Painting a Mirror Dinghy
As repetitious as it may sound the trick to painting and a good finish is all in the preparation.
For best results paint indoors in a dust free environment, in temperatures above 15°C but not in direct sunshine or heat and follow the manufacturer’s instructions.
Clean the boat thoroughly and remove any loose or flaking paint and make sure the wood is in sound condition, dry & rot free.
Remove any hardware from the boat that you can, the more you can remove the better the finish, if items won't come off then mask them off with tape. The finished look will be far superior when fittings are re-fitted to a clean painted surface compared to painting around a masked off fitting.
Sand the boat using something like 80-120 grit sandpaper and if you have one a random-orbit or finishing sander makes the job much easier. This will open the grain and give the new paint a surface to grip onto and also helps promote an even coat of paint. In an ideal world sand away all of the old paint but if it's stuck well then there is an argument to leave it. If you leave old paint check for compatibility with the new paint by trying a small area if you are unsure what paint it is, old paint can also be removed using a hot air gun and a scraper but keep the heat away from the taped seams as it will easily remove tapes and create unnecessary work.
While you sand the boat you will notice any areas that need repair, maintenance or attention and now is the time to carry out those repairs and fill and fair once finished so they won't be noticeable once painted. International paints have the following NOTE:- If you are intending to carry out any filling and/or fairing work on any bare substrates a coat of primer MUST be applied before proceeding with any filling and/or fairing. Once this work has been completed then the second and subsequent coats of primer should be applied before proceeding
When dry sanding it's advisable to wear a respirator and eye protection as paint has old paint has varying degrees of toxicity, especially old paint.
Remove any sanding residues using a vacuum or brush and wipe the surface clean using a suitable solvent making sure the solvent has fully evaporated before applying paint, you could also use a tack rag. Mask off any areas that are not to be painted
We recommend using a 4 inch roller, either felt of foam and keep a wetted edge working to and along the chines of the boat starting in the middle and working along and out, for the best finish tip the paint with a lightly wetted (with paint) quality brush smoothing out the paint that has been rolled on, a felt roller can leave a slight stippled finish and a foam roller can leave small bubble both will dry with these almost vanishing, I have painted the undercoats without tipping off until the final coat.
Check for overcoating times and most primer/undercoats have an extended overcoat time so you can apply another coat without having to sand between coats. If you miss this time a light rub with 180-240 grit sandpaper will suffice again removing sanding residue as described above.
If your top coat is a different colour to the undercoat then it is possible to mix some gloss in with the final undercoat to give some colour to it, this is also a good way of using what paint you have instead of storing part used tins in the garage
Before the final coat lightly sand with 180-240 grit to ideally just smooth the previous coat, remove dust and wipe as previously mentioned and use a roller and tip off with a brush as I go or share the two jobs as it's easier with 2 to keep a wetted edge.
Varnish
Varnishing the inside would also be about 2 coats from a 750ml tin but different varnishing have different coverage and some Mirrors varnish the complete inside and some paint some of it.
For bare wood, the first 1-2 coats are normally thinned (by up to 50%) using a compatible solvent. This will help the varnish to penetrate into the grain providing better adhesion, repainting a boat the wood should already have had these coats so may not need the maximum amount of thinners or thinned coats.
Once these sealing coats have cured, lightly, sand the raised grain using 220 grit paper but try not to break through to the timber on edges.
It is important that end grains are sealed and they should be sealed to the highest grain before counting coats applied
Applying varnish, It is possible to use a roller when applying varnish although we would recommend using a quality brush. Brush it out with firm strokes along and across the grain holding the brush at 90 degrees to the surface.
Finish by gently stroking the surface with the brush at 45 degrees to flatten out the brush marks and pop any bubbles that might have appeared.
On vertical surfaces, lay-off with light vertical strokes. This will let any brush marks flow out and create the best possible finish.
Before the final coat I'd sand the surface with 400-600 grit sandpaper in the direction of the grain and fully clean any residue as previously described. Adding 5-10% thinners to the varnish can help reduce the brush strokes and achieve a smoother finish.
Using Epoxy
It's possible to get a high build finish to plywood by epoxy coating the wood and applying a second coat just as the epoxy has gone off (but still slightly tacky). once the two coats have cured it can be smoothed using wetted wet 'n dry paper then once cleaned thoroughly two coats of varnish (or paint) applied to finish the look and act as a UV barrier to the epoxy
For more in depth and product information please refer to the paint manufacturers website.
Mirror Coating
| Coating | Coverage | Area to Coat | No. of Coats | Quantity Required |
| Primer/Undercoat | 9m²/Lt | Mirror Hull | 2 | 1x 750ml |
| Top Coat | 12m²/Lt | Mirror Hull | 2 | 1x 750ml |
| Varnish | 12m²/Lt | Mirror Inside | 2-4 | 1-2x 750ml |
| Epoxy Coating | 10m²/Lt | Mirror Inside | 2 | 1.3Kg |
| Epoxy Coating | 10m²/Lt | Mirror In & Outside | 2 | 2x 1.3Kg |
The above are approximate figures as products vary from manufacturer to manufacturer, temperature, application technique, condition of boat and personal preference may all make a difference to quantity required.