Topic: Exhaust flange/clamp -- how to clean 'em up? Paint? Treat?

[carnivorous chicken]

While the header gets chromed, I want to clean up the exhaust clamps on the 550F. They're in good shape, but a little rust showing through. Wondering what others have done -- paint? Treat them with something?

I chromed a set once but... that's not what I'm gonna do here (and I understand it's not that great for heat dissipation...)

[Oddjob]

Don’t see why not, they were chromed when new.

When I’m back on my pc I’ll post some pics of mine, I’ve done a lot of work on these clamps to see what works best. Chroming them as they are is a recipe for disaster, they are very poorly cast and extremely rough on the surface.

[Rayzerman]

Quick search..... get new ones??? or sticking to original?
https://www.dimecitycycles.com/honda-exhaust-clamp-14-fins-fits-cb100-cb550.html

[carnivorous chicken]

Thanks guys.

Sure they were chrome, Oddjob? Don't recall seeing chrome ones on any of the bikes I've owned except the ones I did myself.

And I don't want/need new ones, just want to clean these ones up.

[Kelly E]

I used aluminum color VHT high temperature exhaust primer and paint. It is holding up well. I blasted them before painting to eliminate all the rust.

[Dime]

I used aluminum color VHT high temperature exhaust primer and paint. It is holding up well. I blasted them before painting to eliminate all the rust.

This is what I am planning on doing

[Oddjob]

Sure, yeah 100% sure.

https://www.cmsnl.com/honda-cb550-super-sport-550-four-cb550f2-1977-usa_model468/joint-exh-pipe_18231333010/

Later models started to get alloy ones but AFAIK all the SOHCs of that era got chromed exhaust clamps.

Back on the PC now so this may get a little OTT. Bear with me.

Back in the late 70s, early 80s when I first started to restore these bikes I had some clamps rechromed, they looked ok for a short while but as the chromer explained when I picked them up, inside the fins is the problem, they couldn't get anything to fit down there, so they were just cleaned and chromed. The problem is the casting is extremely rough, there are air bubbles in the castings as well. The edges of the fins and around the bolt holes came out great, they could polish those but the rest was chrome but dull chrome, not dissimilar to the pic from CMS. The clamps started to rust within weeks, right at the base of the fin where it curves round. Within 6 months they looked awful.

So this time I decided to avoid that trap and come up with a different solution. I could have bought new but TBH that just means they last a year or so before going the same way. First thought was cut some of the fins off, so they can access in between the fins, so I had loads of spare clamps so decided to sacrifice one to see how it looked. Came out like this. That's not chromed BTW, that's just me and how I prepare my stuff for chroming, they do it real cheap because I've done all the prep work for them.



Not a fantastic look but it might look ok to you.

Then I thought, how about no fins, just a plain clamp ring like I have fitted to my CB1300, so off came the rest of the fins and it looked like this.



Simple, easy to clean and should be ideal to chrome. However I was warned that the chrome would blue due to the heat, I can't say that's true or false, I've not tested it yet. I do intend to test it once I get the bike finished next year and have that ring chromed, I'll just throw it on number 4 pipe and see what happens.

My next thought was to do the job for the chromers for them, polish right down the fins, get them really smooth. I'm really good at polishing but I've got to say that's impossible to do. Firstly the metal looks to have been cast in sand,

it's rougher than sandpaper down there, it would just chew up your polishing mops and cost a fortune. So I decided to grind them smooth, some small grind stones and a Dremel (or similar) this takes hours to do, it's not for those without patience. Each one took me up to 8 hours to do and I was doing 16 of them, 8 for me and 8 for friends. Some took longer, none took shorter.

One half done, the amount of rust is typical for the UK, might be less in hotter climates.



After they were ground smooth I polished them, that wasn't easy either, I needed a really thin mop in order to get to the bottom of the fins. However I got the first 4 done.





So decided to test the theory and took one to my local chromers, he no longer does triple plating, that's copper, then nickel then chrome. It's due to environmental issues and costly equipment needed to comply etc so just nickel then chrome. Cam out like this



Here's where it gets a little OTT, I never stop thinking of ways to improve things and I was getting stuff ceramic coated and one finish was a chrome look. So I thought how about doing 4 in chrome and 4 in ceramic chrome, test them, see what lasts the best. So I took 4 to be ceramic coated and they came out like this. Notice the 2 air bubble holes on the edges of the fins?





Ceramic coating shouldn't rust, shouldn't blue, it should just dull a little with age but a quick going over with some polish and wire wool brings it back up, I've had a set of header pipes done in this finish and it lasted and lasted.

So food for thought, at least you know the pitfalls now.

[CycleRanger]

That's some nice work Oddjob!

[MauiK3]

Great write up, tons of patience, they look great.
I'm not familiar with ceramic coating, looks like a good option.

[BenelliSEI]

A lot of effort! Nice work.

[Deltarider]

Why you'd want to clean, let alone polish, exhaust flanges, exhaust flanges! fails my imagination. The effect of such on a further standard looking engine, is like lipstick on a pig.

[Medyo Bastos]

You in a bad mood DR?


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[M 750K6]

The ceramic coating looks amazing.

[carnivorous chicken]

Sure, yeah 100% sure.

Just brought the flanges up from the dark basement garage I'm forced to work with and sure enough -- you're absolutely right. Sorry for doubting you. I've owned a bunch of these bikes and maybe the chrome was so knackered or flaked off or whatever that I just don't recall seeing anything nice.

