Basing Cement

[Doc B.]

Was just looking at a 1930s chart of the materials used to glue the metal base to an old fashioned incandescent light bulb. The recipe included -
alcohol
marble dust
pine resin
shellac
chalk
bakelite
glyptol
malachite green
Makes one wonder if a similar brew was used to attach the bakelite bases of vacuum tubes of that era.

[Thermioniclife]

I would think so because I have seen separated tubes and burnt out light bulbs that separated from the base when removing, stuff looks similar.

[Doc B.]

So you're saying that, if I dedicate the next 6 years to experimenting with various combinations of these ingredients to get it to work right, I just might come up with a product to sell to the three people who post here per year asking what to glue a loose tube base back on with.

Speaking of old tech I just found out that our neighbor across the parking lot had a 5000 sq. ft. facility that ground and polished aspherical lenses for the likes of Edmund Scientific. The main machines are rather archaic analog control pantographs that used precision machined metal patterns. He's retiring and selling off the machinery if anyone is interested in gigantic pantograph mills. Probably a good thing I don't have the space as he has some pretty cool machinery. I saw a pretty big and beautiful 1880s vintage gear driven lathe that sold very quickly.

[Thermioniclife]

Jeese Dan I did not suggest that they were the same compound. I really don't understand your somewhat contentious opening statement to my reply? Frankly It is no concern of mine what you do with the next 6 years of your life. I merely stated that the stuff looks similar. Am I misunderstanding you?

[Doc B.]

Yes, apparently. It was meant entirely as a poke at my own delusions. I was chuckling to myself that I found some insane new rabbit hole to go down. Apologies that it came across wrong.

[Thermioniclife]

Roger that Dan. No offense taken.

[2wo]

Weren't you the same  guy who was refinishing old racing leathers?😁

[Doc B.]

Yup. Did quite a few sets of leathers for customers and realized I'd never make a decent hourly wage at it. And then of course there was bringing studio quality reel to reel tape to the audiophile. 11 years of energy output into a passion project that sold several thousand albums but never did better than breaking even - though I made good money on the hardware end. Then there was the time I restored an early 60's "portable" electronic camera flash and sold it to a photography professor who told me I should start a business selling them, because the flash had its own unique look that modern strobes don't have. I bet there are at least two more customers for that.

Once we finish getting moved out of the old office I'll attempt to maintain my focus on building my new racing bike. Hopefully that will keep me from starting up another obscure hobby business. I found a new rabbit hole in making contact with the only guy who ever got an Aprilia RSV twin over 200mph. I now own several of the more exotic go fast parts off that bike, all of his notes on the build and even have his phone #. May be attempting to break a 171mph FIM world record for partially streamlined blown 1000cc v-twin bikes in 2026.

https://www.facebook.com/share/r/15eQkBE5Ze/

Getting back on topic, Permatex #1 dries hard and is rated to 400F. Might be worth trying on your next loose tube base.