Author Topic: Can opening an exhaust  (Read 2187 times)

Offline AshimotoK0

  • Grogu
  • *
  • Posts: 7386
  • Mad Scientist.... more power Igor ! ٩(̾๏̮̮̃̾๏̃̾)۶
    • View Profile
Can opening an exhaust
« on: December 23, 2015, 01:51:50 PM »
The holy grail of CB250/350K twin  parts is the original one-piece No.No.  silencer/downpipe combo. You just NEVER see them as they were prone to cracking, if not mounted correctly, and Honda swiftly changed to separate pipe/ silencer clamped together in the late 60's. Also, to best of my knowledge, the  pipe and silencer of the later systems (stamped HM317, then HM344) were never sold separately by Honda. Anyway, the '69 CB350K1 I got from DK had the original one-piece pipes on it in amazingly solid shape. I suspect they were replaced 'back in the day' and then the bike was stored indoors soon after fitting,  for yonks in Wyoming, as all of the chrome on this bike was in unbelieveable condition (rims/ fork top nuts etc). I took them to my favourite  chromer yesterday (every business trip I make nowadays, I always try to centre around Leicester Forest East Services  ;D ;D, as you can't beat one-to-one drop-off and pickup with the guy doing the job IMHO). The pipes are unbelievably solid (he even commented on this) but there's some rust flakes roaming around inside. His take on exhausts is he insists on a one month hot caustic immersion to remove all traces of carbon, so he's doing that and stripping the plating, before giving me them back for some small dent/scratch repairs in either silver solder or braze. He say's that some of his previous customers have de-welded the seams on Honda silencers and inspected the inside/done any baffle repairs, treated the inside surfaces and then TIG welded them back up again . Seems a lot of work I know but these pipes a definitely unobtanium so I don't mind going the extra mile, if I have to. The chromer told me he always base-layer copper plates largish items but NEVER bike exhausts as the high expansion rate/heat would destroy the finish after running hot within a short time. His quote to me for the pair, including external caustic dipping, de-plating, polishing but NO repairs is £250, which , given the amount of work is pretty reasonable, in my view. The only place I have seen the later two-piece version (apart from the pair NOS I bought in 2011 from Govners Bridge for my '69 CB250K0  ;D ) was in Japan and both sets went for well over £700 and had 'shelf wear'.

Has anyone on here any experience of rechroming exhausts and can share advice ? I do have an endoscope type camera at work to do an initial inspection before the 'tin-opening'.
« Last Edit: December 23, 2015, 01:55:31 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline royhall

  • SOHC Jedi
  • Posts: 3383
  • Keep biking I'm not quite bankrupt yet
    • View Profile
Re: Can opening an exhaust
« Reply #1 on: December 24, 2015, 07:17:57 AM »
Good info Ash.
I commented on my 350F exhaust's when I had to cut them down that they weren't copper plated first.
I said at the time that I would probably have to get them redone at some point.
I guess from your info that they are correct.
Good news, I think?

« Last Edit: December 24, 2015, 08:07:42 AM by royhall »
Current bikes:
TriBsa CCM 350 Twin
Honda CB350F in Candy Bacchus Olive
Honda CB750F2 in Candy Apple Red
Triumph Trident 660 in Black/White
Triumph T100C
Suzuki GS1000HC
Honda CB450K0 Black Bomber
Honda CB750K5 in Planet Blue Metallic (Current Project)

Offline whiteylfc

  • SOHC Associate
  • Posts: 75
  • Triumph Tiger 800,CB750 Honda Britain,CB750 PRR x
    • View Profile
Re: Can opening an exhaust
« Reply #2 on: December 24, 2015, 09:36:11 AM »
Hi Ash......who does your chroming?I've got some bits off my Phil Read Replica that let it down and I pass Leicester Forest East every Thursday.Are they reasonable on prices?

Offline AshimotoK0

  • Grogu
  • *
  • Posts: 7386
  • Mad Scientist.... more power Igor ! ٩(̾๏̮̮̃̾๏̃̾)۶
    • View Profile
Re: Can opening an exhaust
« Reply #3 on: December 24, 2015, 06:08:37 PM »
Hi Ash......who does your chroming?I've got some bits off my Phil Read Replica that let it down and I pass Leicester Forest East every Thursday.Are they reasonable on prices?

See here: It's actually about 20 minutes away from Leic Forest East Services.(not far from the Triumph factory)

http://www.sohc.co.uk/index.php?topic=7891.0

http://www.classicsandchrome.co.uk/     (Ask for David McFie the owner)

BTW stripping loads of Chromed Honda parts, the only ones I have found to be copper base layer are the 'tin' points covers on CB250K's and the carb tops plus the link bar for the gear change  lever.
« Last Edit: December 24, 2015, 06:18:42 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Chris400F

  • SOHC Master
  • Posts: 1013
    • View Profile
Re: Can opening an exhaust
« Reply #4 on: December 30, 2015, 04:46:16 PM »
I used Classics and Chrome earlier this year. Probably from having seen Ash's recommendation plus being in Hinckley they are not far from me.
I had a rack chromed, which I know is not the easiest of shapes to chrome.
I supplied photos and got a quote for the job but the price went up when I took the rack in - apparently it was bigger than he thought - so not the best start.
It might be a common problem with chromers but certainly this place didn't seem to be able to polish less accessible parts, such as close to the tubing joints.
I had hoped / expected they may have smaller (hand held?) tools to better get to such places.
The finish is OK but there are some rough areas under the chrome in parts.
If you have the facilities to do your own preparation of awkward shapes like this it would seem a good idea to do it, or check out what your chromer can / will do in this respect.
I live and learn with this sort of work. The finished item is still way better than it started and you do have to look fairly closely to see the defects.
How has anyone else fared with getting this type of job done?
« Last Edit: December 30, 2015, 05:28:59 PM by Chris400F »

Offline AshimotoK0

  • Grogu
  • *
  • Posts: 7386
  • Mad Scientist.... more power Igor ! ٩(̾๏̮̮̃̾๏̃̾)۶
    • View Profile
Re: Can opening an exhaust
« Reply #5 on: December 30, 2015, 11:41:36 PM »
Sorry to hear that Chris. My experiences have been pretty good with him but as yet no complex shaped parts (mainly mudguards and wheel rims). I currently have a batch of stuff that I had  the plating stripped locally, then I will polish myself and try out another guy in Leeds who has been recommended to me. Chroming is a bloody nightmare quite frankly  but there just isn't the NOS stuff out there any more. Seem to remember the chrome was pretty crap on the Tower brand (Fylde) racks, particularly around the joints but not trying to make excuses for C & C.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Chris400F

  • SOHC Master
  • Posts: 1013
    • View Profile
Re: Can opening an exhaust
« Reply #6 on: December 31, 2015, 11:00:03 AM »
Seem to remember the chrome was pretty crap on the Tower brand (Fylde) racks, particularly around the joints but not trying to make excuses for C & C.
I think you may be right about the Tower racks Ash. As I recall the Tower ones had two horizontal tubes. The upper one went below the seat then upwards behind the seat to form the grab handle. The lower one went down from just behind the shock mounting point then backwards and finally up to join the rear of the flat rack part, sometimes with a kink in to clear the number plate.
Mine is a Rickman rack, which came from a member on here, which has only a single main tube. A much more elegant construction in my opinion and I would have said better quality than the Tower ones to start with.
(We've strayed slightly from the original thread topic, but then what's new about that!).

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal