Isolation washers - Nylon vs. Fibre vs. Rubber

[owlexifry]

Gonna be doing some mods this weekend (ground scheme overhaul)

I understand that nylon shoulder washers are probably the best for this task (isolating jacks and pots).
but i will not be able to get hold of any.

I do have access to these at the local:

which is the better choice?

(i'm also considering wrapping a small part of the threads with teflon tape in lieu of the additional protection that shoulder washers offer)

 

[2L man]

I have no knowledge but I recall the black color in rubber is carbon dust and carbon can conduct some current. Of those I would use Nylon.

The shoulder washer sets made for steel jacks were quite expensive

 

[Peegoo]

@owlexifry

Nylon and fibre are better than rubber because they won't deform over years of compression and cause things to become loose. Nylon is better than fibre because it doesn't hold moisture like fibre can. So go with Nylon.

Here's a tip: you can use a thin nitrile O-ring on the control shaft to keep it isolated from the metal chassis. The O-ring prevents the control slipping sideways and contacting the metal panel. Even though the O-ring is soft, it will not deform because it's not under compression.

I omitted the metal washer and mounting nut for clarity in this image.

 

[sds1]

Have you looked at the ones specifically made for Switchcraft style jacks?

Isolation Washers for 1/4" Input Jack - Flat, Shoulder

Lower your noise floor and improve your star ground with these washers.This is the perfect item for isolating the "sleeve" connection of a Switchcraft style input jack from the grounded chassis. Proper isolation requires both a flat fiber washer and a shoulder fiber washer. Additionally, the input

tubedepot.com

EDIT: sorry I didn't read your post thoroughly

 

[owlexifry]

@owlexifry

Nylon and fibre are better than rubber because they won't deform over years of compression and cause things to become loose. Nylon is better than fibre because it doesn't hold moisture like fibre can. So go with Nylon.

Here's a tip: you can use a thin nitrile O-ring on the control shaft to keep it isolated from the metal chassis. The O-ring prevents the control slipping sideways and contacting the metal panel. Even though the O-ring is soft, it will not deform because it's not under compression.

I omitted the metal washer and mounting nut for clarity in this image.

cheers, sounds like nylon is the go.
heck that’s a brilliant idea.
totally gonna do that.

the nut will be screwing down onto a metal washer that will only be touching the faceplate (enamel painted balsa) so i don’t think i really need a nylon washer on the front side as well. the jacks aren’t gonna be long enough anyway.

but yeah that o-ring idea looks to be fairly crucial and effective.

 

[owlexifry]

Have you looked at the ones specifically made for Switchcraft style jacks?

Isolation Washers for 1/4" Input Jack - Flat, Shoulder

Lower your noise floor and improve your star ground with these washers.This is the perfect item for isolating the "sleeve" connection of a Switchcraft style input jack from the grounded chassis. Proper isolation requires both a flat fiber washer and a shoulder fiber washer. Additionally, the input

tubedepot.com

EDIT: sorry I didn't read your post thoroughly

hell yeah, i’d love to get these ….but shipping to australia just for some washers

 

[chas.wahl]

The proper type for isolating a pot or jack body from chassis is a "shoulder washer" that has a ridge fitting between the threads of the bushing and the edges of the hole.

Switchcraft's own set of isolation washers has one flat phenolic washer (#1028) and one black plastic (nylon?) washer with a thin shoulder (#1029) that requires a 7/16" hole rather than the 3/8" hole found in chassis meant for pots/jacks that are not isolated.

Hoffman and other '3rd party' sources make a set of 2 black plastic (nylon?) shoulder washers that require a 1/2" hole.

I personally prefer the Switchcraft ones; they're not nearly as thick as the non-Switchcraft ones, and in most cases (chassis gauge thickness < 0.08" or 2 mm) don't typically require a longer bushing on jacks (or pots) than is "standard". Plus they don't require the holes in chassis to be enlarged that much.

@Peegoo's little o-ring workaround sounds OK, but make sure that you enlarge the holes sufficiently to fit the o-ring, (neoprene rubber, no doubt, though you might find silicone), and that it's large enough so that it doesn't get trapped in the tolerance difference between whatever flat washers you're using and the threads of the jack or pot bushing, which are typically just a bit shy of 3/8" diameter. You can imagine, looking at his drawing, how the o-ring might "skooch out" if the hole in either flat washer is too oversize.

 

[owlexifry]

Switchcraft's own set of isolation washers has one flat phenolic washer (#1028) and one black plastic (nylon?) washer with a thin shoulder (#1029) that requires a 7/16" hole rather than the 3/8" hole found in chassis meant for pots/jacks that are not isolated.

Hoffman and other '3rd party' sources make a set of 2 black plastic (nylon?) shoulder washers that require a 1/2" hole.

I personally prefer the Switchcraft ones; they're not nearly as thick as the non-Switchcraft ones, and in most cases (chassis gauge thickness < 0.08" or 2 mm) don't typically require a longer bushing on jacks (or pots) than is "standard". Plus they don't require the holes in chassis to be enlarged that much.

yeah damn... these are the real deal. they look excellent.

Switchcraft washer S1029 :: Nuts and Washers :: Hardware :: Electromechanical :: Electronic Parts :: Banzai Music GmbH

definitely getting some of these on the next banzai order