Paint

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Paint 3 att250385 7006.jpg

Paint can transform appearance, it can make a style, it can emphasise desired features and partially obscure others.


Contents

Types of Paint

Emulsion

Leyland emulsion 588-3.jpg

Emulsion paints are water-soluble until dried, and are the usual choice for covering walls and ceilings. They are available in matt and semi-matt (often known as 'silk') finishes.

They're prone to mould if used in damp environments. Kitchen and bathroom formulations (and others) are available, or a mouldproofer can be added to the paint, or applied separately.

Prone to mild discolouring if used on radiators.

Covering ability varies widely: the best (such as Dulux Trade) have a mayonnaise-like consistency and can cover even dark colours with 2 or 3 coats, normally requiring only one to give a good coverage on light surfaces. By contrast some 'shed' own brands require many coats to cover even light surfaces. The thicker consistency paints are also less prone to splattering when applied with a roller.

A wide range of colours is available off the shelf and major brands offer ranges which can be mixed to almost any required colour.

Dulux paints at DIY sheds and Dulux centres aren't the same. Quality and price are higher at the Dulux shops.


Household gloss

Gloss dulux 2532-2.jpg
  • Gloss for woodwork
  • Oil based alkyd chemistry
  • Produces fumes during application and for a few days afterwards
  • Use over alkyd undercoat ideally
  • Water based undercoats or primers can reduce paint life
  • May also be used for walls & ceilings where easy cleaning and hard wearing are required, but ventilation during and after application is needed
  • Curing takes longer than drying, so either avoid pressing painted surfaces together as soon as dry (eg door frames), or coat them with a lubricant to avoid sticking, eg washing up liquid, binbags or baby oil


Undercoat

Undercoat 2533-2.jpg
  • Oil based alkyd undercoats mainly for use with household gloss.
  • They can also be used as a stain blocking layer under emulsion, but are slow drying for this.
  • Acrylic undercoat can be used as a cheaper but less durable substitute


Eggshell

Eggshell paint 2551-3.jpg
  • Oil based matt paint
  • mainly used on walls
  • harder wearing than emulsion
  • ventilate the area after application
  • alkyd chemistry


Primer

Red primer 2536-2.jpg
  • A good quality primer underneath oil based paints makes them last better.
  • An inferior primer can cause premature failure
  • Several primer formulae exist


Acrylic

  • Like emulsion but tougher.
  • Sometimes used as an undercoat for alkyd gloss paints


Masonry paint

  • For exterior use only
  • The term covers more than one formulation of paint
  • impermeable exterior paints occasionally causes damp issues on old non-cavity non-DPC walls


Limewash

  • Lime putty & water
  • Dead matt finish
  • Limewash looks very thin on initial application, but bodies up both through drying and through carbonation over several days after application
  • The term is also sometimes used to describe distemper or milk paints.
  • Lasts well outdoors
  • Finish not as fine as commercial paints, not an issue on exterior surfaces
  • Painting technique differs a bit from commercial paints
  • Eye protection necessary, lime does grim things to eyes
  • Exceptionally cheap at under £7 per 100kg
  • See Limewash

Preparation

  1. Buy or prepare lime putty. Its prepared by adding water to builder's lime to make a putty consistency.
  2. Dilute the putty 50/50 with water, and you have paint.

When extra sticking ability is needed, 1% of boiled linseed oil may be mixed in.

Adding skimmed milk to lime paint is occasionally done to improve toughness, but this is only good for indoor use.

Builder's lime gives a coarser paint than a mature putty. It suits exterior masonry.

Use

For exterior masonry, just paint it on. Add a second coat the next day, immediate overpainting just takes the first coat off. It looks excessively thin at first, but don't worry, it bodies up on drying, and bodies up again on curing, which takes a couple of days. Don't put a thicker coat on to try to compensate for its initial thinness, it cracks up on drying if you do.

Lime paint isn't normally thickened, so it drips quickly from the brush. To minimise drips and maximise work rate, rotate the paint brush while you carry it from can to wall.

Cleanup is especially easy with lime paint, as even after drying it redissolves immediately in water. Outdoor work can typically be done with no covering of paths etc, and the path just rinsed off at the end of the day. If cured, the paint is readily removed with acid.

