Parchem Sealing application guide

Sealing Bulletin

Sealing Applications & Sealer Related Issues

Sealing Bulletin

2Important Notice: Since the information contained in this bulletin is intended for general guidance only and in no way replaces the services of professional consultants or technical documentation for particular projects, no liability can be accepted by Parchem Construction Supplies Pty Ltd for its use.

Contents:

PAGE:

2. Important Warning

3. Introduction to Sealers and Sealing

4. Sealing FAQ

5. Troubleshooting

6. Solvent Entrapment

7. Handy Sealer Tests

8. Solvent wash procedure

9. Slip Resistant Additive

10. Stripping Sealer

11. Cleaning Decorative Concrete Surfaces

12. Re-sealing

13. Cold weather sealing

14. Warm weather sealing

15. Colour Sealing

15. Sealing Colour Thru

Important Warning

Sealing is a critical aspect of decorative concrete application and is of a highly technical nature. Parchem Construction Supplies recommends associated products and procedures for professional applicators only. Appropriate respiratory and protective clothing (including goggles, gloves, footwear) must be worn during application.

Ensure that all product instruction, technical information and Material Safety Data Sheets are read prior to application.

The information contained in these bulletins is intended as a guide only and is not intended to replace official information and instructions associated with the products. As such, Parchem Construction Supplies accepts no liability for loss or cost incurred upon acting on the information provided in this bulletin.

Sealing Bulletin


A Quick Introduction to Concrete Sealers

Concrete sealers provide a protective film over decorative or plain concrete surfaces. Most concrete Sealers are Acrylic Hydrocarbon sealers consisting of specialized acrylic resins (solids) suspended in a solvent base to form the sealer solution with other supporting ‘agents’.

When the sealer solution is applied to the concrete surface, the solvent transports the resins across the surface and into the pores of the concrete. The solvent then evaporates off (the beginning of the ‘curing’ process) leaving just the resins which combine to form a uniform protective coating bonded into the pores of the concrete.

An applied sealer will continue to cure and harden throughout its life as solvent continues to export from the surface. A sealer would typically be considered predominantly ‘cured’ after a 4-6 week period (though they are trafficable after a minimum of 7 days for vehicle traffic).

Sealers are designed using different resins to deliver different properties and benefits. Most concrete sealers use a hydro-carbon solvent base, Xylene. However, some use other hydrocarbon solvents or are waterbased.

Recommended for…Limiting ingression of dirt and grime to the surface and improving cleanability. Protection against wear and UV affect on decorative surfaces. Promoting curing of the concrete so that it will be strong and durable.

Limitations… Limited resistance to petrol, brake fluid, solvents, paint and strong chlorine or alcohol based products (except urethane and other purpose built sealers). Unsuitable for nonporous or chemically incompatible surfaces.

Sealer Application

For best results concrete should be left to cure for a minimum of 14 days.

For new concrete, a two-stage application method is recommended.

STAGE ONE: Use sealer primer , such as Lustreseal Superbond, as the first coat. These sealers are both water tolerant and flexible. The sealer will allow the water from curing concrete to pass through without creating whitening from ‘moisture entrapment’. The flexibility will ensure maximum bond and ‘give’ between the rigid ‘Finish Coat’ sealer and Concrete for maximum performance throughout its life. If the surface has been left for a time prior to sealing, ensure the surface is free of efflorescence or ‘salt’ deposits created by the concrete curing process with an Acid Wash prior to sealing. The surface must be thoroughly cleaned and dry (see Patch Test). Apply using a paint roller, suitable broom or low pressure sprayer uniform coverage without pooling. Do not dilute. Prime coat usage approx 3-5m²/litre.

STAGE TWO: Use concrete sealer in 1-2 coats as required, as per above method, allowing to dry between coats. Do not dilute or apply to wet or damp concrete surfaces.

Allow priming sealer to sufficiently cure. Wait 24hrs in summer, 72hrs in winter in normal weather conditions.

Finish coats usage approx 5-6m²/litre.

