Description

UC 205 is a two-component sealing compound based on a polysulphide polymer blended with fillers and chemical curing agents, which cures after mixing to form a durable rubber like seal.

This sealant is highly elastic and able to withstand continuous extension and recovery.

It may be used with most common building materials such as concrete, plaster, brick, and stone.

It exhibits superior resistance to many common chemicals, fuel oils and solvents.

Also resistant to ultraviolet light and ozone making it ideally suited to drinking water reservoirs.

Suitable for exterior use, and for use where the sealant will be subjected to contact with chemicals, solvents, and oils.

Product Application

To form a long-lasting water and weatherproof seal in both horizontal and vertical moving joints and joints which are subject to continuous cyclic movement.

Typical applications include joints in curtain walls, floor expansion joints, in workshops, factories and garage floors, between pre-cast units and filling station forecourts, and in water retaining structures. (Potable water)

Surface Preparation

The correct preparation of the joint faces is absolutely essential to the satisfactory performance of the sealant.

All surfaces should be clean, sound, and dry, and laitance or surface contamination should be removed by thorough wire brushing, grinding or grit blasting.

Vacuum or blow with compressed air to ensure thorough removal of dust.

Metal surfaces should be free of mill-scale and rust and mild steel should be treated with UC 617.

Directions

Joint Design:

The minimum width and depth of a joint should be 6mm by 6 mm.

Horizontal joints, where possible, should be at least 12 mm wide and not more than 25 mm deep.

The depth of the joint should never exceed its width. Except in the case of water retaining structures and where shear movement is anticipated the ratio of width to depth of 2:1 should if possible be maintained.

This ratio provides the optimum geometry to allow movement to occur within the joint without placing excessive force on the joint faces.

Joint faces should be parallel, and the joint width should be at least four times the maximum anticipated movement.

When placing the sealant, the joint opening should be central to its maximum compression/ expansion cycle.

Mixing

UC 205 is supplied in a two-part kit, base, and activator in separate tins.

Transfer the total quantity of activator into the base component and mix thoroughly using a slow speed electric drill fitted with a flat blade stirrer.

Scrape down the sides of the can and the base and remix until the colour is uniform and free from streaks.

Thorough mixing is essential and should take 5 to 10 minutes.

Priming

For porous or friable surfaces or where severe conditions are expected use UC 614 single pack polyurethane primer.

Apply the material with a brush to the joint faces ensuring complete coverage.

Particular attention should be paid to any voids and hollows.

Allow at least 30 min. for the solvent to evaporate before applying the sealant.

Should the primer lose its tack, after approx. 3 hrs, you will need to re-prime.

Protect the primed surface from dust and dirt which could interfere with the adhesion of the sealant.

Bond Breaker

To ensure proper movement of the joint a bond breaker must be used at the base of the joint.

Where a backing material such as polyethylene foam rod is used to ensure the correct joint geometry a bond breaking tape is not required.

For water retaining structures care must be taken to comply with the design requirements.

Application

Fill the sealant into a closed barrel gun using a follower plate or small trowel.

Gun the sealant into the joint using a continuous squeezing of the trigger to ensure a smooth continuous flow of material.

Fill the joint from the bottom up and ensure that there is contact between the sealant and joint surfaces.

To ensure contact of the sealant with the walls of the joint, the sealant should be tooled to a smooth finish using a rounded spatula. A soapy solution may be used to aid the process. Remove any masking tape applied before curing commences.

Cleaning

Clean all tools and equipment with UC 901 before setting of the sealant has taken place.

Safety

Contact with skin should be avoided by wearing gloves and protective clothing.

In case of eye contact wash well and obtain medical advice.