Painting new plaster pva: How and When To Paint New Plaster
i have been told I need to apply a coat of pva after plastering is this so and when do I need to do it.
5
5 Answers from MyBuilder Plasterers
Best Answer
MG Build Services
High Wycombe • Member since 28 Jun 2010 •
184
jobs,
99% positive
feedback
Do not under any circumstances put PVA over newly plastered walls – it will start to flake off in months. Modern emulsions do not require watering down. Leave the walls/ceilings dry completely and paint with 2-3 coats of good quality emulsion like Johnstones Covaplus Vinyl Matt.
2011-09-16T13:05:01+01:00
Answered 16th Sep 2011
B J D BUILDING/ROOFING
Cheltenham • Member since 29 Oct 2008 •
34
jobs,
100% positive
feedback
You dont need to apply pva after the walls have been plastered.
Normally you use pva, prior to plastering 24hr before, then 2nd coat just before plastering and wait to go tacky.
When plaster has fully dried, you give it a mist coat of emulsion prior to your finish coats of paint.
2011-09-16T11:50:01+01:00
Answered 16th Sep 2011
Ben Arnold plastering
Maidenhead • Member since 14 Sep 2011 •
3
jobs,
100% positive
feedback
There is no need to apply a coat of pva after plastering. A watered down coat of emulsion is enough to seal the plaster for another coat of paint.
2011-09-16T11:50:01+01:00
Answered 16th Sep 2011
S.
Vinter Building & Interior Maintenance
Haverhill • Member since 7 Sep 2011 •
15
jobs,
100% positive
feedback
Hi water down some matt emulsion and seal it with that once the plaster is completey dry. hope this helps
2011-09-18T12:05:02+01:00
Answered 18th Sep 2011
Geoff hay stonecraft
Swansea • Member since 5 Mar 2020 •
32
jobs,
100% positive
feedback
Once fully dried apply a watered down coat of emulsion paint to seal it
2020-06-20T10:20:02+01:00
Answered 20th Jun 2020
Pva new plaster before painting – or not!
landyandy
-
-
#1
Just had an extension multifinished over boards and it looks like it has started to dry out niceley.
My plasterer has advised me to apply pva diluted 5 to 1 before painting.
I think this advice is to stop the new paint going nowhere.
Looking through this forum at other posts this advice does not seem to be the correct approach.
Could anyone clear this up for me.
Andy.
HERTS P&D
-
-
#2
NO to the PVA just a mist coat of paint.
Andy
Alastairreid
-
-
#3
Ditto to Andy’s response.
noseall
-
-
#4
NO PVA!
jrplastering
-
-
#5
never pva before paintin the pva is water soluable and will emulsify (cnt spell it) causing the paint so slip and slide all over the place as a result the paint wnt bond properly to the plaster and the finish will be uneven and look terrible.
so many people have been told pva is the way to paint and i dnt know where these people get there information from even my father in law asked me last nite can i plaster his bathroom then he will pva it and paint it with exterior weathershield
Alastairreid
-
-
#6
landyandy said:
My plasterer has advised me to apply pva diluted 5 to 1 before painting.
Andy.Click to expand…
Must be a pretty inexperienced plasterer to be giving out that sort of advice.
Richard C
-
-
#7
Most definitely NO; your plasterer is a complete knob , I hope his plastering work is better than the advice he’s given you
EDIT:
To prime new plaster skim; after letting the plaster dry 10 – 14 days, use ordinary cheap matt white emulsion, thin it 25-30% with water & apply 2-3 coats in quick succession. Let this it dry overnight before applying your chosen paint finish; assuming he’s left a good enough finish not to need any filling!
joe-90
-
-
#8
Can I have a go?
NO PVA.
Richard C
-
-
#9
joe-90 said:
Can I have a go?
NO PVA.
Click to expand…
Fill ya boots joe
roy c
-
-
#10
I have thought about this and I dont think you should use that white stuff that is very sticky and comes in plastic containers.
I just cant think of its name. Maybe the lads on here will know what its called….
Alastairreid
-
-
#11
Polyvinyl acetate
roughcaster
-
-
#12
roy c said:
I have thought about this and I dont think you should use that white stuff that is very sticky and comes in plastic containers.
