Varnishing can be a tricky business... here are a few hints and tips from London-based chandler Arthur Beale

1. Be realistic
Varnished boats are hard work! Don’t take on the project unless you have enough time and/or money to maintain the boat. It can be enjoyable and rewarding work, but not if you are stressed out trying to find the time or can’t afford the basics.

2. Do the maths and invest
If you have decided to buy a varnished boat then it is time to do some maths. If a decent sander with extractor costs £800 but saves you 20 hours a year and your labour is worth £40 per hour then you might as well fork out now rather than in five years’ time. You will also get 20 hours extra sailing every year. The lack of airborne dust will probably add a few years to your life too. So don’t waste time with rubbish gear if you intend to keep your boat for a few years.

3. Read the instructions before you start!

There may be a minimum temperature needed or the product might not be suitable on the existing surface finish. Best find out before you start.

4. Buy decent abrasives
And buy lots of them – you can always use them next year. Some of the sheds sell appalling quality abrasives at very high prices. Best to buy good quality industrial abrasives which work at cooler temperatures and clog less. Consider buying a box of 100 sheets of every grade to last the next few years – you will save money and get the job done quicker. No more trips to B&Q.

5. Dust extraction is wonderful
The abrasives last longer and you will too. The boat next to you in the yard will be chuffed as well. Get an extractor that works automatically from the sander so it is not left running unnecessarily.

6. Don’t wipe down with White Spirits

White Spirits take a long time to evaporate. Even if the timber surface looks dry it probably won’t be just below the surface. Solvent entrapment is a major cause of bond failure. Wipe down teak or iroko with acetone, otherwise use isopropyl alcohol.

7. Tack rags
Always have one of these to hand to remove final traces of dust.

8. Use decent brushes
A cheap brush will not hold enough varnish to allow you to work fast. Hairs will fall out and the result will be a mess. Spend some money and buy a proper varnish brush. Mark it with a V for varnish so it never gets used for paint.

9. Ruthless hygiene
Now you’ve invested in some decent brushes you must clean them ruthlessly twice in White Spirits, then wash them twice in warm soapy water. Then dry them off with paper towel and wrap them in paper to keep dust away.

10. Consider rolling and tipping off with foam brushes
If you don’t fancy the ruthless hygiene, using foam rollers and brushes can give excellent results. One person rolls and the other 'tips off' with a wide foam brush. Also handy for touching up.

11. Think about how you will get it off
If you are thinking of using two-pack varnish, give some thought to how you will remove it in future years. Two packs resist scratches but are really tricky to maintain.

12. Mask off with decent tape
Even if you have a good painting hand, masking off allows you to work fast and avoid losing the 'wet edge'. Buy good quality tape and remove it quickly. Use very low tack tape if adhering to fresh paint.

13. Organise the area so there is no need to stop
Don’t just start varnishing without thinking about where you are going to stop. Try to mask off and do manageable sections. For instance, varnish one side of the hull and mask down the stem and transom. Then do the other side, then the rubbing strake or toe rail, etc. Small areas done swiftly are much better than struggling to maintain a wet edge by doing toe rail, rubbing strake and hull side all in one hit. Rig up scaffolding boards on trestles or at least ensure you can get your ladder to all parts needed.

14. Wind is the enemy
Go ahead if you absolutely must, but you will not get a good finish on a windy day. Dust will be a problem especially if that Volvo Estate drives through the yard with the driving waving out the window.

15. Don’t varnish late in the afternoon
I like to start very early. I wipe off any dew with a chamois and wait until the surface is completely dry, then I blast ahead before that Volvo Estate arrives. It is often very quiet and peaceful at 8am. If you work too late then the varnish won’t set up before the dew comes along, and the finish will go cloudy.

16. Don’t thin with White Spirits

I know it’s cheaper, but not when it takes two weeks to dry. Use the correct thinner which is often different for brushing to spraying. Why spoil the job at this stage?

17. Add some conditioner
If you are working in the sun or if there is a little wind, then try adding some Owatrol. It slows the drying time, allowing brush marks to fall out. It can transform your work. Only suitable for paints that can be thinned with White Spirits (not that we would ever do that!)

18. Stir things up
Please... always stir everything thoroughly; especially eggshell or rubbed effect varnish. It is impossible for the boffins to make everything of the same specific gravity, so separation is inevitable. Allow bubbles to settle before working.

19. Use a paint kettle
Always decant into a paint kettle so your varnish pot doesn’t get contaminated. The kettle will be a bit wider – so less likely to fall over – and it will be easier to work from. Clean your brush in it afterwards.

20. Don’t spread the varnish too thinly
Spreading the varnish too far will result in very rapid drying which will freeze-in brush marks and will reduce its penetrating bond to the substrate. The odd drip isn’t the end of the world.

21. Work fast
Use as big a brush as possible and work quickly, brushing the varnish in figure of eight motions and then laying off vertically. Do a manageable area, a vertical strip around 1ft wide if varnishing a hull is about right. Then move on to the next section, overlapping by about a third. It is crucial a 'wet edge' is always maintained or you will get lap marks. I varnish a 26ft hull in less than two hours (I start at 8am and finish before that Volvo Estate arrives at 10am). The Jenny Foam roller and tip off brush is another way to move fast.

22. A coat a day for a week
If you don’t put enough varnish on to begin with it won’t get through the first year and you will need to start all over again. six to eight coats are about right.

23. Touch up as you go
If you get some damage – and you probably will – touch it up quickly. Mask the area off, sand with 400 grit, clean, and apply some varnish with a Jenny Brush. It will take about 10 minutes and save a lot of grief.

24. Wash off the salt

If you have access to a hose or even a bucket of fresh water it is good to wash off those salt crystals which amplify the sun’s rays and cause increased UV damage.

25. Make some foot rests for your toe rail
A piece of slit hose or transparent plastic tubing placed over the toe rail where people climb on board or where spring ropes may rub can save wear and tear.

26. Cover it up
As soon as you finish your varnishing the clock starts. You can stop the clock with a hatch cover or tiller cover. In the winter a heavy canvas cover, not a flimsy plastic thing from the sheds, will save you a fortune. Go for a strong ridge pole and heavy tarpaulin which will not flap in the wind. If water gets under the varnish edges and it freezes, then it will flake off. If water gets between planks and it freezes then all sorts of things can happen. Just fork out and buy a cover or put the boat indoors!

27. Maintain every year
If you have applied enough varnish in the first place it should hopefully be a matter sanding gently with 400 grit and applying a top up coat. It is the fiddly bits that take the time.