Gina

I'll try the the epoxy/IPA approach. I saw your post on page 74 and I've ordered those conical tools but the earlier link shows several options and I just wondered which of those you got.

Have you tried using a dry tool on an 1100D sensor? These have a much tougher CFA than earlier models. I tried dry on a 350D sensor (I think) and the CFA came off eventually. I tried dry on the 1100D and even after about 5 mins continuous buffing the sensor was polished and very hot but still a strong green colour - no CFA had come off at all and the buffing tool was still white. Maybe the tools you are using are different, harder perhaps. I have some of the pointed tools mentioned earlier, on order from ebay and I'll see how they work. I can say I was surprised how even the CFA removal was with the paint scratch polishing paste - quite different from what I achieved manually.

Still looking out the bits and pieces to make up the test rig. Can't find the Peltier TEC I was going to use - a 12v 3A one from Farnel and more efficient than the Chinese ones. However, I do have a 3.3v 2A one (TEC1-4902) about 7W I/P power and a 50mm square CPU cooler. I have that setup running now and the cold side has already collected a thick layer of ice

Yes, but then it might run over the frame where the cover glass is going to go. Anyway, time will tell

Back to the debayering... I have had a very very quick go at debayering the 1100D duff sensor with Dremel look-alike and felt buffing tool plus paint scratch repair paste. Here is a photo of the result. When I get the epoxy resin I can practice adding resin to the area around the sensor - see if I can cover the gold wires but keep below of the frame so that a cover glass could go back on when I work on the real job (a working sensor).

Yes, I was thinking of a sealed container with desiccant but the problem is to lower the cover glass onto the frame. It has to be clear of the sensor and its frame to allow dry air to get to the sensor. I'm thinking in terms of a transparent plastic box with the cover glass attached to a lever on an axle going through grommets in the sides of the box to seal. Not sure what to do about the glue though.

I agree. "Reliable" is the crux of the matter

Tried the buffing tool on dud sensor and with a bit of the ScratchX 2.0 applied to the sensor and then buffed, the CFA came off immediately and left a pretty smooth golden result. Without the scratch removal paste and dry the buffer tool wouldn't touch the CFA. I think it just removed the micro lenses as the surface turned from matt to shiny but still very green

Yes, I wondered if the epoxy disconnected a gold wire (or two) when cold and remade the contact when warm. OTOH it could have been something entirely different. I need to check the sensor for cold working at every stage. If I were to use my table vice to hold the sensor unit the glass would fall onto the carpet on the floor but I think I'll do something more sensible - hot glass falling on the carpet is not ideal! The sensor will be fitted with a cold finger first anyway so that I can check that it works before I start so I could hold it with that. Removing heat from the sensor is a good idea anyway - helps stop it heating up when removing the glass and failing from that. If the cover glass cracks/breaks I have another from another sensor anyway that I can use. Whether I reuse a cover glass depends if I can devise a way of removing moisture from the sensor either as it's replaced or afterwards. The dew point of the air between glass and sensor needs to be below -20C (or at least -10C). I would prefer to have the sensor sealed with dry air around it and a glass covering as that makes design of the other parts much easier. I have three possible ideas for dehumidifying the air around the sensor. Replace the cover glass in a very dry environment (and dust free) Drill tiny holes in the sensor frame to purge with dry air after replacing the cover glass Use the IR filter (not the colour correction blue filter) in the filter frame and drill tiny holes in this where there's a bit more room to purge with dry airMy past experience of drilling tiny holes is not good - broken drill bits etc. so I would really prefer the first option if I can devise a way to do it

I have found some more information on the PX804C potting resin. The mix ratio is 4.8:1 by volume ie. about 5:1 as opposed to 1:1 for normal epoxy resin. I'll be able to confirm this when I get the resin. So I guess I'll be getting around 200gm of resin and 50gm of hardener or very roughly translated into volume something like 200mL resin and 50mL hardener.

