Let's start with the good news: You do not necessarily have to remove old paints and varnishes before repainting - with our paints you can easily repaint an old layer of paint or varnish. However, if the old paint is damaged and peeling, the first step is to remove it.
It's generally recommended to remove old varnish before applying a new one to ensure proper adhesion and finish quality. However, if the existing varnish is in good condition, you can apply a new coat after thorough cleaning and surface preparation.
If you do decide to go ahead and apply new varnish over the top of old varnish, make sure that the existing varnish is scratch-free and do give the old varnish a light sanding using 120-grit sandpaper and wiping away any dust. This will ensure that the new varnish has something to bond to.
Denatured alcohol or lacquer thinner will generally do the trick on stubborn coatings.
– Existing Finish: If the wood has an existing finish that needs to be removed, stripping is typically the preferred method. – Surface Imperfections: If the wood has surface imperfections, scratches, or uneven areas, sanding is more appropriate.
Here is the step-by-step rundown for how to remove varnish from wood (without sanding!) Firstly, pick a varnish remover to use and then spread it evenly across the wood surface. Give it some time to set in. After a few minutes, it will break down the varnish.
Marine Spar Varnish can be recoated in 10-12 hours at the recommended coverage rate. The varnish can be recoated without sanding up to 24 hours. Beyond 24 hours, sanding is required.
PolyShades stain and polyurethane also allows you to easily change the color of your currently stained or varnished wood without stripping. Over old varnish you can change the color without removing the old finish or hiding the grain.
Many wood surfaces are treated with finishes like varnish, lacquer, or sealants to enhance durability and appearance. Vinegar can strip away these finishes, leaving the wood vulnerable. This not only affects the wood's aesthetic but also its ability to resist moisture and other damaging elements.
Removing Paint or Varnish: For removing paint or varnish, use a coarse grit sandpaper, such as 40 or 60 grit, to quickly remove the old finish. Aluminum oxide sandpaper is a good choice for this task. Shaping and Rough Sanding: For shaping or rough sanding, use a coarse grit sandpaper, such as 40 or 60 grit.
Gloss oil-based varnish, polyurethane and Danish oil can last 10 or 20 years, though satin finishes and stains may fail sooner as pigments and flattening agents disable the driers. Water-based coatings and paints can also be viable longer than three years. Shellac, though, can go bad in under a year.
While polyurethane is water- or oil-based plastic resin, varnish is older and made from resins, oils, and solvents. Because of the higher ratio of solids, varnish is less susceptible to ultraviolet light damage. This protection makes varnish an excellent choice for projects such as outside decks and exterior furniture.
A: Usually when varnish remains persistently sticky it's the result of application in a humid or cold environment. Sticky varnish can also be caused by too-thick application, or by re-coating an insufficiently dry layer. Traditional varnishes made in-studio (e.g. damar and mastic) are most prone to stickiness.
If your varnish isn't flaking and is in good condition, you can paint over the top of it. This is particularly useful if you just want to change the colour of the varnish. However, if you're using a contrasting colour, stripping the old varnish will ensure you have a better and more accurate colour.
Citristrip is a good alternative to Minwax If you're looking for a less toxic varnish stripper. Aside from Minwax, Citristrip was the best for removing finish. While the manufacturer recommends leaving it to soak in for at least 30 minutes, I noticed the finish bubbling up after only about 12 minutes.
Sanding Tips: No sanding is needed if you overcoat within 48 hours. Don't sand unless the most recent coat has dried for 24 hours. Use 320 grit to prevent scratches; sandpaper finer than 320 grit will not allow proper adhesion. Remove residue before reapplying.
Re: removing varnish from furniture
There are two methods to remove the varnish on your table. Use an Orbital Sander in conjunction with 180 grit sandpaper. The other method is to use Bondall 1L Water-based Paint & Varnish Stripper.
White vinegar, also known as distilled vinegar or spirit vinegar, is made by fermenting grain alcohol (ethanol) which then turns into acetic acid. Water is then added to the vinegar, so white vinegar is made of five to ten percent acetic acid and ninety to ninety-five percent water.
Safe Cleaning
It's important to dilute these substances properly. Too much vinegar can potentially dull the wood finish over time due to its acidity, while too much Dawn can leave a slippery residue. The ideal mixture typically involves a mild solution of diluted vinegar with just a few drops of Dawn.
Bonding primer: Specially formulated primers can create a strong bond between paint and varnish, even without sanding. However, these primers can be expensive and may not be as durable as a sanded and primed surface.
Remove any existing varnishes, waxes, oils or stains with a suitable remover or stripper. Then clean off grease, dust or dirt traces with a damp cloth or a dry brush.
Do You Have to Sand Before Staining Wood? Wood needs to be sanded well before it can be stained. The process opens up the wood's pores to better absorb the stain. It also smoothes away scratches in the surface which will only be enhanced by stain.
We recommend using Zinsser Bulls Eye 1-2-3 for glossy surfaces like varnished wood. Zinsser Bulls Eye is a 'bond coat' primer that's great for hard-to-stick surfaces as it offers excellent adhesion without sanding.
For a very durable finish and one that needs to be very tough, say on a kitchen table, coffee table or end table etc, 2 to 3 coats of varnish should be enough on the top, with 1 to 2 coats on the legs/base. For chairs, benches, chests and other such pieces, 1 to 2 coats should do the trick.
Spar varnish (occasionally also called boat varnish or yacht varnish) is a wood-finishing varnish, originally developed for coating the spars of sailing ships, which formed part of the masts and rigging.