also the mold does not need to be cleaned. It is available from Adamy.  [4] 

Ready-made objects ie. boxes, cups, bowls, etc. can act as molds to give generalized cast shapes. Likewise, molds can be made from many common materials like cardboard, canvas, plastic films and sheet, wood, clay, etc. The fragile materials should be stiffened and strengthened with P-II or P-89. All materials are then waxed and sprayed. They may require temporary supports or reinforced mother molds. Securely mount the mold onto a board. 


To get a hard, smooth pin-hole free casting which accurately picks up the mold's details, brush in, in one direction a 1/6" to 1/8" layer of POLYADAM Concrete Neat Mix containing a few drops of Defoamer from Adamy. Bounce the mold to eliminate air pockets, and then allow the Neat Mix to set-up for 5 to 10 minutes; but, before it dries out, a layer of Basic Mix is brushed on in a 1/8" layer for a total thickness of less than 1/4". A layer of precut, shaped Medium-Light Glass Scrim is gently placed into the Basic Mix layer. Likewise, steel wire should reinforce ant thin extensions of the object. Next cover the reinforcements with a Basic Mix. A small piece is now complete. 

Cover the object with plastic film after every work session, and, after completion of the object, for 24 hours, for proper cure. 

For medium and large size objects, additional layers of Glass Scrim (Heavy and Medium-Light duty), are alternated with layers of Basic Mix. Steel wire, rods, and pipe are embedded for structural reinforcement. A total thickness for the System is between 1/4 and 3/4 inches. 

Each piece of a multiple piece mold should be built up as above incorporating a flange, or shelf. into me edge of the casting from l/8" to ½” (depending on size). This flange should be sloped downward from the outer edge inward.  After the individual pieces have cured for 12 hours or more, each flange is brushed with P-II  and then coated with a Neat Mix and the pieces firmly clamped together. Where possible additional Neat Mix is then applied with a spatula or slushd into the seam areas. Glass Scrim is then patted in. The mold is then covered for 24 hours or more to cure. 


A POLYADAM Concrete (or Hydrocal} Neat Mix, mixed with a Jiffy Mixer, with 2 parts Portland (or Hydroca1) and containing Defoamer [5] from Adamy is used as the first layer in order to pick up pin-hole free mold detail. Let it set but not dry out. Subsequent layers can contain more cement, as well as sand and oilier aggregate. This will make the mix thicker and may require more powerful equipment if you are spraying. 

To speed up the set (hardening} of the Neat Mix, use a Jiffy Mixer, mix for a longer time, or add up to 40% Hydrocal to the Portland mix and 20% Portland to the Hydroca1 mix. Experiment and time all these variables including the amount of the Hydroca1 or Portland needed. The latter will depend upon ambient temperature and the freshness of your Hydrocal or Portland. The Hydroca1 will not change the outdoor properties of the POLYADAM Concrete since it simply becomes another aggregate in the mix. 

Several layers are built-up for a total thickness of 1/4" to 1/2", or more, depending upon the size and structure requirements. Glass Strand, Glass Scrim and steel can be added. See the section on "Casting into Molds". 


Laminating is simply making a club sandwich of alternating layers of POLYADAM Basic or Neat Mix plus Glass Scrim. The laminate can be flat or contoured. 

Tamping requires additional cement and sand. Optionally, Glass Strand, can be added to the Basic Mix. A high degree of stiffness is desired, although the first layer into the mold should be a little wetter to pick up mold detail. Again, Glass Scrim, and possibly steel reinforcement can be added. 


Ferro Cement is a great technique that hasn't achieved the popularity it deserves. Huge column less stadiums and racing canoes have been successfully built with the Ferro cement technique. The Basic Mix is pushed into preformed and supported multiple layers of steel hardware cloth. The surface and inside are then finished off. 

We would like to suggest that layers of Heavy Duty Glass Scrim be used instead of steel hardware cloth. It is easier to cut and shape, doesn't puncture hands or tear clothes, doesn't rust, is lighter, and will produce a stronger product to absorb impact and provide for natural expansion and contraction. 


Use ready-made, found or constructed molds of any material to cast generalized shapes which can be carved. See section "Preparing the Mold". 

To the POLYADAM Concrete (or Hydrocal} Neat Mix, add soft aggregates such as perlite, pumice, vermiculite, etc. or hard aggregate such as sand, stones, marble dust, metal chips, etc. Pour the mix into the mold in any thickness desired, cover and let cure under plastic film. Demold and carve the soft aggregate concrete with wood carving tools and the hard aggregate concrete with Stone carving tools. See texts on stone carving for details. Because the POLYADAM Concrete increases in hardness, do your major shaping-carving beginning about 12 to 18 hours after you pour it. When you finish working, rewet with P-II and put under plastic film for 24 hours. 


Since a POLYADAM mold is rigid, no undercuts are possible. The original, or model, to be molded will have to be separated into no undercut sections by use of metal shims or clay. 

The original is first cleaned and mounted on a board, and if porous, sealed with several coats of P-II, P-89 or acrylic auto lacquer. Then waxed and buffed. Do not use shellac, varnish or polyurethanes. Then the shims or clay separators incorporating keys (or locking devices) are put on. Finally, the area to be molded is sprayed with Par Film mold release.  

A POLYADAM Neat Mix containing Defoamer from ADAMY is carefully brushed on in one direction in a 1/16"-1/8" layer and partially set. Then a Basic Mix 1/8" thick is applied, followed by a layer of pre-shaped Glass Scrim. Additional layers of Basic Mix and Glass Scrim are alternated until a mold of sufficient strength is made for the size of the model. The total thickness will be between 1/2" and 1 ". A heroic size piece may require metal pipe reinforcement to maintain stability. 