I just cant think of its name. Maybe the lads on here will know what its called….
Click to expand…
I just cant think of its name. Maybe the lads on here will know what its called….Yoghurt?????
jrplastering
-
-
#13
ahhh alaster i wanted to write poly viynal acatate haha
Damadamski
-
-
#14
I have done similar research into this and one reason for NOT using PVA was because it causes a seal and therefore traps any moisture left in the plaster
DIYnot Local
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Plumber / Gas EngineerElectricianBuilderDecoratorBuilders’ MerchantPlumbers’ MerchantTile SupplierFlooring Supplier
Are you a trade or supplier? You can create your listing free at DIYnot Local
You must log in or register to reply here.
PVA and plastering.
- harrisonline
- Plastering and Rendering
2
- Replies
- 27
- Views
- 8K
Richard C
PVA before blue grit
- diy_dave1978
- Plastering and Rendering
- Replies
- 3
- Views
- 5K
diy_dave1978
To PVA Or not?
- ziggy1979
- Plastering and Rendering
- Replies
- 1
- Views
- 2K
notfilc
Pva between coats of finishing?
- Naz83
- Plastering and Rendering
- Replies
- 14
- Views
- 17K
Naz83
New plaster
- idiots
- Plastering and Rendering
- Replies
- 12
- Views
- 2K
Richard C
Share:
Facebook
Twitter
Reddit
Pinterest
Tumblr
WhatsApp
Email
Share
Link
How to paint metal? – World of Colors
A common problem with outdoor metal structures is self-destruction.
An aggressive environment in a short time triggers corrosion processes in the metal – products from hydrated iron residues are formed on an unprotected surface. Air, water, various chemical compounds, high temperatures deal a crushing blow to the metal.
Sometimes, in 1-2 years, a welded fence or elegant balcony railings are eaten away by rust. A familiar picture? If you do not have brand new galvanized or stainless steel, not products with an ideal powder coating, then you should think about protecting structures with special coatings. Downspouts, bicycle frames, metal gates and garage doors, front doors, welded and wrought iron fences, railings, a variety of grills and railings, garden furniture and tools need periodic protection. How to find the best primer for metal and surfaces with traces of rust, we will understand below.
Traditional technology for painting and protecting metal structures
-
Complete cleaning with a metal brush or sandpaper of the surface from rust and all kinds of contaminants.
- Passivation by transducers. This procedure helps to finally get rid of the stubborn corrosion plaque. As a result, a thin inactive film is formed on the surface, slowing down or even stopping corrosion processes.
- Single-layer priming with special compositions such as GF-021 (in our rating of primers for surfaces Yarko GF 021 primer for metal and wood, Tex Universal GF 021 universal anti-corrosion primer).
- Protective and decorative painting with finishing enamel type PF-115 (for example, Tex Fazenda PF 115 universal enamel for wood and metal) or nitro enamel (for example, Yaroslavskiye Kraski NTs-132 nitro enamel for metal and wood).
If you sum up the time for priming and painting, then the duration of the work will be very impressive. The primer layer GF 021 can dry up to 24 hours. Finishing enamel PF 115 is recommended to be applied in 2 layers with intermediate daily drying. Although nitro enamels dry much faster, they are quite toxic and have a pungent odor.
It may take more than two days to complete only painting work.
I would like to simplify and speed up the process as much as possible – for example, apply some special material to an untreated metal surface and guarantee its protection from the aggressive effects of water and oxygen, as well as create the most decorative coating. And such materials are on the construction market. The best enamel for metal has the following characteristics:
- a protective coating that completely isolates the metal base from the external environment;
- inhibitors (converters) of corrosion in the composition;
- primer to increase adhesion to the base;
- a finish coat resistant to fading, with high decorative characteristics.
These paints are somewhat more expensive than traditional materials, but in combination they greatly simplify the work, improving their quality.
Types of enamels for metal and rust
If ferrous metal is painted with ordinary paint without prior preparation, then such a coating will not provide full protection.
Sooner or later, oxygen and moisture will penetrate under the film to the base. And if there is already existing rust, corrosion processes will start quite quickly.
