Caulking Gun Becomes Useful Press Tool For Fuel Line Fittings

The simple caulking gun is really useful when you’re working on some bathroom repairs or squirting construction adhesives about the place. However, with a few simple mods, it can become a great help in the mechanic’s workshop too.

It’s a great tool for cleanly pushing fittings into nylon fuel line.

This build consists of a series of 3D-printed parts that can readily be adapted to a garden-variety caulking gun. First up are a pair of fuel line clamps which are fastened together with nuts and bolts, The nylon fuel line is inserted between these, and the bolts are tightened up to hold the line firmly in place at the end of the caulking gun. The fitting to be installed into the line is then placed on the caulking gun’s plunger. It’s then a simple matter of pulling the trigger on the caulking gun to slowly press the fitting into the nylon line.

It’s a great hack which creates a useful linear press with just a few cents of PETG filament. If you find yourself doing a one-off fuel line job on a modern car, this could be just the tool you need. Parts are available on Thingiverse for those eager to print their own. The design is made for 3/8ths inch line, but could readily be modified or recreated to suit other diameters.

3D-printed tools can be useful in all kinds of ways, even in heavy-duty applications like press tooling. It often doesn’t have the same longevity of traditional metal tooling, but for small one-off jobs, the price saving is often more important than the hardiness of the tooling itself. If you’ve whipped up some great 3D-printed tools of your own, don’t hesitate to drop us a line!

29 thoughts on “Caulking Gun Becomes Useful Press Tool For Fuel Line Fittings

  1. A nice hack, small removable items to turn one tool into a multi tool. One area to try and make an improvement on might be a quick toggle clamp.
    Not meant to take away from this, just a reminder that boiling water or a hot air gun also makes assembling some hose barbs a LOT easier. Pick your approach according to your application.

        1. Oh I see, by “bust” you meant “make” and thus you were referring to build this contraption out of some material on a lathe (English isn’t my first language, sorry). I was thinking that you were saying about turning a caulking gun itself in some sort of a lathe, thus my confusion : )

  2. Is it really THAT hard to push a barbed fitting into a plastic line?

    I’ve done many with my bare hands. I guess the toughest were high pressure fuel injection lines, still easy enough.

  3. Excellent idea!!!! I’ve hacked them into pushers/pullers. This could help my wire with yard irrigation too!! I help, but she also want’s to do it herself.

  4. Thanks, I see an immediate need for one of these and I will be building one this weekend.

    We push fit beer line fittings into the ends of beer lines coming out of the 2 tap stainless steel beer towers we sell. We soak the end of the plastic tubing in boiling water to soften up the tubing but it’s a pain when assembling 50+ beer towers, or 100+ fittings at a time.

  5. Just be sure not to use the cheap caulking guns, they don’t last long. Sure, for the young and able bodied, it might seem like a trivial task, you just push it on with your hands, but certain conditions, be them age related or not, can make that difficult to say the least. Tools like this become invaluable, allowing people to continue to do more of what they enjoy.

  6. No, it is not hard at all. These caulk guns are all made of cheap stamped steel, the push is not much stronger than you could push with a rod and a plunger using your hands. There are far easier ways to push barbed fittings into a hose…. Someone has too much free time on their hands xD

    1. Sure, the task isn’t that hard. You can do the same job with a variety of tools or even by hand. But this project is all about using a 3D printer to turn a tool that most have laying around and will never use again – a calking gun – into something useful.

      This project shows creativity and thinking outside the box, and I’d call it a great sucess!

      1. As a home owner, I have a caulk gun. It is always “loaded” and gets used several times a year.

        I long ago got rid of the cheap stamped steel one and got one made of thicker and sturdier aluminum. The pistol grip on the stamped steel ones always bent in use. The aluminum one is over ten years old now, and still in good shape.

        The aluminum one cost maybe twice what the steel one did, but it still wasn’t expensive.

    2. @ Walter

      No, not “all made from cheap stamped steel”, mine is cast aluminium and very strong and will probably outlast me.

      Also, sometimes the required force is far more than my hands can deal with as they aren’t as strong as they used to be and if there are “far easier ways to push barbed fittings into a hose” perhaps you could mention them or write some short and informative instructions?


  7. I like this. The idea of using a caulking gun as a press seems obvious now that I have seen it. Stimulates a lot of ideas about other uses. Simple and brilliant.

  8. Now if you could please find a way to stop my caulk from hardening in the old tubes, that would be great :) Yes, I have heard of caps and no they don’t always work well.

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