Note: Further acid washing maybe required prior to the application of finish coats of sealer if efflorescence is present. For previously sealed concrete see the Reseal Guide.

Curing time: Initial curing is affected by wind and temperature at the time of application. At 25ºC, sealer may be touch dry in 30-45 minutes. Under normal conditions allow 48 hours for foot traffic and 7 days for motor vehicles, dependant on weather conditions.

CAUTION: Acrylic clear sealing compounds may not be applied if daytime temperatures are below 10ºC or above 30ºC.

Introduction to Sealers and Sealing

Sealing Bulletin


What are the benefits of sealing?

Sealer allows improved cleanability of the surface. Staining is reduced, and any stains that do occur are more easily removed or fixed. Spray-on resurfacing should always be sealed on the day it is placed as it helps cure and protect the surface.

Which sealer is most suitable?

It depends on the surface you would like to seal and it’s intended use. Parchem Construction Supplies produce a range of sealers to suit different requirements. From standard acrylic sealers to harder wearing high gloss sealers. To achieve higher gloss and increased wear resistance opt for the premium sealers. If you have high traffic or commercial areas a urethane sealer is strongly recommended. Your local Parchem Construction Supplies trade outlet can assist you in identifying the most suitable sealer.

What happens if the pavement is not sealed?

Decorative concrete surfaces should always be sealed to protect the surface from wear, staining, UV fading and potential discolouration. Resurface products should always be sealed as it may absorb moisture and result in white patches.

When should I reseal?

For new work eg. resurfacing, stamp or stencil, it is advisable due to the curing time of new work that the job may require resealing inside the first 12 month period. Refer to the reseal process. Ongoing resealing should be conducted every 18-24mths provided it has been adequately sealed in the first instance. Higher traffic areas should be resealed more regularly. After 2-3 reseals professional advice will be required due to excess build up of sealer etc.

What influences the expected service life of sealer?

The type and frequency of traffic, along with the weather conditions all play a part in how long the sealer may last. Furthermore, traffic over excess dirt, friction (eg from tyres), and other excessive wear and tear (eg, power steering or heavy traffic) may reduce the life of the sealer. Constant UV exposure may also reduce the life of the sealer. Regular maintenance can help extend the useful service life of sealer.

What is the coverage rate of sealer?

Normal coverage is for a first coat is approx 3-5m2/L due to the porosity of the surface. Subsequent coats should deliver 5-6m2/L. for 1 litre of sealer.

How long will the sealer take to cure?

Curing times are dependent on ambient conditions. Under normal conditions sealer may take up to 1 week (7 days) to fully cure. Under milder conditions it can take longer. Exact curing times will vary from job to job.

There are lots of fine cracks in the sealer.

If the sealer dries too quickly (may be caused by wind or heat). Fine cracks can form (also called “crazy” cracks). A light solvent scrub may reduce the effect when it is confined to the sealer.

Why does the pavement appear faded but darkens when wet?

The pavement may need resealing. Seek professional advice. If the pavement has been recently sealed/ resealed it may need a light solvent scrub.

I have seen small bubbles on the surface of the sealer, how are they caused?

There are several possible reasons ranging from high temperatures or wind, pin holes due to porosity, or applying product too thick. See the ‘Troubleshooting’ section.

What if there is peeling/flaking sealer present?

Old sealer may start to peel at the end of its service life without the required maintenance. Existing sealer will require to be stripped before resealing. If a decorative resurfacing product has been previously applied to the surface seek professional advice. Smooth surfaces (such as a steel trowel finish) may peel if not acid etched before sealing. Strip, acid wash and reseal.

What if a client insists on sealing a medium/steep slope or smooth surface?

Parchem Construction Supplies does not advise sealing a sloped or smooth pavement. If the homeowner insists, ensure the surface is adequately textured, use a minimum of Sealer and incorporate a Slip Reducing Additive.

How can I get more information?

Our sales staff can help you with general enquires.

Sealer F.A.Q

Sealing Bulletin


DISRUPTION PROBABLE CAUSES’ SUGGESTED REMEDY

Sealer bubbles occur when applied. Concrete or ambient temperature too high (above 25ºC) or conditions are windy. This causes the solvent to evaporate too fast. Pin holes in the surface may be present beneath bubbles. Warm conditions cause air to expand, creating bubbles.

