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New album posted today. Ken's Pre-Estate sale - page 2. Showing the 6 inch diffusion pump, various valves, cooled shevron baffles, stainless baseplate (20 inch), and pool filter bell jar. This is a project, not a kit. Everything will need to be disassembled, cleaned and tweaked, reassembled etc before being able to be used but this collection of components is a very good start towards having a working coating chamber. Not shown in this group of photo's is the Hy-Vac 28 mechanical pump that goes with this setup. Someone make me an offer then be prepared to come and get it in central Illinois or make arangements for me to meet you half way or ???. Ken - KB7H

Hi, Everybody! I bought an old CVC coater a few years ago, intending to fix it up and start coating telescope mirrors. But I got too busy making the mirrors, so this coater project has languished. Now it's time to sell this to somebody that has the time and energy to put her back into working order. The bell chamber is about 23.5" in diameter, and about 27.5" tall inside. I am including a rebuilt roughing pump, and a rebuilt diffusion pump, neither of which has been used since I bought them. I did run the roughing pump for a minute to make sure it would pull a vacuum. There's also a bunch of stuff like coils, aluminum pieces, SiO, diffusion pump oil, an evaporation boat, a fixture and so forth. I have a write-up on the system, plus many, many photos on my Web site at http://www.waiteresearch.com. Click on the coater item under the "What's New" area at the top left of the page and have a look. Enjoy yourself, and feel free to make any offer on the system that would work for you. It's gotta go, so if you want a good coater project, this is a great opportunity for you. Thanks! Gordon Waite Waite Research

As promised, I have started listing the remaining items that I have related to my aborted attempt to set up a working vacuum coating chamber. This has been a process started at least 25 years ago during which time I have gotten close 3 or 4 times but never quite got it all together. The items I have posted today are in the "Ken's Pre-Estate Sale" folder. The first 9 photo's are of a NEW (I bought it new) Granville-Phillips Vacuum Controller with manual, cables, connectors, Convectron Tube, and 2 Bayard-Alpert ION Guage tubes. It's never been hooked up other than plugged in to have the photo taken with the digits lit. All items are new/unused and everthing is there to set up a complete vacuum system. I expect to sell this for no less than $500.00 plus postage to your laboratory. That is about 1/4th of my investment in these items. I'll wait a week or so to see if there's any interest on the Group at that price then list it all on eBay if not sold here. More to come... Ken Hunter

Has anyone had any luck substituting one manufacturer's RGA head for another's? The controller I have is a Spectramass DAQ100/DXM. It has a BNC and a DB25 female for connection to the head and detector. The controller seems to operate correctly. I've been looking for an RGA head for the controller for a long time. I see lots of similar controllers up for sale, but no heads. OTOH, I see heads for other brands of RGA systems. Has any list member successfully adapted one of these to work with a Spectramass system? By any chance did the Spectramass product line get renamed from, or to, a different brand, perhaps through a merger or acquisition? Thanks in advance, Dave

Well, Guess I just had to "Whack" the hornet's nest to get a buzz going. The Group will remain as long as there's some interest and activity. I have managed to locate a big box full of goodies, I had mislaid it when I moved back up to Illinois from Amarillo two years ago. I'll make a list and take some photo's this weekend. Right now I'm under the weather after having all my top teeth pulled yesterday. Getting old sure ain't for sissies! Now that I'm retired, we're considering a move to Costa Rica so I won't be getting my vacuum system together after all these years of collecting stuff. Hopefully I can find someone who will take everything and pick it all up here. That would be the ideal situation as parting it out and shipping to a bunch of locations would be a pain but we'll see what interest there is. Better go take another pain pill, check back after the weekend for the goodie list. Ken Thomas, Are you too busy to continue Group moderation in my absence? I can appoint another to help out if you wish.

Hi Everyone, Does anybody experience how it is possible to operate paralell two identical dissusion pump? I need greater pumping speed. If I put them paralell and they are identical the pumping speed would be the double too? Regards Attila The Hun

It's been a while since we've had any activity on the Group. Should I shut it down? Anyone interested in the rest of my stuff? Pumps, baseplate, valves, gauges, ION tubes, Gauge controllers, etc. I am for sure getting rid of my vacuum stuff and if there's no interest, this stuff is going on eBay. Ken Hunter

