What oil to fill in the HP gauges?

[bigHUN]

I got couple 50mm and 60mm from ali a while back, came in empty and a sticker is saying to fill with oil before use.

I have some 2-3 smaller like 35 or 40 mm gauges with transparent oil inside but one for inline checking fell out of my hands and it was a bigger nock from the concrete floor, I want to disconnect that one from my use.

At home I have no transparent oils only some engine oils but that would paint the interior yellow/brown, I need to order some anyway, what ya using?

 

[JamesD.]

None. It's originally put in gauges that are on heavy machinery to dampen the needle from enormous vibrations. 

 

[JamesD.]

They use glycerin when they do.

 

[Gerry52]

You didn't mention what you're using it for. If being mounted on a compressor it's good to have a liquid filled gauge due to vibration (use glycerin as mentioned before). If not, you might not need it. 

 

[Healthservices]

From what I remembered it was always glycerin or silicone oil

 

[thumper]

@JamesD. is right on the money on both counts. 

I'll add, just install the gauge and see how it does. If the needle vibrates to the point you can't read it, then add glycerin. I'll bet you don't need it. It's a helluva mess when it leaks out eventually, and it will from my past experiences. 

 

[bigHUN]

THX guys, this gauge will replace what I have inline for double checking the refills both way. I know that the oil dampens any spikes with the needle, I am (was) always very careful but as this accident happened, "we never know when the poop will roll"