Frequently Asked Questions

How do I get the resin off my clothes or examining table?

The water curable polyurethane resin is very difficult to remove from clothing. Every effort should be made to avoid any contact of the casting socks with skin or clothing. Industrial solvent such as Orange Sol (Home Depot)” sometimes” or adhesive remover such as UNI-SOLVE (Smith& Nephew) are useful in removing the product from a vinyl exam table. We recommend using a paper or plastic cover to protect your examining table.

How do you get the resin off your skin?

Latex examining gloves and the plastic baggies that are provided should always be used. If a small amount of the cured resin gets on your skin it will eventually (a few days) wear off. Sometimes using nail polish remover and/or soap will enhance the process.

Do I have to use the plastic baggie that is supplied?

Yes. The polyurethane resin that is impregnated onto each of the casting socks will stick to the skin and therefore all exposed areas of the skin must be protected. Always use the plastic baggie that is supplied.

Do I need special blue gloves when I apply the sock?

No. Any type of examining glove may be used. You do not need to use specially treated blue or green examining gloves. You do however need to wear gloves.

Why is the resin sometimes sticky and why does it cling to the examining gloves?

The polyurethane resin that is used has very unique characteristics. The more water that is applied to the sock the more slippery it becomes. Therefore if you want to achieve a glass smooth finish, make certain that your gloves are very wet or add additional cool water. Having a spray water bottle available (with fine mist setting) while applying the sock makes it convenient to apply additional water during the molding phase.

Why does the casting sock sometimes feel hard?

The polyurethane resin that is used on the casting socks is water curable meaning that it will harden or set up once it comes in contact with water or even moisture from the environment. Very infrequently a seal on the aluminum pouch is breached by a pin hole or a faulty seal. If this occurs we will replace the product for you without question. Merely send the hardened sock to us with the aluminum pouch, with your name and address and we will replace the faulty sock immediately.

What is the shelf life of the casting socks?

All STS products have a printed Lot# representing the date of manufacturing. Slipper Socks are guaranteed for 12 months and all other products are guaranteed for 18 months (from the date of manufacturing).

What is the difference between the Tubular Socks (17″ and 30″) and the Fitted Socks?

Both the 17″ and 30″ Tubular Socks are made from fiberglass and spandex fibers that are knit in a “tube- like” shape and then impregnated with a 4-5 minute water curable polyurethane resin. The fitted casting socks (Ankle, Mid-Leg, Bermuda and Slipper) are made of polyester material and are knitted with a defined heel and toe area and then impregnated with water curable resin.

Is water needed to cure each sock?

Absolutely. Each casting sock should be thoroughly submerged in water and the sock squeezed several times under water for about 5 seconds.

Will the temperature of the water make any difference?

The resin will cure faster with warm water. Generally speaking, cool or room temperature water should be used. You want to avoid using warm or hot water as the resin may cure too quickly.

What should I do if the sock is too long or if I have a portion of the tubular fiberglass that is unrolled?

You should always remove excess material or any portion of a tubular fiberglass sock that is not unrolled with a scissors.. Any unrolled portion of the tubular fiberglass may be quite difficult to cut during removal and may produce too much exotherm or heat in the unrolled portion of the sock.

What is the difference in the set up or cure time of each of the resins?

The resin on the 17″ and 30″ tubular socks will set up in 4-5 minutes using room temperature water. The resin that is impregnated on the each of the Fitted Casting socks (Ankle, Mid-Leg and Bermuda) will set up in about 3 ½ minutes with room temperature water. The resin that is impregnated onto the slipper socks will set up in 90-120 seconds.

Do I need to use the Slipper Clip that is supplied with the Slipper sock?

The Slipper Clip is designed to cinch up the arch area of the slipper sock (just like a “Mary Jane” shoe strap) to help insure excellent conformity of the sock to the foot..

How can I assure that the Slipper Clip will adhere to the slipper socks?

Hold both clips between the thumb and index finger of each hand with the “hooks” oriented downward. You do not have to touch the sock with your fingers to use this clip. Hook the medial clip just under the elastic band at the apex of the medial arch. When the sock is about an inch away from the foot, aggressively “jam” the hook into the fabric of the sock to anchor it securely.

Do I need a cast cutter to remove the sock?

Small specially designed scissors are best used to cut the hardened sock. The STS Company does provide small scissors. A letter opener (envelope slitter) can also be used to cut the material after it is hard. Make sure the cutting strip is in place to the skin.

Do orthotic labs accept casts made of the STS Slipper Sock ?

Virtually all of the major orthotic laboratories willingly accept casts take with the Slipper Sock as long as it is applied correctly.

Do I need to read the entire instruction booklet?

The instructions pamphlet has useful hints that will assist you in obtaining excellent negative casts. It is recommended that you read the instruction pamphlet before you begin casting.

Can the impressions obtained with one of the STS Casting socks be scanned?

The STS casting socks are ideal for cad/cam scanning because of the uniformity of the thickness of the material. As there is no overlapping of material as one would find in either plaster wrap or fiberglass rolls, the negative impressions will be very accurate.

Can I see the skin lines on the negative cast?

No. Because you need to use a plastic baggy on the foot you will not be able to see skin lines as you would on plaster.

How do I mark lesions on the cast? Will marks on the skin transfer?

We suggest that you place an adhesive backed corn pad directly over a lesion that you will want accommodated on an orthosis. The prominence of the corn pad will be transferred to the negative impression that you obtain if you massage the material well during casting. Neither lipstick nor indelible ink will transfer from the skin to the cast.

Do custom shoe companies accept casts taken with the STS Sock?

Most custom shoemakers prefer casts taken with the STS Ankle Sock. The shoe manufacturer often find that casts taken with the STS Ankle Sock are more accurate and more durable then those made from either plaster of paris or fiberglass wrap. The STS Ankle Sock is ideal for CAD/CAM.

Which is the correct casting sock to use for an AFO?

Generally speaking, the STS Ankle Casting sock is used for supra malleolar AFO’s, the Mid leg sock for a custom gauntlet and the Bermuda sock for traditional AFO’s (Posterior Leaf, CROW or Solid Ankle). The 17″ fiberglass Tubular Sock is also recommended for custom gauntlets and the 30″ AFO tubular sock for posterior leaf spring and CROW walkers. If in doubt as to which product to use, contact the lab that will fabricate the orthosis for their recommendation.

What sock do I use for a BK socket design?

The 17″ Tubular sock is recommended for negative impressions of below knee sockets.

Will a cast change shape after it is cured?

We advise waiting 8 hours before placing the negative cast(s) into a box if mailing to a central fabrication orthotic laboratory. It is also a good practice to stuff the cured cast with paper or bubble wrap before shipping. It usually takes 4-5 hours before a cast is fully cured and hardened.

What is the shelf life of the product?

Shelf life of the slipper sock is one year from the date of manufacture. Shelf life of all other products is 18 months from the date of manufacture. Date of manufacture is indicated as the first six numbers of the lot # on the packaging label. Most products are shipped within a week or two from the date of manufacture.