{"title":"Rust Proofing \u0026 Underbody","description":"\u003cp\u003eCorrosion is electrochemistry — iron giving up electrons to oxygen wherever moisture and road salt complete the circuit. This range attacks it at every stage. Bilt Hamber's Dynax cavity waxes creep into box sections and seams, displacing moisture and laying down a self-healing barrier film; Dynax UB does the same job on exposed underbody steel with an abrasion-resistant coat; and vapour-phase inhibitors protect enclosed spaces the spray can't reach. Applied before winter or after a restoration, they stop rust before it starts — far cheaper than cutting it out later. Independent testing has repeatedly ranked Dynax among the most effective cavity protection available.\u003c\/p\u003e","products":[{"product_id":"bilt-hamber-dynax-s50-cavity-wax-corrosion-inhibitor","title":"Bilt Hamber Dynax S50 | Cavity Wax Corrosion Inhibitor","description":"\u003ch2\u003eThe one with the test data\u003c\/h2\u003e\u003cp\u003eEvery anti-corrosion product claims to work. Dynax S50 is the one with a \u003cstrong\u003e42-page independent report\u003c\/strong\u003e behind it, and it is publicly hosted.\u003c\/p\u003e\u003cp\u003eThe \u003cstrong\u003eUniversity of Hertfordshire, School of Engineering \u0026amp; Technology\u003c\/strong\u003e (Report PG-BH13\/001, Dr Phil Green, 2013) ran a \u003cstrong\u003e2000-hour cyclic salt spray test\u003c\/strong\u003e based on ASTM B117-03 — 5% NaCl fog, cycled 10 minutes wet \/ 50 minutes dry at 35°C — with film thickness matched at roughly 50µm across every product tested. \u003cstrong\u003eDynax S50 ranked first\u003c\/strong\u003e, ahead of Mike Sanders Korrosionsschutzfett (which was applied at 500µm — ten times the film), Auson Noxudol 700, Rustbuster Mil-Spec, Dinitrol 3125HS and Waxoyl.\u003c\/p\u003e\u003cp\u003eThe honest caveat, which we'll give you rather than bury: \u003cstrong\u003ethe study was commissioned by Bilt Hamber.\u003c\/strong\u003e Independent laboratory, sponsored research. That's a meaningful distinction and you should weigh it. It's still vastly more evidence than any competitor in this category has put on the table.\u003c\/p\u003e\u003ch2\u003eWhat it does\u003c\/h2\u003e\u003cp\u003eS50 is a solvent-borne wax that \u003cstrong\u003ecreeps\u003c\/strong\u003e. It wicks into welded seams, lap joints and surface defects — the places corrosion actually starts — and leaves a \u003cstrong\u003esoft, brown, wax-like film that self-heals\u003c\/strong\u003e if it gets disrupted. That self-healing property is the entire reason it belongs in a cavity: a box section is a place you cannot inspect and cannot re-treat easily, so the film has to close itself back up when a stone or a bolt scrapes through it.\u003c\/p\u003e\u003cp\u003eBilt Hamber describe the corrosion inhibitors as \"highly polar\" and \"metal-seeking.\" They don't disclose the chemistry and neither will we — you'll find people online confidently naming the wax. They're guessing.\u003c\/p\u003e\u003ch2\u003eThe numbers\u003c\/h2\u003e\u003cp\u003eTarget film thickness around \u003cstrong\u003e50µm\u003c\/strong\u003e. Roughly \u003cstrong\u003e50% solids\u003c\/strong\u003e. Flash point \u003cstrong\u003e44°C\u003c\/strong\u003e. Stores up to five years unopened between 5–30°C.\u003c\/p\u003e\u003ch2\u003eHow to use it\u003c\/h2\u003e\u003cp\u003eAtomise into the cavity through the \u003cstrong\u003e600mm extension wand\u003c\/strong\u003e supplied with the aerosol. If the surface is wet, pre-treat with \u003cstrong\u003eFerrosol\u003c\/strong\u003e to displace the water first. Then the critical step almost everyone gets wrong: \u003cstrong\u003eleave the cavity open for 48 hours\u003c\/strong\u003e so the carrier solvent can escape before you refit the bungs. Seal it early and you trap solvent against the steel.\u003c\/p\u003e\u003cp\u003eCold product gets thick. Condition it at around 15°C for 24 hours before use.