Blacking SW focuser tube outer wall?

[sbooder]

After having flocked my 10" newt (a few years ago) and now having blackened the back and sides of the secondary and even flocked the steel washer I put between the mirror and the adjusters (Bob's Knobs) I look down the tube of blackness only to be confronted with the tube of silver SW have kindly provided in the way of a focuser tube.

Do any of you have a method of blacking the outside of the tube that has proven to be successful please?

I was thinking of using the Sharpie I used on the mirror but thought I would hold off until I had a few opinions regarding the subject.  So any tips would be most appreciated.

Thanks.

[beamer3.6m]

Blackboard paint.

[sbooder]

Blackboard paint.

It had crossed my mind, but I would expect some flakes from the tube to end up on the primary mirror after a period of being rubbed by the bearings and focuser bar.

[Lonestar70]

Hi Simon,

You might be better to use 'Black Nickel Plating'

It is only Microns thick and does not flake off like paint... can be done at home.

Black Nickel can be applied to most metals including Steel, Brass, Copper, Aluminium and Stainless Steel.

http://gaterosplating.co.uk/Black-Nickel-Brush-Plating-Kit.php

It can be applied using the brush technique (as above kit) or can be fully electroplated... Kit available for this from same company. 

http://gaterosplating.co.uk/Black-Nickel-Plating-kit.php

If the drawtube is aluminium then the only other viable option would be Anodising or Hard Anodising.

Hope this helps.

Best Regards.

Sandy.

[sbooder]

Thanks for the info Sandy.  Might wait for a cheaper option but will keep this in mind.  As an aside, I am trying to make sense of your Avatar, it appears to me to be some sort of Sterling Engine?  But is probably something else?

[Uranium235]

I did mine with blackboard paint, just take care not to apply paint to where the bearings touch the drawtube (the tramline marks on the tube give away their location).

[Lonestar70]

Hi Simon,

Yes, the kits are not all that cheap, however, they do produce a good long lasting finish.

If you have a plating shop somewhere close you may be able to get it done there for only a few euro's.

My Avatar is of a 2 cylinder model Marine steam engine with a boiler make up waterpump.

It has a vertical watertube boiler.

I used to manufacture these.

Here are a couple of larger pictures.

Best regards.

Sandy.

[Moonshane]

you only need to black the section that intrudes into the tube when in use. this might be a very short section at the end and you may never go near the bearings? I'd think anything reflective that can be seen down the tube when in use will create losses in contrast although whether you find sorting them out discernible at the eyepiece or not is debatable.

[sbooder]

Hi Simon,

Yes, the kits are not all that cheap, however, they do produce a good long lasting finish.

If you have a plating shop somewhere close you may be able to get it done there for only a few euro's.

My Avatar is of a 2 cylinder model Marine steam engine with a boiler make up waterpump.

It has a vertical watertube boiler.

I used to manufacture these.

Here are a couple of larger pictures.

Best regards.

Sandy.

They are things of beauty.  I love engines.  I have only gone as far as building a laminar flow engine but it was enjoyable to do.