Sealant on 1/8 pipe threads

[Whons]

I'm putting together my oil pressure gauge today. Using permatex high temperature thread sealant on the 1/8 pipe threads. Do I need to wait some time or can I run the engine right away?

[jft69z]

What exact product did you get? Couple different ones, with different tech data sheets.

[Whons]

Joe, it's permatex high temperature thread sealant 59214

[jft69z]

Tech data sheet below.

Says immediate low pressure sealing, full cure in 24 hours, and after 72 hours joint is sealed to full pipe burst pressure.

For your application, I'd probably wait a while, mainly because the oil pressure has the potential to reach 50-60 psi. One reference on their product page says it can be repositioned within 4 hours after application, maybe shoot for that as a guide.

That being said, The taper joint nature of pipe threads is what does the majority of the sealing anyways. 

permatex thread sealant.pdf

[Whons]

thanks Joe, I think I'll give it 24 hrs just to be safe.

[Scott S.]

Hey Wayne,

Just curious, but did you use compression ends on the pipe into the fittings ?

The threads on the compression nuts don't require sealant, except maybe a touch of lock tite to keep them from loosening. 

[Whons]

Scott I have all the 1/8 pipe threads with sealant. Tomorrow I am going to use 1/8 copper tubing with the compression fittings. The fittings that came with the gauge are really nice. The under side is flat and the furrel has a flat and then a nice long taper. I know you don't need the sealant on those threads. What I would like to know is how much to tighten it once it's hand tight. Never used a compression fitting that small.

[Scott S.]

Sorry I haven't responded sooner.

Snug.... Not much more. Make sure you can't pull the tube out, but you should feel when it stops.

Overtightening can split the nut..... depending on where they came from. Some have more "meat" than others.

I ususally take them apart after it feels right, just to take a look at the ring..... See that it has a good bite and not damaged the tube. 

Like I mentioned, a dab of lock tite to keep the nut tight is a good idea.

[Whons]

Sctt ,  I tightened them until snug, then 1/4 turn. They both had a very slight leak.  I tightened them a very little bit more and no no leaks. The fittings had a very nice taper on the feral. 

[Scott S.]

Wayne,

The taper on the feral depends on the manufacturer..... Some brands use the "barrel" ring, others the long, one directional taper. 

Each has it's pros and cons, but I don't believe they can be mixed and matched. The taper contact surfaces are different. 

As I mentioned before, the nuts with more metal seem to be the better choice.

[Whons]

Scott these were the long, one directional taper. From looking at other ones I think these are the best. They came with the 1/8" copper tubing.

[Whons]

here's a picture of my oil sensor fitting. I kept the idiot light as well.

[Scott S.]

Those valve covers look familiar..... lol

[Whons]

They are the tallest valve covers I ever had. They were on the car when I got it last summer. I like the fact that they are thick, no bending like original sheet metal valve covers. No leaks.

[Scott S.]

And easy to remove when one sets the rockers. 👍