styrofoam sculpture coating

[tommyhank]

I have some large pieces of styrofoam that I would like to carve into sculptural shapes, and rather than use the styrofoam to make molds I would like to finish the styrofoam itself and wind up with a sculpture that would be appropriate for outdoors. I understand that there is a sealer that styrofoam can be painted with that bonds to the styrofoam,adding strength, and then a variety of materials can be bonded to the sealer. (i.e. paints, stuccos, concrete mixtures, etc.) I have heard of several examples of this over the years and know that it is done by large companies to make statue replicas, landscape companies for man made rocks, etc. My problem is I have no idea what the name of the type of sealant that is necessary or a source or a price. Anybody out there with any experience in this area, I would appreciate some help.

[EJB]

Before getting to the "oops" stage try to determine exactly what kind of foam you are working with. Different types of foam can react adversely to heat or chemicals and create ruined work or perhaps a dangerous toxic situation. For hard coatings, look up products by SMOOTH-ON or INDUSTRIAL POLYMERS. They make a wide variety of products pertaining to foam and plastics.
Be prepared to drop some cash on polymer based products. They are rarely cheap and tend to have a limited shelf life.
An inexpensive, low tech solution may be to use cementitious materials or plaster to achieve your end. I sometimes make quick, cheap prototypes of an idea using florist foam from the local craft store. To make it more permanent and durable I'll give it a few coats of gesso. If I want to keep it long term I'll follow up the gesso with resin or epoxy and paint it.
I have also seen (don't know exactly how it's done) finished pieces that have been metal sprayed over fiberglass. This produces a durable finished piece that is also lightweight. Not sure what the cost is.

[oddist]

I think this is what you are looking for.

http://www.fxsupply.com/vanillacryl/vanillacryl.html

[Araich]

Fibreglass works well if heavy enough.
Check out Adrians public sculpture http://www.studiomauriks.com/
I believe it is possible to spray aluminium over fibreglass. They start by just dusting, then slowly build up a jacket (tiny molten pellets that fuse together). It is a metallising process and would be easy enough to find locally. Aluminium wire for metallising also comes as a copper alloy called 'bronze', it is brass golden and can be patinated.

[Steven Haas]

Another source of information would be the experimental aircraft industry as they use glass/foam construction routinely as does the boat building industry.
A friend has used polyester resin directly over foam successfully, however he doesn't view it as 'perminent'.

[Mordachai]

There is a product called Steelflex that does exactly what you are looking for.

it is made by Fasco, anyone that carries fasco should have it.

http://www.fascoepoxies.com/

|M|

[GaryR52]

I know this thread's a bit old now, but another shell material for foam is Design Cast, a gypsum-based product that creates a rock-hard shell for outdoor sculpture. http://www.design-cast.com/index.php

Another thing worth mentioning on this subject is that EPS (expanded polystyrene) will have to be coated before using any kind of resin as a covering, as polyester resin dissolves the foam. Where that's concerned, the better foam to use is polyurethane, which doesn't have that limitation and can be obtained in heavier densities, as well. A good supplier of polyurethane carving foam is General Plastics: http://www.generalplastics.com/produ...il.php?pid=19&

For inspiration, check out the work of Don Frost, who works exclusively in fiberglass. I believe he carves foam and then covers it with fiberglass: http://www3.sympatico.ca/g.foy/index.html

Gary

[oddist]

I just came across this company that has a line of interesting sculpting products.

Some can be used to coat foam.

[GaryR52]

Amazing realism, Oddist! I'll be watching TV, wondering if it's real or if it's Zoopoxy from now on!

I'm not sure there is much applicability to non-objective sculpture, though, since I'm not trying to represent anything in the real world. If I were doing the sort of thing Duane Hanson did, then it would be highly useful.

Gary

[oddist]

Gary,

Did you miss my point? It's about the material..not it's application.

I'm sure this stuff can be used for non-objective work. After all, isn't a tree a non-objective piece of work by Nature?