The chrome on my 350F flanges has held up pretty well, although I've had to clean off a little rust here and there. I didn't smooth them out at all however.

And really nice work, BTW.

On the 550F they were mostly dirty and covered in burned oil -- leaking tappets at some point had oil running down the front of the engine. I sprayed them with degreaser and rinsed them, and underneath is pretty nice chrome. I'm not going to go all out, but it won't take much to clean them up nicely.



Especially with the handy dandy Q-tip drill bit. Don't laugh, it works pretty well!



I can almost here Delta grinding his teeth.

Why you'd want to clean, let alone polish, exhaust flanges, exhaust flanges! fails my imagination. The effect of such on a further standard looking engine, is like lipstick on a pig.

I get your utilitarian outlook but some of these bikes are a little better looking than pigs!

[Kevin]

Nice work, Oddjob!
There aren't many people that would have gone through the trouble, but it's the details that really sets a bike apart from another. And maybe nobody else notices the details, but you do, and that is what's important, even if it's only important to you.
I can appreciate the labor of love.

I have painted some, re-chromed some, and replaced with billet aluminum some.
They all did the job they were intended to do and within the budget given.

Happy Thanksgiving, Y'all!

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[BenelliSEI]

Nice work, Oddjob!
There aren't many people that would have gone through the trouble, but it's the details that really sets a bike apart from another. And maybe nobody else notices the details, but you do, and that is what's important, even if it's only important to you.
I can appreciate the labor of love.

I have painted some, re-chromed some, and replaced with billet aluminum some.
They all did the job they were intended to do and within the budget given.

Happy Thanksgiving, Y'all!

Sent from my SM-S908U1 using Tapatalk

+1 to that! A while back, I spent too long refurbishing a very early cb750 seat latch. New ones are available, but I like keeping the old one functioning and looking good. Makes sense to me.

[Oddjob]

Delta has this weird thing that everything I say he says the opposite, makes him happy so that's no problem. I just tend to ignore him as best I can these days.

He hasn't seen my engine, no one has, it's NOT standard, it's as far from standard as I think you can get, externally that is, internally it's also not standard but I'm not one of those seeking power and speed, if I get some that's great but big bore kits and hot cams are not my thing. For example, my engine is ceramic coated, not painted, not powder coated, it's mainly black and silver, the casings are highly polished, like mirrors TBH, I did do chrome casings on the last restoration but it didn't survive the first winter. So learned my lesson with that one and decided on polished instead.

This is the engine the last time I restored it, it was extremely quiet, tickover at 1000rpm was noiseless, it would go down to 600rpm before it started to make any noise, Delta hates me saying that for some reason so I'll say it again, 600rpm.



Oh and I forgot to add, to complete the look for the clamps I decided to clean and grind/polish the exhaust collets or whatever you call them, I didn't want nice shiny clamps and horrible rusty collets on a brand new exhaust system, so I spent many hours cleaning up 24 of them, I gave 8 to a good mate for his 550 and kept 16 for myself. Off they went to be ceramic coated as well and came back like this, you get back what you give in, so give them really nicely cleaned, polished etc parts and you get great results.



And if you're looking for ideas. How about doing the wheel spindles or swinging arm spindle.



Oh and apologies if I've hogged the thread a little, sometimes I get a little carried away.

[Deltarider]

I have invited Oddjod to demonstrate a CB500 running @600 rpm without disturbing noises. I have never heard of one that can do that. The best I ever managed was 800 rpm, when everything was tiptop.
Claims like Oddjob's are easily made. My moto: show, don't tell. Another member, also in the UK site, emphasizes the finetuning after syncing the four carbs by adjusting the airscrews. I have not seen any vid of a CB500 running fine @600 yet or a demonstration of succesfully finetuning CB500 carbs by adjusting the airscrews, not on Youtube, not on any platform. I find that telling. Again: show, don't tell.

[Don R]

 I've used a soft wire wheel to knock off the rust and coated the formerly rusty area with silver high temp engine paint. They aren't as pretty as those chromed or coated ones but do nicely on my old bikes.

[Ozzybud]

+1 on the soft wire wheel.
This wheel on a dremel tool makes lightly rusty flanges look beautiful
.

[carnivorous chicken]

I've used a soft wire wheel to knock off the rust and coated the formerly rusty area with silver high temp engine paint. They aren't as pretty as those chromed or coated ones but do nicely on my old bikes.

I miss having a bench grinder with polishing wheels. Would've done the trick quickly. Don't have a bench. Don't even have a real workspace.

That being said, A little elbow grease, half a q-tip in my drill, and all four actually look really good. They might be repops, dunno, although a lot on this bike is original and in great shape, like the 4-1.

[Oddjob]

Missing the spring washers from under the nuts Ozzybud, fair to good chance the nuts will vibrate off and you’ll lose the collets if you’re unlucky.

[HondaMan]

Oddjob, that's some really nice work!
The clamps were all sandcast, then plated, for the SOHC4 series. Somewhere along the 750K2 era they got copper plated before chrome, too. After the 750K4 they went back to [whatever they were doing at first] and they don't hold up as well, again. On the 500 I only remember seeing the multi-plated approach on the earliest of the CB500 bikes. Then they went to the less expensive plating, again.

I always use a soft wire brush (on my bench grinder) that has been oily for 5 years now. It seems to clean them up real well, but not 'show quality' like your stuff is. After the work with the brush I spray (or dip) them in oil and clean them in solvent (or gasoline). This seems to penetrate the porous steel-ish pot metal and stays shiny for several years before needing it again. But, they almost look 'showroom', while yours look "show".