\u003c\/p\u003e\u003ch2\u003eHandle it properly\u003c\/h2\u003e\u003cp\u003eAerosol, LPG propellant. \u003cstrong\u003eDanger — H220 (extremely flammable gas), H280, H304 (may be fatal if swallowed and enters airways), H315, H336, H411.\u003c\/strong\u003e Ventilation, no ignition sources, respiratory protection if you're spraying volume.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eSafety Data Sheet (Australia)\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Dynax-S50-Aerosol_SDS_au.pdf?v=1784379282\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Bilt Hamber Dynax S50 SDS (PDF)\u003c\/a\u003e\u003c\/p\u003e","brand":"Bilt Hamber","offers":[{"title":"750ml Aerosol + Wand","offer_id":48433207017694,"sku":"BH-Dynax-S50-750ml","price":55.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/750ml-Dynax-s50.jpg?v=1784179133"},{"product_id":"bilt-hamber-dynax-ub-underbody-anti-corrosion-wax","title":"Bilt Hamber Dynax UB | Underbody Anti-Corrosion Wax","description":"\u003ch2\u003eWhy not just use underseal?\u003c\/h2\u003e\u003cp\u003eBecause bitumen underseal cracks. It goes on thick, it dries hard, and the first stone that hits it opens a fissure. Water gets behind the coating, and now you have a sealed, dark, damp pocket against bare steel — which is a better corrosion cell than no coating at all. Every restorer has peeled back underseal and found a horror show underneath.\u003c\/p\u003e\u003ch2\u003eWhat Dynax UB does differently\u003c\/h2\u003e\u003cp\u003eUB contains \u003cstrong\u003eelastic polymers\u003c\/strong\u003e that produce a tougher, more abrasion-resistant film than a conventional wax — but it stays a wax. It flexes. It doesn't crack, and Bilt Hamber state it \u003cstrong\u003ewon't peel\u003c\/strong\u003e. It's touch-dry rather than tacky, so it doesn't stay a dirt magnet forever, and it carries Bilt Hamber's metal-seeking corrosion inhibitors into every seam it reaches.\u003c\/p\u003e\u003cp\u003eIt's a solvent-borne aliphatic hydrocarbon system — Bilt Hamber's SDS declares C7 hydrocarbons and hydrotreated heavy naphtha as the carriers. The wax itself and the inhibitor package are not disclosed, so we won't invent them.\u003c\/p\u003e\u003ch2\u003eThe numbers that matter\u003c\/h2\u003e\u003cp\u003eTarget film thickness is \u003cstrong\u003e80–100µm\u003c\/strong\u003e — noticeably heavier than Dynax S50's 50µm, because an underbody takes physical abuse a cavity doesn't. Build it in \u003cstrong\u003eat least two coats, 24 hours apart\u003c\/strong\u003e. One heavy coat is not the same thing and will not cure properly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCoverage:\u003c\/strong\u003e Bilt Hamber state roughly \u003cstrong\u003e4 × 750ml aerosols to treat a medium-sized vehicle\u003c\/strong\u003e, or \u003cstrong\u003e1 litre per 8–10m²\u003c\/strong\u003e brushed or sprayed. Buy accordingly — running out halfway through an underbody is a miserable afternoon.\u003c\/p\u003e\u003ch2\u003eHow to use it\u003c\/h2\u003e\u003cp\u003eSurface must be \u003cstrong\u003edry\u003c\/strong\u003e. Degrease first — \u003cstrong\u003eSurfex-HD\u003c\/strong\u003e is the right tool — rinse and let it dry properly. Brush, roller or spray. Two coats minimum, a day apart. Around 24 hours to dry at 15°C.\u003c\/p\u003e\u003cp\u003eCold wax is thick wax. Bring it up to about 15°C for 24 hours before you start.\u003c\/p\u003e\u003ch2\u003eAn honest note on the test data\u003c\/h2\u003e\u003cp\u003eYou'll see Bilt Hamber's 2000-hour University of Hertfordshire salt spray result quoted across the internet for the whole Dynax range. \u003cstrong\u003eThat study tested Dynax S50 only.\u003c\/strong\u003e Bilt Hamber separately claim UB outperforms competitors under ASTM B117 conditions, but they publish no report for it. We're not going to lend UB a result it didn't earn.\u003c\/p\u003e\u003ch2\u003eHandle it properly\u003c\/h2\u003e\u003cp\u003eAerosol: \u003cstrong\u003eDanger — H220, H280, H304, H315, H336, H411.