[GaryR52]

Well, the way I see it, the whole point of this material is to pass it off as something else; i.e., wood, stone, etc. and it's chiefly used by those in the prop-making industry, who have to create realistic environments for movie, TV and theatre sets. Its application to non-objective sculpture isn't as clear cut. Since I'm not trying to represent anything, I don't require a material that mimmics other materials. In fact, I rather subscribe to the idea of "truth to materials," which is also known in modern architecture. It is the view that, if you're using steel, for example, it should be readily apparent that steel is being used, instead of trying to disguise it as wood or concrete. In a non-objective sculpture in which the core material is sculpted foam, I'd tend to want a surface finish that is smooth and perhaps one color. Of course, there will also be instances in which I'd want to have a rougher surface texture. This is an issue I've been wrestling with; i.e., whether to make a sculpture look like fiberglass or to make it look like stone or bronze. It's acceptable, in sculpture, to use cold casting to simulate stone or bronze, but there was a time when this was frowned upon by purists and, to an extent, still is. So, my point is, why would I use this stuff and what would I use it for?

Gary

[oddist]

Sorry, I retract my suggestion.

[GaryR52]

No need for apologies or retractions, Oddist. Like I said, I'm conflicted about the issue, myself. Whether to make it look like stone or bronze or not? I just don't know. I guess it depends upon who I'm selling to, right? People just looking for sculpture for their home may not be as picky as more "serious" collectors. It's tough to decide which way to go. Of course, anything I cast in actual bronze is fine, but, especially just starting out, that's an expensive option.

About Zoopoxy, I wonder what else it can simulate, aside from tree bark or rocks? Could it, for example, simulate bronze or other metals? I guess the answer is in the finish; i.e., paint applied.

Gary

[bluedogshuz]

I hva been coaqting EPS for 10 years with epoxies fiberglass and durable faux finishes. I originally did this so I could do large scale armatures for future bronze cast or marble carvings. I have a finished product and would simply say to someone that says its not REAL bronze or REAL marble but like the piece NO PROBLEM I can have it carved in Carrara for $16,000. or bronzed in the US for $14,000. or yo can by the FAKE for $3,000. doesn't matter to me. As a matter of fact I am so confident in the material maybe I should charge more. If I want to fiberglass my pool (which takes 2 days) they charge $5.000. and guarantee it 25 years, thats a long time. With proper sealing and maintenance fiberglass and epoxy can last 100 years. As someone noted you don't have to worry about it being melted down for the bronze. Or, in my neighborhood stolen for junk metal and believe me people do it.

[GaryR52]

Good points, Blue. By the way, can you use an epoxy resin directly on EPS without damaging the foam, as polyester resin does? If so, I'm thinking EPS might be the best route for me, as it's both cheaper and easier to carve than polyurethane. Not as strong, though, unless you get it in higher densities.

Gary

[GaryR52]

I just found some good resin/foam tips from the surfboarding world: http://www.pointblanks.com/tech_highlights.html

Key points:

"...epoxy resin is 15% stronger than typical polyester resin..."

"...extruded polystyrene (Styrofoam®)...has greater shear and compression strength than our previous expanded polystyrene and greater strength than a typical polyurethane..."

"...our new extruded polystyrene foam is "closed cell" and absorbs 73% less water than the standard polyurethane..." (important for outdoor pieces)

"...extruded Styrofoam®...has many advantages over EPS and polyurethane foams."


P.S.: Just found this handy EPS "calculator": http://www.univpack.com/Expanded_Polystyrene__EPS_.aspx


Gary

[bluedogshuz]