What kind of enamels for metal and rust are now presented in the construction markets and in stores? Firstly, these are acrylic / styrene-acrylic primers and water-based primers with the addition of phosphoric acid and its chemical “derivatives”. It is they who convert rust into an insulating polymer protective film. Among the materials in our range:
- Marshall Anticorr Aqua semi-gloss styrene acrylic primer. It dries fairly quickly (interlayer drying up to 6 hours). Almost odorless due to the water base. Tintable in a wide range of shades. And most importantly, it forms a durable elastic coating that is resistant to moisture, air and some chemicals;
- VGT PREMIUM VD-AK-1179 3 in 1 styrene-acrylic rust primer. Contains 2 zinc phosphate inhibitors, anti-corrosion pigments and a special filler to form a film with a flaky structure. The enamel has excellent adhesion to the metal base, which allows you to create a high-quality barrier to O2 and h3O.
The enamel has excellent adhesion to the metal base, which allows you to create a high-quality barrier to O2 and h3O. Secondly, these are enamels based on alkyd resins, which are most widely used. Here the range is much wider.
Acrylic materials are comfortable and easy to use, but they lose to alkyd materials in terms of durability and resistance to aggressive environments. Alkyd enamels are more resistant to fading.
Important! Alkyd enamels have limitations in compatibility with old coatings – they should not be combined with oil, nitro enamels, etc. It is better to remove the old coating altogether before applying a new one. Acrylic materials can be applied to almost everything. The fact is that the solvent in the composition of alkyd enamel can react with the old coating.
Let’s single out the five most popular 3 in 1 materials based on alkyd. TOP 5 paints for metal surface:
- Hammerite Smooth Rust Enamel is the pioneer in the world of 3 in 1 rust coatings. It is used for non-ferrous and ferrous metals. Provides protection up to 8 years;
- Tikkurila Metallista rust paint is an effective material for treating metal structures inside and outside buildings. In addition to alkyd resins and an organic solvent, the composition contains inhibitors, a primer and wax additives;
- Alpina Direkt auf Rost glossy smooth rust enamel;
- Yaroslavl Kraski Spetsnaz budgetary primer-enamel for rust, which includes synthetic resins with targeted additives, pigments, fillers, organic solvents, anti-corrosion additives;
- Tex Rust Stop 3 in 1 Rust Enamel is a specialized coloring composition designed for painting metal surfaces indoors and outdoors. It can be applied directly to rust, does not require preliminary preparation of the base.
It is used for non-ferrous and ferrous metals. Provides protection up to 8 years; These are rust paints for outdoor and indoor painting.
Paint ratings and metal primer ratings are often commercial in nature and not objective. In each price segment, you can find good materials that meet the needs of the buyer.
How to apply rust enamel
Let’s analyze the technology of working with multifunctional enamels using the Hammerite brand product as an example.
Rust application. It is enough to remove loose rust and heavy contamination from the surface, if possible, degrease it with an organic solvent. Base preparation is minimal.
New unpainted surface in steel and other ferrous metals. Degrease the surface with an organic solvent, rinse with water and let dry. Apply Hammerite paint to the surface.
Previously painted base. Remove the peeling coating, sand the surface a little, clean it of dust and dirt. But before you start working on the paint, test it on a small area for compatibility with the old finish. Apply enamel and wait a bit. If nothing happens within an hour, you can continue painting.
Indoor metal paints
And in conclusion, a small selection of materials for interior work on metal. Yes, here an aggressive environment is the exception rather than the rule.
Although the cast-iron risers in the bathrooms have not yet become a thing of the past.
Tikkurila Miranol is a low odor thixotropic alkyd enamel. Can be used for both exterior and interior paint. Enamel is easy to use, almost does not smell and is well distributed over the surface without forming smudges. Suitable for both metal and wood. Thousands of bright glossy shades to choose from.
Tikkurila Pesto in various gloss levels is used indoors and outdoors. Universal in application material – suitable for mineral, wood, metal substrates. You can paint furniture, doors, window frames, various metal tools and even bicycles with agricultural equipment. Indoors, concrete and brick walls can be coated with enamel.
