[cspirou]

Aluminium does "rust", but it is not the same as iron that rusts https://answers.yahoo.com/question/index?qid=20061025141908AAhtPFu.

OMG! OK I don't want this to go off topic but rust as it is understood only applies to iron oxide and is also what the question is about. No one has ever referred to the oxidation of aluminum as rust and is in fact a desirable trait of aluminum since aluminum oxide results in a protective layer. Yahoo answers is generally an unrealible source for answers as well.

 

[grausch]

OMG! OK I don't want this to go off topic but rust as it is understood only applies to iron oxide and is also what the question is about. No one has ever referred to the oxidation of aluminum as rust and is in fact a desirable trait of aluminum since aluminum oxide results in a protective layer. Yahoo answers is generally an unrealible source for answers as well.

Yeah, in hindsight I realise my post does not address what the question was really about. Aluminium oxidises pretty quickly, so by the time anyone receives a top plate that is what it will look like for the rest of its life, unless you of course damage it.
 
OT - Untreated aluminium scuba tanks are also remarkably resistant to corrosion (not oxidation as they already formed the aluminium oxide) even though they are exposed to seawater on a daily basis. Painted aluminium scuba tanks however are exactly the opposite...I could never understand that though...Although that is specific to scuba tanks and I have not heard of a single case of that happening to painted top plates. Guess it is a good idea to never go diving with your Crack - especially if you painted the top plate...

 
Scary as it is - in this case yahoo answers actually gave the easiest to understand answer when I googled. Another I can't quite understand...

 

 

[krikor]

  Yeah, in hindsight I realise my post does not address what the question was really about. Aluminium oxidises pretty quickly, so by the time anyone receives a top plate that is what it will look like for the rest of its life, unless you of course damage it.
 
OT - Untreated aluminium scuba tanks are also remarkably resistant to corrosion (not oxidation as they already formed the aluminium oxide) even though they are exposed to seawater on a daily basis. Painted aluminium scuba tanks however are exactly the opposite...I could never understand that though...Although that is specific to scuba tanks and I have not heard of a single case of that happening to painted top plates. Guess it is a good idea to never go diving with your Crack - especially if you painted the top plate...

 
Scary as it is - in this case yahoo answers actually gave the easiest to understand answer when I googled. Another I can't quite understand...

 

Well, at the risk of continuing off the thread rails... You sure it's not painted steel tanks that have the problem? That I've heard of being issue both with steel scuba tanks and big rig steel wheels which have to be stripped and painted every so often (which makes Al alloy the better choice over time, not to mention the weight savings). 
 
Could also be due to galvanic corrosion if there is any kind of dissimilar metal in the paint perhaps. Of course, this requires moisture which is present with scuba tanks, but hopefully not with your Crack amp

 

[Doc B.]

I'd suggest not trying to over-think this unless you are integrating your kit into an aircraft or an oil rig. We wash the laser cut panels in a dishwasher with low phosphate detergent and then they are brushed. Almost immediately an invisible layer of oxide forms on the brushed surface. The panel surface is fine left naked as long as you don't leave your AC powered amp sitting in the acid rain or at the bottom of the ocean. It can be painted if you wish and the slightly rough brushed surface will help the paint to adhere. I do suggest giving the panels a good cleaning with a degreaser like Formula 409 or for the more daring among you, acetone, before painting since we have no control over what may have gotten on the surface once the package is opened.
 
If you really like to fret about this stuff have your panel anodized, then have it powder coated. That will hold up to damp and salty environments that you should never put one of our kits into. 

 

[grausch]

Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.
 
krikor - painted aluminium has the issue with corrosion. Steel tanks have almost no issue - not sure at all, but I think they are hot galvanised and not painted. Used to live in the Caribbean and was good friends with several dive operators - all of those used alu tanks, so that is what my experience is based on. No experience with steel tanks unfortunately and no scientific background as well. 

