REED Concrete Pumps Shotcrete Pumps and Guncrete Gunite Machines.

DISCLAIMER: Official REED Service Manuals deal with the various aspects of operation, preventative maintenance, system care and maintenance, component adjustment, repair and replacement. This Gunite Machine Operational Troubleshooting Tips guide below is designed to assist you in recognizing the symptom, providing a probable cause and suggested corrective action. The items listed are based on logical symptoms from our experience as well as that of our users.Please email any questions or suggestions for improvement to mike.newcomb@reedmfg.com

Gunite Machine Preventative Maintenance Tips (how to avoid problems) :

Start with typical maintenance to prevent problems in the following order:

1) Are the bowl and wear plate flat, in good condition, and have a low run-out (.005" or 0.13MM max)?

2) If the bowl and/or wear plate have been re-ground are the proper spacers being used? The idea is to have the top surface of the wear plate as close as possible to the bottom edge of pad housing without any contact.

3) Does the rock shear have a sharp square edge and has it been adjusted after meeting requirements items 1+2?

4) Is the felt seal lubricated and is it readjusted every time a bowl/wear plate dimension is changed by grinding or replacing? Is the felt seal retainer ring intact?

5) Is the pad backup assembly in good condition so it properly and equally tensions the wear pad?

6) Is the wear pad and pad clamp mounted and tightened firmly and equally? If it is a cam operator, check for equal contact between cam/pad backup plate with feeler gauge.

7) Check for clogging in the dust collection system from the intake housing all the way through to the bag (if incorporated on the machine)

8) Ensure that the feed wheel housing is secure and square to the base plate assembly. On locking lug models check for gaps with feeler gauges between feed wheel housing lugs and base plate receivers while in the locked position. All need to be positively locked.

9) Make sure the spindle bearings are good. There should be no play or movement of agitator shaft when tightly secured to spindle/bowl/wear plate.

10) Agitator needs to be very tight in order to seal wear plate to bowl and to secure both to the spindle.

REED Gunite Machine Operational Troubleshooting Tips

A. SYMPTOM - EXCESSIVE AIR BLOWING UP AND OUT OF HOPPER

CORRECTIVE ACTION * Adjust rubber pad pressure by tightening the three (3) adjustment knobs to provide a positive seal. * Inspect rubber sealing pad. It may need to be replaced. * Check installation of rubber wear pad. Make sure rubber portion is down against top of feed wheel. * Top of feed wheel may be worn and needs to be resurfaced or replaced. * Foreign material may be clamped or lodged between steel feed bowl and wear pad. This would permit air to blow between the two (2) parts and escape into hopper. * Agitator not securely tightened. N O T E If the above condition is allowed to continue without remedy, premature failure of the rubber pad or feed bowl will occur and as a result will create even more noticeable discharge of air back into the hopper or atmosphere. Do not confuse pocket exhaust with seal failure. Pocket exhaust is rhythmic puffing which should not cause material to be blown out of the hopper.

B. SYMPTOM - INSUFFICIENT VOLUME TO THE NOZZLE

CORRECTIVE ACTION *Pad not completely seated in the pad housing. Pad must be inserted far enough into pad housing to allow the inlet and outlet ports of the pad to align with the feed wheel pockets. When pads are removed, wear patterns should be regularly checked to assure the sealing portions of the rubber face are in alignment with the outer rim, the center divider and the inside hub portion of the feed bowl. *Inadequate air supply or pressure

C. SYMPTOM - EXCESS MATERIAL LEAKING TO THE GROUND FROM AROUND FEED BOWL ON LOWER EDGE OF FEED WHEEL HOUSING

CORRECTIVE ACTION *Felt ring inside wheel housing is not pushed down close enough to the top of the feed wheel. *Check condition of felt seal. It may be hard and dry from the lack of regular cleaning and oiling. Adjust felt pressure. See ADJUSTMENT SECTION of the manual that shipped with your machine.

