Why my sandpaper is clogging when sanding filler？

Have you seem to get clogs or chunks of material on my sand paper when sanding primer and putty? Instead of coming off as dust, some of it comes off as globs that stick to the sandpaper.This causes the sandpaper to not make good solid flat contact on working surfaces, preventing us from getting a good smooth surface.

What's happened ?

At first we need know the mechanism of clogging,clogging have 4 types: embed type,clinging type,adhere type,mixture type.

1.Embed type: dust or chips fills the air inlet or gap of abrasive grains under the pressure.Mostly happened on bonded abrasives,such as bench grind wheel.

2.Clinging type: The chips slide out in front of the grinding particles, causing a local accumulation of dust, and a negative pressure vortex is formed in the area behind grinding particles due to the decrease in air pressure and the effect of rotation. This negative pressure causes the dust to clinging to the back of the grinding particles.

3.Adhere type: Most of the power in the grinding process is converted into heat concentrated on the surface of the workpiece, causing the surface of the workpiece to in a semi-melted state and adhere to the surface of the abrasive grains. By multiple random grinding, the clogging situation will be aggravated and the heat increase, forming a vicious cycle.

4.Mixture type：consist of embed,clinging,adhere types

Now let us return to looking for sandpaper clogging of sanding primer and putty,you will find that was a mixture type clogging.Embed and clinging type happened at firstly,then clogging spread to adhere type. So result to visual clog or chunks on sandpaper surface.

How to improve it?

Through by analyzing the mechanism, clogging are unavoidable.But there have some ways to improve it.

If working condition allowed wet sanding,that will be a good option.Water or oil will crush out chips and take off heat from working surface.

Addtional top coating such as zin-stearate,nanocryst coating as lubricant between abrasives and workpiece.After these coating absorbing heat, it changes from a solid state to a solid-liquid state to fills the gap between grinding particles,that help less dust accumlation.

For workpieces that easily produce very fine dust during grinding,we can used open or semi-open coated technology to reduce clogging，or some special shape such as net or rhombus shape to create a dust slide out channel.

And select higher self-sharpening grians(white aluminum oxide,ceramic),through by gain's broken and stripped to take off clogging dust and chips.But there need a balance between effect,service life and economy.

At last used right grits, sanding speed and pressure also helps for that.

If there have more solution for it,welcome to share us.