Lime is probably the quickest paint to use, as for most outdoor work there's no need to mask or cover anything, drops don't matter, and cleanup takes seconds with a hose. And single coat work is sometimes practical.

Check its not about to rain when painting, it can wash off. Once cured, lime paint is completely rainproof. Dry lime paint is also easily brushed off until it cures. This isn't particularly a problem in practice, as its trivially easy to patch it if ever needed.

Surfaces should be sound before painting, but on occasion the extra work isn't justified. In such situations lime paint soaks in and provides a degree of bonding to a loose or powdery substrate. This works fairly well with crumbly old lime plaster, which coats of diluted lime paint can bond back together. PVA is faster though.

Lime paint isn't for kids, it can do serious damage to eyes.

Colours

Lime is normally white, though off white lime is also available.

  • For a broken white colour, a very small amount of seived subsoil can be mixed in (not topsoil)
  • For pink, add iron oxide, sold as red cement pigment.
  • For sky blue add laundry blue and use the paint immediately, else it bleaches in a few hours.
  • Where a heavily weathered appearance is wanted quickly, add a little yogurt or rotted horse manure to the mix for quick biofilm formation.
  • Coloured emulsion can be added in small amounts
  • Adding kids waterpaints is yet to be tried. It probably would work fine with some colours, but not all.
  • Lime is alkaline, and not all pigments are alkali stable.
  • Red, yellow, green, blue and black can be obtained using sheep raddle powder from a farmer's co-op or agrimerchant.

Thickness, coats and issues

Outdoor work is easily done with 2 coats, but its also possible to use 1 sometimes. Some people prefer 3 thinner coats.

Its possible to use a single thickish coat of slightly thicker mix for outdoor masonry where a fine finish isn't wanted. Wait until you're familiar with the paint's handling before doing this, as if the mix is too thick the paint cracks and crazes. If that should happen, just put another coat on top, it fills the cracks and bonds properly.

For a finer finish for indoor work, dilute the paint further and use several thinly applied coats. Use matured putty rather than builder's lime for the smoothest result.

There's plenty of misinformation about regarding surface compatibility with limewash and distempers, including from sources that should know better.

Paint & fill in one

An unusual way to apply lime is to use putty without diluting, wiping it on with a rubber grout spreader or similar. This fills the uneven masonry surface to a fair extent, producing a smoother finish. Its not as smooth as rendering as the lime shrinks, but it does improve the surface, and later repainting makes it smoother again. It acts as filler and paint in one. A steel trowel is no good for this.

Piccies

Lime paint ok after 7 yrs 4430-3.jpg

Picture 1: Lime paint on semi-rough concrete's still good 7 years on.

Lime paint was trowelled 4431-3.jpg

Picture 2: Top half shows lime painted on, bottom half shows lime putty applied with a rubber edge.

Lime paint crazed 4432-3.jpg

Picture 3: Here the paint crazed from being put on too thickly.


Note the lightness and colour balance of these doesn't match real life very well. In real life the roughness of the wall makes the features & defects shown barely noticeable.

Distemper

  • The forerunner of modern emulsion
  • very matt finish
  • Distemper can be washed off with hot water and detergent
  • Can be cleaned with cold water, but is not as robust as emulsion and will come off with repeated cleaning.
  • Well suited to intricate mouldings, as its easy removal avoids paint build up over time obscuring detail.
  • Mostly available in mid and light colours due to chalk content, but darkish colours are possible.
  • Sometimes chosen for its appearance, which is slightly different to emulsion
  • Covers hairline cracks, unlike emulsion.
  • Distemper can be made at home, but so few people do it that its hard to know which recipes produce a cleanable paint. The basic formula is lime, fat, pigment, water and heat.

Potential Confusion

There are 2 different types of paint called distemper. There is soft distemper, which is discussed below inder the heading /Whitewash/ and oil bound distemper, discussed here, which is the more versatile paint. Oil bound distemper is a mainly water based paint.

Note that of oil bound distempers there is a fair variety of recipes, and not all perform identically. For example some less successful recipes wash off with detergent in cold water. This probably accounts for the considerable amount of confused, conflicting and incorrect advice concerning distemper on the net.

