Water Based Substrate Primer (EWI-301) - 5 Litres

Brand: EWI Pro
SKU: EWI-301
£17.99 Incl. VAT
£17.99 Incl. VAT (regular price)
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    EWI-301 Water Based Substrate Primer

    EWI- 301 Water Based Substrate Primer is designed for priming various different absorptive substrates including ordinary and cellular concrete (e.g. aerated concrete), walls made of bricks, blocks and structural clay tiles, plaster coats, gypsum panels and gypsum plaster boards. It is applied to the substrate prior to the application of paints, adhesives, cement or cement and lime-based plaster coats, skim finish products, ceramic tiling, floor screeds and even wallpapers.

    Preparation

    Water Based Primer comes ready to use in 5-litre jerrycans. The product should be mixed within its container before use. It should not be diluted with water or any other material.

    Application

    For best effects, do not add water and apply using a brush or roller. Weak substrates that need to be strengthened and highly absorptive substrates should re-primed after about 4 hours. Dispersion paints, surface finish products or adhesives should be applied after at least 24 h since priming. Works must not be carried during rain or snow, strong winds and in direct sunlight, without special protection to limit exposure to weather conditions. Recently rendered coats must be protected against rain, frost and over-rapid drying.

    Water Based Substrate Primer Application Conditions

    • Application temperature (air, substrate, materials): from +5°C to +25°C
    • Quantity to be used: approx. 50-300 ml/m2 depending on substrate structure and absorptive capacity)
    • Coat drying time: approx. 2-4 hours
    • Time to painting or plastering: after about 24 h since priming
    • Colour: colourless when dry

    Water Based Substrate Primer Storage Conditions

    EWI-301 Water-Based Primer is available in 5-litre plastic jerrycans. Shelf life: up to 12 months from the date of manufacture. Keep dry and in the original packaging at a temperature of +5°C to +25°C.

    Frequently Asked Questions

    Water-Based Substrate Primer is designed to prime various absorptive substrates, including ordinary and cellular concrete (e.g., aerated concrete), brick walls, blocks and structural clay tiles, plaster coats, gypsum panels, and gypsum plaster boards.

    To apply Water-Based Primer, use a large paintbrush or roller to paint it on the substrate. Allow the primer to dry thoroughly before applying silicone render.

    Water-Based Primer takes approximately 2 to 4 hours to dry; however, it is recommended that you wait 24 hours before continuing work.

    Water-Based Primer will dry completely colourless onto the substrate.

    Water Based Primer comes ready to use in 5-litre jerrycans. The product should be mixed within its container before use. It should not be diluted with water or any other material.

    Reviews & Ratings

    Overall rating

    4.7
    ★ ★ ★ ★ ★
    40 reviews
    5 stars
    30
    4 stars
    8
    3 stars
    1
    2 stars
    0
    1 stars
    1

    Have something to say?

    Rate Water Based Substrate Primer (EWI-301) - 5 Litres

    kirk

    ★ ★ ★ ★ ★ 4
    20.11.2025
    good sealer, worked on concrete. A little too thick/lumpy. 24hr re-prime wait lost time.

    Ryan

    ★ ★ ★ ★ ★ 5
    27.07.2025
    didn't have to water it down, massive time saver. The aerated block suction was instantly sorted for the screed. Spot on.

    Miles

    ★ ★ ★ ★ ★ 5
    24.06.2025
    Cracking. Strong plastic.

    James

    ★ ★ ★ ★ ★ 5
    18.05.2025
    Top quality kit, worked good.

    James

    ★ ★ ★ ★ ★ 5
    25.04.2025
    brill! This sealed my porous brickwork sound as a pound gave an excellent base. No mixing needed, top stuff.

    stavrin

    ★ ★ ★ ★ ★ 4
    07.01.2025
    Absorbed wsell into aerated concrete for skim finish. Dead on! Just took longer than 4h to dry in the cold.

    Lee

    ★ ★ ★ ★ ★ 5
    17.08.2024
    Dead easy prep. Proper good key.

    Philip

    ★ ★ ★ ★ ★ 5
    14.06.2024
    EWI-301 is brill, totally killed the absorbancy of that concrete.

    Thomas

    ★ ★ ★ ★ ★ 5
    27.05.2024
    Easiest prep saved loads of time!

    Hando

    ★ ★ ★ ★ ★ 5
    10.05.2024
    Ready-to-use, so zero mixing faff. Gave the skim coat perfect grip on the porous blockwork. Brill stuff.

    Craig

    ★ ★ ★ ★ ★ 5
    28.09.2023
    Dead easy. Sorted it.

    Paul

    ★ ★ ★ ★ ★ 5
    28.05.2023
    Used this on high-suction blockwork before the render. Brill bit of kit. Ready to go straight from the tub so there was no mixing nonsense unlike other stuff I've tried. Roller went on fine, sealed it perfectly. Recommended.