Roll over the bubble lightly roller damped with Xylene Solvent as soon as you see the bubble. If sealer has dried, Solvent Wash. To prevent occurrences, do not apply sealer above 25ºC, or in windy conditions.

Sealer peels off within a few weeks of application

Dirt or grime on the concrete surfaces may have prevented adhesion. The surface finish is too smooth.

Ensure the concrete is clean, and solvent wash. If the surface is too smooth, strip sealer, acid wash and reseal.

Sealer is dry on surface but remains soft. Solvent entrapment may have occurred if the sealer has been applied too thickly.

Solvent wash affected areas to redistribute sealer.

‘crazy cracking’ or discolouration present in Sealer.

Sealer may have been applied too thickly. Shrinkage during curing creates cracking.

Solvent wash affected areas.

Sealer has white deposits that don’t disappear when wet .

This is most likely to be efflorescence trapped beneath the sealer

Strip sealer, acid wash and reseal refer to sealer application manual.

Sealer has gone milky white Moisture has been trapped in the sealer, most likely applied when concrete was damp, or rained on. Or the surface was not cleaned correctly and impurities affected sealing.

Ensuring the concrete has been dry for at least 48 hours, solvent wash the affected areas.

Sealer disperses unevenly on application and beads or ‘orange peels’

The surface harbors some impurity which is repelling the sealer.

Remove sealer and thoroughly clean the surface. Grinding may be required if the impurity is ingressed into the concrete. Test patch before reapplication.

Sealer becomes sticky after time Petrochemical substances such as oils and petrol will soften the acrylic sealer.

Clean up all spills immediately. Strip and Reseal if required.

Decorative surface has a faded look or patchy appearance

Perform the Wet Test. May be insufficient sealer applied or worn off.

Very porous surfaces will require additional coats of sealer. Reapply as per Wet Test instructions.

Resealed surface shows whitening, delamination or powdering after time.

Existing sealer too aged and hard. Inadequate bond formed and/or stress caused against new sealer as it cures and hardens. Perform Tape Test.

Try a solvent wash and reseal test on a small area. Leave and check after a minimum two week period. If unsuccessful sealer will require stripping by a professional.

Troubleshooting

Sealing Bulletin


What is solvent entrapment?

“Solvent entrapment” is a term used to describe when a sealer cures fastest on the top and the skin formed does not allow solvent to migrate to the surface, although it is not a common occurrence under normal circumstances.

If solvent entrapment occurs the sealer will appear soft and likely create an impression when you press your fingernail into it.

Due to the physical properties of the solvent used in sealers, it can take some time to evaporate (significantly longer than water). If new sealer is placed on top of an uncured coat, the top layer may cure before the bottom.

The chance of this happening is increased when more coats of sealer are applied before the first has cured.

Because the top coat is exposed to the atmosphere it will cure fastest. Once cured, this layer may “trap” the solvent remaining in the layers below. In the process of the solvent trying to migrate to the surface it may cause pockets of solvent gas that could result in disruptions (e.g. bubbles) in the sealer.

The effects described above may also occur if sealer is applied in a coat that is too thick.

Also sealing in hot, dry winds may cause surface hardening and consequently solvent entrapment.

How can solvent entrapment affect resurfacing Products?

Resurfacing products may be adversely affected if exposed to solvent for prolonged periods of time. If solvent is entrapped, it cannot migrate through the cured sealer and may move downwards and affect the resurfacing product by softening the resurface product.

What can I do to reduce the chances of solvent entrapment occurring?

Allow adequate time between coats (actual times will depend on weather conditions) to give the first coat of sealer every chance to sufficiently cure. Ensuring the sealer coats are not applied too thickly will also help minimise the chances of solvent entrapment.

Solvent Entrapement

Sealing Bulletin


Patch TestIs your concrete really dry?

Taping a plastic patch down on all sides to the concrete given least opportunity to dry (shaded or partially shaded area, low point).

