Garden sprayer drain fitting size

[WhoWhatNow]

Does anyone know what type of thread is on the drain port of the Harbor Freight 15 gallon garden sprayer? I need to hook a garden hose to this port and I can’t figure out what type of fittings it is. It appears to have a 1” major diameter and be 9 threads per inch. It is not a 3/4” NPT or a 5/8 garden hose fitting. Is it some weird custom thread?

https://www.harborfreight.com/lawn-garden/gardening-garden-tools/garden-sprayers/12v-15-gallon-spot-sprayer-61263.html

 

[mike93lx]

I doubt it's custom, but I can't find anything that lines up with it. Curious to see where this goes

Bet something could be 3d printed.

 

[Shiftless]

This is Garage Journal. Good excuse to buy a lathe and a chunk of brass to turn a custom metric thread adapter.

 

[PCustoms]

This is Garage Journal. Good excuse to buy a lathe and a chunk of brass to turn a custom metric thread adapter.

Mount a barb fitting to the cap it came with?

 

[PCustoms]

These are 3/4-11.5 fittings:

Blow Molded Applicator Tanks | U.S. Plastic Corp.

These elliptical applicator tanks are designed with injection-molded leg inserts that allow the tanks to be anchored for transportable ap...

www.usplastic.com

 

[Shiftless]

Mount a barn fitting to the cap it came with?

Or epoxy a “close enough” threaded coupling to it and go forward with familiar thread sizes.

 

[PCustoms]

Or epoxy a “close enough” threaded coupling to it and go forward with familiar thread sizes.

Fixed my post from "barn" to "barb".

Epoxy isn't going to adhere well to these tanks.

Years ago I had a similar issue with a fuel tank. Adding a new bulkhead fitting was a good option

 

[Shiftless]

Good idea.
Cut the whole thing out and install a bulkhead fitting.

But the epoxy wouldn’t have to stick much. It would harden around the existing threads and lock on tight. Might even unscrew in the future if necessary,

 

[PCustoms]

In unrelated news, it's comical how wrong Google AI is in this case.

There was just a thread today touting how great it was for electric code too...

 

[Shiftless]

There was just a thread today touting how great it was for electric code too...

The O.P. wasn’t too happy about the comments he got. And a master electrician posted that the A.I. answer was not correct.

 

[PCustoms]

The O.P. wasn’t too happy about the comments he got. And a master electrician posted that the A.I. answer was not correct.

That's the one...

Anyway, trying to help figure out what this thread was AI had some pretty confident answers that were bunk when I actually went and look at a thread table. And the answers were highly dependent on how I phrased the question.

@WhoWhatNow somewhere there is a "bottle" thread specification that eludes me at the moment. I bet these threads fall under that

 

[mike93lx]

That's the one...

Anyway, trying to help figure out what this thread was AI had some pretty confident answers that were bunk when I actually went and look at a thread table. And the answers were highly dependent on how I phrased the question.

@WhoWhatNow somewhere there is a "bottle" thread specification that eludes me at the moment. I bet these threads fall under that

I looked at bottle threads and couldn't find a match. It's really close to 1" Unc but that's 8TPI

 

[PCustoms]

It's really close to 1" Unc but that's 8TPI

Yeah, AI swore that's what it was, then I clicked on the chart...

 

[Shiftless]

It's really close to 1" Unc but that's 8TPI

It’s Harbor Freight. Probably made in China, right? Don’t you think the fittings are metric?

 

[mike93lx]

Yeah, AI swore that's what it was, then I clicked on the chart...

I found it through McMaster. Was clicking through everything... Also checked us plastics

There just be a spec for this somewhere...no way they didn't buy out of a catalog

 

[mike93lx]

It’s Harbor Freight. Don’t you think the fittings are metric?

It most likely is. Just noting what it is really close to

The 9tpi gauge fits perfectly and 9tpi doesn't align with a metric pitch very well

 

[PCustoms]

The 9tpi gauge fits perfectly and 9tpi doesn't align with a metric pitch very well

The OD being spot on 1" doesn't like up well either.

I think the tanks might actually be made in the US.

 

[whateg01]

I'm confused about how the pitch diameter can be larger than the major diameter. Also if I recall Opie said it was nine threads per inch not 11.5

 

[whateg01]

Good idea.
Cut the whole thing out and install a bulkhead fitting.

But the epoxy wouldn’t have to stick much. It would harden around the existing threads and lock on tight. Might even unscrew in the future if necessary,

Won't unscrew from a fake fitting like this. When the blow molded tank is made they leave the threads incomplete where the two mold halves meet so that the thread alignment doesn't have to be as exact.

 

[PCustoms]

I'm confused about how the pitch diameter can be larger than the major diameter. Also if I recall Opie said it was nine threads per inch not 11.5

Huh?

 

[whateg01]

Huh?

Sorry, it was the AI result. But op did say 9 tpi so 11.5 doesn't work.

 

[WhoWhatNow]

AI was useless for this. At first I thought it was metric also, but there does not seem to be a metric standard that is close to this. I could not find anything on USA plastics either. I may try to model this in Fusion360. I am a complete novice at CAD however and it will take me forever.


I should not that the threads are not around the entire circumference. There is a flat spot at 12 and 6 o’clock. Also, the cap has a garden hose type rubber washer so the threads are most likely not sealing.

 

[RoninB4]

-This may be completely wrong but since the thread dimensions don't seem to line up with anything else one would expect I'll just throw this out there. I wouldn't see any reason to create a proprietary thread on a low cost component that doesn't get re-ordered but I suppose it's no less absurd than what my next suggestion is. It may be a multi-lead thread. If that's possible, could be for the application, then there is a thread size in inch (1-18 UNS) and a metric one that has the pitch off by .003" (25M x 1.5). Yes the metric size isn't exactly equal but these are threads blow-molded in plastic for a low cost component and that's not the same as threads created in metal. I may be entirely wrong about all this but it's just spit-balling.

 

[WhoWhatNow]

After a few iterations I have something that sort of works. I used the Coil function to model the threads. The threads are little loose so I think I need to increase the Sectional Size dimension. It is a 1-9 thread.



The next challenge will be to model the garden hose connection. Fusion does not have GH threads listed. I found a YouTube video that shows how to add a file which has the dimensions, but it appears to need a bit of tweaking.

I also think that Ronin4 may be correct about it being a multi-lead thread.

 

[mike93lx]

After a few iterations I have something that sort of works. I used the Coil function to model the threads. The threads are little loose so I think I need to increase the Sectional Size dimension. It is a 1-9 thread.



The next challenge will be to model the garden hose connection. Fusion does not have GH threads listed. I found a YouTube video that shows how to add a file which has the dimensions, but it appears to need a bit of tweaking.

I also think that Ronin4 may be correct about it being a multi-lead thread.

That's awesome.

Maybe print it to fit a 3/4 pvc fitting then adapt to GHT with a commercially available fitting? If the hose is coming on and off, the durability might be nice