Bilt Hamber Dynax-UB is the underbody wax of the Dynax range: a firm, dark wax for the exposed underside of your car. It dries firmer than Dynax-S50 and therefore holds up better against stone chips and abrasion, exactly what the underbody has to endure. Unlike classic bitumen underseals it does not peel off. You will find the Bilt Hamber Dynax-UB in the shop.
What Dynax-UB does
Dynax-UB forms a touch-dry, dark brown-black wax film with elastic polymers that make it abrasion-resistant. Bilt Hamber states that it arrests existing corrosion and, unlike bitumen, does not flake or crack so no moisture creeps underneath. It is safe on PVC and plastics, so you can spray it over pipes and clips without worry. This protects the chassis, wheel arches and the whole underside against road salt and grit.
How to use it
Prepare. Work on a dry underbody, free of loose, flaking rust or coatings. UB displaces surface moisture, but dry application gives the best result.
Apply. From the aerosol with the straw; from the 1L container with brush or roller; from the 5L jerrycan with spray equipment (thinned with white spirit).
Two coats. Apply at least two coats 24 hours apart: the first coat keys in, the second builds the film thickness to about 80 to 100 microns.
Let it dry. Let each coat become touch-dry before you work on.
UB or UC: dark or transparent
Choose Dynax-UB for the hidden, exposed underbody where the colour does not matter and firmness counts. If you want to protect visible areas without a dark film, such as wheel arch lips or sills, choose the transparent Bilt Hamber Dynax-UC. UB can also go over existing protective coatings as an extra measure. The full sequence from converting rust to conserving is in the guide rust prevention and underbody protection. You will find more products in the rust prevention and conservation category.