\u003c\/strong\u003e Ventilate, no ignition sources, wear respiratory protection when spraying overhead.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eSafety Data Sheets (Australia)\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Dynax-UB_SDS_au.pdf?v=1784380297\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Dynax UB SDS – bulk (PDF)\u003c\/a\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Dynax-UB-Aerosol_SDS_au.pdf?v=1784380297\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Dynax UB SDS – 750ml aerosol (PDF)\u003c\/a\u003e\u003c\/p\u003e","brand":"Bilt Hamber","offers":[{"title":"750ml Aerosol","offer_id":48433207050462,"sku":"BH-Dynax-UB-750ml","price":55.0,"currency_code":"AUD","in_stock":true},{"title":"5L","offer_id":48433207083230,"sku":"BH-Dynax-UB-5L","price":165.0,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/750ml-Dynax-ub.jpg?v=1784179133"},{"product_id":"bilt-hamber-dynax-uc-transparent-anti-corrosion-film","title":"Bilt Hamber Dynax UC | Transparent Anti-Corrosion Film","description":"\u003ch2\u003eProtection you can't see\u003c\/h2\u003e\u003cp\u003eDynax UB and S50 both leave a brown film. On a chassis or inside a box section, nobody cares. On a painted underside, a restored bay, a visible subframe or a show car, that brown film is the problem — you've protected the metal and ruined the look.\u003c\/p\u003e\u003cp\u003eDynax UC is Bilt Hamber's answer: a \u003cstrong\u003efirm, touch-dry, virtually transparent\u003c\/strong\u003e protective film at around \u003cstrong\u003e50µm\u003c\/strong\u003e. It goes on bare metal or over paint, it's safe on the majority of paint coatings, and it leaves the finish visible.\u003c\/p\u003e\u003ch2\u003eMulti-metal inhibitors\u003c\/h2\u003e\u003cp\u003eBilt Hamber describe UC's film as rich in \u003cstrong\u003emulti-metal corrosion inhibitors\u003c\/strong\u003e — a deliberate distinction from S50 and UB, which are aimed squarely at ferrous metal. If you're protecting aluminium subframes, mixed-metal assemblies or galvanic junctions, that's the reason to reach for UC.\u003c\/p\u003e\u003cp\u003eAs with the rest of the Dynax range, the wax and the inhibitor chemistry are undisclosed. Bilt Hamber name the carrier solvents in the SDS and nothing more, and we're not going to fill the gap with speculation.\u003c\/p\u003e\u003ch2\u003eWhere it belongs\u003c\/h2\u003e\u003cp\u003ePainted or visible undersides. Restored engine bays. Inner arches on a car you actually look at. Anywhere a dark underseal or a brown cavity wax would detract from a finish you've paid for.\u003c\/p\u003e\u003ch2\u003eHow to use it\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eDegrease with Surfex-HD\u003c\/strong\u003e, rinse, dry thoroughly, then wipe down with white spirit. Apply in \u003cstrong\u003efine coats\u003c\/strong\u003e — this is a low-build product and it is not trying to be UB. The aerosol valve works upside down, which matters more than you'd think when you're under a car.\u003c\/p\u003e\u003cp\u003eIt's removable later with solvent or an alkaline degreaser, which makes it a sane choice for anything you might need to work on again.\u003c\/p\u003e\u003ch2\u003eUB or UC?\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eUB\u003c\/strong\u003e where it takes stone strike and abrasion, and where nobody sees it — outer chassis, floorpans, wheel arches. \u003cstrong\u003eUC\u003c\/strong\u003e where appearance matters or where you're protecting mixed metals. Plenty of restorers run both: UB on the hidden structure, UC on everything visible.\u003c\/p\u003e\u003ch2\u003eHandle it properly\u003c\/h2\u003e\u003cp\u003eAerosol: \u003cstrong\u003eDanger — H220, H280, H304, H315, H336, H411.\u003c\/strong\u003e Ventilation and respiratory protection.