3M 74NF Scotch-Weld Non-Flammable Foam Fast Cylinder Spray Adhesive

Surface Preparation

For best results, all surfaces to be bonded must be clean, dry and free from dirt, dust, oil, loose paint, wax or grease, etc.

Application

Slowly open the cylinder valve and inspect the connections for any leaks. Tighten if needed.

Fully open the valve.

Unscrew the trigger stop/adjusting nut away from the trigger 3-4 turns and spray a test pattern. For more adhesive output, continue to screw the nut away from the trigger. For less adhesive output, screw the nut back towards the trigger.

Hold the applicator 3-10 inches away from the surface to be sprayed and apply a uniform coat of adhesive. (The smaller the spray pattern chosen in step 3, the closer the applicator gun will need to be to the surface and vice versa for larger patterns.)

Apply 1-3 even coats of adhesive. (This will depend on the needed coverage for the bonding application.)

Curing

Allow adhesive to dry until tacky and then apply sufficient pressure to ensure complete contact.

Clean-Up

When using solvents, extinguish all ignition sources, including pilot lights, and follow the manufacturer’s precautions and directions for use.

Testing

Test the tackiness by gently touching the adhesive with your knuckle. If the adhesive transfers to your skin, it is too wet. If the adhesive is aggressively tacky and does not transfer to your skin, it is ready to bond. If the adhesive is too dry or only has a very light tack, it is too dry and another coat of adhesive should be applied to at least one of the surfaces.

Troubleshooting

How to Eliminate Cold Weather Problems:1.) Store the cylinders in a controlled environment with temperatures between 60°-80°F (16°-27°C)

2.) Keep cylinders off of cold concrete floors and away from outside walls

3.) Use heat belts or blankets, approved for use with flammable adhesives, to control the temperature of the cylinders.

4.) Allow additional time for solvents and propellants to flash off, when temperatures are below 60°F (16°C).

If the system sprays poorly or won’t spray at all: The sequence below runs through a complete clog into the cylinder valve. If at any time during the sequence the problem is resolved, stop, clean the needed parts, put the system back together, and you are finished.

1. Make sure the cylinder is not empty.

2. Make sure the cylinder valve is open.

3. Close the applicator trigger stop adjusting nut and clean the nozzle tip. (Does it spray now?)

4. Take off the nozzle and try spraying. (Does it spray now?) Clean the nozzle.

5. Shut off the cylinder valve, CAREFULLY and SLOWLY – loosen the applicator gun/hose connection and look for adhesive to squirt out. If adhesive starts to leak out, allow it to slowly continue to do so until it stops. (This will be a little messy, but you will need to bleed off the pressurized adhesive to clean the applicator gun.) The applicator gun has a clog at the valve, stem or inlet area and needs to be cleaned.

6. If nothing leaks out after fully loosening the applicator gun, CAREFULLY remove applicator gun, realizing that the hose may be clogged but could be full of adhesive and pressure depending on where the clog is. (Secure the open end of the hose into a bucket in case the clog releases and the system flushes.)

7. CAREFULLY and SLOWLY loosen the hose connection at the cylinder valve. Look for adhesive to squirt out. If adhesive starts to leak out, allow it to slowly continue to do so until it stops. (This will be a little messy, but you will need to bleed off the pressurized adhesive in the hose). Clean or replace the hose.

8. With everything now isolated from the cylinder, place a bucket in front of the cylinder valve and slowly open it to see if any adhesive comes out. If it does, put the cleaned system parts back together. If it does not, there is something wrong with the cylinder or cylinder valve and it should be returned.