Retroanaconda Posted March 30, 2021 Share Posted March 30, 2021 My 90 has a galvanised chassis which I painted a few years back during the swap - T-wash followed by two coats of Buzzweld Chassis-in-One. This adhered well but wasn’t durable/thick enough and had effectively been worn away by salt and road dirt in certain areas within a year or so. Because of this and the fact that I need to make some modifications to the chassis for the rear tank etc. I will get it blasted and re-galvanised, so I need to do it all again. Apart from the longevity issue with the paint it was also a major pain to do and took nearly two days, so I’m looking at other options. The plant that I will be using offers a product called Colourgalv which is a powder coating process applied after galvanising. I’m not sure on cost but it will save a hell of a lot of time and hassle painting. My preconceived opinion of power coating is generally that it’s rubbish and cracks allowing water to get in behind, but that may be just poor prep and quality control whereas the factory colourgalv process has a much higher standard of application. I would be interested to hear peoples thoughts on this option. Quote Link to comment Share on other sites More sharing options...
L19MUD Posted March 30, 2021 Share Posted March 30, 2021 5 minutes ago, Retroanaconda said: My preconceived opinion of power coating is generally that it’s rubbish and cracks allowing water to get in behind, but that may be just poor prep and quality control whereas the factory colourgalv process has a much higher standard of application. I would be interested to hear peoples thoughts on this option. My experience of powder coated items is pretty much this! I have purchased Land Rover light guards and bumpers that have been fine for a few years and then water gets in and rust gets behind the coating and it comes off in big nasty flakes. Interestingly the only positive experience I have had are on a pair of Scorpion Racing tree sliders purchased many many moons ago, they were galvanized and then powder coated from new and they held up amazingly well for 15 years. Even when someone drove a Mondeo into one scraping down to the galv the powder coating did not then start lifting either side of the scrape even years after. When I did my rebuild I cleaned everything of powder coat before being re galvanised, including the tree sliders to repair the crash damage. What was interesting was that the light guards and bumper powder coat melted into a gloop when trying to get it off with a sander/wire brush it seemed more like a layer of plastic. The coating on the tree sliders did not melt like that and cleaned off with a lot of persuasion from the wire brush on the grinder It seemed like a totally different coating used between the two items Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 30, 2021 Share Posted March 30, 2021 I think that is the difference, powder coating on steel is naff, and will never last once you have a scratch in it, powder coating on galv means even if water does get through, it won't care. Quote Link to comment Share on other sites More sharing options...
L19MUD Posted March 30, 2021 Share Posted March 30, 2021 2 minutes ago, Bowie69 said: I think that is the difference, powder coating on steel is naff, and will never last once you have a scratch in it, powder coating on galv means even if water does get through, it won't care. Whilst I agree that is also true the two types were completely different in the way they reacted to removal! I gave up with the light guards in the end as the plastic just melted and moved about, the problem was solved when I accidentally left them on the bonfire..... 1 Quote Link to comment Share on other sites More sharing options...
Arjan Posted March 30, 2021 Share Posted March 30, 2021 Powdercoating versus Pain... There is many different methods of PC and some are good, some less good. I have powder coated several chassis after galvanizing and this is the last one awaiting collection in Holland. The various companies in Holland have explained to me the differences and what UK seems to do most is not PC but Nylon Coating - and that is quite different. So I suggest you ask around - give FirstFour a call and ask them where they get their PC done as the did my sliders and they are very, very good. Price wise painting is slightly less expensive. 1 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted March 30, 2021 Share Posted March 30, 2021 I used to work in a bus factory - the underside parts were made of galvd steel (not zintec) and then epoxy powder coated. Before the powder coating they were dipped in detergent to degrease, phosphate and then chromate washed (probably can't do that these days) then were dried in an oven and went straight into powder coat. You couldn't move the resultant coating even if you scratched with a coin. Without the pretreatment, even on degreased galv it was easy to get it to lift off. If the colourgalv is similar process it should be tough. Pre treated it looked like it had been T washed, and felt slightly rough so it must have provided a great key. If you want to paint I used epoxy primer and polyurethane top coat, both 2 pack, on a new galved rear crossmember. Even after 8 years the paint was good (the rest of the chassis in front of it wasn't) Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted March 30, 2021 Share Posted March 30, 2021 I have a feeling Nylon powder coating is initially attached to the metal, prior to baking, with an electrical current. This seals the powder onto the metal. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted March 30, 2021 Author Share Posted March 30, 2021 Thanks folks. It’s definitely a power coating process rather than plastic dipping/coating. They do two grades, Colourgalv and Colourgalv Marine. The latter has an additional primer stage from what I can ascertain. Here’s the specification sheet for it. https://higalv.co.uk//wp-content/uploads/Colourgalv-Marine-specification-for-website.pdf Longevity is what I’m interested in. Chassis do flex as we know so it’ll need to not crack and flake off at the first sign of that. Abrasion damage off road is unavoidable but likewise it would be good if that didn’t lead to large-scale delamination. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 30, 2021 Share Posted March 30, 2021 I wonder what the chassis will end up weighing once all this is done....! Quote Link to comment Share on other sites More sharing options...