Leave for one hour in sunlight.

Remove. If either surface (plastic or concrete) shows signs of moisture, it is too wet to seal. Wait and repeat patch test until correct result is achieved.

Sealing insufficiently dry concrete will result in whitening due to moisture entrapment or possible delamination.

Alternatively – if you don’t have the time. Place your hand firmly on the concrete surface and hold for 30 seconds. On removing your hand if there are any signs of moisture on either surface, there is moisture present.

Cross Hatch Testbond strength and delamination?

This simple test can be used to ascertain whether a visible sealer disruption is a result of poor bonding or delamination and to determine the soundness of a bond.

Use a sharp blade to create a light “cross-hatch” incision through the sealer.

Place a piece of self adhesive tape (suggest clear packing tape) over the incision.

Press firmly for maximum adhesion and remove sharply. Repeat with fresh tape several times.

If there is no sign of sealer adhering to the tape or delaminating from the surface this would indicate that the bond of the sealer is sound.

The Wet TestIs there adequate Sealer?

If a surface is adequately sealed it will be by nature non porous and beading of water will be visible. If a surface is dull, patchy or whitening a simple Wet Test will tell you whether inadequate sealer is to blame.

Pour water over the surface. If the surface shows significant change or bolding of colours, it is likely that the surface is absorbing water, therefore it is inadequately sealed. Address in the following manner dependent on your situation…

For recently sealed surfaces showing no whitening. Clean the surface thoroughly, allow to dry and apply further sealer coats.

For recently sealed surfaces showing signs of whitening. The whitening is likely efflorescence (lime salts) being allowed surface due to a lack of sealer. Clean the surface thoroughly, and acid wash the surface with a 30 to 1 water to Hydrochloric Acid solution to removed the efflorescence. Do not allow the acid solution to dry on the surface. Neutralise by washing. The whitening should not reappear. Apply further sealer coats.

For previously sealed (over 6 months) without signs of whitening, use the approach detailed in Standard Reseal Procedure.

For previously sealed with signs of whitening. The whitening may be signs of efflorescence or of crazing and delamination. Try the acid wash procedure as detailed above. If successful follow “standard reseal procedure”. If whitening remains, subsealer efflorescence or delamination are probable. Surface may require to undergo the “stripping sealer procedure”.

Handy Sealing Tests

Sealing Bulletin


Righting wrongs…In some cases sealing disruptions may be resolved using a solvent wash procedure using Parchem Sealer Prep or Xylene. This procedure will reactivate the sealer present on the surface in effort to allow the disruption present to dissipate.

Employing this procedure earlier in the sealer’s life provides best chance of success.

The Solvent Wash procedure is most commonly used to address problems including surface bubbling, moisture entrapment, solvent entrapment, and early-onset delamination.

Solvent wash procedureNote: Always perform a preliminary test patch of approximately 40cm x 40cm to an affected area in order to determine the effectiveness of the following procedure for you application. Some sealing disruption may reappear after an extended time.

STAGE 1 - 100% Xylene Solvent

Use a broom to work the Xylene solvent into the sealed surface.

Work a limited area at a time thoroughly – suggest 1 square meter.

To be effective you must ensure the area is sufficiently wetted with Xylene, work the solution into the surface with some pressure in a circular motion, and continue to rework the same selected area until reactivation of the sealer is achieved.

Allow area to dry. If the disruption is still evident, move to STAGE 2.

If the disruption has been suitably resolved, allow 24 hrs and reseal the entire area.

STAGE 2 - Sealer Prep Solution

Sealer Prep is a highly aggressive solvent. Sealer Prep solution provides advanced ability to reactivate the existing sealer coat.

Apply as per the procedure in STAGE 1.

Allow area to dry. If disruption is still evident, move to STAGE 3.

STAGE 3 - Xylene/Sealer Prep/Sealer Solution

Sealer Prep solution as per STAGE 2. Now add 10% of the recommended Parchem Sealer to the solution. Introducing additional sealer will ensure that the solvent washing process does not overly redistribute the existing sealer to the extent that some areas will be left bare (therefore appearing as disruptions)

Apply as per previous procedure.

