Sticking sensor to primary mirror

[CraigT82]

Hello, im trying to attach a wired temp sensor yo the back of my newt primary mirror. The mirror has a satiny surface and I can't get anything to stick to it! Ive tried various sticky tapes but no joy. 

Anyone any tips on what to use to stick the sensor to the mirror? 

Cheers 

[tooth_dr]

Blob of silicone?

[CraigT82]

Just now, tooth_dr said:

Blob of silicone?

I did think about that but thought that the silicone would act as an insulator between the glass and sensor. 

Also thought about the thermal paste for CPU heat-sinks but not sure if that will adhere to the glass 

[fozzybear]

thermal paste would not work as sensor would fall off with gravity plus one for a blob of silicone to the sensor btw what type of sensor is it?

[Dr_Ju_ju]

try 'gorilla' tape, it's like 'duck' tape, but stronger... 

[CraigT82]

15 minutes ago, fozzybear said:

thermal paste would not work as sensor would fall off with gravity plus one for a blob of silicone to the sensor btw what type of sensor is it?

Sorry meant thermal adhesive not thermal paste, found some on Amazon but do t wanna spend £6 on it if it won't stick to the glass! It's a temp sensor, so do t think a blob of silicone will work as it'll act as an insulating layer. 

I think I may have sorted it anyway, I've wedged the sensor between the mirror edge and the tube wall... used a thin slicer of wood to wedge it in tight so that there's good contact between glass and sensor. Just need to see if it falls out at all 

 

[Marci]

This stuff has been my go to thermal adhesive for better part of 20 years... never failed to do it's job, other than at sub -60.

https://www.ebay.co.uk/p/Arctic-Silver-Aata-5g-Alumina-Epoxy-5g-Premium-Ceramic-Thermal-Adhesive-2-Set/1900394448

[bottletopburly]

Gaffa tape ?

[Peter Drew]

I don't think wedging anything tight against a mirror edge is a good plan, easy to introduce distortion optically.    ?

[JamesF]

I don't see why silicone couldn't be made to work.  If the sensor is placed on the mirror and a very small bead or a couple of small blobs used to hold it in place, especially if a small weight can be used to hold it tight to the glass, then a larger amount could be applied once the first has cured without getting any between the sensor and the glass.

The Arctic Silver adhesive looks a good bet if you know you'll never want to remove the sensor though.

James

[CraigT82]

33 minutes ago, Peter Drew said:

I don't think wedging anything tight against a mirror edge is a good plan, easy to introduce distortion optically.    ?

Very good point! 

21 minutes ago, JamesF said:

If the sensor is placed on the mirror and a very small bead or a couple of small blobs used to hold it in place, especially if a small weight can be used to hold it tight to the glass, then a larger amount could be applied once the first has cured without getting any between the sensor and the glass.

This could work, just applying silicone round the edge of the sense to hold it in place. I'll give it a try.

Don't really want to try the thermal adhesive, seems tobe very strong so might pose a problem when the time comes to get the mirrors recoated .