Antique Machine...I Think I Found Asbestos City - Page 1
Forum section: electronics / repair

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 19, 2015, 12:12:03 am
content: Bought a really old self-heated "master oscillator" at the antique electronics auction to use as a reference oscillator. I removed the rectifier tube (don't want to blow any bad components) to test the heater. Well it won't start.I unscrewed the back of the largest chamber (where the heater must be) and found a large slab of a yellowish and fibrous insulating material with white faces. Wearing gloves and a bandanna on my face (already realizing it might be asbestos), I removed this first sheet (about 1/2" thick) and found lots more packed inside. Can't even see any components (except a few tubes sticking out the back), it's solid full.I know the heated part has to be insulated, but why everything?Well now what? Is it asbestos or fiberglass? I have to remove the insulation to get to the circuits (obviously outside), but damaging it may produce toxic dust. How can I remove it without damaging it? If I get it out safely do I put it back in or is there some other insulation I can use? This would have to be a solid insulation, like fiberglass, so it can be easily removed for access to the circuits.

author: Vgkid
author_rank: Super Contributor
timestamp: May 19, 2015, 12:38:13 am
content: Pictures pictures pictures.any brand /model info on the unit?

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 19, 2015, 01:40:09 am
content: I didn't want to risk taking the back off again, but you can see some of the stuff through the holes.https://imgur.com/sAljiY5,R3bhxh4,dsnXw64#2(once again, can't get pictures to work)Front of unithttps://imgur.com/sAljiY5,R3bhxh4,dsnXw64#1Placardhttps://imgur.com/sAljiY5,R3bhxh4,dsnXw64#0

author: helius
author_rank: Super Contributor
timestamp: May 19, 2015, 02:03:23 am
content: You can't see much of the insulation in those pictures.For reference, asbestos (in its raw form) looks like this:https://www.flickr.com/photos/asbestos_pix/3563807102/in/photostream/(It's amazing that this was used as tinsel.)Fiberglass is different in several ways, the most obvious being the length and uniformity of the strands. You can see that asbestos is irregular and has pieces that are planar or ragged. Fiberglass looks more like cotton. There are also other insulating minerals, like expanded gypsum, or mineral wool that might have been used.

author: Vgkid
author_rank: Super Contributor
timestamp: May 19, 2015, 03:32:07 am
content: Interesting unit, contains Flintkote. Google says that they made asbestos products.operating manualhttp://www.virhistory.com/tmc/tmc_pages/NorthernRadio/northern_115_operate.pdfparts breakdown with revisionhttp://www.virhistory.com/tmc/tmc_pages/NorthernRadio/northern_115_partsbd.pdfhttp://www.virhistory.com/tmc/tmc_pages/NorthernRadio/northern_115_partsbd_rev.pdfService manualhttp://www.virhistory.com/tmc/tmc_pages/NorthernRadio/northern_115_service.pdfBTW you posted the same pics all three times, unless imgur isnt working.

author: miguelvp
author_rank: Super Contributor
timestamp: May 19, 2015, 03:42:58 am
content: Quote from: Cyberdragon on May 19, 2015, 01:40:09 amJust use the BBCode links:Code:http://i.imgur.com/sAljiY5.jpghttp://i.imgur.com/R3bhxh4.jpghttp://i.imgur.com/dsnXw64.jpgEdit, the images are too big (4288x3216) and blurry and take a long time to download on the page, so I'll just put the links:

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 19, 2015, 04:32:30 am
content: The pictures are blurry 'cause my camera was being stupid and taking like 5 seconds to take a picture. -_-After a quick examination of the service manual...the problem is simple. It is what I feared as the worst case.The relay is the thermostat relay which runs off the main D.C. power. But I have purposefuly disabled the main power to prevent full power on an untested device. Apparently they don't want you to do that, so it's all or nothing. (I'm pretty sure a variac will also not work, it's regulated) Please don't explode... Hopefully if it fails the fuses actually blow... (unlike last time when Mr.Capacitor smoked in a non-smoking zone)EDIT: It's looking like that stuff really is asbestos, IDK how safe it is to handle. Any advice on proper handling and care of this stuff is appreciated. Also whether I should replace it with modern insulation and what type I should use.

author: helius
author_rank: Super Contributor
timestamp: May 19, 2015, 04:58:50 am
content: Quote from: Cyberdragon on May 19, 2015, 04:32:30 amHandling: as little as possible. Don't touch it at all if you don't need to, and use a respirator and gloves. The asbestos you can see isn't the harmful part: the danger is from microscopic fragments that float into the air when the material is disturbed.

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 19, 2015, 05:09:41 am
content: It's Celotex says the manual. They did make asbestos, but it looks exactly like their fiberboard products. Yet it's called "insulation"...hmmm....the mystery deepens. I will try to get a more detailed desription from the manual (I would assume this would be included in the bill of materials).Edit: the parts list just says insultion with part numbers.

author: pickle9000
author_rank: Super Contributor
timestamp: May 19, 2015, 05:50:25 am
content: Asbestos is typically wet down with soapy water (sprayed on not dripping), the clumps are then removed. That reduces the airborne particles, it's then double or triple bagged (while moist). It is dangerous to inhale.I'm not saying you do this but the procedure would be to bag the entire unit and use long arm gloves (sealed to bag), open the cover, spray on the soapy water (tools and spray preloaded in bag before you start), remove clumps and place in bottom of bag. Then move the unit to another bag (while the unit is wet) and repeat until the unit is clean. Normal vacs must not be used. The material must remain wet at all times, even on the way to disposal. There are variances on procedures for things like this but this gives you an idea of the issues involved.Tack cloths are used for final cleaning.

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 19, 2015, 06:28:04 am
content: Um, wash electrical parts? Still using a mask and gloves though. If I have to remove any stray fibers I'll wipe it with a damp paper towel, taking it outside of course.However, it appears to be common fiberboard, the only asbestos products Celotex made appear to be using white asbestos, this stuff is brown though. I'll try to very carefully get a better picture of the stuff later.

author: pickle9000
author_rank: Super Contributor
timestamp: May 19, 2015, 06:36:32 am
content: Quote from: Cyberdragon on May 19, 2015, 06:28:04 amYup, wash. Paper based items are the hardest hit, a freeze dryer is handy. When it's all clean conformal coating can be used to glue remaining bit's in place.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 19, 2015, 10:51:05 am
content: FWIW, it may well be high quality, true asbestos, which doesn't fray so much. The cheap hazardous stuff is chrysotile, which was usually used in chopped form to stiffen insulating compounds, add fire retardancy and so on. Which, of course, went into nasty decay over the decades, releasing microscopic particles...Tim