I need to approach this scientifically viz. arrange a test setup that I can use relatively easily. It will need to have cooling as in one case previously I found the sensor was fine at ambient temperature but failed when cooled. Warmed up again, it worked again. This surprised me as I expected debayering to either work or fail. This was one with the ordinary slow set epoxy resin so I'm hoping the potting resin won't do that (if it was the resin - no way to be sure). I have the 1100D carcass I've used in the past for astro so I can use that. I also have an almost complete camera where the back has been replaced with a cold finger and ambient temperature cooling. Whereas an uncooled camera would reach 30C with long exposures, I could reduce the sensor temperature by at least 10C producing a significant noise redustion. I could add Peltier TEC and control system to provide astro level cooling. Misting up of the sensor won't really matter as the previous sensor failed completely at low temperature and that will be what I'll be testing for. I need to produce a new control system as the previous one relied on a large manual control box that I had on the pier. Most of that has been dismantled and cannibalised long since The new control system will want to be a lot smaller and I plan to have it computer controlled. In fact I will want to control it remotely with local netbook wi-fi linked to my main desktop indoors. I'm planning to use the final debayered, cooled camera with built-in FW and OAG on my second pier for widefield DSO imaging.

Seems JTW use epoxy resin to protect the gold wires and that definitely seems to be the way to go. But it has to be the right sort of epoxy as I found out for myself! Do you use the felt tips dry? I ask because I tried that with a dry tip on the dead 1100D but even after some time it just polished the surface - I think it will need the car paint polish I used with the manual method. It's very easy to go too deep and destroy the sensor that way. Some parts cause dead pixels, some dead rows and/or columns and some complete failure - I've seen all of these! I've yet to try a blowtorch on a complete cover glass but I have hopes of success.

I tried my Bremel blowtorch on the remains of the cover glass on the 1100D sensor and yes, they dropped off. The sensor got rather hot but that may have been because most of the glass had already come off in bits. I'll try a full cover glass removal tomorrow.

I have ordered the epoxy resin I already have several syringes of various sizes that were used for medicating the goats. I can clean these out and use them for resin. I got the resin directly from Maplin Electronics. I actually got 10 times as much resin for the cost of the postage I reckon I can find other uses for this resin besides the sensors. Once I get the resin I can see how much space it will need and sort out some suitable size containers. I already have some plastic containers with lids that I think might do.

Thank you for all that I'm looking into this whole business again. Several reasons, one of which is I think my 450D debayered sensor is now dead having sustained a broken gold wire in storage I am short of 450D parts but have plenty of 1100Ds. Several bodies less sensors, one with cold finger and one I've recently bought as not working but I believe the problem simply to be a broken battery connector - I haven't had it apart yet. So I'm looking again at using an 1100D for my mono DSLR experiments. A big advantage over the 450D is the more recent image processor with a maximum ISO of 6400 rather than 1600 which is very useful for DSO finding and setting up. We now have a seemingly useable method of removing the cover glass and you have found a satisfactory epoxy resin which makes actual debayering far less risky. I used the polishing method before but by hand which was very tedious but now there's the epoxy solution I would be happy to use my Dremel look-alike with polishing mop. I have a dead 1100D sensor with broken cover glass and many broken wires on which I can practice CFA removal. Regarding killing the sensor while debayering, yes, the short edges (without wires) ARE delicate and will cause failure if touched. This was discussed much earlier on in this very long thread.

Wish that worked with DSLR sensors!

That's good - thank you for the tip I found it incredidly difficult to get the epoxy resin to go in the right place and it really loved to form a whisker that went onto the image area I found warming it up a bit to reduce the viscosity helped. That was with standard slow setting epoxy - I haven't tried Maplin's potting epoxy though did consider it. I would have thought that it should be possible to take the individual parts out of the pack and put them in separate syringes. Then squirt out equal amounts from each and mix it on a non metallic board before dripping onto the job with a toothpick.

I already had a camera modified with a cold finger and Peltier TEC cooling but failing that I guess you could put it in the freezer. Probably the whole camera with the USB cable coming out past the seal.

Thank you I may warm this thread up again before long - I've just bought a duff 1100D to play with from ebay auction

I too will be interested if this epoxy resin works - I tried ordinary slow cure epoxy and that didn't. I had one debayered sensor that was fine at 20C but failed when cooled. Whatever is used it needs to be good down to at least -20C. Sometime I'm planning to have another go with an 1100D sensor as this is a better model than the 450D I have working ATM. The 450D isn't yet in use for astro imaging as I haven't finished the enclosure. I'm waiting on a replacement control board for my 3D printer as I shall be printing plastic parts to my own design. In order to reduce the optical path to accommodate a filter wheel and OAG I'm replacing the main plastic frame that connects sensor and shutter to the front of the camera.