    Luke

    ★ ★ ★ ★ ★ 1
    19.05.2023
    opened this ewi-301 and it looked absolutely MANKEY, full of curdled bits and lumps. couldnt yrust that contaminated rubbish to bond my substrate. if i used it the whloe plaster coat would fail. total waste of money and hlf a day finding DECENT primer. shocking QC on this gear! learnt my lesson: buy cheap buy twice.

    katy

    ★ ★ ★ ★ ★ 5
    15.12.2022
    Brill! Fixed a proper porous plaster wall drinking everything. Ready to use out the can, no dioutin faff, just mixed and rolled straight on. Keyed the skim perfect. Will use again, 5 star.

    Phillip

    ★ ★ ★ ★ ★ 4
    06.08.2022
    Used this on weak blocks before the skim. Took 4hrs to dry but needed the re-prime on the thirsty bits to properly kill the suction. Took a good key for the topcoat tho. Decent quality primer good value.

    Matt

    ★ ★ ★ ★ ★ 5
    23.04.2022
    Brilliant stuff. Blockwork was porous, this fixed the suck quick. Used a brush/roller straight up. Key was rock solid for the skim coat.

    Chris

    ★ ★ ★ ★ ★ 5
    05.01.2022
    Brill primer for blockwork that. Got a perfect key and no issues with the render bubbling on the weak areas this time. Went on lovely and fast dries proper clear too. Perfect works good.

    Maria

    ★ ★ ★ ★ ★ 5
    03.01.2022
    Proper quality.

    Richard

    ★ ★ ★ ★ ★ 5
    07.09.2021
    Proper job--no dark primer bleeding through. Gripped the weak wall. Spot on!

    hugh

    ★ ★ ★ ★ ★ 5
    13.04.2021
    EWI-301 is mint! Sorted the huge water draw on the porous block easily. Rolled out dead quick, skim went on flawlessly afterwards. No faff, Top stuff!

    Neil

    ★ ★ ★ ★ ★ 4
    25.02.2021
    brill prep & bond. But pricey for the M2 I managed to get.

    Luke

    ★ ★ ★ ★ ★ 5
    26.08.2020
    brill primer. Rolled on dead eadsy, used it straight from the can. Strengthened up the aerated concrete nicely, and the plaster took solid. Top stuff.

    Darius

    ★ ★ ★ ★ ★ 5
    19.08.2020
    Top kit. Perfect block coverage first time no fuss. 4hr re-prime svaed hours. Sorted.

    Josh

    ★ ★ ★ ★ ★ 5
    23.12.2019
    Brilliant for the cellular concrete walls, proper job!

    Maria

    ★ ★ ★ ★ ★ 5
    12.12.2019
    Great stuff!

    qobad

    ★ ★ ★ ★ ★ 5
    12.11.2019
    Mint stuff. Stopped the old highly porous plaster sucking the moisture. Bolted on the new finish proper fast.

    Mike

    ★ ★ ★ ★ ★ 4
    18.09.2019
    Primed the concrete bang on, plaster stuck wsell. Only gripe: felt a touch thin and went through the bucket faster on high absorb areas. Needed a vigorous rattle too.

    Rene

    ★ ★ ★ ★ ★ 4
    22.08.2019
    Solid stuff for the price. Drying felt long, 24 hr wait.

    paul

    ★ ★ ★ ★ ★ 4
    09.01.2019
    Spot on for conc base jobs. Felt it needed a bit more bite/bond on the clay tiles though.

    sukhy

    ★ ★ ★ ★ ★ 5
    27.11.2018
    Best primer used for porous concrete blocks, made the skim coat stick good.

    Mark

    ★ ★ ★ ★ ★ 5
    12.05.2018
    ace Primer Kit! Proper job. Dried sound and quick, even on that bad dusty blockwork. Cracking price too. Use this always.

    Zulqarnain

    ★ ★ ★ ★ ★ 5
    23.04.2018
    Brill! Firmed the walls dead quick.

    Dan

    ★ ★ ★ ★ ★ 5
    20.03.2018
    Saved a load of faf. Perfect on the concrete blocks.

    paul

    ★ ★ ★ ★ ★ 4
    07.11.2017
    Great stuff, ready to go in the 5L tub. Keyed the porous base up perfectly for the skim.

    Alexandru-Marius

    ★ ★ ★ ★ ★ 5
    20.02.2017
    Strong bond achieved on all surfaces. Dried in 3 hours. Great value and top quality stuff.

    jake

    ★ ★ ★ ★ ★ 5
    07.11.2016
    top notch. Best primer for fixing weak concrete walls and controlling suction. Ready-to-use mix was spot on and my plaster coat keyed straight on without issuf.

    wayne

    ★ ★ ★ ★ ★ 5
    26.10.2016
    Absolute saviour on that highly porous block! Locked the suction down brilliantly. Ready mixed quick to dry. Proper job!

    Richard

    ★ ★ ★ ★ ★ 3
    06.10.2016
    coverage rate was poor used nearlu double the amount on one side. So much for value. Needed the ull 4hr wait time too.

    pashko

    ★ ★ ★ ★ ★ 5
    30.09.2016
    Proper job. Top quality.

    Dumitru

    ★ ★ ★ ★ ★ 5
    12.02.2016
    Cracking primer. Arrived quick. Used on porous blockwork —spot on!

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