# What kind of tube fitting do I want? **URL:** \ **Category:** Factual Questions\ **Created:** [January 29, 2023, 4:29pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991 "2023-01-29T16:29:46Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![74westy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/74westy/32/3950_2.png) [@74westy](https://boards.straightdope.com/u/74westy)\ **Post date:** [January 29, 2023, 4:29pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/1 "2023-01-29T16:29:46Z")
I want to have a 3/16" OD plastic hose pass through a hole in the side of a plastic bin so that some of the hose is inside the bin and some outside. The hole through the bin will be under water so I don’t want it to leak. The bin is a reservoir and not under pressure. I am making a hydroponic thing like this and looking anything that solves the same problem as part H is solving in this diagram. Need to know what it is and where I can get it. Thanks. [![](https://dl.dropboxusercontent.com/s/j10gynwyc83x285/IMG_20230129_101755%5B1%5D.jpg?dl=0) ](https://dl.dropboxusercontent.com/s/j10gynwyc83x285/IMG_20230129_101755%5B1%5D.jpg?dl=0) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 29, 2023, 4:37pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/2 "2023-01-29T16:37:50Z")
Is the tube a stiff plastic or something softer like silicone/rubber? If it’s soft, a barbed connector and a hose clamp will work. If it’s something more rigid (like the plastic line you’d see for an ice maker or RODI filter), a push-to-connect fitting will work. Something like [this](https://www.lowes.com/pd/SharkBite-3-8-in-Push-to-Connect-x-1-2-in-Mip-dia-Male-Adapter-Push-Fitting/1000192613), except with a rubber washer and nut in the inside part. ETA, I realized you wanted the hose to pass through the wall, not be terminated at it. How important is it for the hose to pass through it? Would it work if you had a water tight connection but it was two hoses that connect at that point? The other option would be to get a very tight fitting grommet, install that in the side of the bucket and then push the line through it. Something like [this](https://www.menards.com/main/hardware/fasteners-connectors/specialty-fasteners/snaps-grommets/midwest-fastener-reg-3-16-x-5-16-rubber-grommet-1-count/83011/p-1541140100308-c-19476.htm), maybe? ---
**Author:** ![74westy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/74westy/32/3950_2.png) [@74westy](https://boards.straightdope.com/u/74westy)\ **Post date:** [January 29, 2023, 4:55pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/3 "2023-01-29T16:55:12Z")
> [@Joey\_P](#): > > How important is it for the hose to pass through it? In the diagram, the hose connects an air pump “D” outside the tub to an air stone “F” inside. I am tasked with sealing the hose in the tub so I don’t know what everything else is. If we think the grommet will not leak or can be easily sealed with some silicone then I think it’s the perfect solution. Thanks. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [January 29, 2023, 4:56pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/4 "2023-01-29T16:56:44Z")
I think you want a compression bulkhead fitting, but it will be tricky to find something that allows a hose to pass through it. Could you cut the hose and use barbs on either side of the fitting? [Here’s an example of the fitting.](https://www.freshwatersystems.com/products/gray-dmfit-bulkhead-union-1-2-x-1-2) ---
**Author:** ![74westy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/74westy/32/3950_2.png) [@74westy](https://boards.straightdope.com/u/74westy)\ **Post date:** [January 29, 2023, 5:00pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/5 "2023-01-29T17:00:50Z")
Bingo. Bulkhead fitting is the search term I needed. You have about 5 minutes to talk me out of ordering this and thanks to both of you. > **[Amazon.com: Feelers 3/16" Hose Barb Thru-Bulk Bulkhead Fitting Hex Barbed...](https://www.amazon.com/Feelers-Thru-Bulk-Bulkhead-Fitting-Splicerr/dp/B08FJGTH5V)** > > Amazon.com: Feelers 3/16" Hose Barb Thru-Bulk Bulkhead Fitting Hex Barbed Fitting Plastic Adapter Union Mender Splicer with Gasket for Water/Fuel/Air (Pack of 2) : Industrial & Scientific ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [January 29, 2023, 5:02pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/6 "2023-01-29T17:02:21Z")
