Tag Archives: epoxy

Choosing the right disposable glove

First, I wish to offer a caveat; I don’t write much about safety, because it’s a highly complex area, especially once you start talking about safety around chemicals. I’m not an expert, and if you are in a workplace situation, there are actual regulations, standards and laws that need to be followed. The last thing I want is someone’s sum total of knowledge about safety coming from “Eric Hart’s Props Blog.” Still, the home hobbyist may not know where to look for information, and the prop shop employee may not know what questions to ask their employer, or what their employer is responsible for providing. Thus, what follows is not a guide for choosing the right disposable glove; rather, it is a guide to what questions to ask and what information to look up to learn which disposable gloves are best for each situation. All the safety data in the world is useless if we don’t know what information we are trying to find, or even that we need to find certain kinds of information. Often, we don’t know what we don’t know.

Dozens of companies make disposable gloves, offering hundreds of combinations of materials, thicknesses and liners. You need to find the permeation data for the specific gloves you are using. This will tell you how long it takes for specific chemicals to work their way through the glove and onto your skin.

No single glove will protect you against every chemical. There were approximately 50,000,000 chemicals registered by the CAS on September 7, 2009, with more being added at the rate of twenty-five per minute. Luckily in theatre, we only use a small percentage of those chemicals. If you work at a theatre or shop in the USA that employs ten or more people (that’s counting the whole theatre, not just the prop shop), then it is subject to OSHA regulations, and your employer is required to inform you of any toxic chemicals you may be using.

As a general rule of thumb, you should be wary of rules of thumb when it comes to safety. But a good rule of thumb to follow in safety is “don’t get stuff on you, and don’t breathe anything that isn’t air.” Choosing the right glove falls under the “don’t get stuff on you” part of the rule. Gloves are necessary because many chemicals can be absorbed through the skin. Chemicals commonly used in prop shops that can be absorbed through the skin include solvents and epoxies. Solvents don’t just include pure solvents like acetone, xylol and mineral spirits, but also any product that includes solvents: spray paints, cleaners, adhesives, etc.

Another good rule of thumb is that latex gloves don’t stop any chemicals. They can keep your hands dry, and they’re great for keeping blood and other bodily fluids from getting on your hands. They’re also useful for the reverse: keeping your own sweat and oils from getting onto your work surface. But as far as working with any sort of industrial or household chemicals, they may as well be invisible.

Notice how I mentioned household chemicals above. Just because you can buy something in a grocery or drug store doesn’t make it safe to work with without proper protection. For example, many cleaners like Windex, 409 and Simple Green use a chemical called 2-Butoxyethanol. The toxic exposure level of 2-Butoxyethanol is less than that of acetone and hexane, placing it in the category of “highly toxic” chemicals. When you start looking at permeation charts for popular glove brands, you see a trend; latex gives you no protection, while neoprene and vinyl will offer only several minutes before exposure begins. If you are using anything other than nitrile, you are exposing yourself to a highly toxic chemical.

If you are using a glove and the substance is splashing or spilling onto your bare arm, it defeats the purpose. Make sure you are wearing sleeves that offer similar chemical protection, or use longer gloves.

Many chemicals we use for prop making are toxic through skin absorption. An example is any of the two-part epoxies we use: sticks of epoxy putty, five-minute epoxy glue, epoxy coatings for fiberglass and carbon fiber, epoxy resin for casting. Epoxy is a sensitizer, which means our bodies do not react to it on the first exposure. Rather, it is on the second or subsequent exposures where we develop what is essentially an allergic reaction. It can even be after decades of using a product before one reacts to it. But reaction can be severe. Here is a chilling but not uncommon description of a reaction:

Open, oozing, and itching insanity hives virtually all over my body and my eyes literally were swollen shut for a week on two separate occasions. Recovery, each time, took better than a month.

Once developed, it is not reversible, and occupational physicians may advise you to not only never use epoxy again, but none of the “two-part” chemicals in that category. No more Smooth-On products, Great Stuff, A-B foam, etc. If you make your living as a props artisan, you pretty much have to do all your molding and casting out of plaster.