Allow area to dry. If the disruption is still evident, strip the entire area and reseal.

NOTE: After solvent washing, some sealer issues can take up to 3 months to reoccur as the affected sealer continues to cure (expel the solvent reintroduced to it). Where the solvent wash is not effective, there is little option left but to strip the sealer and reapply.

NOTE: Extreme caution must be used when applying solvent or sealer prep to resurfacing as damage/ softening can occur

If the disruption has been suitably resolved, monitor for 14 days prior to resealing.

Solvent Wash

Sealing Bulletin


Using Slip Resistant Additives (SRA)SRA ADDITIVE

To achieve the best result slip resistant additive should be used in the final coat of sealer.

Add up to 2 x 250g bags to a 20lt drum of the selected sealer.

Mix with paddle mixer & re-mix thoroughly throughout the sealing process.

Pour a small amount of sealer mixed with the SRA into a paint tray.

By using a lambswool roller, apply an extremely thin coat of sealer to the concrete surface.

NB: The slip resistant product is only effective if the sealer is applied in a thin coat to allow the SRA particle to protrude above the finished sealer level. If applied too thickly the particle will be over coated by resin & therefore be rendered ineffective.

5KG CRUSHED GLASS

Apply a thin coat of the selected sealer as per the manufacturers sealing procedures.

Broadcast the glass particles over the “tacky” surface. Work in small areas to ensure the sealer is still wet enough to allow the glass particles to stick.

NB: broadcast can be achieved by utilising the following; hopper gun, salt & pepper shaker or by hand. Hand application can result in an uneven finish.

Once dry overcoat the surface with a final THIN coat of sealer to “lock in” the glass particles.

*Both the SRA & the crushed glass will give a good slip resistant surface when applied correctly. They also provide a harder wearing surface.

Slip Resistant

Sealing Bulletin


WARNING:It is advised that the stripping of sealer should be carried out by a professional applicator.

THE REST OF THIS PAGE HAS BEEN LEFT INTENTIONALLY BLANK.

Stripping Sealer

Sealing Bulletin


MaintenanceGeneral maintenance and cleaning are highly recommended to ensure many years of enjoyment from your decorative pavement.

Regular Cleaning

Regularly sweeping is recommended to avoid buildup of stubborn soiling. Scrub soiled areas immediately with a stiff bristle and hose as required to maintain a clean surface free of dust. Dust and dirt are abrasives that will shorten the lifespan of your sealed surface.

Heavier Duty Washing

Use a general purpose household dish washing liquid.

Mix in a bucket and pour on the most affected areas. Again, scrubbing the pavement with a stiff bristled bush or broom to help loosening the dirt.

Hose the pavement with plenty of fresh water to remove cleaner.

Note: Detergents containing bleach or solvents are not suitable for cleaning decorative surfaces as they may adversely affect the sealer.

Oil and Grease Stains

Even sealed pavements only have short lived protection because the chemicals in the oils and grease will break down the sealer.

If an oil spill occurs, stop spreading by quickly covering with absorbent material. Treat with a “degreasing” compound according to the manufacturer’s instruction if required.

Rubber or Tyre MarksUse Parchem Construction Supplies Sealer Prep for tyre marks or other surface scuffs & markings.

Soak a clean rag with solvent. DO NOT pour Sealer Prep on the stain. Tyre marks are better treated by using a “dabbing” action rather than wiping to avoid the ingress of the rubber into the sealer.

Turn rag regularly and do not attempt to clean an effected area with a previously used rag. Reseal treated area if required.

Please Note:

INSTRUCTIONS

• YOU MUST WEAR NITRILE GLOVES.

• Soak a clean, white rag with Sealer Prep. (Do not use synthetic fibre or coloured material as rag).

• Wipe the stain from the outside and move towards the centre to avoid stain spreading.

• Wipe away tyre marks with the soaked rag, turning regularly to ensure marks are not reapplied to surface.

• Repeat if necessary.