Stove enamel

  • A hard thick coating
  • An exceptionally tough thick paint-like finish
  • Used on cookers, a minority of high end cookware, and some other goods with long life expectancy
  • Relatively expensive
  • Not possible to paint such a finish on, the coated item is kilned after application
  • Any repair to damaged stove enamel is inevitably of much inferior durability


Powder coat

  • Tough finish for metal goods
  • Dry powder is sprayed onto the item
  • Heated after application to fuse and bond.
  • Resin based
  • Widely used on metal appliances


Whitewash

  • Whiting (chalk powder) and water soluble glue.
  • Very cheap
  • Short lived
  • Useful for temporary applications, such as greenhouse summer shading, where it gradually washes off, giving little shade in winter

Also known as soft distemper, it was widely used on ceilings until about 50 years ago. It is a matt paint. The natural colour of a greyish shade of white was normally used but occasionally it was tinted.

It can be (and should be) washed off before another coat is put on. During WW2 it was used on walls because it was the only paint readily available, but this gave it a bad name because it easily brushes off onto clothes. If you find an old painted wall that drops chalk when brushed or wiped, its probably this stuff, and probably dates back to at least the 1940s.


Water based gloss

Water gloss 2546-2.jpg
  • A semi-gloss household paint used for interior woodwork
  • Durability not comparable to oil based gloss paint
  • Not very robust


Pliolite

  • Matt
  • Synthetic resin
  • Pinholes heavily
  • Longer lived than budget masonry paints
  • Contains naphtha


Linseed oil paint

  • Takes days to dry
  • Nice but strong smell while drying
  • Non-toxic
  • Soaks into woodwork
  • Boiled linseed oil is used to ensure drying
  • Made with & without added driers (chemicals). Driers speed up drying time but shorten paint life.


Hammerite & Smoothrite

Smoothrite 3511-4.jpg
  • For metal
  • Can be painted directly onto rust
  • No primer or undercoat required
  • Pinholes badly, resulting in rust spots reappearing later

'Hammerite' paints were originally distinguished by (and named after) their orange peel texture.

There are 3 versions of hammerite:

  1. Finnegans pre-1989
  2. Finnegans post 1989
  3. ICI

Finnegan's hammerite was a xylene based solvent paint. It pinholed a lot, so rust spots soon reappear and spread. Other manufacturers produce solvent based metal paints, including Ronson, Dulux and others.

Xylene (for thinning paint) isn't cheap. Cellulose thinners have been used successfully at a fraction of the cost.

  • Note the pre-1989 formulation requires a different thinner, details

The current ICI version of Hammerite is an alkyd paint, and not popular on uk.d-i-y. Cheaper brands of alkyd are available (see household gloss section).

Some varieties can be applied by sponge roller, which can give a consistent finish free of brush-strokes.


Enamel

Enamel 3511-6.jpg

Enamel is not one specific type of paint. It simply means a paint with a hard finish.

  • The term enamel means the paint imitates stove enamel, which is an optimistic description for any paint
  • Suited to rigid metalwork.
  • Not suitable for wood
  • Often a solvent based paint of some sort


Car paints

  • much tougher than a lot of household paints
  • more expensive
  • not flexible enough for use on wood
  • Good for small items that will see a lot of use, eg painted handles.

Cellulose

Tough long lasting car paint.

Acrylic

A less expensive type of car paint used for respray work, still tough but more prone to fade.


Japan black

  • A high durability low cost black paint.
  • Very popular during the early part of the 20th century.
  • More info


Zinc paint

  • Often called cold galvanising paint
  • a good option for iron & steel
  • Offers some of the benefit of galvanisation:
    • the zinc corrodes in preference to the steel
    • but the paint to substrate bond is much weaker than real galvanisation
    • and only some of the zinc in the paint film is water accessible


Clay paints

  • Limited range of dull earthy colours possible
  • Minimal cost
  • Easily made, just sieved clay subsoil plus a binder (eg lime, milk, glue etc)
  • May be mixed with lime, red iron oxide and soot to give a limited range of colours.
  • Widely used in the 3rd world


Silicate paints

A type of masonry paint


Vinyl Dye

  • For painting plastics
  • Penetrates the surface of the plastic for a more durable finish
  • Solvent based
  • Stinks


2 part polyurethane gloss

  • Marine grade paint
  • Very tough
  • Currently around £40 per litre
  • For GRP, steel and light alloy
  • Correct primer also required
  • Complete stripping normally required before application


2 part epoxy paint

  • Very tough
  • Epoxy plus a coloured filler
  • Not cheap
  • Small quantities are easily made at home using a cartridge of epoxy, or tiny amounts from retail packs


Anti climb paint

This paint never sets, and is used to deter and mark climbing intruders. It can be bought ready made, or (so we're told) made by mixing equal amounts of household gloss and engine oil. Presumably it accumulates bugs over time.

