Mirror re-coating

[mert]

So I reckon it's time to get my dob primary and secondary mirror re-coated. At a guess I think the primary weighs 25 kilos, any advice on packaging it?

[Jonk]

Whilst I had my 250 mirror out of the scope for a couple of weeks, I washed it, dried it, then put cling film over it to prevent dust / touching.

When I peeled the cling film off, I had to wash it again - so just in case you were thinking it, perhaps you shouldn't use cling film!

As it's going to be re-silvered anyway, perhaps just wrap as much large bubble wrap as you can all around it and secure in a large box.

[ronin]

I would suggest 2 boxes, as I would expect the mirror to move and if the single box got damaged then the wrapped mirror could escape.

Lets face it couriers are not known for their safe handling of items.

Where are you going to have it resilvered ?

[Stu]

I think probably best to put layers of very soft cotton over the surface of the mirror, then perhaps tissue paper then as much bubble wrap as you've got and packed in a secure cardboard box

[damnut]

As it is such a big mirror, I would contact the company who is doing the re-coating and see what they advise. Then they cannot accuse you of poorly packaging the unit.

[Stu]

As it is such a big mirror, I would contact the company who is doing the re-coating and see what they advise. Then they cannot accuse you of poorly packaging the unit.

Good plan!

Thinking about it, is it not worth delivering yourself just to be sure if at all possible??

[Astrobits]

It doesn't really matter what is next to the mirror surface as long as it is not scratchy ( cotton wool CAN be scratchy ) and does not contain anything that could etch the glass. When your mirror is returned to you it will probably be covered with acid free tissue paper against the new coating so use that for sending it.

Apart from that as much shock absorbing material as you can. Expanded polystyrene sheet is good, probably better than bubblewrap.

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Lets face it couriers are not known for their safe handling of items.

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Quite!

Nigel

[mdstuart]

When I got mine back from a 're coat it had very soft cotton wool all over it...I gather there are some special types of cotton wool that are not scratchy...

[niallk]

My 15" mirror came in two tightly nested tough cardboard boxes, polystyrene shims around the edges/sheets over faces, and tissue paper - like 'lens paper' over the reflective surface. I've stored the box etc away for hopefully many years to come in case I need to send for recoating.

[Charic]

So I reckon it's time to get my dob primary and secondary mirror re-coated. At a guess I think the primary weighs 25 kilos, any advice on packaging it?

How bad are the mirrors? Do you do this as a regular service , ie: " its time" ?

My assumption here, your talking about the 5" Dob rather than the  GoTo Dob, but then at 25KG it must be the 22" GoTo!

Could you image the mirror so that we can see how bad a mirror needs to be, before re-coating. 

[wiseone]

When sending mirrors off for aluminising, especially large ones, I have always securely taped a square of plywood (at least 12mm thick for a 24 inch mirror) to the front surface. A layer of soft tissue first will help. Duct tape is a good bet to firmly secure the wood to the mirror.

You have to then pack the mirror very well in a sturdy cardboard box. Best to make sure that even if dropped, the mirror will survive. A made-to-measure wooden box is even better to guard against the most determined of lousy couriers.

Hope that this helps.

[Peter Drew]

A "wise" method. 

[estwing]

Yes John nichol packs his mirrors in wooden boxes with kingspan insulation...very sturdy

[mert]

Hi guys

Sorry for my late reply. We had a death in the family and it's been a nightmare dealing with lawyers and all the other vultures out there. I'll read all the replies and thank again.

[mapstar]

A sturdy ply box made out of at least 12mm thick material and internally at least 2" bigger all round than the mirror.

If the mirror is 2" thick then the box would need to be 6" deep to pack with 2" of packing (Kingspan is great) behind and in front of the mirror.

As others say when it's returned it will have acid free tissue against the surface.

I have a pic of my box somewhere on here?

[Dave In Vermont]

I agree that you should double-box it. And pad each box thoroughly in bubble-wrap or similar to absorb any shocks. The guy I sent mine to told me this was the best way, and he'd never seen one damaged following this guideline.

Dave

[mert]

Thanks for the replies guys. I'll get some pics of the mirrors up next week, it's the secondary that looks like it needs done. I think I can get away with the main mirror for now.