[AR] Re: Electroforming Experiment

  • From: Peter Fairbrother <peter@xxxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Sun, 14 Jul 2019 14:48:06 +0100

On 14/07/2019 03:57, johndom@xxxxxxxxx wrote:

I looked at the URL clip. Complicated stuff.
It does not mention how thick a copper layer can be deposited using such electrodeless procedure.

electroless

Any idea?

Only a very thin layer, typically about 1 micron - nowhere near thick enough for a chamber wall.

Mechanically strong enough for a
combustion chamber?

The copper layer can be fairly strong at room temperature, but it contains phosphorus, which destroys the high-temperature properties of the copper, making it totally unsuitable for a chamber.




However, electroless copper can plate on almost anything, and it is often used to make surfaces conductive for further electroplating or electroforming operations.

A thin layer of electroless copper, covered with a normal thickness of electroformed copper, would be unnoticed on a chamber.


It is common to prewash the substrate in a palladium-containing mixture before applying electroless copper - sounds expensive, but the amount of palladium used is tiny.


As an aside, PCB's generally go (or went, I am out-of-date here):

drill holes
clean
mask off holes (sometimes)
palladium/tin wash
electroless copper
high-throw electrolytic copper



Peter Fairbrother




















John

------ Origineel bericht------
*Van: *Norman Yarvin
*Datum: *za, 13 jul. 2019 21:21
*Naar: *arocket@xxxxxxxxxxxxx <mailto:arocket@f reelists.org>;
*CC: *
*Onderwerp:*[AR] Re: Electroforming Experiment

On Sat, Jul 13, 2019 at 06:50:19AM -0700, Ed LeBouthillier wrote:>The largest benefit of this approach is the 
elimination of the minimum>gauge issue. As shown, making a 0.0025" thick shell is trivial. So, for>example, 
a low pressure propellant tank which needs to be 0.005" thick>(say in nickel instead of copper) is quite 
feasible.Minimum gauge issues don't end with fabrication, though; 0.005" ispretty flimsy and floppy, the latter 
perhaps being moreimportant.Ma  <http://important.Ma>ny an engineering design has looked good when analyzed at 
zerofrequency but failed due tooscillations.Be  <http://oscillations.Be>sides electroplated copper, by the way, 
the
  re's also electrolesscopper, which is better at plating the inside of 
cavities (which inelectroplating are farther away from the anode and thus plate 
moreslowly).  There's a DIY recipe 
at:https://www.youtube.com/watch?v=Z228xymQYho



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