Harley use it to glue aluminium to steel inside their motors, it's an unbelievable product, toxic as buggery though...

Conro Electronics is a leading supplier of materials and tools in the electronic manufacturing industry. High elasticity - cures to a tough, durable, flexible consistency with exceptional cut and tear -resistance. Suitable for: valve cover gaskets, oil pan gaskets, threaded connections, cover plates & hose connections When fully cured, Halfords Petrol Resistant Lacquer provides a tough, durable gloss protective finish which is petrol resistant. Features & Benefits:PTFE tape lubricates in off direction, allowing fittings to loosen under dynamic loads and resulting in loss of clamping force and leakage. Dynamic loads may accelerate creep, causing leakage over time. The lubricating effect of PTFE frequently results in over-tightening of fasteners, adding stress or causing breakage of parts. Application requires good professional skills to avoid stressing fittings or castings. Designed for low and high pressure applications, thread sealants fill the space between threaded parts and provide an instant, low pressure seal. When fully cured, they seal to the burst strength of most pipe systems. But having thought about that a bit...You're over-thinking it H1. Brake cleaner has no lubricant in it, carby cleaner does. Hence, a poor bond comes from the lubricant in carby cleaner. Any suggestions on the best sealant for sealing a fuel pump flange to an aftermarket fuel tank that's not flat

Petrol resistant sealants need to have exceptional chemical resistance coupled with good mechanical properties. Finding the right petrol resistant sealant for the right application can be a challenging task: certain sealants may be effective on some petroleum-based products, but not others. Has many applications as an elastic adhesive between materials with dissimilar coefficients of expansion. Any suggestions on the best sealant for sealing a fuel pump flange to an aftermarket fuel tank that's not flat..,Yamaha Bond, Honda Bond, etc all make a fuel-proof adhesive. Yamaha's is Y-bond #4. The POR-15 Petrol Tank Sealer is the finest tank sealer you will ever use and the only tank sealer you will recommend. The tough flexible coating chemically bonds to the inside of your tank forming an incredibly strong permanent seal. Please note for complete protection, please use the Cleaner/Degreaser and the Metal Prep prior to using the sealer. Otherwise the sealer may not adhere properly to the surface.Gasket sealants. These products are used to seal gaskets and prevent leaks. Polyester urethane-based products are especially effective, as they will resist extreme temperature changes without hardening. Polyurethane has exceptional resistance to petrol, oils, kerosene and other petroleum-based chemicals. Hylomar Universal Blue is a high-performance gasket compound: it resists petrol and a wide range of fluids, and it also provides a wide operating temperature range.