Arjan Posted March 30, 2021 Share Posted March 30, 2021 The Ninety chassis gained 107 kilos when it was galvanised and powdercoated. 3 Quote Link to comment Share on other sites More sharing options...
landroversforever Posted March 30, 2021 Share Posted March 30, 2021 Biggest thing with powdercoat and why it gets a bad rep in the UK is prep. So many of the parts we buy have been coated in the cheapest possible way which is where the reputation for it peeling off in sheets comes from. Most stuff also doesn't get any kind of zinc prime like the high quality stuff does. It wouldn't surprise me if some of the really cheap stuff isn't even blasted first. Funny that First Four are mentioned above.... my old bumper was 3rd or 4th hand and had several rusty bits where it was grazed hard on rocks and the coating was only damaged there. No spreading of corrosion under the surface. @Nonimouse I think all forms of powdercoat are applied electrostatically. @L19MUDI think your melty vs burning is down to the different coating types, either thermoplastic or a thermoset. 1 Quote Link to comment Share on other sites More sharing options...
L19MUD Posted March 30, 2021 Share Posted March 30, 2021 27 minutes ago, landroversforever said: @L19MUDI think your melty vs burning is down to the different coating types, either thermoplastic or a thermoset. Thermoset sounds like the one to go for then if you have a choice? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted March 30, 2021 Share Posted March 30, 2021 I can't remember the the names the coaters use for the two different material types Quote Link to comment Share on other sites More sharing options...
JohnnoK Posted March 31, 2021 Share Posted March 31, 2021 21 hours ago, Retroanaconda said: My preconceived opinion of power coating is generally that it’s rubbish and cracks allowing water to get in behind, but that may be just poor prep and quality control whereas the factory colourgalv process has a much higher standard of application. I would be interested to hear peoples thoughts on this option. I think you are right about the cracking and corrosion. Most powder coaters don't prime first, which is a waste of their powder and your time. Personally, I'd galvanise it and leave it, but if you insist on covering the galv, then Id look into the Jotun Marine coatings as a final coat. IMO, an undercoat/primer of some sort is ESSENTIAL, too. They are really durable and touch ups are simple. Quote Link to comment Share on other sites More sharing options...
JohnnoK Posted March 31, 2021 Share Posted March 31, 2021 20 hours ago, Nonimouse said: I have a feeling Nylon powder coating is initially attached to the metal, prior to baking, with an electrical current. This seals the powder onto the metal. Correct, but without a clean, primed substrate, it's a waste of time for anything that will see the weather head-on. 1 Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted March 31, 2021 Share Posted March 31, 2021 We had some stuff powdercoated at my previous job and there's a big difference in quality (and price) for the more durable stuff. I'd be tempted to agree with @JohnnoK galvanise it and then a decent paint which is easy to touch up afterwards. I got a bucket of this stuff: https://www.mj-supplies.com/product/modified-vinyl-black-gloss/ for painting the gateposts to the tradesmans entrance and it's survived being dragged across the workshop floor, picked up using pallet forks on the JCB and dragged across the tarmac and maneuvered into place using crow-bars and the JCB . Getting a decent finish might be a little bit of a challenge but so far after a couple of months it's holding up well. I slapped on a coat onto the rear cross member of my 110 as a short term measure until I clean off the whole chassis and do the same. So far been relatively impressed but it's not been very long. 1 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted March 31, 2021 Share Posted March 31, 2021 An old friend, once told me that the toughest finish for paint, was cheap agricultural enamel, thinned down by 10% with cheap thinners then applied to at least 5 layers. It's what I use to paint diiger buckets, timber winch ground anchors, grab saws, snips and shears and the lower part of the weight box on a 360. The damn stuff is like armour plate 2 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 31, 2021 Share Posted March 31, 2021 27 minutes ago, Nonimouse said: An old friend, once told me that the toughest finish for paint, was cheap agricultural enamel, thinned down by 10% with cheap thinners then applied to at least 5 layers. It's what I use to paint diiger buckets, timber winch ground anchors, grab saws, snips and shears and the lower part of the weight box on a 360. The damn stuff is like armour plate That and so easy to make shiny! I use it on roll cages, bumpers and the like too. 1 Quote Link to comment Share on other sites More sharing options...
Quagmire Posted April 1, 2021 Share Posted April 1, 2021 Tractol! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 1, 2021 Share Posted April 1, 2021 Teamac Quote Link to comment Share on other sites More sharing options...
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