HighlandRover Posted October 24, 2009 Share Posted October 24, 2009 Ive recently purchased a Galvanised Richards chassis and before I start the rebuild im contimplating wether or not to paint the chassis, wax oil it or just leave it as it is. Obviously painting it would add another layer of protection and would not stick out to thieves as much, but is it worth it? Ive noticed that alot of people who rebuild on a galvanised chassis just leave it as it is so im looking for your opinions and advise on the matter. Cheers! Quote Link to comment Share on other sites More sharing options...
jbs Posted October 25, 2009 Share Posted October 25, 2009 Why would you want to waxoyle the chassis? it's not going to go rotten is it,as you point out painting it would be a good idea to hide it from thieves-i've only painted my rear cross member, as much as i like the galvanised look after doing all the work changing the chassis on my 90 it just looked better in black paint, i did mine with some matt black paint from focus do it all -the paints by international and hasn't chipped off yet and i also did all my chequer plate with it too-and thats still on there aswell so it can't be that bad can it! Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 25, 2009 Share Posted October 25, 2009 Not sure how painting it stops the thieves...but for my 2p - paint it. I personnaly hate the sight of galv chassis', but its a personal thing. You need to use an etch-primer for long term succesful results, Richards advised me to use Hammerite Special Metals Primer, and then a good quality top coat, like an International Enamel paint. Richards advice to me was to paint and waxoyl it, the Galv is good but its not the be all and end all. contrary to popular believe, Galv is not a permanent solution. A Galv chassis left as it comes, will rot through eventually, and you can expect to be seeing rusty holes in around 20 years, less if you live in harsh areas. The worst thing is the rust hides under the galv, and the first you see of it is when a piece falls off. In Britain we use thousands of tons of salt on our roads every winter, and this salt gets thrown up onto the chassis, and attacks the steel. A Glav chassis should be treated in exactly the same way as a normal chassis every winter, for maximum protection. Quote Link to comment Share on other sites More sharing options...
jbs Posted October 25, 2009 Share Posted October 25, 2009 How does a galvanised chassis rot?-i thought that was the idea of replacing a ordinary metal (OE)chassis with with a galvanised one to stop it rotting away And as for painting the chassis it makes it less shiny to the light fingered brigade apparently Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 25, 2009 Share Posted October 25, 2009 In Britain we use thousands of tons of salt on our roads every winter, and this salt gets thrown up onto the chassis, and attacks the steel. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted October 25, 2009 Share Posted October 25, 2009 Galvanisation is a rust preventative measure, it won't stop it from rotting away...merely prolong the useful life of the metal. Road salt is a major contributor, a good reason to wash your chassis reguarly during winter. http://en.wikipedia.org/wiki/Galvanisation#Eventual_corrosion Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 25, 2009 Share Posted October 25, 2009 Galv is not a permanent solution. A Galv chassis left as it comes, will rot through eventually, and you can expect to be seeing rusty holes in around 20 years, less if you live in harsh areas. Absolutely true. Painting will extend the period before the galv has to sacrifice itself. The worst thing is the rust hides under the galv, and the first you see of it is when a piece falls off. This is incorrect - galv actually forms a metallurgical bond with the steel and will corrode in preference to the steel until it has all gone. A Glav chassis should be treated in exactly the same way as a normal chassis every winter, for maximum protection. Yep, although you may find the rest of your truck has disintegrated in the meantime!! Quote Link to comment Share on other sites More sharing options...
jimmy_neutron Posted October 26, 2009 Share Posted October 26, 2009 I'm just doing the same job and mine will get waxoyled. The rear x may get underseal cos wax tends to rub off easily when loading in the rear door. Reasons are .. 1) If the van looks like it had loads of cash spent on it then it'll probably not belong to me very long. You have just got a new chassis so you can imagine how much it will make on flea bay. 2) road salt turns galv into like a blackish pitted mess which doesn't look too pretty and probably shortens the life of the galv slightly. I wont be injecting the chassis though. Quote Link to comment Share on other sites More sharing options...
q-rover Posted October 26, 2009 Share Posted October 26, 2009 For painting galv you need to use the following procedure. -Wash using alkaline soap(strong) solution -Rinse thoroughly -Dry -Use quality etch primer -Then use a top coat suiited to the primer. Quote Link to comment Share on other sites More sharing options...