Yes Gary I use epoxy because it won't melt the EPS. My supplier fiberglass coatings showed me the vinyl stuff and something else to cover theatrical foam. I may have missed something but I'm pretty sure It won't work for permanent sculpture. EPS has no structural strength it function as a filler/armature. My first experiment was wood with EPS over it so I could screw it together. I did'nt properly seal the wood and water rapidly infiltrated the design cast layer which then cracked,big time! Next I sealed the wood with epoxy, fiberglass, and collodial silica, then the foam then the design cast. I think it will work, my construction friend does not. The epoxy directly with 2 layers of 6oz fiberglass amd microsilica mixed in is virtually bullit proof for a skin. It is probably good for public sculpture cause quite frankly you take a hammer to a bronze or marble and youv'e got problems. you bust up a fiberglass piece (recently happened to a piece in front of city hall) it can be repaired in a couple of days. One more note regarding layup on foam, it SUCKS! complex curves with a fluid substance? I was reading poly techs stuff
and have figured it out. Cast thin sheets of epoxy/glass over surface treatment then cut the sheet to the eps and lay up (glue) to the EPS. Its that or multiple layers of epoxy and carve (not).

[GaryR52]

Hmmm...so, I guess it's polyurethane, then, if strength is an issue. That last link I posted (the EPS calculator); I tried the calculator and found they only have up to 2 lb density. Even at that, a 48" x 96" x 12" sheet is $250. Of course, 2 lb density is way too weak. Even in polyurethane, I wouldn't use less than 6 or 8 lb. foam. I guess if I'm going with polyurethane, the epoxy resin vs. polyester resin thing is a moot point.

P.S.: I'm thinking Design Cast is preferable to either resin, as it won't run.

Gary

[GaryR52]

Hey, guys, get a load of this stuff! http://www.alsacorp.com/

They make some amazing paints and coatings for many applications, including heat-reactive paints and color-shift coatings.

P.S.: These are incredibly expensive paints, though.

Gary

[bluedogshuz]

Just keep those links coming Gary someday I'll get a chance to read them, for know i'm putting them in my favorites! By the way, I recieved sample of that celled aluminum stuff. Looks like crushed tin cans. I can't see an application except maybe high tech coffe tables or something. Also remeber if you are working with foam you need a hot knife, I just replaced mine and it was $250. with several attachments. Also design cast is recommended for EPS open cell because it really needs to grip the surface. It is quite structural when you use fiberglass (previous post) but I bond all connection points with epoxy resin/glass so they won't break (which the will).

[GaryR52]

Yep, that's what I thought. Aluminum foam is being used mostly as partitions/dividers, that sort of thing. I was thinking it might have an application as a sculpture material, but, I guess not.

Well, if you're cutting EPS you need a hot knife, yes. Polyurethane is best worked with conventional wood carving and power tools, though, as it can't be heated. I'm still on the fence, as to which foam to use. I think polyurethane is more widely applicable because it doesn't require a barrier coat for use with polyester resin, but it's more expensive and doesn't carve as readily, also. Some of these purpose-made hot knives I've seen are pretty expensive, though, as you noted. Sounds like you bought the Original Hot Knife Kit.

So, with Design Cast as the shell material, I should use open celled styrofoam, as opposed to closed cell foam, eh? Yep, that makes sense. How about the use of fiberglass cloth with it? Is that necessary, or can I just lay the Design Cast directly on the foam without it? I guess I could if I mix chopped strands of glass fiber into the Design Cast, right?

By "all connection points," I assume you mean you're rolling the Design Cast into constant thickness sheets and then laying them up on the surface and "stitching" the seams together to form a continuous surface, right? That's the way I have imagined it working, anyway, otherwise, you'd wind up with a lumpy and inconsistent covering of Design Cast.

Gary

[bluedogshuz]

You have to use fiberglass with EPS that is where the strength is. Buy 2-3" fiberglass tape that way you dont have fraying, cut small pieces soak it then smooth it over EPS just like plaster. Put on your top coat and sand. You can also use chopped fiberglass short pieces high amounts to get a very strong piece.

[GaryR52]

Thanks for the tips! Now I know how to proceed....as soon as I have the money to, that is.

Oh, one thing; what about the resin? Should I use epoxy resin or polyester? Epoxy, right?

Gary

[bluedogshuz]

Yes. Ill send you my bill

[GaryR52]

Just put it on my tab.

Whoohoo! Another useful material for us to play with: http://www.systemthree.com/p_sculpwood_2.asp

Gary