In this blog entry, we’ll be looking at:
- Applying varnish
- Why does my varnish not look smooth when dry?
Well, this is the easy bit. It’s pretty obvious, but here’s how:
- Buy a can of marine-graded varnish. Any brand sold in Australia is ok. The smallest size is usally 500ml.
- Pry open the can with a flat-headed screwdriver. Try not to mangle the lid. Chances are, you will not finish one can in one sitting. A 500ml can of varnish can completely restore 15 paddles, with 3 coats of varnish covering the whole paddle. If you are only restoring one paddle, you want to reseal the can after each use.
- Brush on the varnish with a brush. From my experience, a 25mm or 30mm (width) brush will do just fine if you’re only using a single brush. If you have the luxuary of different brushes, then a brush about 1/3 of the width of your paint area what I’d use.
- Brush along the wood grain. This allows any imperfections to be hidden in the grain when the paddle reflects light.
And you’re done! If only life is so easy. Unless you’re painting over a paddle in mint condition, you probably need to consider a few things.
Why does my varnish not finish smooth?
There are a lot of reassons for this:
- Too much varnish
- Too little varnish
- The wood was wet when you applied varnish
- Water got on the paddle before the varnish dried
- You applied the next coat before the previous coat dried
- The wood absorbed all the varnish
Too much varnish
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. And you have a finish that looks like the text in a Halloween poster.
Your brush is an instrument that transfers liquid varnish from the can to the paddle, much like a ladle transfers soup to a bowl, or a spoon transfers soup to your mouth. The trick is to not put so much varnish on your brush that it starts running when your brush touches the wood.
Side tip: people generally dip their brush well into the can, soak up a heap of varnish, then scrape the excess off the inside edge. Don’t do that. Dip a tiny part of the brush (1cm, more or less depending on how big the surface area is that you want to paint) and put all of it onto the wood. If you’re hoping to keep this can fo varnish over a long period (e.g. more than a month), you want to keep contamination out of the can. This means dust, sawdust, even dried varnish that stayed on your brush from a previous job. Remember that your brush transferrs stuff. It transfers anything, in either direction.
So what do you do if this happens:
- If your varnish is still flowing wet: get your brush, spread the stuff out. Done.
- If it’s starting to look/feel like goo (say you tried to brush it, you still moved it but it looked sludgy): dip a tiny corner of your brush (and I mean tiny) in mineral turpentine and work that into the goo. It’ll become more liquid again and you can spead it out.
- If touch dry (you still feel a bit of softness under the surface): grab a small knife (safety disclaimer), shave off the drip. let dry. See next point
- If your varnish is dry: That’ll depend on how nice you need your surface to be. If you don’t care, just sand it flat. If you want it looking like a display piece, then you’ll need to put a new layer of varnish over it. You don’t need to cover the whole paddle again. Just make sure the new layer is very thin (maybe use a tiny art brush or a nail polish applicator), and use wood patterns to your advantage. For example, if it’s on the shaft of the paddle, then just make sure your brush strokes follow the general direction of the wood grain. If you’re painting the blade, and the blade surface is made of strips of wood glued together, then paint one strip of wood and stop at the edge of the strip. And stop if you get to a place where the wood significantly changes colour.
Too little varnish
Not much to do – sand it flat with a fine sandpaper (e.g. 600 grit sandpaper), and paint again. Don’t sand too much off, what’s painted on is good stuff! Just make sure it’s flat.
You applied varnish to wet wood
Ouch. Let me explain some high school science. When water heats, it becomes steam. And it expands. Try this: put a bottle of water in your car on a hot day. Check it after a few hours. The bottle has probably puffed out. Now, think about what this means to your paddle.
Trouble is, you may not realise this until some time later (on a hot day out paddling), unless your paddle storage gets very hot.
There are two symptoms:
- If your paddle is used less than 10 days after the varnish is applied: chances are, your varnish is still curing beneath the surface. The steam will make the varnish look like it’s developing a series of blisters.
- If your paddle is used over 2 weeks after painting: the varnish will likely crack, or develop a large bubble, as the steam finds a single weak spot, gathers there, and lifts the varnish off the wood.
Unfortunately, you’ll need to cut out that section of varnish, and… let it fully dry before you make this silly mistake again.
Side tip: if your wood has been affected by weathering and mould (like it’s black where the damage is), wet mould wood is black. Fully dry mouldy wood is grey. Dry weathered wood will have a grey, powdered look. You’ll need to be patient – as the wood dries on top, moisture from deeper in the wood will gradually come to the top. You can speed up the process by leaving the paddle somewhere warm and dry, but don’t leave it in full sun or any carbon fibre in the paddle will be ruined if it’s allowed to reach 85 degrees celcius. Don’t be tempted to use a hairdryer, it doesn’t really speed things up to much, unless you’re willing to stand there for 2 hours, blowing on the wood with low heat. If your wood is in great condition, then you’ll have to rely on touch. But the wood is less porous than weathered wood, so if it’s touch dry, it’s dry.
Water got on the paddle as it was drying
Rare, but well, beginners make mistakes. The first is that you flicked water onto the paddle as you were washing the brushes. If it’s this early on, and the water stayed on, your varnish may dry milky. Remove and reapply. See earlier sections regarding how.
The second is if the wood is touch try. When this happens, your varnish may look wavy. This is because varnish is not necessarily a consistent liquid, and bits dry at different speeds. When moisture gets on it, fully-dried areas are unaffected (as it is now waterproof), and still-wet areas absorb and expands. Sand down, and depending on your visual requirement, repaint.
Next layer applied too soon
This only really happens if you painted a layer quite thick. It’s like the second symptom in the section above. When a new coat of varnish is applied to a surface that appears dry and is not fully dry, different minute sections of the surface interacts, and expands, differently to the solvents in the new varnish. Sand down, and depending on your visual requirement, repaint.
Wood absorbed all the varnish
And it looks like you’ve barely painted it. It clearly looks like you’ve varnished it, but all the wood structure is still showing though.
This post already looks a bit long. Stay tuned and we’ll talk about it in the next post in the series.