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Vacuum tube technical question
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I once used regular 2-part epoxy of the type sold in small tubes in a
variety store. It was visible but inconspicuous and did the job well. Tom, N3IJ "Argus" wrote in message hlink.net... Gentlemen: Can anyone tell me what the tube manufacturers used to cement the plate caps to the tube envelope? Thanks-for-reading Prof. R. Long Ivy Tech State College |
I have fixed a couple loose bases with 5-minute epoxy as well... on 01a
tubes... I agree it gets it done. Tom Coates wrote: I once used regular 2-part epoxy of the type sold in small tubes in a variety store. It was visible but inconspicuous and did the job well. Tom, N3IJ "Argus" wrote in message hlink.net... Gentlemen: Can anyone tell me what the tube manufacturers used to cement the plate caps to the tube envelope? Thanks-for-reading Prof. R. Long Ivy Tech State College -- If it's a "new economy," why do they want my obsolete old money? |
I have fixed a couple loose bases with 5-minute epoxy as well... on 01a
tubes... I agree it gets it done. Tom Coates wrote: I once used regular 2-part epoxy of the type sold in small tubes in a variety store. It was visible but inconspicuous and did the job well. Tom, N3IJ "Argus" wrote in message hlink.net... Gentlemen: Can anyone tell me what the tube manufacturers used to cement the plate caps to the tube envelope? Thanks-for-reading Prof. R. Long Ivy Tech State College -- If it's a "new economy," why do they want my obsolete old money? |
Argus wrote:
Thanks a bunch for your input guys. Tube caps and bases used to be cemented with high temperature frit-type cements. Sauereisen cement or a mixture of litharge and glycerine used to be popular. The same sort of things that are used to cement bases onto light bulbs today. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Argus wrote:
Thanks a bunch for your input guys. Tube caps and bases used to be cemented with high temperature frit-type cements. Sauereisen cement or a mixture of litharge and glycerine used to be popular. The same sort of things that are used to cement bases onto light bulbs today. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Sauereisen cement is still available. See www.sauereisen.com under cement
products, air dried. I have also had success with high temperature silicone gasket cement, the red stuff. It is available at any auto supply store. No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. 73, Joe K3ICO "Scott Dorsey" wrote in message ... Argus wrote: Thanks a bunch for your input guys. Tube caps and bases used to be cemented with high temperature frit-type cements. Sauereisen cement or a mixture of litharge and glycerine used to be popular. The same sort of things that are used to cement bases onto light bulbs today. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Sauereisen cement is still available. See www.sauereisen.com under cement
products, air dried. I have also had success with high temperature silicone gasket cement, the red stuff. It is available at any auto supply store. No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. 73, Joe K3ICO "Scott Dorsey" wrote in message ... Argus wrote: Thanks a bunch for your input guys. Tube caps and bases used to be cemented with high temperature frit-type cements. Sauereisen cement or a mixture of litharge and glycerine used to be popular. The same sort of things that are used to cement bases onto light bulbs today. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
In article om, "Joe Curry"
writes: No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. I have never had cyano glues (Crazy, Super, etc.) hold *anything* together for any length of time, even at room temps. I've come to consider these glues as one big consumer fraud. Certainly don't work on plastics. --Mike K. Oscar loves trash, but hates Spam! Delete him to reply to me. |
In article om, "Joe Curry"
writes: No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. I have never had cyano glues (Crazy, Super, etc.) hold *anything* together for any length of time, even at room temps. I've come to consider these glues as one big consumer fraud. Certainly don't work on plastics. --Mike K. Oscar loves trash, but hates Spam! Delete him to reply to me. |
Mike Knudsen wrote:
In article om, "Joe Curry" writes: No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. Red silicone RTV is great for tube bases and for caps, even on power tubes that run very hot. However, it's also very expensive compared with the standard cements. Fine if you are doing one or two tubes, not so fine if you are on a production basis turning out thousands. But great for repair work, and available at the auto parts store. I have never had cyano glues (Crazy, Super, etc.) hold *anything* together for any length of time, even at room temps. I've come to consider these glues as one big consumer fraud. Certainly don't work on plastics. --Mike K. Cyanoacrilate glues are very strong in expansion mode. You can cement two things together and put a heavy force pulling them apart and they will stick very effectively for a long time, even when wet. They are very weak in shear mode. Even a very small amount of shear force across a cement join will cause it to fail eventually. Sometimes that eventually is in a few hours. Almost every application where you would be using cement involves some shear force. They also do not fill voids at all, even the fancy "gel" types. You need a VERY clean mate between the two surfaces. Even a slight bit of surface roughness will dramatically weaken a join. The cyanoacrilate stuff is very effective for a few things, like rubber O-ring belts. For most things, though, it is a temporary fix at best. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Mike Knudsen wrote:
In article om, "Joe Curry" writes: No matter what you use, it will have to handle the heat. It is not clear that the cyanoacrylic materials (such as Crazy Glue) will hold up under the temperatures to which power tubes are subjected. Red silicone RTV is great for tube bases and for caps, even on power tubes that run very hot. However, it's also very expensive compared with the standard cements. Fine if you are doing one or two tubes, not so fine if you are on a production basis turning out thousands. But great for repair work, and available at the auto parts store. I have never had cyano glues (Crazy, Super, etc.) hold *anything* together for any length of time, even at room temps. I've come to consider these glues as one big consumer fraud. Certainly don't work on plastics. --Mike K. Cyanoacrilate glues are very strong in expansion mode. You can cement two things together and put a heavy force pulling them apart and they will stick very effectively for a long time, even when wet. They are very weak in shear mode. Even a very small amount of shear force across a cement join will cause it to fail eventually. Sometimes that eventually is in a few hours. Almost every application where you would be using cement involves some shear force. They also do not fill voids at all, even the fancy "gel" types. You need a VERY clean mate between the two surfaces. Even a slight bit of surface roughness will dramatically weaken a join. The cyanoacrilate stuff is very effective for a few things, like rubber O-ring belts. For most things, though, it is a temporary fix at best. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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