Vacuum Coatings Scientific Mirrors

For orders please telephone us on 020 8 520 5353

  Aluminising (Astronomical) & Optical Testing

Although this price list is specifically for astronomical mirrors, we are happy to undertake the re-coating of any optical component as may be used in printing or copy machines, flat, projection mirrors, parabolic projector mirrors, head up display units in cars and collimators.

  Aluminising Prices

  Newtonian Flats (listed by Minor Axis)
  Minor Axis Price Minor Axis Price
  1" - 1.5" £12.00 3" £20.00
  1.6" - 2" £14.00 3.5" £24.00
  2.1" - 2.25" £16.00 4" £28.00
  2.3" - 2.5" £17.00 4.5" £35.00
  2.6" - 2.9" £18.00 5" £40.00

  Circular Mirrors (Primary and Cassegrain/Gregorian Secondaries)
  3" (70-80mm) £18.00 8.5-9" (220-230mm) £54.00
  4" (95-105mm) £24.00 10" (245-255mm) £65.00
  4.5"(110-120mm) £28.00 11" (270-280mm) £70.00
  5" (125-130mm) £32.00 12" (295-310mm) £75.00
  6-6.25" (150-160mm) £44.00 14" (350-360mm) £95.00
  8" (190-210mm) £48.00 16" (400-410mm) £125.00
  Heavier mirrors with edge thickness over 1 1/2" up to 1 3/4" (40-45mm) - Large Chamber Coating
  16" (400-410mm) £135.00 22" (555-565mm) £160.00
  18" (450-460mm) £140.00 24" (605-615mm) £200.00
  20" (500-510mm) £150.00 30" (755-765mm) £280.00
  Larger circular mirrors with greater than 2" (55mm plus) edge thickness - Large Chamber Coating
  16" (400-410mm) £140.00 22" (555-565mm) £200.00
  18" (450-460mm) £150.00 24" (605-615mm) £260.00
  20" (500-510mm) £165.00 30" (755-765mm) POA


The prices above do not include return postage
Post and packing charges are below. For astronomical main mirrors, this is with or without optical flats. Small items would be sextant mirrors, camera prisms and optical flats and secondary mirrors.

Non specific
Small items up to 1k in weight
£8.50 (Rec.Post)
14.00 (Next Day Ins.Post)
6" mirrors etc.
Over 1 kg and up to 2kg weight
£10.00 (Recorded Postl)
£16.00 ( Next Day Ins. postl)
8" - 12"
Over 2 kg in weight
£24.00 (24 hour Parcel Force)
£20.00 (48 hour Parcel Force)

£30.00 ( Courire Next Day Delivery)

£30.00 (24 hour Parcel Force) £24.00 (48 hour Parcel Force)
Over 14"

carriage prices on application. .


See our packing notes page on how to pack your mirror safely or click Here

We are willing to undertake the re-coating of any optical component.

Refurbishment Service for Camera Mirrors, Sextant Mirrors and Prisms.

We can only coat these once they are removed from your camera/sextant. Please contact a camera specialist if uncertain. Camera prism re-coats are £10.00 to £25.00 plus p&p. Multiple facet prisms can cost up to £60.00 to clean, re-coat and re-paint. Camera mirror re-coats are £10.00 to £20.00 plus p&p. Re-makes are £15.00 to £20.00 plus p&p.

Aluminising Information

Prices quoted for mirrors up to 16 inches (400 mm) in diameter, are for double aluminising and silicon over-coating. Please state clearly with your order if you do not require your mirror to be over-coated (there is no price difference). If your mirror is being sent for re-coating, there is no charge for the removal of the old aluminium coat. Only in very rare circumstances would a telescope user choose an unprotected aluminium coating. There would be a three to four percent gain in light reflection, peaking towards the blue end of the spectrum. However, unless stored for many months to develop a natural surface hardness (oxidisation) the coating would probably degrade very quickly in present day atmospheric conditions.

What does double aluminising entail as mirrors are usually only given one coating?

Once the mirror is clean and ready to coat is is given a semi (not totally opaque) aluminium coating and overcoating. It is then taken out of the chamber and cleaned with a pure cotton cloth and isopropyl alcohol. This ensures the removal of any poorly adhering particles in the aluminium coating and toughens the surface. It is then returned to the chamber and given a second aluminium coating and overcoating. This double coating is therefore aimed at giving the mirror as long an observing life as possible with maximum immediate protection from atmospheric pollution.

Mirrors larger than 16 inches (400 mm) diameter are given a single coating and overcoating in our larger chamber(s) with evaporation from multiple evaporation points. This partly mimics the double coating of the smaller mirrors. A complete double coating process can be carried out for these larger mirrors, but with a sixty percent increase in cost. If you are working within a budget and do not require maximum double coating protection as offered for the smaller mirrors, a standard single coating run is available at a 25 percent reduction.

How long will a protected aluminium coating last?

If subjected to sea water, or sulpherous fumes, perhaps only a few days. If used close to the sea, or in an industrial area and stored uncovered perhaps only a year. With a close fitting, acid free cover over the mirror, in the same circumstances perhaps two or three years. Used in averagely polluted air (everywhere?) with a close fitting cover, perhaps four to eight years. (One way to make sure you ruin the coating is to wrap it tightly in polothene or plastic to trap in all the pollution and condensation when not in use!)

Can the coating be cleaned?

Yes. We supply basic cleaning advice with mirrors. Six months or longer after coating, correct cleaning should toughen and harden the coating for a longer life. Please go to one of our customers websites, to see their 30 inch mirror being coated. They also have pictures of the mirror being cleaned and even how they remove the old coating ready for re-aluminising. DATSCOPE 30 INCH.





For orders please telephone us on 020 8 520 5353

(We are not always able to immediately answer. If you connect with our answerphone, please leave a message stating, if possible, what you need and where possible size(s) if applicable. Also make sure you leave a contact telephone number for reply. Mobile phone reception can be variable, so please be as clear as possible when using mobile phones). Payment may be made by including a cheque payable to VCSM, with the item(s) to be re-coated. Otherwise we can call you for a card payment when your goods are ready to return to you.



V.C.S.M. offers an economical service for amateur astronomers, wishing to ascertain the working quality of an optical system or component. This will be specified as a suitability guide for the intended purpose of use and a statement of actual optical quality in comparison to a 'perfect ' system. Please contact us for more details if interested.