Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tiny_Daddy on January 11, 2011, 05:44:20 pm

Title: Vacuum Tube base glue
Post by: Tiny_Daddy on January 11, 2011, 05:44:20 pm

Finally a description:
http://www.antiquewireless.org/otb/vt0108.htm
It's a shellac and resin compound.
Does this mean that loose tube bases can be fixed with alcohol? I'll have to check.

Title: Re: Vacuum Tube base glue
Post by: FYL on January 11, 2011, 06:59:11 pm

Quote

It's a shellac and resin compound.

Mostly marble flour (powdered marble):

" This recipe for RCA's basing cement, yielding about 200 pounds of material, was "standard for all bases." [9, 10]:

    Coarse marble flour      170 lb.
    Orange flake shellac      19-1/2 lb.
    Durite phenolic resin LR275-2      7-1/2 lb.
    Medium-color (grade G) rosin      3-1/4 lb.
    Denatured alcohol      9 liters
    Malachite Green aniline dye      10 g.
"

Title: Re: Vacuum Tube base glue
Post by: stingray_65 on January 11, 2011, 09:45:46 pm

don't forget the 150 C degree curing temp.

Title: Re: Vacuum Tube base glue
Post by: LooseChange on January 12, 2011, 04:40:22 am

Quote from: Tiny_Daddy on January 11, 2011, 05:44:20 pm

Does this mean that loose tube bases can be fixed with alcohol? I'll have to check.

Did you try the alcohol?

Title: Re: Vacuum Tube base glue
Post by: loogie on January 12, 2011, 06:32:58 am

Dude, alcohol isn't the answer to all problems.  Just some.  Maybe most. 

Title: Re: Vacuum Tube base glue
Post by: Bub on January 12, 2011, 07:39:37 am

Hi Gent's

Being new to this and not knowing the answer, would thin cyanoacrylate work?. You can get very small capillary tubes at hobby stores to inject the ca into the base.

Thanks

Rob

Title: Re: Vacuum Tube base glue
Post by: FYL on January 12, 2011, 08:25:25 am

Cyano works sometimes. You may use it on a cheap tube.

Emission Labs sells two versions of a dedicated tube base glue:
http://www.emissionlabs.com/datasheets/glue.htm

Available in Europe for €8.50 per bottle.

Title: Re: Vacuum Tube base glue
Post by: PRR on January 12, 2011, 08:43:48 pm

General-purpose Crazie-Gloo will fail at high temperatures.

Probably fine for battery-radio octals. Dubious on 6SN7. Will probably fail on 6V6/6L6 hot tubes.

Title: Re: Vacuum Tube base glue
Post by: supro66 on January 13, 2011, 07:58:19 am

J B Weld epoxy
500 Degrees F
I use this a lot

http://jbweld.net/products/jbweld.php