Okay I didn't realise which belly pan was welded on. I am missing the side ones and the centre one is welded on. I was worried I would get everybody saying that I was going to structurally compromise the van by removing it. It is little hard to identify exactly what is the chassis rail and what is the remains of belly pans. there is a lower edge that looks like two sills meeting on the chassis rail. I purchased a load of POR15 tins back in 2011, they might not be any good now anyway. It was being talked about back then as good even though there was a divide on opinion. What rust converters and primers should I be looking at then and would you recommend? Have you guys had the whole underside of your vans, sand blasted, vapour blasted, acid dipped? Wondering what people generally do when it comes to surface rust on top hats, sills, outriggers and complex areas underneath?
Nope, that would have been way toooo sensible for me. I clean a bit and paint a bit but im usually late to the party and most bits ive made even harder for myself by not doing it nicely in the first place. Be very wary of the wire brush in a drill scenario as it can look fantastic but in reality youve just shined the rust up to look pretty. The shinier the better but metal shine is what you need and not rust shine. Try and shine a bit of rusty crap just to prove my point, once youve got it shiny then scratch it deeply so you can see the difference. You can always then use it as a reference when youre under there covered in crap and vegemite and wondering if its good enough. Always give it a wipe down when youre done with white spirits or similar before you whack that primer on, leave for twenty minutes and bang some top coat on. Dont worry about matching your van, just get some paint on and worry about pretty colours another day when youre all cleaned off and you have all the time in the world. Once the paint by numbers is all joined up, then get some stoneguard or similar stone proof paint under it and then you can play pretty colours if youre not totally jacked off with being under and not in that van. Ozziedog,,,,,,,,,,,,Dont forget to ,,,,,,GO Camping !!!!!!!
Wire brushes as @Ozziedog says make shiny rust. Ideally you would use a laser rust remover as these take off paint and rust without needing blasting media or compressed air. But they are pricey units (£10000+) and I havent seen them at sensible prices to hire.. So scraping with a tungsten carbide scraper to break off the rust, welding patches where its confetti (tap with a hammer around the holes, metal will give way, cut round in solid metal, needs to be basically unrusted to weld to, weld in patch..) Jenolite is the rust converter that converts to bare metal. Then wash/dry and use a phosphoric acid type treatment to convert the tiny bits of rust left behind. Wash and dry that, then paint. My usual thorough treatment is primer, stone chip then a layer of spray underseal. Nothing too thick. Or I just run it over with 80 grade sandpaper to remove the rust coat, kurust the pitted metal and stonechip then underseal, knowing I will be back.
Right so looking at Jenolite products and reading on their website. I sandblasted sections, or used kurust, or painted directly over but never experienced any liquid that actually removes the rust. I am curious how successful this will be and if it will do a similar job (on a smaller scale) to what they do when they dip the whole vehicle in an acid bath. Are these rust removers something that you can spray into the box sections and into the other complicated sections where you would struggle to maybe sandblast anyway? When it comes to primers, I see people mention Zinc rich primers and Etch primers. What type of primer should I be getting? Surely I then need to put a top coat before any stone chip gummy stuff? Previously I bought POR15 chassis paint, so what is the better product that people are using to coat their chassis now?
I've never had Jenolite do very much. I'd attack the rusty bits with a wire brush in a drill - that'll remove the rust. Do any welding that's necessary and forget about the rest (that black stuff is likely the original wax underseal). Slop black Rustoleum over any exposed metal, then spray the whole lot with Bilt Hamber Dynax UB (S50 in the cavities). That'll give you better rust protection than stripping and painting the whole lot. Life's too short.
Once you start you'll realise most of the rustiest bits are the bits it's impossible to clean/treat/paint properly. What Snotty says. ^ Life's too short. Access to every nook and cranny is murder/impossible/a whole restoration in itself. Your van doesn't look too bad to me. If you're pushed for time and will come back to it, don't do the underseal bit. You have an engine to mend too?
Indeed. Leave any original wax underseal. It's quite robust, has lasted 40-odd years, and you'll likely to do more harm than good trying to remove it.
If you must use a rust stabiliser before painting, MetalReady is good, if pricey. They're all a variation on phosphoric acid (MetalReady is phos acid + zinc)..
I've seen so many photos of removing underseal and in the process gouging to bare metal through the paint that's protected it for 50 years. (done it myself too). Just remove the loose stuff.
Thats the sad thing, unless you really go to town on dipping whole body shells and chemically treating rust inside structures, once it starts rusting from behind coating just one side of the metal cant stop it. And welding leaves hidden rusty metal behind the panel, so you end up with having to just weld in thicker pieces like Schofields provide for chassis legs...
Pitted rust eh? I used to try and eat it all with phosphoric acid but it's a hell of a long job and you never really get it all. I'd say it's very important that whatever rust is left after mechanical removal is thoroughly dry, not just surface dry. That means heat at this time of year. Not too hard to organise a bit at a time with a fan heater.
That's a good tip. The rusting process needs three things, iron, oxygen and water; take away one and the process stops. Then get something on there asap before the moisture and air get to work again. I used Rustoleum before the Dynax S50 wax. Thin the first coat right down with white spirit, as white spirit "leeches" into all the nooks and crannies and this helps to freeze the rust. Or that's the theory. Soak everything after that in S50 on a hot day so the wax flows better.