How do I adjust the knob on an air DA sander?

[rcx132]

The sander has an off centre axle, then a second axle and a knob. How should the knob be adjusted?

 

[brightspark]

it works as a counterbalance so should be out over and disc shuffles . turned in over and it locks and the disc and just turns . I think from memory

 

[rcx132]

The knob can be rotated. In one position it partially restricts the rotation of one axis. In the other position is allows full rotation of both axis.

 

[armalites]

It will have two flat sides, when they are next to the centre shaft it will be in random orbit mode. With the knurled bits next to the shaft it will be in scurf mode and won't orbit.

You'll know immediately once you spin it up.

I rarely if ever use the fixed mode.

 

[rcx132]

It will have two flat sides, when they are next to the centre shaft it will be in random orbit mode. With the knurled bits next to the shaft it will be in scurf mode and won't orbit.

You'll know immediately once you spin it up.

I rarely if ever use the fixed mode.

Thanks, that seems to explain it. When the knob is set to partially limit the second orbit it rips paint off quick but leaves serious marks. When set with both orbits totally free it leaves a lovely surface but sands much slower.

This tool is 20 times faster than the electric sander I started with !!!!

 

[Ruffian]

with the pad locked works really nicely as a soft grinder on doing door skin edges or similar.

 

[rcx132]

Thanks. So I locked it to get the bulk of the paint off, and then unlocked it to get the nice finish. This was an easy evenings work. Glad I went back to bare metal, there were a lot of rust pin holes. DA sander is awesome!

 

[armalites]

We can discuss the overheads of a compressor etc but air DA are great tools, you can even get discs up to 3000 grit and that is scary to watch someone using a DA on a car that looks fine then polishing it out to a mirror finish

 

[rcx132]

Can in use the DA sander to buff the clearcoat with wool pad?

Yes I was amazed how quickly it took the paint off.

 

[armalites]

Can in use the DA sander to buff the clearcoat with wool pad?

Yes I was amazed how quickly it took the paint off.

Not sure about a wool pad but a guy on the D3 fourm posted some pictures of paint correction on a black D3 where they used a DA with 3000 grit on the whole body, I would have been crapping myself

 

[Ruffian]

3000grit is normal for paint correction,

Have seen people use 1200 to flat runs out and polished up fine,
Even worse when you take a 80grit to a plastic airplanes window.

As for polishing with a da i wouldn't risk it personally, in locked aka single action.
To fine tune the speed and control i just don't think it would work too well.

On dual action would buff but not cut into the paint like a rotary.

 

[rcx132]

The Eastwood videos say to start with 1000 grit on the clearcoat, then 1500 then 2000, then buffing pads.

I thought I saw DA sanders being used with buff pads but not sure.

 

[graffian]

This was an easy evenings work.

I am impressed I would have gone and got my grinder/sander;-)

 

[the snooper]

No you cant use a da to finish paint work you need the proper machine polisher for that

 

[rcx132]

No you cant use a da to finish paint work you need the proper machine polisher for that

Boo, more money and tools! I might try a wool pad anyway and set the air pressure real low and try.

 

[rcx132]

I am impressed I would have gone and got my grinder/sander;-)

Sorry I really don't know, is that actually a better way? I tried poly discs but they were generating difficult amounts of heat and were not any faster than the DA sander when the second orbit was locked.

 

[postie jon]

lock for grinder mode ,turn for sanding.