3M

• Polyurethane Construction Sealant 525 • Polyurethane Sealant 540

• Polyurethane Adhesive Sealant Fast Cure 550 • Polyurethane Adhesive Sealant 551

• Polyurethane Adhesive Sealant 560

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Directions for Use

Surface Preparation:

Surfaces to be sealed or bonded should be clean and dry. Surfaces should be free from

grease, mold release, oil, water/condensation, and other contaminants that may affect

the adhesion of the sealant. Abrading with 180 to 220 grit abrasive followed by a

solvent wipe will improve the bond strength. Suitable solvents include 3M™ Adhesive

Remover or methyl ethyl ketone (MEK).*

*When using solvents, use in a well ventilated area. Extinguish all sources of ignition in the

work area and observe product directions for use and precautionary measures. Refer to

product label and MSDS for further precautions. Always pre-test solvent to ensure it is

compatible with substrates.

Local and federal air quality regulations may regulate or prohibit the use of these products

or surface preparation and cleanup materials. Consult local and federal air quality regulations

before using these products.

Note: Alcohol will interfere with the curing process and extra care must be taken when

using alcohol as a cleaning solvent to prevent any contact with the sealant.

Primer:

Use of a primer is an extra step and cost and will depend on substrates and the final end

use. Using primer can improve the corrosion resistance of certain metals as well as

improve the durability of the bond when exposed to high humidity conditions. For most

applications, high strength bonds on metal can be achieved without the use of a primer.

Pre-testing for adhesion is suggested to determine if a primer is needed. Contact your

3M Technical Service representative for primer recommendation and application advice.

Application:

Loading the applicator gun: make sure the applicator is set up with correct plunger

attachment for cartridge or sausage pack.

Cartridge: Puncture seal in nozzle and remove the pull-tab seal at the bottom of the

cartridge. Load into applicator and fix retaining ring (if applicable). Assemble the

nozzle (if applicable) and cut to desired size and shape.

Sausage Pack: Make a 1" slit close to the crimp on one end of the sausage pack. Load

the sausage pack into the applicator barrel (slit side out). Place the rounded end of the

supplied sausage nozzle onto the slit end of the sausage package and fix with retaining

ring. Cut nozzle to desired size and shape.

Product should be used within 24 hours after seal is punctured. Dispense product with

the nozzle tip in contact with the substrate to insure good gap filling. Bonding must

occur within the first 50% of published skin time

Do not apply polyurethane sealants and adhesive sealants on frozen nor wet surfaces.

Do not apply over silicone nor in the presence of curing silicone nor hybrid products.

Avoid contact with alcohol and solvents during curing. Sealant can be tooled

immediately after applying to give desired appearance.

Cleanup:

While sealant is still soft, cleaning can be done with the same solvents used for surface

preparation. Avoid cleaning with alcohol as it will interfere with the curing process.

If sealant is already cured, removal is done mechanically with razor knife, piano wire,

sanding or 3M™ Scotch-Brite™ Molding Adhesive and Stripe Removal Disc. This

disc is available from 3M Automotive Aftermarket Division.