Pitot adapter question

[Clayvt]

I'm finishing up the last few things in my wings and went to start mocking up the dynon pitot tube with the lines to see how to route them. I tried threading on the plastic line compression fitting to the flared adapter but it only goes on a few turns before becoming quite difficult. I did not want to start forcing it and figured I'd ask here first. The flared side goes right on with no difficulty.
Also, any thread sealant recommended or not on these connections?
Below is as far as it would go in by hand.
These came in the pre-packaged dynon pitot kit sold by ACS.

 

[Ironflight]

Yes, that’s a tapered pipe thread - it is only designed to go in a few turns, then tighten up and seal. And yes, you use your favorite sealant (not Teflon Tape please!) on teh pipe threads before screwing it in tight. Check Section 5 of the build manual for more information, and recommendations on sealant. I personally usually use Permatex Aviation Sealant (sometimes Permatex #3) - black, tar like stuff that has been used since forever. Young whippersnappers swear by expensive LocTite products….

 

[Clayvt]

Yes, that’s a tapered pipe thread - it is only designed to go in a few turns, then tighten up and seal. And yes, you use your favorite sealant (not Teflon Tape please!) on teh pipe threads before screwing it in tight. Check Section 5 of the build manual for more information, and recommendations on sealant. I personally usually use Permatex Aviation Sealant (sometimes Permatex #3) - black, tar like stuff that has been used since forever. Young whippersnappers swear by expensive LocTite products….

Much appreciated thank you!
I used a bunch of permatex Aviation sealant on my ‘48 CJ engine rebuild. It has a nice smell to it.

 

[Walt]

Nothing wrong with teflon tape on pneumatic fittings, but if you prefer goopy stuff, permatex thread sealant is my alternative:
https://www.aircraftspruce.com/catalog/cspages/permthrdseal.php?clickkey=4275
(I also prefer Nylo over push-ons)

 

[Low Tailwheel rider]

Yes, that’s a tapered pipe thread - it is only designed to go in a few turns, then tighten up and seal. And yes, you use your favorite sealant (not Teflon Tape please!) on teh pipe threads before screwing it in tight. Check Section 5 of the build manual for more information, and recommendations on sealant. I personally usually use Permatex Aviation Sealant (sometimes Permatex #3) - black, tar like stuff that has been used since forever. Young whippersnappers swear by expensive LocTite products….

Anyone happen to recall the NPT size of that fitting? Want to order elbows for those connections.

 

[RV6_flyer]

Anyone happen to recall the NPT size of that fitting? Want to order elbows for those connections.

1/8" is what I remember. 1/8" is the smallest NPT size I remember using on airplanes.