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A Couple of Pointers on Blast Hose

Clemco blast hose uses the best materials available.  It’s about the most rugged and reliable blast hose you will find, but it does wear out.

Just as your car’s tires wear away from contact with the road, the friction created by abrasive flowing through the hose wears away the rubber inside. The tube is made from high-quality rubber that resists abrasion and dissipates static electricity. Once the abrasive wears through the rubber inner tube, it makes short work of the hose’s reinforcing plies of braided strands and tough outer casing.

The reinforcing plies are designed to withstand pressure and hold the hose’s shape.  The outer casing protects the plies from external cuts and abrasions.  Neither layer will stand up to high-speed abrasive.

You can take steps to make your blast hose last longer.  Inspect the hose and its couplings for leaks every day.  Check for soft spots by squeezing it about every six inches.  Also, look for holes, cracks, and disintegration of the outer casing.  If the hose is soft or damaged in just one area, cut the hose about a foot beyond either side of the bad spot, install couplings, and put the hose back into service.  If you discover several soft spots, holes or general deterioration replace the hose.

Look through the couplings and nozzle holders to see how well the hose fits.  The hose should be cut square and inserted into the coupling or holder until it rests against the shoulder inside.  Gaps between the hose and coupling, screws sticking through the hose inner wall, or bubbles in the hose casing require immediate repair.  Remove the coupling, cut the hose about a foot back, and reinstall the coupling.  To get a good square cut, put the hose in a miter box and use a fine tooth saw.  If the end is crooked, it creates turbulence inside the hose and leads to rapid wear.

Do not use tape or other materials to fill a gap between the hose and the coupling. The coupling can blow off under pressure, risking serious injury to anyone nearby.  Use the screws specified by the manufacturer.  Screws that are too long may penetrate the inner tube and cause a leak that wears away the coupling.  Screws that are too short may allow the coupling to fly off under pressure.  To ensure the screws get a good grip, insert a dowel (just slightly smaller than the hose ID) to support the hose while you tighten the screws.   

Replace any coupling that looks deformed, has cracks, or that has bent or worn locking lugs.  Replace the nozzle holder if the threads show wear.  Once you have determined that your hoses and coupling are in good shape, you can help keep them that way with proper care.

Lay hoses in straight lines, keeping them away from vehicle traffic, chemicals, and sharp edges.  Make bends gradual.  Sharp turns will cause rapid wear.  This is why hoses wear rapidly near the nozzle where the operator bends the hose over his shoulder to direct it at the surface being cleaned.  Experienced contractors use a short length of flexible whip hose for the last few feet before the nozzle and discard this whip hose when it wears.

Use blast hose that is at least 3 to 4 times the ID of the nozzle.  This helps control the rate of flow through the hose.  If you use a hose that’s too close in size to the ID of the nozzle, abrasive and air flow too quickly, causing rapid wear to the hose and nozzle.  When you use a worn out nozzle, you create the same high-velocity abrasive flow.

If the hoses run up scaffolding or structures, secure them every 20 feet and install safety cables to keep the weight of the hose from pulling apart couplings.

After blasting, close the metering valve and blow air through the hose to remove any remaining abrasive.  Moisture and abrasive left in the hose overnight may collect in clumps, causing restrictions that increase wear.  Gently coil the hose to prevent kinks and store it in a clean, dry area away from oil, chemicals, and paint.  Do not hang blast hoses from racks for prolonged periods.  This can cause kinks or worn spots on the outer casing.

Even if you take all of these precautions, your blast hose will wear out eventually.  When it does, replace it with high-quality Clemco blast hose.

© Clemco Industries Corp.


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