Who knows about pipe threads? NPT and NPS?

[stephenspann27]

I'm at my whits end.. I ended up welding 1.25'' barbed fittings to my T fitting. However.. I can't get the welds to seal.. I've made three passes.. and even in areas where the welds look perfect.. good penetration and nicely puddles its leaking.. wtf? Its difficult to weld because the smoke from the galvanized barbs is toxic and can make you pretty sick.. so I have to hold my breath.. heh.. I don't know what to do.. I have so much time in this, and probably $40 in plumbing crap.. so frustrating.

 

[hubs97xj]

I think you do, in fact, know what to do. And why are you so attached to this gauge? Couldn't you have gotten one that wouldn't need so much work?

 

[stephenspann27]

so I just did some googling.. and found that making welds air tight.. is pretty challenging and that migs are not able to make air tight welds due to cold starts..

 

[stephenspann27]

I think you do, in fact, know what to do. And why are you so attached to this gauge? Couldn't you have gotten one that wouldn't need so much work?

I went through a lot of trouble to mount these summit gauges in my stock cluster.. that's why I'm going through so much trouble to get the water temp one working..

 

[hubs97xj]

Ah, I remember seeing that cluster now. Maybe this is a good time to call Summit and see what they have that will accept the sender?

 

[stephenspann27]

Here is version 2.. which was a failure due to the weld not being air tight.. even after grinding and three passes:

Here is version 3 which finally worked! I took a single 1'' pipe that was threaded on both ends and I cut the ends off, then I flipped the ends and threaded them into the T so that I would have about 1'' of non threaded surface to mount the hose on. Then I wrapped the heck out of the remaining exposed thread with teflon tape. No leaks so far.

 

[souske]

Why not put the teflon on all threads and just crank it as tight as it will go?

 

[5-90]

Thread together, then solder. The wedging action of the tapered thread starts at the point, so there's still a little room to wick in the solder at the outside end.

Soldering has the additional advantage of being "undoable" - just heat it up to break it.

When putting hose onto a straight pipe (non-beaded) fitting, use some RTV black on the outside of the pipe, and two clamps - have at least 1/4" of hose past the clamp closest to the end, at least 1/4" of hose between the two clamps, and both clamps fully seated on metal pipe.

 

[stephenspann27]

Why not put the teflon on all threads and just crank it as tight as it will go?

The way I have it right now, the entire pipe is not threaded, just the section nearest to the T.

 

[stephenspann27]

Thread together, then solder.
When putting hose onto a straight pipe (non-beaded) fitting, use some RTV black on the outside of the pipe, and two clamps - have at least 1/4" of hose past the clamp closest to the end, at least 1/4" of hose between the two clamps, and both clamps fully seated on metal pipe.

Should I use the RTV ect, in order to keep the hose from slipping off? I don't have enough room for two clamps, because there isn't a long enough portion of the hose that is straight. I'm hoping the threads will grip the hose enough to not allow the hose to pop off. I tightened the ever living crap out of the hose clamps.

I'd rather not disturb it unless it starts leaking..

 

[stephenspann27]

I went wheeling today for about 5 hours, no issues.