 

[JamieMcC]

  Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.
 
krikor - painted aluminium has the issue with corrosion. Steel tanks have almost no issue - not sure at all, but I think they are hot galvanised and not painted. Used to live in the Caribbean and was good friends with several dive operators - all of those used alu tanks, so that is what my experience is based on. No experience with steel tanks unfortunately and no scientific background as well. 

Going slightly off topic but my experience with tanks is that steel dive tanks generally have a longer service life than alloy ones due not down to corrosion issues but to the service life as alloy ones are more prone to scrapes and dings. In the UK 2mm dent in a alloy tank will mean it fails testing and it doesn't take much to ding a alloy tank in regular use. Steel ones bounce much better 

  It is also reasonably inexpensive to shot blast and re galvanise the inside of steel tank to extend its life span. Mind you scuba tanks are lot more affordable than they used to be so I doubt that gets done much nowadays.

 

[Doc B.]

  Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.
 

Thanks for the kind words. That finish came about when I was developing the Tode guitar amp kit. I had been intrigued by some of the metal sculpture I had seen, that the artist had decorated with a flap wheel. I had also been influenced many years ago by Don Garber of Fi, who leaves his aluminum chassis amps in the raw mill finish, feeling it is a very "honest" looking finish. The grained finish process we had been having put on our panels for years had been passed from one finisher to another and the quality had become disappointingly inconsistent.
 
We made up a couple of test panels and I had one glass bead blasted, the other I tackled with a wire brush. When we compared them I thought the random brushing was far more interesting to look at. And so it now goes on all of our aluminum panels. The only downside is that I seem to be the only guy who understands the angle to hold the rotating brush at to get the particular look I want. Thus I brush every single panel that goes out of here myself. Hundreds every year. I tend to do them in batches of 5 to 20, as the process is kind of tiring on my old back.

 

[Jeb Listens]

Being quite vain about my equipment it was the clean and restrained look of the Crack that attracted me to it even before I remotely knew what it was, let alone that I would probably need to build it myself!
 
For me its one of the best looking amps out there, which always blows my mind given the price and that it is simple enough that many skill levels are able to build it.  I think some of the most attractive & enduring designs often come partly from a need for simplicity.   
 
When my Dad came round last night you should have seen the look on his face when I told him I built it myself.  It still surprises me too since I have no prior electrical experience - but I received lots of great help & encouragement over on the BH forum. 
 
My other headphone rig uses the LCD-2s but right now the 650s/Crack are seeing all the action.  I've been rolling a few tubes. Very impressed with the Russian 6H13C - wide, clear and has plenty of guts.  Perhaps not as forgiving or warm as some of the others but the top is extremely well extended and the bass is tighter & more well defined.   It has its own brand of extra sweetness & sparkle.   I always seem to love Soviet tubes.    
 
Listening to Paul Simon - Rhythm Of The Saints  as I type this ....sounds wow, beautiful! Very easy to just get lost in it all. 
 
 
Yours Sincerely,
 
Jeb - another UK Crack Addict.  
 
 
 

 
 
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[masterfuu]

Got the crack from another headfier recently beautiful amp with amazing power and tonal clarity. Truly amazing value drives HD800 and T1 (v2) like dream come true. I plan on keeping this baby for a long time.

 

[imadeadkat]

I cant believe I've missed this, Now I must re-evaluate my Head system. Thanks for the work here

 

[cspirou]

There's currently a deal on the bottlehead crack where you can add on the Speedball upgrade for $20. Deal is good until Sept 17th.

 

[ZoNtO]

There's currently a deal on the bottlehead crack where you can add on the Speedball upgrade for $20. Deal is good until Sept 17th.

For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?

 

[Mich4lle]

For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?

I would really enjoy building another crack, but the South African post is really slow, so transport will take awhile.

 

[cspirou]

  For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?

If you visit the bottlehead forum they have someone that will build the Crack for a fee. I would do it but I live in France and it might cost too much for shipping back and forth.

 

[ZoNtO]

 
If you visit the bottlehead forum they have someone that will build the Crack for a fee. I would do it but I live in France and it might cost too much for shipping back and forth.

Looks like they charge $250 for the service. Not worth it at that point.