Honda ct70 1975 Question please

Not sure if I asked this before, I can’t really find the tread.
I have a 1975 ct70, it has some external rust, it appears to be surf rust, i will like to improve the looks with out restoration, i want to keep it as original as it is.
Any suggestions on improving the chromes?
Also i posted pictures of the inside of the frame, what do you guys think? I want to apply some kind of protection inside against rust. Should I lightly sand inside with a steel wool 00 and then apply rustoleum rust inhibitor? Its an oil based coat, not paint.
https://www.rustoleum.com/product-catalog/consumer-brands/stops-rust/rust-inhibitor

Thanks

That surface rust inside the frame looks bad but, it isn't. Problem I see is the extent of the surface rust, over everything. Plating, like paint, is a layer of material, over a substrate. Once you see rust, the substrate (base metal) is rusted and beyond what you see. Only way to get those surfaces looking good again is to refinish them. The paint has so much rust bubbling-through that it's going to look awful; rust contrasts starkly against light ("Mighty") green. And the chromed pieces are so extensively pitted that even if you were to remove all of the rust, the pitting would still look really bad. That muffler guard has the surface texture of 120-grit sandpaper.

Honestly, applying any coating to the inside of the frame would be worse than trying to polish a turd. It won't get rid of the rust, may make it worse over time and, will make refinishing much more difficult. If POR-15 were used, it'd be a nightmare to remove. Any petroleum, or worse yet silicone, coating would get into the seams and likely ruin a future repaint. This color is straightforward to apply; and there's only the frame, swingarm and chainguard that wear it. If you're looking for maximum bang for the buck, blast & repaint the green frameset parts. Start with a coat of epoxy primer-sealer and you'll have the frame looking great and the metal protected from further rust. From there, you could paint the fenders & muffler guards. There aren't that many chromed parts on this model. The only place where you're kinda stuck is the headlight ears. OTOH, you get a break with the TL bracket, rear signal stalks, brake pedal, footrest asm...they were painted black originally.

I understand the "it's only original once" thing. But it didn't have rust, originally and this is past the point where "it can look bad forever".

Here are a few pix of a Z50 HL shell I'm redoing. I noticed that a light hit with the blasting gun removed the paint and revealed all of this surface rust lurking beneath. Didn't take much to remove the rust, btw. The point is that you have the same thing going on with your frameset...much more extensively spread rust; and, from here, it'll only spread further & faster.

Poor thing- tough decision on not painting. Something like Fluid Film sprayed inside the frame might be better than a rust converter,it would be way easier to get out if needed when the time came. Not directed at you Bob but as a side note you have to remember these things were built to a price point- so things like surface prep,primer,high quality paints were not in the mix,same with the chrome. Then add the fact that I'm sure Mr Honda did not expect these things to be as desirable or last as long as many have. In his defense he did promise to supply parts for every model he sold and it was done until he passed. Didn't like how a part looked just go to your dealer and buy a new one,cheaper than having your's rechromed/painted. It did however create headaches for the supply chain just think of the supply needed just for z50 K0 and K1 gas tanks with all the different colors available- for example same tank but 4 different colors plus one available even in primer. Also with todays bean counters thinking- not good for profits if you keep riding the same machine for 50+ years

No offense taken, Gary. I'm sharing an opinion based on decades of experience. Most of the time, I tend toward over-optimism. This bike is different. It's straight & solid, the ravages of moisture exposure affecting every surface. It has to come apart, just to do the minimum needed. Most of the chromed pieces could be painted...not stock but, they are bolt-ons that could be redone at any time. The aluminum parts, such as the brake plates, lower fork legs, handlebar clamp can be metalfinished & polished; they'll take a fair bit of elbow grease but not much money. The black parts are easy enough to repaint with automotive wheel paint; they can be bead blasted cheaply enough. IMO, seems a bit absurd to hang clean parts and a fresh engine on a shabby-looking frame, that's only going to get worse, over time. The frameset is the toughest part to redo, once the bike has been reassembled; it's also the core of the bike...the main visual cue of a CT70. Mighty Green is available in rattlecans; Colorite should still have it, Dratv had it listed on their site and it's a DIY-friendly color. I'd estimate $125 to have the frame carefully glass bead blasted. The only really pricey items are chromed and they all cost what they cost. In 2019, there aren't many chrome plating shops left in the US of A. Chrome parts can be painted, until such time as the budget will allow plating or replacement. Done this way, the difference between bare minimum and done well isn't all that much.

As for 50-year-old vehicles, no manufacturer ever planned for that. Everything is built to a price point, always has been. The fact that so many of them have survived and the marque remained popular speaks volumes about the quality of the machinery and the integrity of the manufacturer. Naturally, a lot has changed in the interim....some for the better. Paint technology has come a long way since 1970. even the rattlecan type is better than what was used prior to 1980, nothing wrong with that. Other than the sky-high cost of chrome, which is a separate discussion of its own, small Honda owners have faced few unhappy compromises. And the "80/20 rule" usually applies, which is why IMHO, it makes sense to do at least certain things the right way from the get-go. These are just my opinions...YMMV

My main goal is to make sure the rust inside doesn’t expand, continue or progress.
Any simple and easy suggestions?
Thanks

Keep the frame dry, store the bike indoors, preferably in a climate-controlled building. No joke, these frames really aren't prone to rusting from the inside-out, unless kept in a humid environment.

If you want to coat it with something effective, that can be removed normally, use a "conversion" primer, such as Corrolless sold by Eastwood. It may be under a different name, as of this late date. You'd only need a small quantity, 8oz should be plenty and it can be applied by brush. You'll need to scrape & wire brush away all of the loose & scaling rust, degrease the surfaces first. The stuff works by converting ferrous (red) oxide, a.k.a. "rust" into ferrice (black) oxide which is chemically stable...and sealing the steel.

Turqui said:

Not sure if I asked this before, I can’t really find the tread.
I have a 1975 ct70, it has some external rust, it appears to be surf rust, i will like to improve the looks with out restoration, i want to keep it as original as it is.
Any suggestions on improving the chromes?
Also i posted pictures of the inside of the frame, what do you guys think? I want to apply some kind of protection inside against rust. Should I lightly sand inside with a steel wool 00 and then apply rustoleum rust inhibitor? Its an oil based coat, not paint.
https://www.rustoleum.com/product-catalog/consumer-brands/stops-rust/rust-inhibitor

Thanks

Click to expand...

Some external rust? C'mon. I see it inside & out. Can't sugar coat this; rust is a cancer that has to be terminated, if you try to contain it, by spraying over it, it will come back. It's a hard call but you may be at the tipping point on rehabbing this Mighty Green before it starts taking lots O time and lots O' buck$ for new parts. Because, once the rust starts on chrome, its toast.

The frame is still good, it needs coarse steel wool and maybe a metal prep solvent. Then some Dupont self etching primer is what works good for rust. But the rust has to be sanded or blasted off. Rust never sleeps. Good luck.

Adam-NLV said:

Rust never sleeps.

Click to expand...

Rust is like Chuck Norris. He doesn't sleep.....he waits! Lol