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All openings of the tube should be closed if not used. The tube should not be stored in cold and wet rooms, corrosion of the metal parts and destruction of mirror coatings will take place over long time periods. You should also consider that some moisture might get into the tube during observations. Thereafter the tube should dry out in a worm room (open the tube covers). Do not dry the mirrors with clothes, do not even touch the mirrors by your fingers. Serious scratches might occur on the reflective coating, which is not very hard and durable.
Some dust on the mirrors surfaces can not be completely avoided. You can ignore it for a while, because some separated particles will not affect the optical quality. But if the mirrors are entirely covered by dust particles you should clean them and the following cleaning procedure is emphasised:
To get access to the inner frame and to the mirrors you have to remove the telescope cover entirely. Therefore you have to remove some screws and thereafter it is possible to remove the cover completely. You need a cross-like screwdriver to do this. First you should locate the telescope on a stable table. Than remove the metal cover at the backfront which is attached by some screws. It might be necessary that you also remove the knobs of the focuser by removing the central screws. Afterwards you have to remove all the screws on the topside of the telescope cover and also the adapter rail of the finderscope. Then you should turn around the telescope (topside down on the table). You have to remove the mounting plate which is attached by 4 screws. Remove also all other screws from the underside of the cover.
Now the cover can be moved in a horizontal direction against the inner frame. To remove the cover you should press weakly against the forefront of the frame so that it moves into the cover. Than you can hold the frame at its backside and slowly move it
out of the cover. Take care that it not falls down.
Now you have access to the mirrors surfaces, but take care not to touch them. They can be cleaned according to the following procedure. After you are ready with cleaning, let the mirrors dry and then set the frame into the cover. You should first attach the mounting plate and all the screws at the underside. You have to move the cover a little bit to manage that the threaded holes of the frame fit to the holes of the cover. Then turn around the tube and install the mounting rail, all screws on the topside and at least attach the cover to the backfront.
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With some air pressure (produced by a compressor, a plastic bottle or a spray) most of the dust particles will disappear from the surface. Make sure that you do not though the mirrors. No brushes should be used for cleaning, because even the finest of them can produce tiny scratches.
If the removal of dust is not sufficient (their might be some spots and speckles on the surface) you should look for a small plastic bottle with a small hole at the top and fill it with distilled water. You should set the telescope frame some cm higher than the top of the table. Then you spray the water with some pressure entirely over the mirrors surface. The water will rinse down and the mirror will dry. Locate some clothes under the mirrors to remove the water.
Look at the mirrors surface after they had dried and if you see any color speckles which might be produced by fingerprints or some fat spots, you should repeat the cleaning procedure by using Alcohol or Propanol in a plastic bottle. Please do not use other chemicals because they might damage the coating.
You can also mix a cleaning solution composed of two parts of distilled water, one part of Propanol and some drops of a cleaning agent (not an agressive one).
The mirrors surfaces can be perfectly cleaned by this method, without touching the surface mechanically. You should always consider that the mirrors are the most valuable part of your telescope.
Do not remove the mirrors for cleaning purposes from their cells. A serious misalignment of the optics will result after reinstallation of the mirrors. A perfect alignment could only be managed by experienced amateurs or by an optical shop.
Some dust might also be present at the inner tube walls. This can be removed by using some wet cloth and by pressing it against the black rough coating.
You should not use oil in the interior of the tube, a thin film of Vaseline might protect screws from corrosion. Do not change the position of the adjustment screws and do not remove any screws for cleaning purposes.
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After years of usage and storage a new coating of the mirrors might be necessary. The protective coating might be damaged and the aluminium or dielectric coating might be come off. A new coating is performed by specialised coating or optical companies. You should take care that a reflective coating with high reflectivity (at least about 94% for all visible wavelengths) is applied. A protective silver coating can be applied, which reaches 98% reflectivity, but our experience is that this coating is sometimes not very durable. Ask the company for details.
To remount the mirrors you have to loosen 3 plastic nuts around the mirror cell and than remove the plastic screws and the clamps. The clamps should be removed entirely before the mirror is taken out. Hold the edge of the mirror by one hand, when loosening the screws, otherwise the mirror could fall out of the cell.
After remounting the mirrors a complete adjustment will be necessary, which should only be done by an experienced amateur or by an optical shop.
Our company will do recoating and adjustment of mirrors if you send us the telescope back. You should first inquire about the costs and delivery time.
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