The New Hotness

One of the soaker hoses in Mary’s Vassar Farms garden split lengthwise near one end:

Soaker Hose Plug - hose split — Soaker Hose Plug – hose split

Although the hose is fully depreciated, I thought it’d be worthwhile to cut off the damaged end and conjure an end cap to see if a simple plug can withstand 100 psi water pressure.

A pair of Delrin (because I have it) plugs with serrations fill the hose channels, with the outer clamp squishing the hose against them:

Soaker Hose Plug - channel plugs - side view — Soaker Hose Plug – channel plugs – side view

In real life, they’ll be pushed completely into the hose, with a generous layer of silicone ~~snot~~ caulk improving their griptivity.

I started with 8 mm plugs, but they didn’t quite fill the channels:

Soaker Hose Plug - channel plugs - 8 mm test fit — Soaker Hose Plug – channel plugs – 8 mm test fit

Going to 8.5 mm worked better, although there’s really no way to force the granulated rubber shape into a snug fit around a cylinder:

Soaker Hose Plug - channel plugs test fit — Soaker Hose Plug – channel plugs test fit

Fortunately, they need not be leakproof, because leaking is what the hose does for a living. Well, did for a living, back before it died.

The clamps have a solid endstop, although it’s more to tidy the end than to hold the plugs in place:

Soaker Hose End Plug - Slic3r — Soaker Hose End Plug – Slic3r

The clamps need aluminum backing plates to distribute the stress evenly across their flat sides:

Soaker Hose Plug - installed — Soaker Hose Plug – installed

Those are 8-32 stainless steel screws. The standard 1 inch length worked out exactly right through no fault of my own.

The OpenSCAD source code as a GitHub Gist:

	// Rubber Soaker Hose End Plug
	// Ed Nisley KE4ZNU June 2019
	// 2020-05 Two-channel hose end plug

	Layout = "Hose"; // [Hose,Block,Show,Build]

	//- Extrusion parameters must match reality!

	/* [Hidden] */

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	Protrusion = 0.1; // make holes end cleanly

	inch = 25.4;

	function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

	//———-
	// Dimensions
	// Hose lies along X axis

	HoseTubeOD = 12.0; // water tube diameter
	HoseTubeOC = 12.5; // .. spacing
	HoseWebThick = 7.8; // center joining tubes

	Hose = [100,25.0,HoseTubeOD]; // X=very long, Y=overall width, Z=thickness
	HoseSides = 12*4;

	PlugLength = 25.0; // plugs in hose channels

	PlateThick = 5.0; // end block thickness

	WallThick = 2.0; // overall minimum thickness

	Kerf = 0.75; // cut through middle to apply compression

	ID = 0;
	OD = 1;
	LENGTH = 2;

	// 8-32 stainless screws
	Screw = [4.1,8.0,3.0]; // OD = head LENGTH = head thickness
	Washer = [4.4,9.5,1.0];
	Nut = [4.1,9.7,6.0];

	CornerRadius = Washer[OD]/2;

	ScrewOC = Hose.y + Washer[OD];

	echo(str("Screw OC: ",ScrewOC));

	BlockOAL = [PlugLength + PlateThick,ScrewOC + Washer[OD],2*WallThick + Hose.z]; // overall splice block size
	echo(str("Block: ",BlockOAL));

	//———————-
	// Useful routines

	module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
	Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
	FixDia = Dia / cos(180/Sides);
	cylinder(d=(FixDia + HoleWindage),h=Height,$fn=Sides);
	}

	// Hose shape

	module HoseProfile() {

	rotate([0,-90,0])
	translate([0,0,-Hose.x/2])
	linear_extrude(height=Hose.x,convexity=4)
	union() {
	for (j=[-1,1]) // outer channels
	translate([0,j*HoseTubeOC/2])
	circle(d=HoseTubeOD,$fn=HoseSides);
	translate([0,0])
	square([HoseWebThick,HoseTubeOC],center=true);
	}

	}

	// Outside shape of splice Block
	// Z centered on hose rim circles, not overall thickness through center ridge

	module SpliceBlock() {
	difference() {
	hull()
	for (i=[-1,1], j=[-1,1]) // rounded block
	translate([i(BlockOAL.x/2 – CornerRadius),j(BlockOAL.y/2 – CornerRadius),-BlockOAL.z/2])
	cylinder(r=CornerRadius,h=BlockOAL.z,$fn=4*8);
	for (j=[-1,1]) // screw holes
	translate([0,
	j*ScrewOC/2,
	-(BlockOAL.z/2 + Protrusion)])
	PolyCyl(Screw[ID],BlockOAL.z + 2*Protrusion,6);
	cube([2BlockOAL.x,2BlockOAL.y,Kerf],center=true); // slice through center
	}
	}

	// Splice block less hose

	module ShapedBlock() {
	difference() {
	SpliceBlock();
	translate([(-Hose.x/2) + (BlockOAL.x/2) – PlateThick,0,0])
	HoseProfile();
	}
	}



	//———-
	// Build them

	if (Layout == "Hose")
	HoseProfile();

	if (Layout == "Block")
	SpliceBlock();

	if (Layout == "Show") {
	ShapedBlock();
	translate([(-Hose.x/2) + (BlockOAL.x/2) – PlateThick,0,0])
	color("Green",0.25)
	HoseProfile();
	}

	if (Layout == "Build") {
	SliceOffset = 0;
	intersection() {
	translate([SliceOffset,0,BlockOAL.z/4])
	cube([4BlockOAL.x,4BlockOAL.y,BlockOAL.z/2],center=true);
	union() {
	translate([0,0.6*BlockOAL.y,BlockOAL.z/2])
	ShapedBlock();
	translate([0,-0.6*BlockOAL.y,BlockOAL.z/2])
	rotate([0,180,0])
	ShapedBlock();
	}
	}
	}

view raw Soaker Hose End Plug.scad hosted with ❤ by GitHub

The original doodle, with dimensions vaguely related to the final model:

Soaker Hose End Plug - hose dimensions — Soaker Hose End Plug – hose dimensions

There is, as far as I can tell, no standardization of dimensions or shapes across manufacturers, apart from the threaded hose fittings.