Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: "Rod Speed" Newsgroups: aus.electronics,aus.cars Subject: Re: DIY Electronic Vehicle Rust Prevention Date: Wed, 28 Feb 2024 08:38:27 +1100 Lines: 122 Message-ID: References: <65dab557@news.ausics.net> <65dadebe@news.ausics.net> <65db345a@news.ausics.net> <65dbb725@news.ausics.net> <65dc10ed@news.ausics.net> <65dc4285@news.ausics.net> <65dd0795@news.ausics.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit X-Trace: individual.net ZoZZYaXTa05SRDippPKsKQNeeiIjGFUUIagcla8cLp5Af8Hco= Cancel-Lock: sha1:cH9w01p/c+Y6dD2yNaGsHCZANwY= sha256:1fqO8qRidbCzzjpKmRwMoDOr6SgtXQ/ANZFPDGmZYxY= User-Agent: Opera Mail/1.0 (Win32) Xref: csiph.com aus.electronics:35778 aus.cars:364186 Xeno wrote > Computer Nerd Kev wrote >> Daryl wrote >>> Computer Nerd Kev wrote >>>> OK well I'm asking for trouble with that onereally because it's a >>>> 1989 Jaguar XJ40. >>> Seems to be some debate on whether or not Jags were actually >>> galvanized. >>> https://www.jaguarforum.com/threads/galvanised-body-fact-or-myth.44736/ >> OK, it looked galvanised in a wheel arch where some of the >> undercoat was chipped off, and there was no rust there even though >> the metal was (or at least looked) exposed. Probably just in >> certain spots like the forum thread says. > It most likely was galvanised and, I might add, the Jaguar was one of > the forerunners in a process that became common during the 90s. Pretty > much every car this century has been hot dipped galvanized and that > process began in the US and AU around 1995. > The problem with paint as a protective barrier against corrosion is that > it needs 100% coverage. A scratch or stone chip is all that is needed to > provide a start point for rust to begin attacking the base metal > underneath - so you once needed to fix up stone chips and scratches > immediately. I never did and never had a problem with rust. > Enter the galvanising process. Cars tend to be hot dipped because it is > the easiest process and the coating is thicker - that's important. The > layer of zinc functions first as a barrier, just like paint, to those > atmospheric components that would like to react with the iron - water > being the perfect example. Secondly the chemical reaction of the zinc > with, say, the water, creates a thin layer best known as a patina. In > this process the water splits into ions and reacts with the zinc thereby > creating the "protective" patina layer. That mangles the chemistry involved. > This patina forms a second barrier to keep the underlying steel free of > rust. Thirdly, there is cathodic protection. In the electrochemical > reaction, the cathode (steel) gets protected whilst the anode (zinc) > gets sacrificed. Doesnt happen with cars. > Because of the hot dipped galvanizing, the paint coaton modern cars is > purely decorative. > That sacrifice is important to note - because it is time constrained. > Car bodies will be protected for some 30 years and, by then, enoughof > the zinc will have been sacrificed for rust to begin to take over. Utterly mangled all over again. > At 30 years, most cars would be well and truly past their use by date BULLSHIT. > and well on their way to being a recycled Chinese car. Not because of rust. > So, if you have a car older than 30 years, it might be time topay more > attention to rust prevention and general maintenance. Depends on the car. > This reminds me of a little debacle with a Chinese ute on the Gold Coast > recently; > https://www.queenslandjudgments.com.au/caselaw/qcat/2021/316 > Was the LDV ute hot dipped galvanised? I suspect it wasn't. Or if it > was, it was a piss poor job. >>> Then there's a 1996 Nissan Navara ute where the >>>> once-galvanised tray is most of the trouble, >>> >>> Once galvanized indicates that much of the gal has been rubbed off? >>> If so bare steel doesn't have much rust resistance. >>> >>> but the cab's started >>>> showing surface rust lately too. >>> >>> It is almost 30yrs old so not surprising that there is some rust. > > >> I'm not surprised either. Such are valid use cases for a rust >> prevention device _if_ they worked, which was my only point. >> >>> The truck is a 1980 International >>>> ACCO 610A, where the cab is possibly better than most others still >>>> out there, but that still makes it pretty rusty. >>> >>> Those trucks were notorious for rust, finding one without significant >>> rust would be near impossible. >> Yes I more or less said that. At least the steel is farly thick so >> there's some time to catch it before you get a hole. > Any vehicle from the 70s or 80s was notorious for rust. BULLSHIT. > Note too, most of these rusted *from the inside* exacerbatedby lack of > owner attention to cleaning out mud collectionpoints, unblocking drain > holes, and the like. Never needed to do that and I used dirt roads extensively. >>>> I won't be that surprised if it doesn't do anything, but since I >>>> haven't seen any tests showing that they don't work, I'd like to >>>> find out for sure. >>>> >>> >>> Worth a try if you have some spare time, just don't hold your breath >>> expecting much of a result. >> Sure, I enjoy electronics tinkering anyway. More fun than arguing >> over what consitiutes an experiment/test, but I guess I forgot that >> aus.cars is only a place for arguments. >>