Anti-climb should only be used out of reach of people on the ground, and a warning sign should be fitted.


Varnish

Varnish 2544-2.jpg

Varnishes can be regarded as clear paints. Several formulations exist with their own varying characteristics. Fancy writing an article on them?


Road paint

Yellow road paint 5168-3.jpg

The paint used on roads is an approved thermoplastic paint with reflective glass beads. Wearing of the paint surface exposes fresh reflective glass beads. It comes in 25kg bags, and needs a boiler with a mixing paddle to melt. Its not cheap.

Spray cans of road paint don't last well by comparison.


Coal refurbishment paint

Paint for refurbishing coal? Almost - its for painting artifical coals used in gas & electric fires.

Finishes

  • Gloss - shiny
  • Silk & eggshell -partial surface shine
  • Matt - no surface shine, or almost none
  • Distemper & limewash are matter than matt emulsion.
  • Car spray paints give more gloss than household gloss.
  • Where the smoothest shiniest finish is wanted, spray the paint.


Preparation

General

Sugar soap 2523-2.jpg

Its possible to paint directly onto almost any household surface, but a little preparation helps ensure good results.

Sugar soap is the detergent of choice for paintwork. (see Discussion )

  • Remove any flaking or bubbling paint
  • Remove any unsound surface, or in the case of masonry glue it together with PVA


New plaster

New plaster is very absorbent, and needs extra water for the first coat of paint. There are 2 ways to do this.

Piss coat

  • Paint with a 50/50 mix of emulsion and water.

Water coat

  1. Paint the wall with a coat of water. There's no need for any particular care with this, so it can be done very fast.
  2. Wait 5 minutes
  3. Paint with normal strength emulsion.
  • This method is quicker and no paint mixing is involved.
  • Gives a full strength coat rather than a thin coat.
  • If you paint before the water has soaked in the paint doesn't stick to the wall, if you make this mistake just give it a few more minutes.


Solvent weld plastic

Paint adhesion to solvent weldable plastic can be improved by wiping the plastic with solvent before painting. This has an etch like effect on the surface.


Unsound Surfaces

Surfaces not in good condition should be repaired before painting, but the demands of time and budget sometimes mean that crumbling plaster needs to be painted. The simplest approach is to brush off any loose material using a household cleaning brush, then coat the surface with PVA diluted 1:4. Once dried this will normally give a surface that will last years if not poked about.

Don't overdo the PVA. If a slick surface of PVA forms, paint doesn't stick to it, and painting be problematic.

If the existing surface is chalky, due to it being deteriorating lime paint or lime plaster, well diluted lime putty is a traditional alternative to PVA. This soaks in and rebonds the materials together, without the downsides of PVA, but several coats are needed.


Tobacco staining

Sugar soap is particularly effective at tackling tobacco staining. With staining not too heavy, a few hours of persistence removed more or less all trace of tobacco discolouration in an average room.


Paints by purpose

Ceilings

  • Emulsion usually
  • Distemper
  • Limewash
  • Gloss if a shiny easy clean finish is desired


Walls

  • Emulsion usually
  • Eggshell is a matt alkyd paint, tougher than emulsion
  • Household gloss (alkyd) for a tough easy clean finish. Not as good looking as matt paints.
  • Distemper
  • Limewash for walls subject to light wear


Woodwork

  • Alkyd gloss usually
  • Waterbased gloss
  • Emulsion can be used but tends to not wear well
  • Distemper to preserve fine detail where the woodwork is not subject to heavy wear
  • Linseed oil paint
  • Water based paint (usually emulsion) then varnish


Asbestos

  • Emulsion
  • Household gloss


Wood floors

  • Paint not recommended, normal wear makes it look very bad in time.