That looks perfect. ---
**Author:** ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)\ **Post date:** [January 29, 2023, 5:03pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/7 "2023-01-29T17:03:07Z")
I would use metal bulkhead fittings. I’ve had problems with plastic fitting developing leaks. [Amazon.com: Beduan 3/8" Hose Barb Thru-Bulk Bulkhead Straight Hex Union Stainless Steel Fitting : Industrial & Scientific](https://www.amazon.com/Beduan-Thru-Bulk-Bulkhead-Straight-Stainless/dp/B07NYPGN4D/ref=asc_df_B07NYPGN4D/?tag=&linkCode=df0&hvadid=385430374989&hvpos=&hvnetw=g&hvrand=4699385885619267054&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033304&hvtargid=pla-827660702542®ion_id=373786&ref=&adgrpid=80249223762&th=1) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 29, 2023, 5:12pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/8 "2023-01-29T17:12:26Z")
> [@TroutMan](#): > > but it will be tricky to find something that allows a hose to pass through it. They have those, in fact, they’re common in the 3D printer hobby. I’m sure they’re common elsewhere, but that’s where I know them from. I believe they’re water tight, but it’s not something I’ve ever tested out with the application I use them for. [These](https://www.amazon.com/BIQU-Straight-Pneumatic-Connector-Extruder/dp/B01IB81IHG/ref=d_pd_sbs_vft_none_sccl_4_7/139-3011144-7930645?pd_rd_w=7fVsi&content-id=amzn1.sym.1e7a0ba4-f11f-4432-b7d8-1aaa3945be18&pf_rd_p=1e7a0ba4-f11f-4432-b7d8-1aaa3945be18&pf_rd_r=0PC3GBHS6KQEF29M90DX&pd_rd_wg=yjVd3&pd_rd_r=6a179663-b6c7-4c54-bc49-fbb3c29f95b1&pd_rd_i=B01IB81IHG&psc=1), for example, don’t have a stop and allow the hose to be pushed all the way through, but it won’t back out on it’s own. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [January 29, 2023, 6:16pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/9 "2023-01-29T18:16:23Z")
Nice, I was thinking something like that to screw into one side of the bulkhead fitting, and that would be a good option if it really needed a continuous hose. But unless you have some precise flow requirements such that barbs will be too restrictive, I think barbs are less likely to leak. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 29, 2023, 7:41pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/10 "2023-01-29T19:41:12Z")
Also, if you use a barb fitting and need a hose clamp (which you might not), use either zip ties or [plastic hose clamps](https://www.amazon.com/gp/product/B07VTMQHW9). The metal ones will rust, even the ‘normal’ stainless steel ones will rust (plus the screw is often regular steel). You can get ‘good’ stainless steel ones from Marine/Boating supply places, but they’re usually kinda pricey. The plastic ones will work just fine in this application. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 29, 2023, 8:06pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/11 "2023-01-29T20:06:46Z")
In a complete coincidence, I was just moving something in my house that had a few of these on it. It’s just about exactly what you’re looking for. 1/4" tubing pushes right through it.\* I’m not sure if it would be water tight if it’s submerged, but it’s a pretty tight fit and some silicone caulk would likely seal it the rest of the way. (Don’t buy that one though, you need something bigger. > **[Replacement Bulkhead](https://poseidonreefsystems.com/products/replacement-bulkhead)** > > Price: USD 2.99 ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 30, 2023, 10:38pm UTC](https://boards.straightdope.com/t/what-kind-of-tube-fitting-do-i-want/978991/12 "2023-01-30T22:38:21Z")
Huh, in this situation, I’d just cut a hole, put the hose through, and surround it with a bunch of silicone caulk.