Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: theriddler on September 23, 2018, 09:18:05 PM
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Hi does anyone have any suggestions on how to rejuvenate the finned exhaust clamps? I can get them clean but would then like to get them treated as they seem to be prone to rusting?
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You have to remove every trace of chrome/nickel plating by reverse plating in the chroming bath. Then media blast them, then clean up with a rotary wire brush.
Well that's what two chromers I have used both told me anyway. Very difficult items to chrome and even originals tend to spot rust very easily.
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The fins were designed originally to be rough as this increases surface area and
causes turbulence over the surface to dissipate heat.
Back in the 70's when it was 'cool' to polish the fins on heads and barrels bikes frequently seized as they ran too hot .
Yes they don't seen to last very long when replated .
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You would be better off sourcing new ones, this would be a cheaper option, they would still end up rusting quite quickly though as the fins shield the recesses during plating and the underlying nickel remains very thin and chrome is not waterproof.
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You would be better off sourcing new ones, this would be a cheaper option, they would still end up rusting quite quickly though as the fins shield the recesses during plating and the underlying nickel remains very thin and chrome is not waterproof.
Agree ..it's about fifty quid to get a set of 4 re-chromed.
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You would be better off sourcing new ones, this would be a cheaper option, they would still end up rusting quite quickly though as the fins shield the recesses during plating and the underlying nickel remains very thin and chrome is not waterproof.
Agree ..it's about fifty quid to get a set of 4 re-chromed.
How about asking Philpotts if they would do them? The hardchrome they use on forks is not quite as shiny as say that on exhaust downpipes/silencers, but it is very hard wearing.
Sent from my X6pro using Tapatalk
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I have had them zinc plated or nickel plated which is normally much cheaper than chroming
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Just a thought. I had a DOHC CB750 and had the whole motor plastic coated, which included the clamps (similar style). The cases and head were black and the block silver. I had no issues with the finish or engine performance even with a pretty heavily tuned motor. I appreciate this is probably not your answer unless you simply want practicality....
Would the ceramic coatings people use on exhausts work? Lots of colours available.
Tim
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Every couple of years I take the exhaust rings off the bikes and, after masking up the polished areas where the retaining studs pass through, paint them with high temperature aluminium paint. This looks fine (at least to me, much better than rust!) and usually lasts through two riding seasons. The areas that remain polished seem to go quite well with the painted finish.
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I had mine re chromed and to be fair they lasted a lot of years but one went rustier than most, so I bought a new NOS one and it was as bad as the one that I wanted to replace, so I now do the same as flatfour, the rusty parts get a clean up and then the High temp Aluminium paint treatment, this also works on the welds on the header pipes.
Cheers
Dennis
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Mine have also been painted as rust is inevitable.
I went a slightly different route as I have veriouse differnt rattle cans kicking around for special effects at work.
I treated the rust then painted them with gold rustoleum combicolor and then rustoleum chrome metallic.
They have lasted very well over two years. They have lost there shine but are still looking better then if they were done in VHT paint.
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Cleaned mine up & was going to paint them, but took bike out for a ride instead ... oops! Then cleaned down bike & already exhaust clamps are rusty after a fortnight! :(
I have a spare set which aren't too rusty which I'll paint then swap over ... wonder if exhaust will come off enough to swap over fins clamps without disturbing pipe to collector box & muffler seals?