Concrete floors

  • Concrete floor paints
  • Epoxy paints last longer but cost a fair bit more


Exterior Masonry

  • Commercial masonry paints for cavity walls
  • Limewash, especially for old non-cavity no DPC walls
  • Pliolite


Iron & steel

  • Car paints
  • Zinc bearing paints
  • Solvent based metal paints
  • Enamels
  • Hammerite, smoothrite & similar aren't much liked on uk.d-i-y
  • Household gloss can be used, but is prone to fade and isn't as tough


Fireplaces

Plastics

  • Vinyl dye

PVC

  • Household gloss topcoat, no undercoat or primer
    • This chemically bonds to the pvc, giving much longer paint life than on wood.
  • Vinyl dye


Solvents

Water

Needs water
  • for all water based paints, such as emulsion, distemper, lime paints etc.

Turps substitute

  • Thins oil & alkyd paints
  • Will also thin linseed paint, but not the best choice for this
  • Real turpentine is too expensive for housepainting


White spirit

White spirit 2529-2.jpg
  • Very similar to turps substitute, but affects the paint handling characteristics. Turps substitute is the better choice.
  • Can also thin linseed paint, but not the best choice for this
  • Good choice for brush cleaning with oil based paints
    • Dirty white spirit can be left to settle and decanted for re-use


Linseed oil

  • 2 types of linseed oil exist, raw and boiled. Boiled has added chemical dryers.
  • Boiled linseed sets in days, raw takes very much longer and is not recommended for paint uses.
  • Extra chemical dryers can be added to boiled linseed to make it set faster, but the resulting paint is then a bit less durable
  • Linseed thins linseed based paints.
  • Can also thin other oil based paints, but heavily extends their drying times.
  • sometimes used to make lime paint stick to a wider range of surfaces. In the region of 0.5-1.5% is added


Cellulose thinners

  • for volatile solvent based paints: cellulose, old xylene based hammerite & smoothrite, etc


Mixing

Mixing paints of the same type is straightforward. It works, and what you see is what you get.

  • Be sure that every drop of the mix is well mixed
  • Be sure you've mixed enough to do the whole job, trying to match it later is often unsuccessful
  • Keep some spare mix for maintenance
  • Store your spare mix properly so it'll be usable
  • Mixing can turn unpleasant colour leftovers plus white into nice pastel paints

Mixing paints with different base formulae isn't recommended, but isn't a no-go either.

  • sometimes it works fine
  • sometimes it doesn't work, they just won't mix
  • sometimes it works but colour issues occur, eg the colour changes noticeably during drying.

Paint mixing can also be used to create special effects if you're willing to experiment. I once mixed 2 types of car paint in blue & green for use on some metal. It took persistence to mix it, but the 2 paints separated during drying, giving a fine hexagonal lattice of one colour filled in with dots of the other. The result was pretty and robust.


Paint Effects

Paint Effects can liven up an otherwise featureless wall. Effects include:

  • woodgraining
  • ragrolling
  • spotting
  • marbling
  • sprayed fades
  • colourwash
  • fibres
  • camouflage


Paint Styles

A wide range of colour schemes & styles are readily found on search engines.


Online Paint Scheme Tool

Paint schemes can be tried out at Online Paint Scheme Tool though its worth bearing in mind that on-screen colours will not generally be accurate.


Troubleshooting

Cracked paint finish
generally due to use of a paint coat that was too thick.
Failure to adhere
usually due to surface contamination, eg with oil, grease or excess dust
Shrunken paint patches
when putting water based paints over gloss, the old paint should be matted to enable new paint to stick. Otherwise the paint shrinks into little islands while wet (called "cissing"), and it takes several coats to get full coverage. A few options:
    • paint the gloss with a coat of matt oil paint.
    • lightly sand the old gloss first
    • rub in whiting with a damp cloth.
    • Or just persist with painting, after a few coats its all good
  • For problems with masking tape see Tapes


Lime

  • Lime rendered exterior walls should be painted with porous paints, if paint is wanted.
  • SPAB recommends using porous paints such as lime on the infill of exposed timber frame buildings. Use of impermeable paints traps water, sometimes causing rot
  • Brickwork on old houses with no wall cavity should be painted with porous paints such as lime. Such walls evaporate damp from the exterior surface to keep them sufficiently dry, and use of impermeable paints increases water content in the wall. Water both enters into and evaporates from a wall via permeable paint, but evaporation normally exceeds ingress.
  • Lime paint behaves a bit differenly to other types, see Paint#Limewash for troubleshooting


Stains

Stain block 387-3.jpg

Stain appearance is due to an underlying stain that is (fully or partly) soluble in the paint being used. 2 options:

  1. Use a layer of paint based on a different solvent to block the stain. This normally means using an oil based alkyd undercoat on water based paints.
  2. If this doesn't work try a stain block paint, which are sometimes more effective
  3. Water based acrylic can also be used as a stainblock layer

For severe or very stubborn staining, use alternating coats of any 2 of emulsion, oil based matt paint and stain block. Sometimes several coats are needed.

