Cold Weather Application Guidelines

COLD TEMPERATURE GUIDELINES FOR THE APPLICATION OF ARBO SEALANTS AND ADHESIVES

• The industry generally recommends not applying sealants and adhesives below 5°C.

• Frost ice and condensation on surfaces is the main problem.

• Store materials at a minimum of 10°C.

• The use of the correct primer on porous surfaces will assist adhesion in cold weather.

• Non porous surfaces can be cleaned with Arbo Cleaner T16 and dried with a clean rag.

• Primed surfaces should be sealed as soon as the primer has dried in cold weather.

• Primers can be applied below 5°C but drying may be slow.

• Silicones can be gunned out at very low temperatures (-20°C) but if the surface is ice or damp effected then this is not recommended.

• Other polymer sealants could thicken and be difficult to extrude at low temperatures.

• Cloaking the building helps to prevent ice forming.

• Expect the curing of sealants at low temperatures to slow down dramatically.

• Prolonged low temperature on curing can affect mechanical properties of sealants.

In short it is the surfaces that give the major problem in cold weather not the sealant so a responsible approach to application is essential.

If the contractor is demanding that the joint must be sealed then the applicator should take all the above into consideration and carry out a pull test (see below) after the sealant has sufficiently cured.

Should the pull test fail, then the work must be cut out and resealed and the contractor should pay for the remedial. This course of action should be agreed between both parties in writing before cold weather work commences.

Post Application Field Adhesion Test

As published by SWI, March 1980

As a check for adhesion, a hand pull test may be run on the job site after the sealant is fully cured. (Usually within 14 to 21 days)

The hand pull test procedure is as follows:

1. Make a knife cut horizontally from one side of the joint to the other.

2. Make two vertical cuts approximately 50mm long, at the sides of the joint, meeting the horizontal cut at the top of the 50mm cuts.

3. Grasp the 50mm piece of sealant firmly between the fingers and pull down at a 90 degrees angle or more, and try to pull the uncut sealant out of the joint.

4. If adhesion is proper, the sealant should tear cohesively in itself before releasing adhesively from the substrate.

Note: Adhesion may be adversely affected by:

1. Moisture in or on the substrate during sealant application and cure.

2. Contaminated or weak surfaces.

3. Poor application technique.

Repair of sealant in adhesion test area

Sealant may be replaced in test area easily, by merely applying more sealant in the same manner it was originally installed (assuming good adhesion was obtained). Care should be taken to assure that the new sealant is in contact with the original, and that the original sealant surfaces are clean, so that good bond between the new and old sealant will be obtained.

ACTUAL JOB TEST APPLICATIONS ARE THE BEST MEANS FOR AN APPLICATOR TO BE CERTAIN THAT PROPER SEALANT ADHESION AND SUBSEQUENT PERFORMANCE WILL BE RESULT FROM HIS WORK.

These tests, installed on-site, can determine compatibility with actual substrates used on the job site and the type and degree of preparation required for adhesion.

The recommendations made in this letter are based on current industry good practice, product knowledge and experience gained through site application and laboratory testing.

All content is given in good faith but cannot be exhaustive. Where applicable, please consult the British Standard Codes of Practice or other specialist authoritative organisation documents. Adshead Ratcliffe & Co. Ltd shall not be held responsible for any procedural errors, incorrect application techniques or issues that arise from inaccurate information received.

If any of the letter content requires clarification, or prompts additional advice to determine suitability of a particular sealant, application technique etc, then please do not hesitate to contact us.

Adshead Ratcliffe Manufacturers of Arbo Products

www.arbo.co.uk

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