A clogged spray foam gun can bring an otherwise productive job to a stop.

Sometimes the problem is obvious. Other times, a gun that repeatedly clogs is telling you that something else in the spray system needs attention.

If your spray foam gun keeps clogging, don't just clean it and immediately go back to spraying. Identifying why the blockage occurred can help prevent the same problem from happening again.

Here are eight common areas spray foam contractors should check.

1. Material Beginning to Cure Inside the Gun

One of the most obvious causes of a clogged spray foam gun is material curing where it shouldn't.

Even relatively small amounts of hardened material can interfere with proper flow through gun components.

Regular inspection and cleaning of serviceable components can help prevent buildup from becoming a job-stopping problem.

Always follow the spray gun manufacturer's maintenance and cleaning procedures.

2. A Dirty or Restricted Mix Chamber

The mix chamber has to maintain properly sized and unobstructed passages for the gun to spray correctly.

Contamination or cured material in these passages can restrict flow and affect the spray pattern.

Contractors should keep the appropriate spray foam gun cleaning tools, drill bits and maintenance supplies available on the rig so routine gun maintenance can be performed when necessary.

Browse our Spray Foam Tools, Parts, Equipment & Accessories for professional maintenance tools and jobsite supplies.

3. Clogged Side Ports

The small material passages feeding the mix chamber can become partially or completely obstructed.

A partial restriction can sometimes be particularly frustrating because the gun may continue spraying—but not correctly.

If you're repeatedly cleaning the chamber but the problem returns, inspect the appropriate material passages according to the manufacturer's service procedure.

4. Worn or Damaged Seals and O-Rings

Not every apparent clog is simply hardened foam.

Worn O-rings, seals and other gun components can contribute to improper operation and material problems.

This is why experienced contractors often keep commonly used replacement O-rings and spray gun parts organized and available in the rig.

A small replacement part can sometimes prevent hours of downtime.

5. Improper Gun Shutdown or Storage

How the spray gun is handled between jobs matters.

Leaving equipment dirty or improperly prepared for storage can allow material residue to create problems the next time the gun is used.

Before extended downtime, follow the gun manufacturer's recommended shutdown, lubrication and storage procedures.

A few minutes of preventive maintenance at the end of a job can be much easier than dealing with a clogged gun at the beginning of the next one.

6. Material Temperature Problems

Spray foam chemicals are designed to process within specified temperature ranges.

Material that's too cold can become more difficult to process properly and may contribute to poor spray performance.

If the gun appears to be clogging or spraying incorrectly, don't automatically assume the problem is inside the gun.

Check the entire system—including material temperatures, hose heat and proportioner settings—against the foam manufacturer's specifications.

7. Pressure or Supply Problems

Restrictions elsewhere in the system can sometimes appear to be a gun problem.

If one chemical isn't reaching the gun correctly, investigate the supply side as well.

Depending on the equipment, that can include checking:

• Material levels

• Transfer pumps

• Supply hoses

• Filters and screens

• Proportioner operation

• Heated hose condition

• Gun inlet screens or filters, where applicable

Troubleshooting the entire fluid path can prevent you from repeatedly disassembling a gun that isn't actually causing the problem.

8. Poor Preventive Maintenance

A spray foam gun shouldn't receive attention only after it stops working.

Regular maintenance helps contractors identify contamination, worn components and other developing problems before they cause downtime.

Keep commonly needed cleaning tools, lubricant, seals, O-rings and replacement components organized in the rig.

If you haven't checked your rig inventory recently, see our guide to 10 Spray Foam Tools & Accessories Every Contractor Should Keep on the Rig.

Don't Just Clear the Clog—Find the Cause

When a spray foam gun clogs repeatedly, simply clearing the blockage may only address the symptom.

Look at the gun and the system feeding it.

Material condition, temperature, pressure, restrictions, worn components and maintenance practices can all affect spray gun performance.

Finding the actual cause can reduce repeat failures, unnecessary parts replacement and costly jobsite downtime.

Need maintenance tools or replacement parts?

Browse Spray Foam Gear's Spray Foam Tools, Parts, Equipment & Accessories for professional spray foam gun maintenance supplies, replacement parts, tools and jobsite accessories.

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