Yellowing

Some paints yellow a bit as they age, such as alkyd gloss. Its limited what can be done about it, but sometimes the following prove useful.

After the fact:

  • clean it
  • rub with cutting/polishing compound
  • rub with a cloth on a buffer machine and diesel (non-metallic non-clearcoated car paints)

Prevention:

  • pick a non yellowing paint where practical
  • overcoat the paint with a clear non-yellowing finish
  • pick a colour that won't show slight yellowing
  • add a drop of blue to white paint to disguise slight yellowness
  • one uk.d-i-yer uses pale greay instead of white to avoid yellowing being noticeable

Alternatives to paint

Wax polish 5443-3.jpg

For Wood

  • Varnish
  • Wax
  • Stain
  • Liming
  • Oiling
  • No coating

For Walls

  • Wallpaper
  • Fabric drapes
  • Panelling
  • Wood cladding
  • PVC cladding, not highly recommended

For Ceilings

  • Wallpaper
  • Fabric drapes

For Metal

  • Polishing
  • Plating
  • Varnish/lacquer

For exterior walls

  • Removing all paint with a stripper eg caustic
  • Pebbledash
  • Cladding
  • Bare brick/stone/wood etc


Paint retouching

Paint retouching may be used between repaints to extend the life of existing paint finishes. It can also be used when there is not enough time to repaint.

Paint retouching is a fast minimal cost way to make a house look in much better decorative order. The ok can be made to look good, and even the tatty can be made to look ok.

Typically a room can be decorated this way using a teaspoonful of paint or less.


Alkyd/Oil paint

  1. Clean the existing paintwork. This brightens it up as well as cleans it.
  2. Obtain a teaspoonful or a miniature pot of matching paint. If you don't already have the paint you need, match to a cleaned fragment of paint, otherwise you won't get quite the right colour.
  3. Colour matching is critical.
  4. Use an artists brush with the matching paint to fill in any chips in the paint finish.

The 2 golden rules:

  1. Paint tint must never be brighter than the existing paintwork, not by the tiniest bit. The match must be either exact or the new paint should be a fraction duller.
  2. Never allow any paint whatever to overlap the edges of the chip hollows. Absolutely none. Its not necessary to fill the hollows fully, but any overlap at all ruins the effect.

This method works very well if the 2 golden rules are followed, but it looks like a poor bodge if they're not.


Emulsion

Simply paint over any marks on the wall. Use the minimum amount of paint possible, aim for a layer that covers imperfectly. The trick is to avoid patches that look new, so don't put too much on.

The result isn't as good as touched up gloss paint, the patches are visible, but as long as only a thin paint layer is added they don't stand out, and they do make a wall look a lot better than unpatched, enabling it to go longer before repainting.


Removal of Paint

Several removal methods are unsafe to use with historic paintwork. See #Toxic Paints section.


Blowlamp

  • A cause of house fires and damage to woodwork
  • Not advised with lead paints


Heatgun

  • Not advised with lead paints


IR Heatgun

  • Used around windows this avoids the risk of heat cracking the glass.
  • More energy efficient, as the heat isn't being blown away
  • Heat absorption dependant on paint colour


Steaming

A steamer which is normally used to strip wallpaper can be very effective in lifting layers of paint and should be safe to use on lead paint


Scraper

A scraper is the most popular method


Sanding

  • Not advised with lead paints


Stripping chemicals

Caustic soda

  • Strips oil based paints
  • Caustic soda with wallpaper paste added makes a gel which keeps the stripper in contact with the workpiece.
  • Caustic destroys wallpaper paste unless its concentration is kept fairly low.
  • Caustic & wallpaper paste makes a low cost stripper
  • Avoid skin contact, caustic burns.
  • No toxic fumes
  • Splashes to the eye can cause major damage over time after the incident, so any such splash must be treated immediately and properly. Seek medical assistance.
  • Neutralise caustic residue with a mild acid before repainting, eg citric acid or vinegar.