Immediately upon removal from the mold, the casting's flash should be removed with a knife and file. Any voids should be wet with P-II and then over-filled with the same recipe used to make the original surface. The object should then be covered with plastic film and let cure for 24 hours, after which the over filled voids are shaped and smoothed with knives, files, and sandpaper. Emery block and cloth, or carborundum wheels or blocks may be used to smooth and polish. 



The goal is to find a mixture which “models like clay, and cures as concrete". Clay needs firing and is fragile. Cement doesn't model well, it slumps and won't hold together in coils. So, one can incorporate additives to the POLYADAM Concrete System to make it more plastic or workable. The POLYADAM Concrete System, with additives, still cures as permanent, durable, outdoor use concrete. We call our on going efforts POLYCRETE. 

We start with a Basic P-89 mix; 2 parts P-89. 1/4 part water, 4 parts Portland Cement, 2 parts play sand or marble dust, and then add approximately 122 part Hydrocal or plaster. Then add 1 to 3 parts of some of the following: vermiculite, perlite, pumice, ash, or powdered clay. Add more P-89 as the mix gets too dry. Experiment with proportions to get the plastic and mechanical properties you desire. Then follow the instructions given in the various fabrication techniques already discussed. 

Please call with the results of new additives, or modified fabrication techniques you have tried. Thanks. 


Hydrocarbon or oil based paints, penetrating oils, and waxes should be applied only after the concrete, plaster or pulp object is thoroughly dry which may take days or several weeks. Otherwise, the paint may blister and peel. 

Water based paints may be added into the mix at any time, while the object is still damp or when dry. The preferred colorants for concrete are not only lightfast but alkali resistant. Most artist’s acrylic latex paints can be used. 

P-89 and acrylic auto lacquers weather-seal and/or color coat concrete, plaster, Hydrocal, clay, paper pulp, paper, canvas, cardboard, wood, foam, metal, and plastics. They seal porous molds and canvas, paper and wood painting grounds, and provide additional binding strength to other acrylic paints. P-89 is an excellent medium into which pigments can be dispersed. 

Mineral oxides or commercially prepared liquid colors, in earth tones, can be added from 3% to 5% by weight of the oxide to the weight of the Portland. Unfortunately, except for black and brown, the colored concrete doesn't have an appealing look. Daubing in pigment while the object is still wet or painting when dry gives more intense colors.  [6]


While P-II, P-89, Portland Cement, Hydrocal, and Glass Scrim are relatively safe, common sense precautions include good working habits, proper house cleaning, and personal hygiene. Styrofoam has already been discussed. Wear a mask when working with cement and Hydrocal in dry form or when tooling. Sand is a free crystalline silica which is hazardous, and breathing its dust may cause silicosis. Please protect your eyes, wear a NIOSH approved vapor and dust respirator, wear gloves and work in a well-ventilated area which is vacuumed often. Don't smoke, eat, or allow children in your work place. 


For traditional papermakers as well as artists who don't make their own pulp, we offer an exciting and simple new approach to making large 3-D objects with Polymer and pulp fibers. It is called The POLYADAM Cast Paper System. 


POLYADAM 89 (P89) 


If you wish to stiffen and make winter resistant only fabric (from pantyhose to rugs) or paper (from rice to cardboard), dunk it into P-89, drain the excess and arrange on a pre-shaped armature made of any material (P-89) is adhesive); or, smooth into a mold (small pieces can be overlapped). 

Wear plastic gloves. P-89 is water based and non-toxic but sticky. 

Once dry the fabric or paper may require additional coats of P-89 (brush or spray on) to further stiffen.  For even greater stiffness and strength mix a little plaster or cement into the P-89 before dunking; or after drying, apply to the back. Glass Scrim can be used for backing on large pieces. 

To inherently color, mix pigment or acrylic paint into the P-89 before dunking.  Various fabrics and papers can be combined for a collage effect. 


If you wish to strengthen and make water resistant, add P-89 to dry chopped pulp-fiber or paper mache to desired degree of wetness and then form on to armatures or into molds 

Follow the above directions about further stiffening, backing and color. 

FOOT NOTES by Sherri Warner Hunter

[1]  I have settled on using two variations of Adamy’s mixes for the applications on my sculpture. The AR  fiberglass mesh/glass scrim are layered with the POLYADAM Concrete after being slurried.

The two mixes I use are:
          SLURRY – I think of the slurry as a binder or primer and apply it to every surface when    adding more  concrete.  It should be the consistency of a thick latex paint.  Add more PII to correct  consistency.             
            1 part cement
            1 part PII
            ¼ part water, never more.
             POLYADAM Concrete – Should be the consistency of soft clay.  Add more PII if needed.
             3 part cement
             3 part sand
             1 part PII
              ¼ part water, never more.


2]  The product P-89 referred to in this article is currently not in production.  11/02/08 

[3]  I’m a huge fan of working with closed cell, polystyrene foam and typically use hot tools for carving and cutting.  Using the foam has been important in controlling the weight factor of large sculptures.  The key to working with any sculpture material is to know the product and following recommended safety procedures.  Good ventilation is essential to working with hot tools and foam because the resulting fumes are noxious. 

[4]  Par Film Spray is currently not available from SWH Art Studio Inc.  11/02/08 

[5]  Defoamer is currently not available from SWH Art Studio Inc.  11/02/08 

[6]  I prefer an inherent color; a mineral based colorant added to the mixture.  Refer to Product Information at the Supply Store section of this web site for more information.



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