D. SYMPTOM - SURGING MATERIAL THROUGH THE HOSE AND NOZZLE.

CORRECTIVE ACTION *Feed wheel spinning too fast resulting in too much material being discharged into material hose for the amount of air being used. Adjust RPM of feed wheel or increase air. *Some pockets in the feed wheel may be plugged. *The pockets in the feed wheel may be too large for the small diameter hoses. *Material may have a high moisture content causing the material to bridge above feed wheel causing material to feed sporadically. * Insufficient air supply.
*Uneven feed rate maintained into the hopper by material loading system.

E. SYMPTOM - FEED WHEEL RUNNING TOO SLOW OR STOPS

CORRECTIVE ACTION *Insufficient air supply to motor. Check air motor valve that it is fully opened. Check motor throttle valve that it is set properly. *Check that compressor is of sufficient size for the intended operation. *Check air filter at motor that it is not plugged. *Check for possible obstruction in feed wheel. *The air muffler is iced, restricting the air flow through the motor. If it is necessary to remove the muffler, make sure a plug or cap is installed during service in its place to prevent the entrance of foreign material into the motor. *Check the pressure on the pad clamp that it is not too tight. *Vanes in air motor may be worn out. Never operate motor without the air filter or lubricator in proper working condition.

F. SYMPTOM - EXCESS REBOUND WHEN SPRAYING

CORRECTIVE ACTION *Using a poor nozzle spraying technique. Water to cement ratio is out of balance. Improper angle or distance to work face. *Plugged water ring or water chamber in the nozzle assembly. *Imbalance of sand, water, and cement ratio. *Mixture too dry or wet *Contamination of the mix and/or water. *Excessive large aggregate, fiber, or wire mesh.

G. SYMPTOM - HOSE BLOCKAGE

CAUSE - Often the cause of hose blockage is the result of: *Using oversize material *Operating with an insufficient supply of air *Feeding the hose too much material *A prehydration of the material inside the hose *Not clearing the hose after turning off material feed *Sharp bends or kinks in the hose *Improper coupling of hose ends *Faulty hose (Liner separation from outer hose jacket.)

CORRECTIVE ACTION - CLEARING A HOSE BLOCKAGE When a line blockage occurs, turn off air and start searching for the point of blockage beginning at the nozzle and working back toward the machine. The hose will continue to be soft from the nozzle to the point of blockage. When blockage has been found bend or pound on the hose careful not to damage hose at that point to free the blockage. Slowly turn on the air. W A R N I N G Exercise EXTREME CARE when attempting to blow the material clear using air. ALWAYS have the nozzle end securely held and have a person at the machine who will be ready to cut back on the air if and when required.

H. SYMPTOM - INSUFFICIENT COMPRESSED AIR

CORRECTIVE ACTION - HOW MUCH AIR IS ENOUGH? Most problems occurring on the average gunning jobs are the result of improper application of air or insufficient amount of air. *Make sure the compressor is of adequate size, is properly adjusted and capable of producing maximum capacity. *Multiple compressors may be used to gain the required volume of air. In this situation, the compressors should be arranged so that they discharge into a certified central air receiver. From this a single air line of proper size can then be run from receiver to machine. *Always supply the machine with the same size air supply hose as the material hose being used for gunning. Multiple small hoses often do not have the carrying capacity of a single larger hose. *Make sure all valves are open between the air source and machine. Check that supply line is free of kinks or blockages. *Run material hoses from the machine to the nozzle in as straight a line as is possible. This will improve the flow characteristics and reduce wear. *Exercise caution when coupling hoses that no foreign objects are present or restrictions at point of connection. *Always use good premium hose specially manufactured for gunning applications. *The amount of air flow being received can be tested for proper volume as follows when flow meter or orifice testers are not available: *With hopper empty of material and having the pad loosely clamped, open main air valve to full open position. *Open the air motor main valve and the throttle valve to full open. *The air motor should reach full RPM without hesitation. If air motor does not come to full RPM, the air supply to the machine is marginal. This condition could result in a marked decrease in the volume of material introduced into the air stream within the machine and out of the material hose.