One of the questions I am most frequently asked is how to prepare varnished furniture for painting, quickly followed by do I need to sand it?
My answer to this is definitely yes, you do need to key the surface to enable the paint to adhere to it if you are intending to apply a Mineral Paint which is essentially an acrylic resin-based paint such as Bunty’s Mineral Paint, Fusion, Fusion Mineral Paint and Fleur Designers Paint.
In this blog, I will cover the seven steps you need to follow, and I will be revealing how the correct prep is the secret to achieving durable and professional results every time.
Initial Check: How to Eliminate Woodworm
Always check your piece of furniture for evidence of woodworm. Look out for tiny round holes and new sawdust. Check around the round the back and the underneath of the piece.
If you find woodworm holes, deal with them immediately. Liberally paint on the woodworm treatment following the manufacturer’s instructions and isolate the piece away from other furniture until you are confident the treatment has been successful.
Don’t waste your time with the nozzle where you squirt the treatment into each hole, because if you miss a single hole and there is live woodworm in there you will not eradicate the infestation.
Step 1: Ensuring Smooth Operation of Doors and Drawers
Check that cupboard doors and drawers open and close with ease. As a rule of thumb, to allow for clearance once the piece is painted make sure you have a gap the depth of a two-pence piece around all the edges of the doors and the drawers.
Firstly, for doors make sure the screws are fixed tightly in the hinges, and if they are loose just tighten them up with a screwdriver. After years of wear, this is often a quick fix for sticking doors.
If the doors and drawers are sticking follow step 3 and clean the edges and sand them to fit. Go steady with the sanding, do a little at a time and keep checking the fit, just repeat this process until everything opens and closes with ease.
Step 2: Safely Remove and Store Hardware Prior to Painting
If you intend to remove the hardware (handles and hinges) this is the time to do it. More often than not you will find an interesting accumulation of dust, grease and dirt underneath them.
Carefully remove the hardware and put them and put them straight into a container and label it. That way nothing will go missing and you will find them easily when it comes to re-attaching them.
Believe me, it’s so easy to pop them down somewhere thinking you will easily remember where you have put them and then you spend forever looking for them. I know: I have done this many times.
Top Tip: Always keep the screws together with the item they attach to, that way you don’t need to work out which screws go where. Also if there is a risk that you are going to forget how to put the piece back together again either photograph or take a video before you start taking it apart.
Step 3: Essential Pre-Sanding Cleaning of Your Furniture
The most important step is thoroughly cleaning your furniture with a good degreaser.
Why do we need to clean before we sand, I hear you ask. Over the years dirt will naturally have accumulated, the furniture will have been waxed and polished by many a proud homeowner and it will have been touched by many fingertips that deposit natural oils.
During the sanding process, these greasy deposits warm up and liquefy causing them to soak into the wood, which will affect the adhesion and durability of your paint.
I use Fusion Phosphate-free Organic TSP, which is a great degreaser.
Bunty’s has the benefit of being more economical, but you do have to rinse off the residue: if you don’t rinse it can affect the adhesion of your paint. Fusion is a little bit more expensive but you don’t need to rinse it afterwards.
I fluctuate between the two depending on how lazy or energetic I’m feeling 😊. Follow the quantity guidelines on the bottles, but you are basically just adding a couple of capfuls to warm water. I just apply them with a washing-up sponge or you can put them into a spray bottle if you prefer. Once you have finished just wipe down with a lint-free cloth.
Allow your furniture to thoroughly dry, this will make the sanding process much easier.
Step 4: Effective Techniques for Sanding Your Furniture
You don’t need to sand back to bare wood: you just need to dull down the shiny surface to enable your mineral paint to adhere.
As a general rule, you just need to scuff-sand the surface of your furniture with 220-grit sandpaper, but you may need to go coarser depending on how thick and tough the varnish is on the piece. I wouldn’t recommend you go any lower than 80 grit.
You will find, depending on the age of the piece, varnishes that will sand very easily because they are so old and brittle. These are great to work on because you will spend very little time and effort removing them.
Other varnishes can be as tough as old boots and you will find your sandpaper is literally skimming the surface and it could take you a month of Sundays to sand the piece.
In these instances, you can try using a carbide scraper, a varnish stripper or a heat gun. Be careful with a heat gun if the piece is veneered as you run the risk of melting the glue under the veneer causing it to lift and bubble, and that’s a whole new job for you to do.
Another alternative would be to simply apply a bonding agent such as Fusion Ultra Grip.
Note that if you do need to use a coarser grit, I recommend that you go over the piece again with a finer grit to eliminate any scratch marks caused by the sandpaper. Again, you don’t need to sand back to bare wood, you just need to dull down the shiny surface to enable your mineral paint to adhere.
Think of a bath sponge: it has lots of tiny holes. This is the microscopic effect you are creating on the surface of your furniture when you sand it, so when you apply your paint, it flows into those tiny holes anchoring it to the surface.
Top Tip. If possible, scuff-sand on a sunny day. The sunshine will soon show you where you have missed a bit, and it will be right there shining back at you.
Step 5: Post-Sanding Cleaning - Removing All Dust and Residue
I tend to favour repeating the cleaning process in step 4 as a belt and braces approach, but try and be careful not to oversoak the wood especially if it’s a veneer. Give it at least two hours to dry in warm weather and I would recommend leaving it to the following day in colder weather. Although you are using water-based paints, you don’t want to trap water under the paint, as this can reduce its adhesive qualities and cause it to lift.
Alternatively, simply remove all traces of sanding dust firstly with a soft bristle brush then wipe it over with a slightly damp lint-free or micro-fibre cloth and keep rinsing, wringing and wiping your cloth until your water is clear.
Step 6: Pre-Painting Checklist - Is Your Furniture Ready?
Your piece is now almost ready for you to begin the fun bit, which is painting. But before you start, just follow this quick checklist as it will save you time and effort in the long run.
- Fill any holes or cracks with wood filler, allow to dry thoroughly and sand flat.
- Glue and clamp any loose joints, using a good quality wood glue. Remove any excess glue while it is still wet with a damp cloth.
- Check for any lifting veneer and glue it down.
- Assess if you need to apply a primer.
The Power of Proper Preparation - Key Benefits for Your Painted Furniture
With the correct preparation, your paint will adhere to the surface of your furniture, so it won’t lift, peel, or scratch off, giving you a durable surface for many years.
No dirt or grease will pull through to the surface which would otherwise cause your paintwork to stain and discolour.
You will achieve a smoother and more professional finish to your painted surface.
I personally find the sanding process very satisfying and it’s because I know that extra little effort in the beginning saves you so much work.
If you miss these fundamental steps to professionally prepping your furniture, no amount of layers of paint, varnish or wax you then apply in an attempt to resolve this will stop your paint from coming off and the only way to rectify this is to start again.
Remember: Prep for perfection!
Happy Prepping x