• For best results re-apply Sealer Prep to the affected area (treated areas may have a different surface shine for approximately one month).

• Extreme care must be taken when removing stains from resurfaced pavements as this product may temporarily soften the surface material.

Cleaning to ResealPrior to resealing the surface must be completely clean and free of all impurities.

Use a suitable mould remover if there is any present.

High pressure wash at minimum 2500 psi. Ensure surface is completely dry prior to proceeding.

See Reseal Procedure bulletin.

Cleaning decorative concrete surfaces

Sealing Bulletin


Reseal Suitability

Resealing decorative concrete surfaces can be a highly specialised process. Following the below procedures and guidelines will help you achieve the best results.

Has the existing sealer deteriorated beyond it’s reseal life?

And is the sealer compatible?

The following test will help you to determine a surface’s suitability for resealing.

Select a high wear/exposure 1 meter square area for testing. Apply sealer to this area as per the “Standard Reseal Procedure” (below) using only the priming coat sealer that you have elected.

Leave the area for observation for over 4 weeks. If there are no visible defects to the new coat the surface may be suitable for resealing – perform the “Tape Test” to affirm adequate bond.

THE TAPE TEST

Create a light “cross-hatch incision through the sealer of the test area. Place a piece of self adhesive tape (suggest clear packing tape) over the incision. Press firmly for maximum adhesion and remove sharply. Repeat with fresh tape several times.

If there is no sign of sealer adhering to the tape or delaminating from the surface. The surface should prove suitable for resealing. Follow the Standard Reseal Procedure.

If there are visible defects to the sample area or the “Tape Test” shows failure, the area will require to be resealed using the “Aged Reseal Procedure” (below). Sealer which shows signs of crazing, delamination, whitening, or complete wear through to concrete, will regularly prove unsuitable for resealing and may immediately be treated under the “Aged Reseal Procedure”.

Standard Reseal Procedure

Step 1: Select your sealers. Select the appropriate sealer suitable for the individual job situation.

Step 2: Prepare the Area. The cleaning and removal of impurities from the surface is critical to facilitating a proper reseal bond. If any mould is present use a high quality mould remover, scrubbing to ensure that all mould is removed.

Step 3: Pressure Cleaning. Waterblast the entire area with a high pressure water blaster at minimum 2500 psi. Allow the area to completely dry prior to commencing (see Patch Test)

Step 4: Prime Coat. The prime coat is a mixture of 30% Parchem Sealer Prep added to your selected sealer. Sealer Prep is a highly aggressive solvent which has the ability to reactivate significantly cured sealer resins. This reactivation will provide a much improved bondability for the reseal.

Mix the solution well and apply one coat to totally wet the surface using a solvent resistant broom working it into the surface. Avoid pooling of the solution.

Step 4: Finish Coat. Allow the recommended drying times for your priming sealer before over-coating with the finish coat sealer.

Note: Apply in cool conditions (below 30°c but above 15°c) If the concrete is too hot, bubbles may form. Read Application and Technical Data prior to using above products. This information is to be used as a guide only.

Aged Reseal Procedure

Step 1: Strip the existing sealer. Seek professional applicator.

Step 2: Ensure the surface is dry. Leave the surface to dry completely. Test the surface by taping a plastic patch down on all sides to the concrete. Leave for one hour. Remove. If either surface shows signs of moisture, then it is too wet to seal. Repeat patch test until correct result is achieved.

Step 3: Prime Coat. Liberally apply one coat of diluted selected sealer with a soft broom or a roller. Allow to dry completely. The prime coat will ensure maximum penetration of the surface and essential flexibility between the rigid concrete and finish coat.

Step 4: Finish Coat. Once the prime coat is completely dry apply two coats of finish coat sealer using a broom or roller, allowing to dry completely between coats.

PRODUCT WARNINGResealing is a specialised application. Its success depends on variables such as; moisture in concrete, condition and age of original sealer, thickness of sealer, weathering, application procedure, temperature, surface preparation, oil in concrete etc. Therefore, these products are sold without warranty expressed or implied. As the conditions and use of these products are beyond our control Parchem Construction Supplies will accept no responsibility for its use or subsequent work arising from its use.