It is important to note that permeation data charts tell how long it takes for a chemical to permeate through a glove. This implies that no glove will offer permanent protection; they are called “disposable” for a reason. In fact, the most a glove gets tested is for 6 hours. If you use a pair of gloves all day, don’t set them aside for the next day. In fact, you should throw the gloves away. Trying to stretch the use of a pair of gloves to save money may seem thrifty, but it is actually counter-intuitive. The same is true of any safety measures and products you use. If you use or reuse them improperly, you get the worst of both worlds; you are spending money but not keeping yourself safe. If you feel you are spending to much money on safety equipment to make props, the best solution is to stop making props. You don’t go scuba diving without an air tank. We often get in situations where the easiest solution seems to be to continue on and finish a prop; it’s late and you’ve run out of gloves, and all the hardware stores are closed, and all you need to do is get one more coat of epoxy on so it can cure by the morning and they can use the prop in rehearsal. When you get to those situations, remember this: Your goal in life is not to finish that single prop. Your goal in life is to build props for the rest of your life. Taking shortcuts now will affect your health later on. No prop in the existence of humankind has ever been more important than your health.

A good shop foreman will be consistent in his or her purchasing of disposable gloves, so you don’t have to hunt down the permeation data every time he or she buys a new brand.

In conclusion, don’t get stuff on yourself. You should know what is present in any material or substance you are working with. If it includes chemicals that can be absorbed through your skin, you need to find out what glove will offer protection from that chemical, and how long it will offer that protection. Remember that gloves from different companies may differ in their permeation data, even if all the stats on the box seem the same.

Five Prop Quick-Fixes

Sometimes you need to fix things right, and other times, you need to fix them right now. Here are four things which prop people rely on to fix a prop when the audience is already seated and the curtain is about to go up.

Hot Glue

hot glue gun
Hot Glue Gun

It’s a common prop adage that “anything can be fixed with hot glue.” That’s true in many cases, and the fact that it cools in minutes (sometimes seconds) and is removable makes it a great candidate to hold two things together at the last minute. When you need to┬áseparate┬áthe items, just peel them apart. Keep in mind that it is not structural, and it will not come out of most fabrics.

Gaff tape

gaffers tape
Gaffer's Tape

Gaff tape is short for gaffer’s tape, so named because of its use by gaffers to tape down cords and cables. It’s like duct tape for prop people; unlike duct tape, it leaves no residue when removed, and most importantly, it comes in black, so it disappears on stage (and can be used in a pinch to make other things disappear on stage as well).

Wire

wire
Wire

Wire of all different thicknesses is great for tying things together when adhesives just won’t stick. It’s also key for hanging things from walls or ceilings. With glue, there’s always a chance the weight will prove too much for the bond and cause the prop to come crashing down on someone’s head.

Mortite

Mortite rope caulk
Mortite Rope Caulk

Mortite, or rope caulk, is a type of caulk that will not dry out. It’s great for keeping glasses from sliding around on a tray, or vases from toppling off of a shaky table. It also makes it very easy to remove the prop when needed, as when an actor needs to pick up the vase during a scene.

5-minute Epoxy

5 minute epoxy
5 Minute Epoxy

I prefer the kind that comes in the easy-dispense tubes, which makes this product as idiot-proof as possible. Epoxy resin is a liquid which comes in two parts; when mixed, it sticks to many materials and becomes rock-hard. As the name implies, 5-minute epoxy hardens in 5 minutes, making it one of the quickest ways to get a very secure bond.

Medusa Head

I was contacted to make the head of Medusa for a show. An actor would pull it out of a bag, but it did not have to stand up on its own. The face did not need to match any of the actresses in the cast, so that freed me up in my options. It needed to be inexpensive too, so I used as many store-bought items as I could.

Supplies for the Medusa head
Supplies for the Medusa head

I bought a Beetlejuice mask and some rubber snakes from Halloween Adventure, a year-round costume store in the East Village. His hair turned out to be a wig which pulled right off.

Filling the face with foam
Filling the face with foam

I filled the inside of the mask with a layer of expanding foam insulation. In order to keep the foam from distorting the shape of the face as it expanded, I buried the face in a tray of sand. Expanding foam gives off harmful vapors when curing, so use in a well-ventilated area, preferably in a spray-booth or near some kind of system that can pull the air away from you. Expanding foam does not cure properly when you put it on too thick, so fill the mask one layer at a time. I ended up rotating the mask after each coat and putting only a single layer on each side. The mask remained hollow but the sides were strong enough to hold the shape.

Snakes
Snakes

I used wire to hold the snakes on the head. I arranged it so it would be easy to grasp Medusa from the top. I had printed out some pictures of various depictions of Medusa in art through history, and that gave me a good reference on how to arrange the snakes so they would look the most “Medusa-like”.

