20-04-2012, 07:37 AM
I think that the graphite based aerosols are what was used on CRTs as 'aquadag'. I'm not sure how conductive it is as compared to silver based products. The conductivity is usually expressed in Ohms per square or some such thing, but it's not something I know anythng about. There are many firms who manufacture and supply such sprays and brush applied paints, but not at a retail level, and needless to say, they're eye-wateringly expensive.
In vintage radio circles it's a topic that most often crops up in relation to restoring the metalic sheilding paint flaking off valves, which affects both the functionality of the valve and its appearance. For red painted valves, if most of the original paint is still firmly adhered to the glass, very good results can be had from the mini-tubes of silver loaded paint as used for such things as repairing the conductors on car heated rear windows. I've renovated EBL31 valves by applying two or three coats of the paint, then overspraying the valve with red primer, which is a very good match. (A little tube of the silver loaded paint covers quite a large area). On silver/grey metalic sprayed valves, after applying the silver loaded paint, I've oversprayed the valve with U-Pol 'Weld Thru' primer spray, which is zinc loaded but has no RF shielding properties and isn't conductive, though is a good match for the original colour of the shielding on valves. It's true purpose in life is as a primer on steel fabrications to inhibit rust, preparatory to welding, and which - as its name implies - can be welded through.
A firm called MG Chemicals in the US makes silver loaded aerosols, and similar products, as can be found here:
http://www.mgchemicals.com/products/842-coating.html
The only sell via distributors, and there isn't one in the UK. Mouser is the international distributor.
Most of these products are so expensive that there is no cost/benefit case for the use by the likes of us.
Hope that's of passing interest, although you seem to be sorted Al.
In vintage radio circles it's a topic that most often crops up in relation to restoring the metalic sheilding paint flaking off valves, which affects both the functionality of the valve and its appearance. For red painted valves, if most of the original paint is still firmly adhered to the glass, very good results can be had from the mini-tubes of silver loaded paint as used for such things as repairing the conductors on car heated rear windows. I've renovated EBL31 valves by applying two or three coats of the paint, then overspraying the valve with red primer, which is a very good match. (A little tube of the silver loaded paint covers quite a large area). On silver/grey metalic sprayed valves, after applying the silver loaded paint, I've oversprayed the valve with U-Pol 'Weld Thru' primer spray, which is zinc loaded but has no RF shielding properties and isn't conductive, though is a good match for the original colour of the shielding on valves. It's true purpose in life is as a primer on steel fabrications to inhibit rust, preparatory to welding, and which - as its name implies - can be welded through.
A firm called MG Chemicals in the US makes silver loaded aerosols, and similar products, as can be found here:
http://www.mgchemicals.com/products/842-coating.html
The only sell via distributors, and there isn't one in the UK. Mouser is the international distributor.
Most of these products are so expensive that there is no cost/benefit case for the use by the likes of us.
Hope that's of passing interest, although you seem to be sorted Al.
Regards, David.
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