Aloha group, I live on Hawaii's Big Island and exposed to a very corrosive atmosphere (SO2/H2SO4 primarily). My 20" mirror needs recoating very frequently, and I am looking for a cost-effective alternative to constantly shipping it to the mainland coaters. I am not very knowlegable about details of vacuum coating, nor have the time to build, or funds to buy, a sophisticated apparatus. My question is: Would it be practical to make a "simple" vacuum apparatus to achieve a useable Al coating even if the coating comes out "below commercial standards" due to insufficient vacuum, etc.? That may not be so bad, since I need to recoat it anyway every few months. I would appreciate any advice as to whether such an approach is worth pursuing for my unique situation? Thank you! Mike

Just a thought. I have not heard this discussed before here or maybe I just missed it. I know that you guys want just the purest optics possible so this idea may make you gag but I work at Cape Canaveral and they have some pretty impressive optics there. I believe that some of their solutions to the corrosion are to mount a flat glass over the opening and understanding that the rest of the tube is sealed flood the chamber with nitrogen or some other inert cheap gas. Is that a workable solution for you? Russell

Wow. We strip our mirrors at the NCA_CCCC ATM workshop in a very similar fashion to what they did in this video: http://mmto.wordpress.com/2010/08/11/mmt-primary-mirror-coating-removed-for-re-aluminization/ Seriously!!! Never thought to use mops, though. We tend to use cotton balls instead. I just don't see any need for mops, somehow. Then again, we don't do very many 20-meter mirrors. The only things we don't do: add KOH to the CaCO3 solution use HNO3 afterwards. I'll try those. I was more than a bit surprised that it did not look to me as if they were wearing masks when using the HCl + CuSO4 step ('green river) or the HNO3. Maybe I wasn't looking closely. I always have fans on when we use that.kind of stuff; it hurts my nasal passages... Could anybody figure out what sort of towels those were? Guy Brandenburg, Washington, DC My blog, mostly on Education in DC: http://gfbrandenburg.wordpress.com/ My home page on astronomy, mathematics, education: http://home.earthlink.net/~gfbranden/GFB_Home_Page.html or else http://tinyurl.com/r6fh2 =====================================

Our old no-name, government-surplus diffusion pump has a problem. After pumping the diff pump for a while (minutes or hours, doesn't seem to make a difference) and after loading the mirror to be coated into the bell jar, this is what happens: when I close the connection between the mechanical pump and the diffusion pump, and begin pumping down the bell jar directly, the pressure in the diffusion pump all of a sudden rises dramatically, going up to ~200 millibars if I don't immediately switch back to pumping down the diffusion pump directly again. It becomes quite a dance, closing one valve then opening the other, then reversing again, and again, and again. Eventually it always settles down and I get decent vacuum levels, but it's annoying for a while. Guy Brandenburg, Washington, DC My blog, mostly on Education in DC: http://gfbrandenburg.wordpress.com/ My home page on astronomy, mathematics, education: http://home.earthlink.net/~gfbranden/GFB_Home_Page.html or else http://tinyurl.com/r6fh2 =====================================

Hi, There is a somewhat related forum at www.coultersmithing.com/forums/index.php It has vacuum, sputtering, physics, electronics, and even a theory and rag-chewing section. Check it out. -bill

I have a couple of old (old, old) Danielson-Tribodyn pump stations. Danielson is defunct. Ideal / Pchemlabs services them, but after a couple of go-rounds with them, I'd rather service my pumps in-house. These are small turbos with big diaphragm fore-pumps. The diaphragm pumps were made by Gast but on one of my systems, they have Danielson labels and I can't tell what model numbers they are. The two systems are different sizes, and don't use the same backing pumps. In fact, the one I can't identify has two 2-stage diaphragm pumps of different sizes in series. I need to order rebuild kits (seals, diaphragms) for these from my Gast distributor. If anyone knows of any place I can find service manuals, operating manuals, schematics, any documentation at all for these pumping stations, please let me know.