Paint 3 in 1, which one is better, we will not single out again. The selection of the right material for high-quality performance and compliance with the rules of painting is a guarantee of long-term protection of your metal structures.
The best rust paints are the ones that solve your problems.
Dry building mixes: from A to ZDry building mixes: types and propertiesClassification and selection of dry building mixesDry mixes: characteristics and applicationsCement plasters for exterior and interior worksChoice of masonry mix for bricksMasonry mortars: what to chooseLeading trade brands of dry building mixesChoose plasterWarm plasterPlastering of complex basesWet plaster: features, finishing technologyLeveling slopesUsing plaster for ceiling finishing – pros and consGrid for plaster: selection and applicationPlaster mortars: types and characteristicsDefects of plaster and their eliminationPutty – the basis of repairPolymer finishing putties: characteristics and applicationFinish putty: types and applicationDry mixes for leveling floors Self-leveling floors: characteristics and applicationDry mixes for floor screedThe best screedPour and forget. Self-leveling floors. Self-leveling floors are in trend Self-leveling floors in the interior Self-leveling floors: features and applications Types of floor screed: what to choose Such different plaster Choosing decorative plaster Finishing walls: decorative plaster or wallpaper? applying decorative plaster. The optimal material for decorating walls.Venetian plaster on wallsPainting decorative plasterDecorative plaster “bark beetle” – types and applicationsDecorative plaster in the bathroomLiquid wallpaper – what is it?Decorative plaster in the interior of the kitchenGypsum plaster for wallsGypsum plasters – characteristics and applicationsGypsum plaster: types and applicationDry mixes based on gypsumTechnology application of gypsum plasterGypsum mixtures: types and applicationsFacade plastersFacade insulation for plasteringFacade finishing puttyPlaster for outdoor workFacade plaster mixturesMesh for facade plasterWe became a KNAUF 9 dealer0106 |
|
Published 01/07/2019 |
|
If you do not want to redo the plaster, you should make sure that there are no serious deviations and defects on it. The causes of plaster defects are divided into technological and operational. Technological ones arise immediately after improper preparation and poor-quality application of the solution to the surface to be treated. Among the defects there are dutiki or cracks in the plaster, its peeling or swelling. Slits. The reasons for the occurrence may be too thin a plaster layer, greasy mortar, shrinkage of the structure, lack of a protective metal mesh at the joints, quick drying of the plaster mixture, the fact that the surface to be plastered is made of wide boards or upholstered with wide shingles. Dutik, small swollen bumps, occurs when unseasoned slaked lime, which contains unslaked particles, is used in the preparation of cement-lime mortars. If greasy (with a large amount of binders) or poorly mixed mortars are used, shrinkage cracks may appear on the surface of the plaster. These defects arise from the rapid drying of the plaster in conditions of too warm air or drafts, as well as as a result of applying soil or coating on the previous layer that has not set. To prevent the appearance of cracks, fillers and binders should be carefully dosed during the preparation of the mortar, as well as thoroughly mixed. If the surface is poorly prepared for plastering, if there is dirt or the surface is very smooth, or a weak notch is made, peeling of the plaster may occur. The same unpleasant phenomenon is observed when applying a strong solution to a weaker one, say, cement to lime. The plaster swells if the solution is applied to very damp or waterlogged surfaces plastered with lime or lime-gypsum mortar. The solution to the problem will be the dismantling of the plaster in the area with a defect and the subsequent re-application of the solution on a sufficiently moistened surface. Swelling of the plaster occurs, on the contrary, due to excessive moisture content of the substrate. This defect is eliminated by altering the plaster in separate areas with a defect after the base has dried. It is necessary to beat off the plaster in places of swelling, clear these places, dry and re-plaster. A rough plaster surface is obtained if coarse, unsifted aggregate is used. It is necessary to moisten the surface, grind the plaster with a solution on fine sand. Plaster does not harden or shrink. This happens because the solution was mixed for a long time or gypsum was added to it to the covering layer. Rusty and other stains appear on the plaster. Efflorescence occurs when chemicals such as salt have been added to the original plaster. Mechanical damage to the plaster surface. This is the result of a violation of the correct sequence of construction work. For example, immediately after the completion of plastering work, you took up electrical or plumbing without waiting a certain time. Operational plaster defects are the same cracking and flaking, only