The allure of a fresh coat of paint is undeniable, but when it comes to varnished wood, skipping the sanding step can be a tempting shortcut with disastrous consequences. It's like trying to build a sandcastle on ice – the paint may cling precariously for a while, but eventually, it's all going to come crashing down.
Yes, you can restore wood without sanding using various techniques such as chemical stripping, steam cleaning, or applying a new finish directly over the existing one. Each method has its pros and cons depending on the condition of the wood and the desired outcome.
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.
The main reason people sand between coats of paint is to achieve a perfect, silky smooth layer of paint. For most drywall interior painting projects, sanding is not necessary.
Yes, you can put varnish over painted wood, but it's important to ensure the paint is fully dry and cured before applying a varnish layer. This helps protect the paint while giving the wood a glossy or satin finish.
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.
Make sure to sand the polyurethane between coats. Sanding removes drips, bubbles and other uneven spots in each coat. Dry the first coat for a full 24 hours. If the coat feels tacky or sticky after that, let dry until it feels completely dry.
Sanding lets you strip away these layers and start with a clean slate. If you paint directly over old paint or finish without sanding, the new coat of paint may not adhere properly or react with the existing layers, leading to a poor finish.
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.
– 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.
Wipe on three coats in succession allowing each to become "tack free" before the next coat is applied. Then, allow the varnish to 'cure' for 8 to 12-hours. When the first set of three coats has cured, lightly sand to remove any dust particles that may have settled in your finish.
Can I use any type of primer on varnished wood? For the best results, use a water-based primer that adheres to varnished surfaces without the need for sanding.
Medium Grit (80-120 Grit)
Medium grit sandpaper is the most commonly used type. It's perfect for general sanding to prepare surfaces for painting or varnishing. This grit range is typically used after the coarse grit in a multi-step sanding process.
No. Varnish IS a sealant.
Instead of sanding, use a liquid deglosser to dull the existing finish. This product helps you prepare the surface for new stain or paint without the need to strip or sand.
Waterborne polyurethanes usually require a minimum of 3-4 coats to be effective. Although there is some evidence that too many coats can result in a plastic-like finish, waterborne polyesters are thinner than other types and therefore require several more coats to provide the same protection for hardwood floors.
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.
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.
You do have have to sand if “off” to bare wood if you want to “restain.”. Restaiing is not possible unless you sand down to clean wood grain. You can repaint over poly but it is best to sand that surface first to give paint something to cling to.
Sanding between coats of varnish is important because it achieves two things: First, it knocks down the “high spots” and second, but more importantly, it provides a tooth for the next coat to adhere to. Otherwise, the subsequent coats can delaminate and lift off in large sheets.
The symptom of you applying too much varnish is that it runs. Surprise! When there's too much liquid it flows somewhere. Except it then dries.
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.
It's best to use a brush with natural rather than synthetic bristles for oil-based finishes, and synthetic brushes (often called 'nylon' brushes) for acrylic or water-based varnishes. But you can also use rollers or rags for both kinds of finish.