PRECAUTIONS FOR USEApplicators must read the relevant Material Safety Data Sheets prior to using the above products. The relevant safety equipment must be worn and

precautions taken, as these products can be a Health and Safety Hazard.

Resealing

Sealing Bulletin


The colder winter conditions require significant changes in sealer application practices to those used in summertime.

This bulletin addresses necessary precautions for application of sealer in wintertime and discusses practical methods used to achieve the result intended results.

How Sealers WorkBasically, there are two essential ingredients; Solvent and Acrylic resins. The solvent carries the acrylic resins in liquid state. When applied, the solvent evaporates leaving the “film-formed” acrylic on the concrete surface.

The colder, damper conditions of wintertime slows the normal rate of solvent evaporation and in some cases this process may cease completely.

When the normal rate of solvent evaporation is reduced, atmospheric moisture particularly greater in wintertime afternoons may be absorbed into the “wet” sealer, resulting in a white “milky” appearance in the finished sealed surface and / or delamination of the product altogether.

Shorter daylight hours and slower concrete setting times produce “moisture sinks”.

The time to complete finishing in wintertime can have a significant effect on sealer application. Reduced concrete surface temperatures and slower setting times in cold weather give rise to greater retained moisture within the slab itself. This combined with the reduced rate of solvent evaporation from the “wet” sealer increases the likelihood of moisture absorption, resulting in a white “milky” appearance in the finished sealed surface and / or delamination of the product altogether.

To avoid problems…Do not seal finished slab in moist overcast conditions particularly in wintertime afternoons and / or mornings.

Do not seal at ambient temperature below 10°C.

Seal only if the daytime temperature will rise above 15°C before 3pm in the afternoon.

Do not seal if the overnight temperature falls below 10°C.

The slab temperature will be too cold to seal.

Seal only after the daytime temperature rises above 15°C.

Test the slab surface for dampness before sealing. Place palm of the hand flat onto the slab for 30 seconds. After removing hand from the slab surface, if there is moisture on your skin, DO NOT SEAL.

Recommended Sealers may be applied to “cured” or “green” concrete but then only if the surface is completely and thoroughly dry or damp-free.

After periods of rain, allow at least 48 hours of dry weather before sealing.

Cold weather sealing

Sealing Bulletin


The warmer summer conditions require significant changes in sealer application practices to those used in winter time.

This bulletin addresses necessary precautions for application of sealer in summer time and discusses practical methods used to achieve the result intended.

Sealer Mechanics and Warm Weather

Sealer is supplied dissolved in solvent so that it can be easily transported and applied.

After it is placed and exposed to the atmosphere, the solvent evaporates and results in a hard (cured) sealer with little or no solvent remaining.

The warmer conditions of summer time speeds up the normal rate of solvent evaporation.

In warmer ( or windy ) conditions the sealer may cure faster on the surface and create a skin. In the process of the solvent trying to migrate to the surface it may cause pockets of solvent gas that could result in disruptions (e.g. bubbles) in the sealer.

This is called “Solvent Entrapment”.

The effects described above may also occur if sealer is applied in a coat that is too thick. It is also possible that warmer conditions will cure the sealer prior to adequately penetrating the concrete surface resulting in an inferior bond to the surface.

Further, higher ambient or slab temperatures can result in bubbling of the sealer as gases expand and attempt to escape.

It is best to seal when the ambient temperature is below 25ºC.

It is recommended that sealing is done in the morning prior to the midday sun heating the pavement, whilst ensuring the surface is dry.

The temperature of the slab to be sealed is also an important consideration

Because of the nature of concrete, it will hold heat for prolonged periods of time. Sealing a warm slab may cause the sealer to blister off the surface.

All summer related sealer bubbling and blistering are easily rectified by applying a solvent wash.

*Consult the Sealer Application Manual for instructions*

To avoid problems…

Do not seal at ambient temperature above 28°C.

Do not seal if the overnight temperature does not fall below as 25°C.

In these cases the slab temperature will be too warm to seal.

