What are the different grades of Universal Blue that are available – Aerograde PL32, Racing Formula, Aerograde Ultra, Advanced Formula, Universal Blue Medium?
The original formulation of Hylomar Universal Blue was made with methylene chloride as a solvent.Over the years, health and safety concerns with methylene chloride have led to the introduction of Hylomar AF (a solvent free version) as well as substitute acetone and ethyl acetate formulations. In the US, products containing methylene chloride are subject to stringent OSHA regulations, and their sale is largely prohibited in California and the ten compact states. Hylomar Aerograde PL32 is the product which which conforms to the original Rolls-Royce specification. Aerograde Ultra is a Rolls- Royce specified product which uses a different solvent (acetone) than Aerograde (methylene chloride). Aerograde Ultra has now been approved by Pratt & Whitney, Siemens, Honeywell, the US military, and many airlines for use on their engines as a replacement for Universal Blue is the original non-setting sealant used for all non aircraft applications. Racing Formula and RF use acetone-based formulations