Methylene Chloride

Stripper 624-3.jpg

Methylene chloride, also known as dichloromethane, will strip nearly any type of paint. It is fast acting and aggressive. It is a solvent with an array of known toxic effects, and good ventilation is important in use. Use it outdoors when possible.


Boiled linseed oil


Ecover washing up liquid

  • Removes emulsion paints. Soak in a dilute solution overnight and the paint just wipes off. Long soaking is often impractical though


Alcohol

  • Softens emulsion
  • Long soak needed


Acids

  • Remove all lime based paints on contact
  • See acid


Dip stripping

Dip stripping baths are routinely run until so weak that long immersion times are needed. Long immersion in caustic attacks the glues in the workpiece, often resulting in doors cracking apart and joints coming loose. The wood surface is also often left in poor condition after a dip strip. Dip stripping is quicker than hand stripping, but has a habit of producing poor results and damage. Where the woodwork is of value, dip stripping is best avoided.


Electric Scraper

Power scraper 1614-3.jpg

Electric scrapers have a vibrating blade, and are reasonably good at pulling layered paint off.


Wire wheel

Wire cup wheel 5451-3.jpg

High speed wire wheels (run on angle grinders) are extremely effective paint removers. They also damage wood surfaces quite a bit unless used lightly, and even then are much too rough for goods with a fine finish. These are a fast way to remove paint from hard surfaces (eg tough concrete) or where surface finish is unimportant. There is no paint tough enough to resist them, but they don't get into depressions in a rough workpiece.

Low speed wheels (run in a drill) are reasonably effective, but a little force may need applying to get it to do the job, and they won't always remove everything.

Miniature wire wheels run in a die grinder are effective for very small areas of detail.

Since all of these are rotary wheels, none reach into corners properly.


Paint stripping wheel

Paint remove disc 2600-4.jpg

Abrasive impregnated nylon mesh disc, used with drill or angle grinder. Far less damaging than wire wheel, though not as effective.

Toxic paints

White lead, grey lead and red lead are well known. Some lead paints are still in use. Historic arsenic green paints are also found very occasionally.

The others are unlikely to be encountered in house paints, but are readily found in artist's murals, frescoes etc.

A list of some of the more common toxic paint pigments:

Flake white 
lead carbonate
Cremnitz white 
lead carbonate
Grey lead 
lead monoxide
Red lead 
lead
chrome yellows 
lead chromate

Less common:

Naples yellow 
sometimes includes lead antimoniate
Cadmium yellows
Chrome green 
lead chromate
Paris green, emerald green, Schweinfurt green, (Paul) Veronese green, Emerald green, C.I. Pigment Green 21, Imperial Green, Vienna Green, Mitis Green 
seldom contains copper acetoarsenite
Scheele's green 
seldom contains copper acetoarsenite
Cadmium reds
Cadmium orange
Viridian 
chromium
Chrome oxide
Manganese blue
Manganese violet
Cobalt violet 
seldom contains cobalt arsenate
Raw & burnt umber 
manganese
Vermilion 
mercuric sulfide


Removal of toxic paints

Lead

Lead paints are common, more so on older houses. They are still in use, although much less common than previously, and were widely used on buildings as recent as the 1970s. They can cause serious health problems if handled wrongly.

On exterior surfaces its generally safer to leave lead paint in place and overpaint it rather than remove it. This also gives the benefit of greater woodworm resistance and a more durable base coat. Interior lead is a risk to chewing young children.

Leaded paints should be removed when necessary in a manner which does not produce dust, and traps any dust that may occur. A gel paint stripper is ideal. Lead paints should not be removed with a blowtorch or hot air gun, or by sanding, which produce dust and disperse it into the air.

Arsenic & others

Arsenic pigmented paints are rare, being mainly used in the 1700s and 1800s. Removal of those also poses a health risk. In damp locations, a reaction may occur liberating an arsenic gaseous compound (arsine).

Handling of paints containing arsenic and other toxins is beyond the scope of this article.

More info

For paint testing services, a good place to look is water testing companies, who test drinking water for a wide range of contaminants.

More information on toxic paints


Don't paint

IMAG0245-2 painted electrics.jpg

That's what it'll look like later.


See Also

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