Test the slab surface for heat before sealing. Place palm of the hand flat onto the slab,if the pavement feels uncomfortably warm to the touch DO NOT SEAL.

Warm weather sealing

Sealing Bulletin


COLOURED SEALERS

Part A = Lustreseal Acrylic Sealer, or Extended Wear Plus.

Part B = 2lt Colour Tint, or 1lt Colour Tint

or 20lt pre-tinted drums.

The procedure for coloured sealer depends on if the surface is to be a reseal on aged concrete, or to be applied to new concrete. If new concrete, the prime coating steps apply as previoulsy stated. If surface is an aged reseal application, that procedure applies for a prime coat.

FINISH COAT

The finish application is achieved by using Parchem Construction Supplies 2 part system which includes part A, 18 ltr clear baseand 2 ltr sealer tint part B. Part B requires mixing independently first to ensure all tint in the tin can be poured out when added to Part A. Ensure NO sediment is left in the Part B tin as colour variation may result. After adding the part B to the clear base the sealer must be mixed for at least 5 minutes to ensure a consistent colour is achieved. Mix using an appropriate paddle mixer. Once mixed the sealer should be poured into a roller tray and rolled out evenly onto the surface. It is important to keep the sealer in the drum mixed at regular intervals to reduce separation of colour. It is also important to lay off with your roller. This is done by making sure the frame of the roller is kept on the one side. And your final stroke should be away from you and then the roller lifted up off the surface. This reduces roller marks being left that occur when the roller reverses the nap when you pull the roller towards you. 2 coats of coloured sealer maybe needed.

Sealing Colour ThruWhen sealing Colour-Thru the best option is to:

• Leave the concrete for a minimum of 14 days as per recommendation this will allow the moisture & efflorescent compounds to evaporate from the concrete.

• Once this process takes place it is advisable to acid wash the surface with a 30 parts water 1 part acid solution.

• This can be achieved by using a plastic watering can with a large showerhead, with the same dilution and apply to the surface in a chequerboard motion, again rinsing to neutralise the acid.

• Apply to about m2 and hose off before acid dries and leaves a laitance on the surface. If this is left, staining will occur.

• Repeat each section until the entire job is finished.

• It is necessary to do a final wash off using a pressure cleaner min 2500psi .

• Start at the bottom of the driveway and work your way uphill.

• Once surface is completely dry a 30% xylene diluted coat of clear sealer can be applied as a primer. 24 hours later the finish sealer can be applied to finish the job. Other coats maybe required depending on the porosity or finishing methods of concrete.

• Failure to leave Colour-Thru concrete for a minimum of 14 days prior to sealing and not following the above procedures WILL result in colour variation.

Helpful Hints:

Finishing concrete with a broom finish will give you a much more even colour, a more slip resistant surface and better adhesion if sealing steel trowel or wet cove finishes, sealing too early or without curing and acid washing WILL result in colour variation.

Final colour is not accurately represented in comparison to the colour chart until the concrete has been acid washed and sealed in accordance with guidelines and allowed to cure for 28 days.

Colour sealing Sealing Colour-Thru

Important Notice: Since the information contained in this bulletin is intended for general guidance only and in no way replaces the services of professional consultants or technical documentation for particular projects, no liability can be accepted by Parchem Construction Supplies Pty Ltd for its use.

Sealing Bulletin

Parchem Construction Supplies Pty Ltd7 Lucca Road, Wyong NSW 2259Phone: 1300 737 787www.parchem.com.auABN 80 069 961 968

For any product or technical advice call

1300 737 787or visit one of our Trade Stores located across Australia. For locations visit

www.parchem.com.au

Safety Message

We encourage all users of our products focus on safe application and suggest you use: Solvent resistant gloves, safety goggles & a mask when using the exterior solvent based sealers. Ask our friendly staff for these products.

Parchem also stock:

ROLLER FRAME

SOLVENT RESISTANT ROLLER COVER

EXTENSION POLE

COVERING TAPE

PAINT TRAY

Parchem Sealing application guide

Documents

Transcript of Parchem Sealing application guide