Force 80g Brake Pipe & Air line sealant Liquid PTFE Sealer Instant Seal | eBay
Amazon.com: Loctite 545 Pneumatic/Hydraulic Pipe Thread Sealant, High Lubricity, High Pressure, No Fillers, Solvent Resistance, for Fine Threaded Fittings | Purple, 36 ml Bottle (PN: 492145) : Industrial & Scientific
How to Create Leak-Proof Joints with Pipe Dope | Oatey