PDA

View Full Version : Anti-oxidation lube product for high heat standard e-26 screw base?



gellfex
06-14-2016, 10:11 PM
I have a 12"x18" vacuuformer that uses these conical, screw base, nichrome coil wrapped ceramic heating elements. Cool little unit I got at auction for $35 years ago. The main problem is the socket connection gets wonky from the heat. It's the proper ceramic receptacle with high heat leads, but I'm frequently needing to jiggle the elements or take them out and sand the contacts. Is there something I can put on there, like silicone heat sink grease, that will help maintain oxidation free contact?

Doozer
06-14-2016, 10:25 PM
They make some mica based white grease for mounting heat sinks on
electronic components. (The stuff will get on your fingers and get totally
everywhere, worst traveling grease I have ever seen.)
This might work well.

-Doozer

darryl
06-14-2016, 10:52 PM
Cramolin might have a product for that, if they're still in business. Years ago we used a graphite based lube in toasters, etc- not sure if that would work for contacts, but possibly. Maybe graphite powder by itself would help.

Willy
06-14-2016, 11:06 PM
I believe the problem you are experiencing is called high temperature fretting corrosion, correct me if I'm wrong.
Electrolube makes a product just for combating this problem, I've seen it used at remote power generation sites. Some of the guys onsite said they swore by it, not being curious enough I don't recall the exact product but contacting Electrolube should give you an answer.

As it was explained to me at the time, you want a liquid lube that can not only withstand the heat but also self heal in order to minimize oxidation.

I believe Fastanal is one of their distributors.

J Tiers
06-14-2016, 11:24 PM
Those heating elements sound like they are from the year 1...... I think they were used in the ancient electric version of the classic "bowl fire"......

https://s-media-cache-ak0.pinimg.com/736x/6b/97/c6/6b97c6591b1a29261d14e6b99c9ed4b5.jpg

The alloys used in the contacts are not exactly immune to problems.......

boslab
06-15-2016, 03:13 AM
We had to plug ladle gates in to the controll system in work, big 3 phase plug, there was a conductive grease available, I swear it was ordinary copper grease myself, the downside was it caused the plugs to flash over, it was getting everywhere, even more mobile when hot so pins were arcing out
Mark

gzig5
06-15-2016, 11:00 AM
They make some mica based white grease for mounting heat sinks on
electronic components. (The stuff will get on your fingers and get totally
everywhere, worst traveling grease I have ever seen.)
This might work well.

-Doozer

I don't think heat-sink thermal grease is appropriate for this use. Most of the types we use at work are electrically isolative, or show poor electrical conduction. What you want is a high temp conductive grease. The one I used to use for bonding sections of bus bars to 250 KVA welding transformers seemed to be a silver powder mixed in a grease suspension, but I don't know if it would stand up to the 1000+ degree temps.

H380
06-15-2016, 03:21 PM
http://i786.photobucket.com/albums/yy145/H380/50CA1EBB-10E7-41C5-9B75-A377B1E8A861-2312-00000534FBB1BFA6_zps859799af.jpg (http://s786.photobucket.com/user/H380/media/50CA1EBB-10E7-41C5-9B75-A377B1E8A861-2312-00000534FBB1BFA6_zps859799af.jpg.html)

gellfex
06-15-2016, 05:49 PM
Thanks guys, the brain trust here never fails! I got the current vacform job done, it turns out the socket failed from all the retightening and the wire separated from the female threaded part. Fortunately I had ordered a replacement years ago, and even more fortunately was able the find the part in the bowels of my shop. Now I should follow through on this info so the NEXT job I'm not struggling and wondering what it was you guys said....

Jtiers, yup, that looks like the same element. I thought about upgrading to ceramic units but was concerned they were too directional down, and not using the reflector structure to achieve more even heat.

old mart
06-17-2016, 08:03 AM
Try Googling "ceramic grease", these are normally non conductive electrically, but in a plug and socket you want to stop fretting corrosion. Normal greases for electrical connections are non conductive, copper grease would not be a good choice. The ceramic greases are rated for 1500C.