[ngcles]

Hi All,

One fabric I know works very well and stands the test of time is German 100% black cotton velvet. This is amazing stuff and when you spread it out on the floor it looks like a hole -- it swallows light. I have used it on several telescopes and it does not shed -- even after 15 years. Synthetic velvets look shiny by comparison. It is quite expensive and not easy to source either.

Don't expect to trip on down to the local Spotlight or some such place and pick it up my the roll. You'll have to source it from a specialist draper or on-line. You can stick it down on the tube interior with wall-paper paste, though I have also used an epoxy style glue in the past on my old 10" (that had a 12" id tube). For a tube like this, strip out the interior fixings and optics and then roll the velvet up on an old broom handle. Paint say, a 20% strip of the inside of the tube, put the broom handle with velvet attached down the tube, roll it out, smooth with hands, paint the next section with glue, roll it out, smooth with hands etc etc. Works very well though if you do use epoxy-style glue you may end up stoned (on the glue) by the end of the job (as I did) as you will spend a lot of time with your arm down the tube smoothing out and your head almost inside it.

Another (cheap and very effective) alternative is to crush up some peanut shells (or walnut) with a mallet or rolling pin into 2-3mm diameter fragments, coat the interior of the tube with glue and apply the nut-shell fragments very liberally, pat them down into the glue. Allow to dry and then paint this new (very rough) surface with two coats of matte black paint using a roller designed for stippled surfaces. If you buy a cheap roller handle you don't need afterwards, you can straighten it out to paint the interior of the tube more conveniently.

Trust me though, German cotton velvet is the duck's guts!

Best,

L.