very nice chassis

[david counter]

I tripped over this on ebay, oh that I'd sold my amp and had some spare cash, http://cgi.ebay.co.uk/ws/eBayISAPI.d...ADME:B:SS:UK:1

[andrew ivimey]

Hello David, they look lovely but I am sure after I have done a little cutting drilling filing and bleeding, such a chassis will look less than perfect.

This chap has been selling his 'limited number' of copper chassis for at least a year now. I bid and failed a good few months ago. This is not to say he isn't pukka and reliable.

Oh yes, Canada too adds a little more to the price. That was perhaps the straw that broke my back.

[Paul Bannister]

Are these a little small for any major internals?
Anyway, copper chassis are a pain to work on without damaging the surface with wandering drills etc. let alone tx cut-outs - so you have to realy want one (or 2)! You can leave them without a sealing finish but cleaning with brasso after fitting out is hopeless. You can get them lacquered, but it's difficult to get it done well and is easy to scratch and then it tarnishes. You can have them stove enamelled in clear, but it can turn out a bit orangey. The most painless solution is to have them powder-coated in black. Funny thing is - you then loose that great look!
If anyone knows how the Kondo San copper is finished I would persevere - it looks like a gold sparkle semi-gloss finish, which seems to hide all the metal blemishes.

[John Caswell]

Hi all,
My 300Bs PSEs are built on 2mm copper "L" shaped chassis (top and rear) with wrap around mahogany type timber front and sides stained rosewood, and varnished/waxed with an aluminium baseplate.
The biggest problem I found was "work hardening" which made punching and cutting large holes somewhat difficult.
Finishing was as follows, remove all burrs around cut-outs and holes, then orbital sand it with something like 180 grade emery cloth, blow off the dust and wipe over with Isopropanol. Immediately place in an oven at about 30/40ºC until warm throughout then spray with clear laquer. This gives quite a nice semi gloss finish which I think looks very acceptable.
All visible bolt heads are black and the transformer covers and baseplates are going to be sprayed gloss black Hammerite when a suitably warm day arrives.

John aka Dr John

[Paul Bannister]

Dr. John,
Sounds interesting method - have you got a picture you can post here or in the gallery which shows the finish?
I re-read my post, which was somewhat gloomy, especially as I do like using copper chassis, but have found sealing an issue. I polished mine and went for Electro-lacquering - it's not very durable, but there again it doesn't have to be if I'm careful.

Paul

[John Caswell]

Hi all,
Will do what I can, not very good at this photo on the web lark, bear with me

John aka Dr John

[John Caswell]

Hi all,
Piccy's in the gallery, focus on a couple not too good but I will get better, but you get an idea of the finish

John aka Dr John

[Paul Bannister]

Thanks Dr John for sharing the pics. I will try and join in if I can figure out how to from the instructions on the BB.
Paul

[petercom]

What's the problem, Paul?

[Paul Bannister]

Hi Peter,

No problem, just my lack of computer savvy. However, as you will see even I managed to post my 300B PSE variation to the gallery. It's a great way to share experiences and for me particularly to learn how others have solved situations and think about future builds.

Regards,
Paul