HighlandRover Posted October 26, 2009 Author Share Posted October 26, 2009 Cheers for your thoughts guys. Think i'll probably end up painting it and cant see the harm in waxoilying it aswell. Appreciate the help! Quote Link to comment Share on other sites More sharing options...
Fatboy Posted October 26, 2009 Share Posted October 26, 2009 One of the features of galvanising is that it "protects" the steel because it corrodes preferentially.. To do this, it needs to be in direct contact with the elecrolyte. ie: If the galv is scratched off, the steel and other undamaged areas of zinc are connected through the structure and also electrically though liquid (water, salt water etc). In theory, if you completely coat the chassis, then I'd think that if the coating gets scratched off along wwith the galv, through to the steel, the steel will corrode as per normal. The galv won't be able to assist in protection. Now - You can't practically paint every square inch of the chassis from the outside but I'd suggest if it was dipped when it was galvanized, there are areas inside the sections which are not perfectly galzanized either. These probably rely on the cathodic circuit to prevent corrosion so if reduce the zinc exposed to the elements, you reduce the protection of these areas too. Personally, I waxoyl the obvious areas like the rear crossmember and front legs so that its not really obvious that its a galv chassis but leave the majority of the chassis bare. Quote Link to comment Share on other sites More sharing options...
JimC Posted October 27, 2009 Share Posted October 27, 2009 The honest-to-goodness hot ticket for metal preservation is galv followed up with a re-blast to prep the surface (not to strip the galv) and a zinc-rich epoxy primer on top of it (followed up with whatever paint you like - its just for color at that point). That is the spec used for bridges, marine applications, etc. The ZR epoxy is actually every bit as good as galv, but dipping in zinc gets inside places that the paint can't. Its up to you as to whether or not your application demands that degree of protection... Quote Link to comment Share on other sites More sharing options...
HighlandRover Posted October 27, 2009 Author Share Posted October 27, 2009 I'm just doing the same job and mine will get waxoyled. The rear x may get underseal cos wax tends to rub off easily when loading in the rear door. Reasons are .. 1) If the van looks like it had loads of cash spent on it then it'll probably not belong to me very long. You have just got a new chassis so you can imagine how much it will make on flea bay. 2) road salt turns galv into like a blackish pitted mess which doesn't look too pretty and probably shortens the life of the galv slightly. I wont be injecting the chassis though. Out of curriosity, what is the reason for not injecting it? Quote Link to comment Share on other sites More sharing options...
lansalot Posted October 28, 2009 Share Posted October 28, 2009 Out of interest, if you're going to be off-roading ( and if not, why not ), then the inevitable scrapes will eventually scratch the galv off. The more layers on top, the better ? Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 28, 2009 Share Posted October 28, 2009 A Galv chassis left as it comes, will rot through eventually, and you can expect to be seeing rusty holes in around 20 years, less if you live in harsh areas. The worst thing is the rust hides under the galv, and the first you see of it is when a piece falls off. That is quite a strong statement and entirely incorrect. Please could you expand on it with some scientific evidence ........... especially the statements of '20 years', 'rust hides under the galv', and 'when a piece falls off'. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 28, 2009 Share Posted October 28, 2009 I would like to ask JimC how big the galv baths are in the states though - the only bridges I have managed to fit in one were Bailey bridges and they come to pieces on purpose. For those with a UK interest, the specification for painting bridges can be found on page 15 (Table 19.2B) of MCHW Series 1900. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 28, 2009 Share Posted October 28, 2009 If galvanising is done properly then it will not flake off as it forms a metallurgical bond between zinc and steel. The hot zinc chemically forms to zinc carbonate on the steel surface giving that nice dull grey finish. Testing has shown that even in extreme harsh environments the Zinc Carbonate surface will last 30 years ………… in the normal UK environment 40 to 70 years is expected. Knowing Richards chassis like I do ……………..I would not have thought they would have put a 20 year life on their chassis (there are plenty of originals around that are that age & older !) ………… and I would expect them to know that if the zinc carbonate flakes off then the process was either faulty or not complete. I will concur that some galvanising companies are better then others. The process within the hot dip environment is vitally important. If electrogalvonising is used then the zinc coating is thinner but the bond is slightly stronger. No hard feelings, but we need to get the facts right on such an important issue. Quote Link to comment Share on other sites More sharing options...
JimC Posted October 29, 2009 Share Posted October 29, 2009 For the record, most bridges in the US are assembled out of component parts. Various parts are treated before they are assembled . Anyway, my local galvanizer actually has the largest tanks in the country, like 20x20x40 feet or some such ridiculous size. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted October 29, 2009 Share Posted October 29, 2009 Personal experience: I've a 1981 LWB with the standard galv bumper. Last year I replaced the bumper because it had rusted so badly that there were holes along the front beam, the back of the bumper had gone completely. It was used in the UK by a local authority before it came to me. Less than 30 years old. I'd strongly suggest you treat a new galv chassis as bare steel, with the exception for the need for etch priming. Etch. Prime with tar coal paint, repeat, repeat, topcoat. For areas that are subject to spray I'd apply the plastic undercoating. Interior of the chassis fully waxoiled. G. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 29, 2009 Share Posted October 29, 2009 There is no set lifespan for galvanised steel. Fact. The thickness of the coating, (which is a function of the thickness of the coated steel and the galv process used) and the exposure conditions during it's life will significantly influence the corrosion rate of the zinc. If you are interested (Nige, look away now you luddite! ) then click HERE. Quote Link to comment Share on other sites More sharing options...
Troddenmasses Posted October 29, 2009 Share Posted October 29, 2009 [puts hand up] Ooh Ooh - a topic that I actually know something about for a change - yey. I'm a technical consultant for a metalurgical company, particularly looking at laboratory testing. Galvanising absolutely should form a chemical bond with the parent material, and in fact if you do a Quantitive depth profile of a coated piece of material, you will find that you should get about a 10 micron depth where the material is a mixture of zinc and steel (identified by the Fe). A large steel works in the UK makes the zinc coated steel for drinks cans, and about 10 years ago they found that a lot of the cans were going rusty around the bottom before it got to the consumer. They called us in, and we did a trace exactly like the one in the link above. At the intersection - about 15 microns in, we found a small carbon peak. It turned out that the accountant had found a cheaper brand of detergent to wash the lubricant off the steel, before it was galvanised. This prevented a proper chemical mix of the Zinc and Iron. Galvanising is an excellent method of corrosion resistance, but it has to be done well - especially the preparation of the parent material (usually the problem), and the temperature of the dip. Long story short - pretend that it's a steel chassis (except for using etch primer) and take all of the usual precautions - waxoyl inside, good paint or waxoyl outside, and be happy with the fact that if you miss a bit, it will probably be ok. Quote Link to comment Share on other sites More sharing options...
TD5 power Posted October 29, 2009 Share Posted October 29, 2009 hi I have also got a galvanised chassis for my 90, and like the op im looking for ways to increase its life span. I have been told that paint doesn't like sticking to newly galvanised metal so in my research i cam across a product called T Wash which is meant to prepare the surface for improved paint adhesion, has anyone heard of it or better still tried it? many thanks matthew Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 29, 2009 Share Posted October 29, 2009 Richards themselves told me to use a good quality etch primer- the only thing that will work, and recommended Hammerite Special Metals Primer. A friend of mine is a plater and recommended the same, but did a bit of digging and discovered that old and dulled galv can in fact be suddesfully painted without. I've tried it on an old galv jug that the wifes painting up narrowboat style, and he was right. Of course it doesnt apply to a new landy chassis...we hope!! Quote Link to comment Share on other sites More sharing options...
garymorris Posted October 29, 2009 Share Posted October 29, 2009 hi I have also got a galvanised chassis for my 90, and like the op im looking for ways to increase its life span. I have been told that paint doesn't like sticking to newly galvanised metal so in my research i cam across a product called T Wash which is meant to prepare the surface for improved paint adhesion, has anyone heard of it or better still tried it? many thanks matthew Hi I've used T wash(it's also called mordant solution) on steel fabrications that have been galvanized then require painting ,basically you brush it on ,leave it a few minutes then wash off with water . it will turn the galv from shiny finish to black . As far I know it's the correct thing to use when you want to paint a galvanized product , no doubt an adult will be along in a minute to correct me ! Quote Link to comment Share on other sites More sharing options...
TD5 power Posted October 29, 2009 Share Posted October 29, 2009 thanks for the replies i was planning to use etch primmer just wanted to make sure it didn't start peeling off again in a year many thanks matt Quote Link to comment Share on other sites More sharing options...
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