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eSafety Data Sheets (Australia)\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Dynax-UC_SDS_au.pdf?v=1784380297\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Dynax UC SDS – bulk (PDF)\u003c\/a\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Dynax-UC-Aerosol_SDS_au.pdf?v=1784380297\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Dynax UC SDS – 750ml aerosol (PDF)\u003c\/a\u003e\u003c\/p\u003e","brand":"Bilt Hamber","offers":[{"title":"750ml Aerosol","offer_id":48433207115998,"sku":"BH-Dynax-UC-750ml","price":55.0,"currency_code":"AUD","in_stock":true},{"title":"5L","offer_id":48433207148766,"sku":"BH-Dynax-UC-5L","price":165.0,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/750ml-Dynax-uc.jpg?v=1784179133"},{"product_id":"bilt-hamber-atom-mac-vapour-phase-corrosion-inhibitor","title":"Bilt Hamber Atom-Mac | Vapour-Phase Corrosion Inhibitor","description":"\u003ch2\u003eA corrosion inhibitor that protects metal it never touches\u003c\/h2\u003e\u003cp\u003eThis is the most interesting chemistry in the Bilt Hamber catalogue, and almost nobody explains it properly.\u003c\/p\u003e\u003cp\u003eAtom-Mac is a \u003cstrong\u003evapour-phase corrosion inhibitor\u003c\/strong\u003e — a VpCI. Bilt Hamber's SDS declares it as an \u003cstrong\u003eamine carboxylate salt at 20–35%\u003c\/strong\u003e, CAS 38344-72-8. That CAS number resolves to \u003cstrong\u003emorpholinium octanoate\u003c\/strong\u003e — the 1:1 salt of octanoic acid and morpholine. It is textbook amine-carboxylate VCI chemistry, and Bilt Hamber declare it openly, which is more than most manufacturers in this category do.\u003c\/p\u003e\u003ch2\u003eHow a vapour-phase inhibitor actually works\u003c\/h2\u003e\u003cp\u003eThe amine carboxylate has enough vapour pressure to volatilise in an enclosed space. The volatile amine \u003cstrong\u003emigrates through the vapour phase\u003c\/strong\u003e, dissolves into the thin film of moisture that's always present on steel, raises the local pH and adsorbs onto the surface. The carboxylate anion then chemisorbs onto the metal and forms a passivating monolayer.\u003c\/p\u003e\u003cp\u003eThe consequence is the useful bit: \u003cstrong\u003eit protects surfaces the liquid never physically reached.\u003c\/strong\u003e The back of a box section. The inside of a seam. The underside of a bolt head. This is why Bilt Hamber tell you to bag or seal the item — you are trying to trap the vapour, not just wet the metal.\u003c\/p\u003e\u003ch2\u003eThe flash-rust problem it solves\u003c\/h2\u003e\u003cp\u003eAnyone who has stripped rust with \u003cstrong\u003eDeox-C\u003c\/strong\u003e or \u003cstrong\u003eDeox-Gel\u003c\/strong\u003e, or wet-blasted a panel, knows the feeling: you now have chemically clean, utterly bare steel, and it will bloom orange within the hour. \u003cstrong\u003eAdd Atom-Mac at 2% to your rinse water\u003c\/strong\u003e and it doesn't. That alone justifies the bottle.\u003c\/p\u003e\u003ch2\u003eDilution\u003c\/h2\u003e\u003cp\u003eDilute in \u003cstrong\u003edeionised or distilled water\u003c\/strong\u003e — Bilt Hamber are specific about this, and tap water minerals will work against you.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eGeneral use:\u003c\/strong\u003e 2–5%. \u003cstrong\u003eMotorcycles and bicycles:\u003c\/strong\u003e 1–2%. \u003cstrong\u003eCars with disc brakes:\u003c\/strong\u003e 5%. \u003cstrong\u003eEnclosed voids:\u003c\/strong\u003e 2ml of neat product per litre of void volume. \u003cstrong\u003eAfter Deox-C, Deox-Gel or blasting:\u003c\/strong\u003e 2% in the rinse water. \u003cstrong\u003ePressure washer:\u003c\/strong\u003e aim for 2% at the nozzle, applied at the end of every wash.\u003c\/p\u003e\u003cp\u003eIt's water-borne, it's safe on painted surfaces, and the SDS records it at \u003cstrong\u003epH 7\u003c\/strong\u003e — neutral. It carries \u003cstrong\u003eno CLP dangerous classification\u003c\/strong\u003e, though Bilt Hamber advise an A2 or A2-P2 respirator if you're atomising it.