Original P-90 Cover Material

[belwar]

I was thinking this morning about original P-90 soapbar covers (As used in the 40's and 50's). What material were they made from? We know that gibson used butyrate for bobbins in that era, but what about covers? Where they butyrate as well?

belwar

[Spence]

They were styrene.

[Possum]

....

Dog ears were butyrate I have one here along with a shim of the same material.

[Spence]

Sorry Possum, dogears were PVC not butyrate.

[David Schwab]

Sorry Possum, dogears were PVC not butyrate.

PVC and styrene are two different things. Styrene is vinyl benzene, while PVC is polyvinyl chloride, of course.

ABS (acrylonitrile butadiene styrene) is in the polystyrene family.

I could see the covers being ABS, or PVC, but not styrene. I have some styrene here, and it's not as flexible.

[greenfingers]

What about Bakelite?

[Spence]

PVC and styrene are two different things. Styrene is vinyl benzene, while PVC is polyvinyl chloride, of course.

ABS (acrylonitrile butadiene styrene) is in the polystyrene family.

I could see the covers being ABS, or PVC, but not styrene. I have some styrene here, and it's not as flexible.

I know what you're thinking David but he first asked about soapbar covers and Dogears came up second. I am well aware of the difference and mould covers with both.

[David Schwab]

I know what you're thinking David but he first asked about soapbar covers and Dogears came up second. I am well aware of the difference and mould covers with both.

I only brought it up because you mentioned both.

[Possum]

....

regardless, I do have a butyrate dog ear made by Gibson from the mid-50's nothing else has that kind of smell.....

[salvarsan]

regardless, I do have a butyrate dog ear made by Gibson from the mid-50's nothing else has that kind of smell.....

There ya go. Cellulose butyrate slowly decomposes giving off butyric acid which us regular folks would say smells like puke.

PVC will be more flexible.

-drh

[Possum]

...

Actually butyrate is pretty flexible....

[jack briggs]

PVC and styrene are two different things. Styrene is vinyl benzene, while PVC is polyvinyl chloride, of course.

ABS (acrylonitrile butadiene styrene) is in the polystyrene family.

I could see the covers being ABS, or PVC, but not styrene. I have some styrene here, and it's not as flexible.

Because the styrene molecule has a vinyl group with a double bond, it can polymerize to give plastics such as polystyrene, ABS, styrene-butadiene (SBR) rubber, styrene-butadiene latex, SIS (styrene-isoprene-styrene), S-EB-S (styrene-ethylene/butylene-styrene), styrene-divinylbenzene (S-DVB), and unsaturated polyesters.

[soundmasterg]

Were the metal covers used on things like an Epiphone Casino made out of nickel silver like the humbucker covers, or were they plated brass like so much stuff is these days?

Greg

[David Schwab]

Were the metal covers used on things like an Epiphone Casino made out of nickel silver like the humbucker covers, or were they plated brass like so much stuff is these days?

The covers on the mid 60's ES-330TD I had were nickel silver.