How to remove dust after sanding before applying paint/oil/glue?

Question

Before one can paint a piece of wood, it should be clean from any dust on its surface.

What is the recommended way to remove the dust?

I tried using

1. a hand brush, which only got rid of the rough bits and pieces
2. a vacuum, which worked great for the most part, but did not remove the very fine dust. The suction could cause the nozzle to bump into the surface and leave scratches
3. a glue soaked cloth (called "tack cloth") from the hardware store, which was intended for exactly that purpose and got the job done. Working with it was not very nice though, reusability is questionable and who knows what kind of stuff is used to make it sticky.

I guess that a wet cloth has similar sticky properties than the aforementioned shop bought cloth, but has the disadvantage of applying moisture to the wood (leading to warped wood).

Is there a better/recommended way to do this?

Answer 1

Is there a better/recommended way to do this?

All the methods you list are recommended ways of removing dust from the workpiece.

Brushing is actually a very good way to get dust off wood, and for many woodworkers it's the main method they rely on. It's just that you usually can't do it properly with only one brush. You can use a large soft hand brush to get the worst of it off but you need switch to something with stiffer bristles for the finer stuff. Paintbrushes work well for this and their small size makes them good at getting into corners.

Some people swear by tack cloths*, others don't like them because they hate how they feel and they worry that they'll leave a residue behind which will cause problems with the final finish (this doesn't appear to be much of a concern however).

I guess that a wet cloth has similar sticky properties than the aforementioned shop bought cloth, but has the disadvantage of applying moisture to the wood (leading to warped wood).

The real 'danger' to this is not warped wood, normally wood has to get really wet for there to be a risk of warping.

What you would worry about is raised grain (surface wood fibres swelling due to soaking up water). But this doesn't happen if you moisten the cloth with mineral spirits, acetone or very pure alcohol.

A very good modern material to wipe with that isn't often recommended is microfibre cloth. The very same surface texture that makes these so good at cleaning glass and polished surfaces make them very good at removing traces of fine dust from tiny imperfections in the wood surface. A lightly dampened microfibre cloth may be the best way to remove dust from sanded wood.

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* Homemade tack cloth
You can make your own quite easily, from a clean scrap of lint-free cloth (old sheets and t-shirts can be good donors for the fabric), a few drops of varnish, the appropriate solvent for the varnish and a little water.

Answer 2

Your item #3 is called a tack cloth and is quite commonly used for removing dust, because, as you noted, it's quite effective, and it's a highly recommended solution.

According to the linked Wikipedia article, there may be some VOC concerns, however, with increasing environmental regulations, those are either A) listed on the packaging, or B) being phased out of the manufacturing process.

Answer 3

Instead of sucking it up you can blow it away using compressed air (or just your lungs).

A moist (not wet) cloth will minimize the water you apply to the wood. A micro-fibre cloth is dry but will also have a very good dust grabbing properties.

Answer 4

Recommend an intial pass with a shop vac, which will capture probably 95% of the dust. It is good to use a shop vac to clean the surface between sanding grits, removing the larger grit particles from the wood before sanding with the next higher grit. While blowing the dust off with compressed air removes the dust, it also mixes it into the air so some of it can settle back onto the surface and so you can breath it.

To get the last 5%, tack cloths are ok if using solvent based stains/dyes/top coats. Do not use tack cloths if using water based stains/dyes/top coats. Microfiber cloths are excellent dry "tack cloths" - they do not need to be wet or tacky with anything, so there are no worries about contaminating the surface before using a either type of stain/dyes/top coat. Also, microfiber cloths can be re-used multiple times - simply take them outside and shake the dust out.

Answer 5

In a pinch I once used an old t-shirt lightly sprayed with hair-spray. The spray then dried on the cloth for a few seconds before use.

It worked surprisingly well.

Answer 6

"Swiffer" dusters have worked well for me in the past

Answer 7

I like to use a soft terry cloth to wipe down before I apply finish. So far it has worked well for me in getting the fine dust off the wood. On wood with larger open grain (like padouk) I sometimes will blast it with air from the air compressor as well.

Answer 8

try water pressure and an air hose to dry. a little Clorox can't hurt either. removing active biological really helps with the finished piece if its old.