Last year I decided to get my car underbody treated. Bilt Hamber was my choice, and an email to confirm my product choice resulted in my receiving this email from them.
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Tue, Jun 3, 2025, 12:37 PM
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Hi Stephen,
Excellent choice for areas where corrosion cannot be fully removed mechanically — Hydrate 80 chemically stabilises residual corrosion and forms a protective barrier.
For best results, ensure all loose and flaking rust is removed with mechanical cleaning before application.
Dynax UC (Topcoat)
Dynax UC is a clear, thin-film wax that provides good corrosion protection, especially on clean or lightly rusted areas.
However, it does not form as mechanically durable a film as Dynax UB
Dynax S50 (Cavities)
S50’s superior creep properties mean it will penetrate seams, spot welds, and boxed sections effectively, protecting even difficult-to-reach areas.
For the underbody:
If the garage has fully removed rust and cleaned to a sound substrate, consider applying Epoxy Mastic over Hydrate 80 for superior mechanical protection — then top with Dynax UB or UC if desired.
If you’re using Hydrate 80 as your main rust stabiliser and topcoating with a wax, be aware that Dynax UC is less durable mechanically — so it may require more frequent reapplication than Dynax UB.
For seams and welds, Hydrate 80 is appropriate, but again, Epoxy Mastic or a similar protective coating over the Hydrate 80 layer would provide longer-lasting protection if the budget and time allow.
For cavities, Dynax S50 is absolutely the best option.
Kind regards,
Pete Hamber
w: www.bilthamber.com
t: 01277 658899
e: sales@bilthamber.com




Steve.