Question to all: How do you perform your final mirror-drying operation before putting that sucker into your backyard or basement vacuum chamber? In our plain-vanilla mirror-coating operation at the NCA-CCCC telescope-making and mirror-coating and nose-picking workshop here in DC, which I 'inherited' from a previous leader, I think that I am finding recently that there is some sort of weird residue on sections of a number of newly coated mirrors - coated by us. I suspect that it seems to come off of paper towels - at least some brands of them, I suspect. Unfortunately, I have not done a systematic evaluation to see if this is true, and the conditions are always just a little bit different every time I coat or re-coat a mirror. So I am really not sure on this at all, one way or the other. I have no idea whether it's the final rinsing that's inadequate, or if it's something in certain brands and varieties of paper towels themselves, or something else. I avoid types that advertize hand-softeners or anything like that. Sometimes I wonder whether I forgot and blew my nose on the paper towels first. Or maybe the Green River wasn't mixed properly. Or perhaps these mirrors just have cooties?Or perchance the ion bombardment (aka glow discharge) wasn't long enough. Or I'm just an idiot. Etcetera. In any case, I don't recall seeing it much before, and it seems to be getting worse. (but even that data point is suspect.) BTW, the setup that we have is something that was scrounged together from 1950-to-1960-era US government surplus equipment coupled with a variety of modifications and improvements that were crafted by my predecessors, or donated by others. My predecessors are mostly either deceased or are in poor health. We do this aluminization for purely nominal fees that allow us to buy some more pitch and grit and glass. (The mirrors are certainly usable, but they are not elegantly clean like I would prefer. You can see thin, dusty streaks when you look at the mirror at certain angles. I know, I know, I should have taken a picture. Will do so. (But the workshop location is clear on the other side of town. And when I'm there, unless I go on off-hours, there are always lots of folks building telescopes at one level or another, and they all have questions or need advice. So I don't get to do much for myself. And they are closed on Sundays, and normal closing time is 10 PM.) I have read and heard of lots of ways of doing this final drying, including distilled water blown off by compressed nitrogen; pure ethanol; pure this, pure that, microfibers, and more. What methods are preferred by the present readership? Guy Brandenburg, Washington, DC My blog, mostly on Education in DC: http://gfbrandenburg.wordpress.com/ My home page on astronomy, mathematics, education: http://home.earthlink.net/~gfbranden/GFB_Home_Page.html or else http://tinyurl.com/r6fh2 =====================================

Hmm. Mine doesn't seem to look like that. Have had zero problems with cooling of oil and so on. I could be wrong. WIll coat a mirror in the next couple of days and take photos. AND I will use a different brand of paper towel, too. Guy Brandenburg, Washington, DC My blog, mostly on Education in DC: http://gfbrandenburg.wordpress.com/ My home page on astronomy, mathematics, education: http://home.earthlink.net/~gfbranden/GFB_Home_Page.html or else http://tinyurl.com/r6fh2 =====================================

Greetings... I have changed the availability of the Group's Archives to allow non-members to access the past messages, perhaps this will cause a bit more interest in the Group and lead to a more active membership. Also, I changed the Home Page photo and description to reflect more recent activity on the Group. In addition, I will be retiring from my high paid (MYTH) Government job at the end of the month and will lose my access to a high speed internet connection (during my personal time) making moderation of the Group more sporatic than it is already. I'm looking for one or a couple of volunteer moderators to help out when I am away from the computer. It's not really a time consuming position and is definitely not a high profile post but it would be nice to be able to go away for a few days and not worry about the Group. Lastly, I still have some vacuum pumps (mechanical and diffusion) as well as valves and other asundry goodies to peddle since it is looking more-and-more likely that I will not get my system together before 2012 rolls around. Anyone need a project or some goodies? Be well and don't forget to vote. Ken Hunter Owner/Moderator VacuumX Group

Hi All, Does know anybody, what kind of UV lamp should use in a vacuum chamber, for heating. Eliminating the water vapour? ThX! Attila The Hun

I am having INFICON XTM 300 for film thickness measurement. The orginal iintruction manuals has been lost. If any of our community member having these manuals, kinlfy send me the scanned copies to me. Regards Zafar Iqbal

I have an old Veeco vacuum system with a ≈3" diff. pump (air cooled) using 100cc of DC-704 (per factory spec). I've torn down the entire system, cleaned it (I had to clean and rebuild the DP, as it had been dived to atmosphere hot with octoil or the like in it, and was full of tar / carbon). The original unit should have had a 375 watt heater in it. The heater on it now is dissipating 428 watts. Interestingly, Duniway and a couple of other places sell only 350 watt heaters as direct replacements for this pump. I don't recall what temp Octoil wants, but I know that different oils require different temperatures. What I don't know is how critical that temperature is. There is no temperature control, although I could install one at minor expense. As I understand it, too-high heat should not harm pumping action, but FAR too much heat will cause erratic pressure variations as excess condensation interferes with the jets. So, how important is precise temperature control of the boiler? Should I pick up a temperature controller (using the present too-high wattage heater and a thermocouple) or should I replace the heater with a 375 watt unit, or a 350 watt unit, or should I just not worry about it?

Hi guys, I've just joined this group and i'm from Pakistan. Recently I finished a 6" f/11 mirror for telescope. Now it is ready for an aluminium coat. In my country, a coating chamber is about unavailable. Some industries may have it but they clearly denied to coat my mirror. I wanted to know that is there any guy having a coating chamber for telescopic mirrors? If someone can help then I'll be grateful to him throughout my life. Thanks, Asad