If you don't have the patience to slowly fill the void with spray foam through holes drilled in one of the studs, you could (if you were an experienced carpenter) use a Sawzall to remove one of the studs and re-frame the corner as a two-stud corner. Then you could either insulate the void with a fiberglass batt or simply present the two-stud corner to the spray-foam contractor as an accessible corner.
DID YOU KNOW? Spray FOam insulation out-performs conventional insulation materials because they (conventional insulation materials) trap still-dry air and if that air moves or becomes wet, the thermal resistance can drop by 50%. Spray Foam protects against air infiltration, which can increase energy costs in buildings by 10 to 40%. Eliminate these drafts and live in a more energy-efficient, comfortable and healthier building by choosing spray foam insulation.
Open-cell is also known as half-pound foam. It has an R-Value of 3.5-3.6 per inch, and its density is bout 0.5 pounds per cubic food. Low-density foams like these are made partially from raw biological materials Carbon dioxide or water is also used in the makeup. Open-cell uses far less material than closed-cell, but its R-Value is lower. Also, open cell requires a vapor retarder (like gypsum wallboard) and is riskier when used for roof sheathing. It's not highly recommended that you use open-cell insulation if you live in a cold climate unless you have that extra barrier. You should also compare how much money you spend versus how effective the open-cell insulation is wherever it's installed.
Simple – we’ve seen experienced contractors work with the separate nitrogen tanks and spray foam rigs and have one heck of a time. These spray foam insulation kits are quick to learn and simple to use. They’re designed to be easy so you get results the very first time you spray. Thorough Instructions, 24/7 Product Support, and videos make it easy to install.
For large jobs, professionals such as Dr. Energy Saver use two-part foam, which comes in larger containers. With 2-part spray foam, it's necessary to mix separate resin and catalyst compounds at the application nozzle. Combining these ingredients starts a chemical reaction that creates expanding foam. Contractors use small 2-part foam "kits" to air-seal an attic or to seal and insulate ductwork. To insulate an entire attic or wood-framed wall with spray foam, the resin and catalyst compounds are pumped to the application nozzle from 50-gallon drums in a specially equipped truck.