I have found a big advantage of a truss dob - that of being able to wash the mirror without taking it out and all the dramas re-collimating, losing screws etc. Why did I need to wash my brand new Lightbridge? Well, 2 reasons. 1) curiosity and challenge
2) I stuffed it up the other night by wiping several lens cloths across the mirror - never again - chuck away those ghastly lens cleaners!!! They left smears all over the mirror.
This is what I did.....
1) dismantled Lightbridge and put the lower mirror section CAREFULLY on work bench propped up with towells such that the mirror was pointing slightly down towards the open end that was facing me. MAKING SURE it could not roll off!
2) Go down to Super Cheap Auto and buy 5 litres demineralised water and 2 cheapo squirty bottles
3) Raid kitchen and grab 1 roll toilet paper and 1 box of Kleenex tissues - the plain ones - no vitamin E or Aloe Vera.
4) Grab a teaspoonful of washing up liquid.
5) Back to workbench, fill up the bottles with demin water and 1 tsp wash liquid into one bottle. Label the bottles.
6) The mirror has a largish gap all around it between its outer edge and the inside of the metal can. Into this gap, stuff the toilet paper or tissues not too tightly, but sufficiently to stop too much water going past the mirror.
7) put tissues in inside of can to soak up the excess water.
8) Now all you do is get the squirty bottle with the soap mixture and squirt the mirror from close up working from side to side - say 25mm from mirror - easy as the metal can is short and you can get your hand in. Give a good squirt, the bottle gives quite a powerful jet if you adjust the nozzle. Leave to soak for a few minutes then repeat, checking that the surface looks really wetted.
9) mop up water as it drains towards you.
10) Get the bottle of pure Demin water and empty that at the mirror, in several short bursts, to wash away the soap mix.
11) Leave for a while for most of the water to drain off the mirror and then hit the mirror with several long bursts from the wife's hair dryer. WATCH ELECTRIC WIRE. ..DOESENT MIX WITH WATER. Wipe as much water away as poss except of course NOT from off the mirror, which will only have a few droplets on it anyway.
12) The warm air from the dryer will evaporate the remaining water. Any stubborn water droplets can be removed by wicking the drops up with a rolled up Kleenex tissue.
13) Take out all the soggy tissues, give a few more bursts with the hair dryer and leave to thoroughly dry for a couple of hours
Hey presto mirror is nice and clean and no physical touching.
Well this worked for me, and all the smudges were gone.