Basecoated mask
Basecoated mask

I made eyes out of epoxy putty. Epoxy putty comes in tubes, and you simply break a piece off and mix it around in your hands until it is a uniform color. It has the consistency of a clay like Sculpey, and hardens over time (depending on which kind you get, that can be anywhere from five minutes to an hour). Epoxy can be absorbed through the skin and you can become sensitized to it over time, so where disposable gloves when working with it. I had set the eyes in place before filling the mask with the expanding foam, which held them in place when it dried. I sprayed a coat of paint over the entire mask (I actually did this before putting on the snakes).

Cutting the eyes out of paper
Cutting the eyes out of paper

I found a picture of an iris and pupil and printed it out to the appropriate size. I cut two of them out and used five-minute epoxy to attach them; I coated the entire eyeball with the epoxy to make it glossy, and lay the paper iris on top of that. After the first coat dried, I covered the entire eyeball with another coat of epoxy. This made it appear like the iris and pupil were behind the cornea.

Don't look into her eyes
Don't look into her eyes

At this point, I also cut off some of the nose and upper lip and carved it down to look less like Michael Keaton and more like Medusa. Once happy with the new shape, I re-coated the foam with automotive filler (Bondo). This is also toxic and requires a well-ventilated area. The advantage is that it dries very quickly; if you have more time, you can use something far more innocuous, such as Foam Coat.

Face painting
Face painting

The next several steps involved painting the face with acrylics and spray paints.

Filling in the neckhole
Filling in the necknole

I filled in the bottom of the neck with a chunk of blue foam carved to fit. I spray painted it with red, and then blasted it with a hot air gun to create the above effect. Again, you need a well-ventilated area for this, preferably a spray booth.

Covering the head with blood
Covering the head with blood

I thought the head needed some splattered blood. I mixed up some more five-minute epoxy, and then stirred in some paint. I had some red paint and some black paint. I did not mix it to a uniform color, but rather swirled it so the parts had differences in both translucency and tint. I filled the rest of the neck hole, smeared a lot around the bottom of the neck, and then splattered and flung some upwards so it would look like her head was sliced off in one swipe.

The head of Medusa
The head of Medusa

Now that you know how to make your own head of Medusa, get Kraken!

Monday Link-ography

For your Monday’s enjoyment, here is a short list of some more sites to augment your prop making skills:

Coating Foam

My wife and I are currently working on a project for a new show which is essentially a Styrofoam sculpture. It got me thinking about the various ways to treat and coat foam.

You need to coat foam with something. If you tried to paint raw foam, it will eat all the paint up. If you tried to use anything with a solvent, such as spray paint, it will dissolve the foam. Finally, uncoated foam is just too fragile for many uses, especially in theatre.

Coating the foam with Gesso or joint compound will smooth it out and give it a paintable surface. If you mix the joint compound with glue, it will make give it a little more flexibility, as joint compound tends to crack and flake off. Though your Styrofoam will look nice with these kinds of coatings, they will still be fairly fragile.

At the display company I’ve worked at in the past, we made a lot of sculpted pieces out of foam. For the most part, we used Rosco Foamcoat on top of our pieces. Foamcoat goes on a little like joint compound, and creates a hard but flexible coating. It can be sanded and painted, but it doesn’t fall apart like joint compound. It gives a good amount of protection, though it will still dent if you hit it or drop it.

Another product we use at the display company is Aqua Resin. This takes a lot more time, but you are left with a very hard and very smooth surface.

You can use other types of resin on Styrofoam. Polyester resins will eat through the foam, but epoxy resins will give you a very hard, very smooth surface. These are normally used in conjunction with fiberglass or other composite fibers. You can use fiberglass or carbon fiber over foam to give it a lot of strength; this is how some surfboards and skateboards are made. At this point though, are you making a Styrofoam prop, or are you just using it as a form for the fiberglass?

For the project we’re currently working on, we’ve decided on the following compromise; we are going to cover the foam in muslin strips soaked in glue. After this dries, it will create a hard outer shell which can be painted. With a fibrous coating, the piece will resist cracking or crumbling. We will then coat the piece in Foamcoat to smooth it out and hide the texture of the muslin. Finally, we will cover the whole thing in epoxy resin to make it smooth, waterproof, and even stronger. I did a few tests, and this gave the best result for our timeframe and budget.

Finding out this kind of information online can be difficult, so most of what I’ve written here is based on my experience, experimentation, and some research. If anyone else out there ever sculpts in foam, I’d love to hear how you finish it off.