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eSafety Data Sheet (Australia)\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Atom-Mac_SDS_au.pdf?v=1784379283\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Bilt Hamber Atom-Mac SDS (PDF)\u003c\/a\u003e\u003c\/p\u003e","brand":"Bilt Hamber","offers":[{"title":"500ml","offer_id":48433207181534,"sku":"BH-AtomMac-500ml","price":69.5,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/atom-mac_500ml-scaled.jpg?v=1784179154"},{"product_id":"bilt-hamber-ferrosol-penetrating-lubricant-water-displacer","title":"Bilt Hamber Ferrosol | Penetrating Lubricant \u0026 Water Displacer","description":"\u003ch2\u003eThe four things it doesn't contain\u003c\/h2\u003e\u003cp\u003eBilt Hamber's technical data sheet states it plainly: \u003cstrong\u003eFerrosol contains no silicone, no PTFE, no molybdenum disulphide and no chlorinated solvents.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe silicone one is the reason this product exists. Silicone contamination is the classic cause of fisheyes and craters in fresh paint — it migrates, it's persistent, and a single careless spray of a silicone-bearing penetrant near a booth can ruin a respray. Ferrosol is formulated to be \u003cstrong\u003esafe to use in automotive body shops\u003c\/strong\u003e where silicone-containing fluids cause paint defects. If you paint, or you work near people who paint, this matters more than any performance claim.\u003c\/p\u003e\u003ch2\u003eWhat it does\u003c\/h2\u003e\u003cp\u003ePenetrates close tolerances, frees seized fasteners, displaces water, protects against corrosion, and works as a cutting fluid for drilling, tapping and reaming. Bilt Hamber describe it as containing molecules that \u003cstrong\u003ebond electrochemically to metal under friction\u003c\/strong\u003e to form an anti-wear barrier.\u003c\/p\u003e\u003cp\u003eBilt Hamber also claim a four-ball wear test result showing it substantially outperforming the market leader. We went looking for the supporting reports they link to. \u003cstrong\u003eThey're dead links.\u003c\/strong\u003e So we're not quoting the figure. If they republish the data, we'll say so.\u003c\/p\u003e\u003ch2\u003eHow to use it\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eSeized fasteners:\u003c\/strong\u003e soak for a few minutes — then apply a \u003cem\u003etightening\u003c\/em\u003e force first. Cracking the rusted interface in the direction it's already been sitting is what lets the penetrant wick in. Trying to undo it immediately just rounds the head.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWater displacement:\u003c\/strong\u003e apply liberally; displacement is rapid. Isolate electrics before treating them.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eTar, gum and adhesive:\u003c\/strong\u003e apply, wait 10–20 seconds, wipe with soft cotton.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBefore Dynax S50:\u003c\/strong\u003e if the cavity is wet, Ferrosol first. It displaces the water so the wax can actually bond to steel rather than to a film of moisture.\u003c\/p\u003e\u003cp\u003eThe residual film wipes off with a mild solvent when you want it gone.\u003c\/p\u003e\u003ch2\u003eHandle it properly\u003c\/h2\u003e\u003cp\u003eFlammable aerosol. Ventilate, no ignition sources, don't breathe the mist.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eSafety Data Sheet (Australia)\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/Ferrosol_SDS_au.pdf?v=1784380297\" target=\"_blank\" rel=\"noopener\"\u003eDownload the Bilt Hamber Ferrosol SDS (PDF)\u003c\/a\u003e\u003c\/p\u003e","brand":"Bilt Hamber","offers":[{"title":"500ml Aerosol","offer_id":48433207214302,"sku":"BH-Ferrosol-500ml","price":31.5,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/0707\/8878\/files\/ferrosol-new-straw-scaled.jpg?v=1784179154"}],"url":"https:\/\/www.alphadetails.com.au\/collections\/rust-proofing-underbody.oembed","provider":"Alpha Details","version":"1.0","type":"link"}