Fixing dented exhaust

[mako]

Gday. The exhaust pipe on my motorbike has small dents and scapes. They are chrome. Is there any way of pulling the dents out? filling the scrapes and getting it re-chromed ? They are on an old classic bike and these pipes would be hard to replace and/or expensive. Any suggestions from you wise folk? cheers
ps what sort of money would i be looking at to re chrome say a rim on a motorbike or an exhaust pipe. Any idea of price for re chroming?

[China]

I have a mate who repairs and restores bikes, I've watched him carefuly knock them out from the inside with various sized madrels made from pipe or steel rods with the end rounded, then fill any remaining blemishes with bronze, polishing them and have them chromed. The last ones I know about were a set of two pipes price to chrome was about $200

[Fossil]

You can try blanking off one end and then filling the pipe with water.
Place vertically in deep freezer for 24hrs.

[mako]

Thanks guys. The main problem is the small 'gouges'. They are only a mil or so deep but quite a few along the pipe for about a foot. It actually fell over when on the stand onto gravel. So i will have to bronze them up. I have a bit of an idea of this process but have no experience. Is it a managable job for the inexperienced? I can weld (arc and mig) quite well.

[DJ’s Timber]

I use to fix the expansion chamber pipes on 2 stroke bikes.

Plug both ends up securely and with a connection on one of the plugs to feed in compressed air, fill it up to about 20psi sometimes up to 30 or 40 psi and using an oxy heat the dings and the pressure will pop them out. This will only work on the fairly thin walled stuff, so if its more than say 2mm it may not work.

[Fossil]

Thanks guys. The main problem is the small 'gouges'. They are only a mil or so deep but quite a few along the pipe for about a foot. It actually fell over when on the stand onto gravel. So i will have to bronze them up. I have a bit of an idea of this process but have no experience. Is it a managable job for the inexperienced? I can weld (arc and mig) quite well.

Brazing is not difficult if you have the right gear.
You will of course need an oxy torch for the job.

Re- Chroming is not that expensive either. I would suggest getting in contact with a bike club, that should give you a decent contact for the chroming work.

[peter_sm]

Either bronze or silver solder can be chromed.

Quality of chrome work varies. The actual finish you get is only as good as the polishing of the underlying metal. The process the platers use can start with copper plating to essentially 'putty up' the fine surface scratches. Then they polish it, nickel plate it, then the very thin hard layer of chrome is put on. This is what is often referred to as 'triple plating'.

To give you an example, a standard acceptable chrome bumper for an old Holden like a HQ will cost $250. In triple plate show finish, you may end up paying double that, as the labour hours to polish the copper (and possibly second coat of copper)

I would think $200 for two pipes is a good price, however I would be prepared to pay $200 each pipe if they were done show standard and that is what I would do for my own rare bike.

I personally use Vinneys in Dandenong to do my stuff, and they certainly will do the quality according to what finish you want and want to pay for.

[mako]

Thanks guys. Just for those who are interested this is the bike the pipes are damaged. Can just see dints on rear of pipe in pic.
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=56072&d=1190257907

[patty]

Half breed Triumph/Norton Nice looking Bike my mate would love this!

[mako]

Cheers Patty:2tsup: