For the past 12 months I have kept my pillar mounted, 8" Newtonian dry without scope, mirror or mount deterioration, while enclosed in a TeleGizmos 365 series cover. I have weighed down the pillar with sand bags and tied the cover tightly at the bottom to stop air getting in and out, as much as possible. I also tied it in the middle to reduce the volume of air inside. Recently I have started putting a ground sheet over the scope to stop the covers metal foil inner tearing, which it does easily. I wipe the scope down after a session as I get a lot of condensation on the top of the scope during the night very often, as the RH is often >80% during winter months here in south Devon , UK, near the sea.
I put 5 bags of silica gel arranged inside the cover which I dry out roughly weekly either in the over or in the microwave. This must be done with care as if it gets too hot it becomes very dark and will not absorb moisture any more and the bags will melt, spilling silica gel beads all over the kitchen and this doesn't go down well and is a pain at 3 AM! It will also get very hot if heated for too long in the microwave and it doesn't do a microwave any good to have no moisture for it to heat.
There is plenty of advice on the internet for how long to heat it for in the oven or the microwave. In the oven the bags should be emptied first and not put in the oven. I tend to heat the bags several times in the microwave, letting them cool each time until the bags stop feeling wet and the silica gel turns orange. Older silica gel turned blue but it has been withdrawn from sale because of health risks.
It should not be heated so much that the bag cannot be touched but long enough for the gel to be refreshed. I have bought 100 mesh bags to contain the gel as I melted several in places in getting the heating right. 1 bag should not contain too much as the beads will get hotter in the middle than the outside. I also put a cloth over the microwave turntable otherwise the bottom of the bags can melt too easily. I bought a 5lb container of silica gel which comes with 10 empty bags and I fill 5 of them. Little sachets are not any use.
I also have a small cheap battery operated temp and RH sensor with remote display that I hang on the scope. The receiver unit is in my study 25 metres away in a thick walled cottage and gives a continuous readout of temp and RH. When the RH gets over about 75% I like to refresh the silica gel. The sensor should not be allowed to get saturated for long as RH sensors do not cope with this well and can fairly quickly become inaccurate. I have no connection with any manufacturer or distributor and just thought my experience might help someone.
The technique will not work so well on a tripod mount as the bottom of the cover will be open to the elements and the silica gel will get exhausted too quickly. Without the silica gel the inside would get wet in the climate here and the mirror would suffer and some surfaces would likely rust. I forgot the silica gel recently and everything was wet inside the cover and the mirror had condensation covering it.
I cover the stainless steel part of the tripods feet with grease as I have noticed a tiny amount of corrosion after 12 months outdoors.
I put 5 bags of silica gel arranged inside the cover which I dry out roughly weekly either in the over or in the microwave. This must be done with care as if it gets too hot it becomes very dark and will not absorb moisture any more and the bags will melt, spilling silica gel beads all over the kitchen and this doesn't go down well and is a pain at 3 AM! It will also get very hot if heated for too long in the microwave and it doesn't do a microwave any good to have no moisture for it to heat.
There is plenty of advice on the internet for how long to heat it for in the oven or the microwave. In the oven the bags should be emptied first and not put in the oven. I tend to heat the bags several times in the microwave, letting them cool each time until the bags stop feeling wet and the silica gel turns orange. Older silica gel turned blue but it has been withdrawn from sale because of health risks.
It should not be heated so much that the bag cannot be touched but long enough for the gel to be refreshed. I have bought 100 mesh bags to contain the gel as I melted several in places in getting the heating right. 1 bag should not contain too much as the beads will get hotter in the middle than the outside. I also put a cloth over the microwave turntable otherwise the bottom of the bags can melt too easily. I bought a 5lb container of silica gel which comes with 10 empty bags and I fill 5 of them. Little sachets are not any use.
I also have a small cheap battery operated temp and RH sensor with remote display that I hang on the scope. The receiver unit is in my study 25 metres away in a thick walled cottage and gives a continuous readout of temp and RH. When the RH gets over about 75% I like to refresh the silica gel. The sensor should not be allowed to get saturated for long as RH sensors do not cope with this well and can fairly quickly become inaccurate. I have no connection with any manufacturer or distributor and just thought my experience might help someone.
The technique will not work so well on a tripod mount as the bottom of the cover will be open to the elements and the silica gel will get exhausted too quickly. Without the silica gel the inside would get wet in the climate here and the mirror would suffer and some surfaces would likely rust. I forgot the silica gel recently and everything was wet inside the cover and the mirror had condensation covering it.
I cover the stainless steel part of the tripods feet with grease as I have noticed a tiny amount of corrosion after 12 months outdoors.