they do not appear immediately after application, but over a long time as a result of aging. To prevent and eliminate operational defects, regular preventive inspection and subsequent repairs are necessary, which can be combined with other work, for example, with cosmetic repairs of the entire premises. Wall plaster repair involves removing the damaged area and applying a new coat. To achieve the best result, you need to clearly know how to remove the old plaster. Any sharp tool that scrapes off the damaged finishing layer will help in the work. When removing a defective area, a small area of undamaged space should also be captured. The layer of plaster is scraped off down to the base, which must be thoroughly cleaned. On the surface of the base, including the edges of intact areas, any binder is applied, for example, PVA glue. After applying the binder, it is necessary to wait an hour until it dries completely. A new layer of plaster should be applied, observing all technological standards to prevent the recurrence of plaster defects. The areas where the old, undamaged and new layers come into contact must be carefully smoothed out to avoid bulges or depressions. In the process of applying the plaster, the base should be moistened with water, and at the end, brush with a damp brush over the entire surface where the repair was made. Repairing Venetian plaster is a little longer and more difficult than repairing regular plaster. The beginning here is the same: removing the old, damaged layer. Next, an adhesive solution prepared from PVA glue (1 part) and water (5 parts) is applied to the base, and the edges of those areas that remain on the surface must also be lubricated. This method improves the adhesion of the old and new layers of plaster. Next, the first layer of plaster is applied, after a while – the final layer, decorative. On the site with new plaster, it is necessary to reproduce the texture of the remaining sections. To do this, you need sponges to roughen and spatulas to create relief. The junctions of the new and old sections must be smoothed as much as possible so that the entire surface looks like a single whole. As the plaster dries, the relief projections should be smoothed with a damp metal spatula. Finally, Venetian plaster will dry in two to three days, after which the surface can be painted in the desired color. To level surfaces, not only plaster is needed, but also putty. For the correct use of both materials, you need to know how plaster differs from putty. Plaster is nothing more than a building mixture used to level the surface. It is coarse-grained, therefore it is suitable for surfaces with irregularities of 1-5 cm. Putty is a plastic mass that eliminates surface flaws, such as depressions or scratches. Unlike plaster, the putty is fine-grained, therefore, with its help, small imperfections up to one and a half centimeters are leveled. Another difference between plaster and putty is that the latter is viscous, so it does not change in volume when filling voids, does not give bubbles or cracks. Therefore, when deciding what will help repair cracks or other defects on the surface: plaster or putty, it is necessary to take into account the size of the defect, and also remember that putty is applied before finishing (wallpaper, painting, finishing plaster), and plaster is an intermediate leveling layer. |
The layer of plaster on the surface must be even and smooth, firmly connected to the base without peeling, cracks and bumps, roughness, non-plastered gaps. Plaster defects can vary in causes and appearance. They must be removed before painting. 
Then the lumps of lime in the plaster layer begin to be extinguished, increasing in volume and forming tubercles (dutiki) with a white speck in the middle. Such plaster must be completely removed (pre-moisten the surface to fully open the dutik) and apply a new, better one, because lime lumps located throughout the entire thickness of such defective plaster are quenched at different times (depending on the distance to the surface), and in the deep layers of the dutik may form a year or two after the application of the plaster. 
If the plaster is applied to the surface in hot weather, it is necessary to protect the applied layer from rapid drying: pour water or hang it with a damp cloth. Small cracks are eliminated by grinding with an existing solution or gypsum test with chalk (two or three parts of chalk are taken for one part of the gypsum test). Large cracks should be well moistened with water, cut with a cut-off, cleaned with a steel brush, moistened with water and smeared with a solution and rubbed. 
Before removing the old plaster, it is necessary to inspect the entire surface for peeling. When re-applying the plaster, it is necessary to ensure that the strength of the solution changes in descending order, that is, a stronger layer must be kept on the base. 
This is due to the fact that the plaster was made with lime mortar on a metal mesh and the spots themselves on the surface being plastered were not eliminated, although it was necessary to perform plaster with cement mortar. 
