Rubbing down paint

[Jack155Q4]

I have a poor out of the gun finish and I am trying to rub 100% flat for buffing.

I have been using 1500, 2K, 3K and 4k sanding discs on a DA polisher (Meguires) and then using 2 types of compound to get a nice finish. This works well for the most part but it takes forever. I find the sanding discs are ineffective after just about 30 seconds and I can't see any more colour coming off.
I have now tried two manufacturers of these.

Instead for the 1.5K I was using Klingspor W&D on a block (then proceeding with 2, 3 and 4K on the DA (whether it is effective enough or not).

It is supposed to be a well know good producer of paper but i find it wears out really quickly and will wear through to the green backing in to time at all.
It was eBay bought and I don't know if I have a bad few sheets or not.

If you have any advice on how I can rub down quicker or another type of W&D paper supplier it would be very much appreciated.

I am considering using 1200 in more areas or even 800-1000 grit (followed by the rest up to 4K for an easy cut with the compounds)

Thanks,
Jack

 

[steveo3002]

maybe the paint isnt fully hard

you could prob sand a whole car wet with 2 sheets of 1200

 

[Jack155Q4]

What makes you say that. I would have thought the opposite - the paint is so hard I can't rub it down easily. The was done in Aug 11.

 

[steveo3002]

uncured paint can clog the paper

last year should mean its gone off , maybe your expecting too much it , knock the peel off with 1200 wet

 

[Jack155Q4]

Possibly, ok I will take it down with 1200 from now and 1500 by hand and use the DA for the 2, 3 and 4Ks.

Once 1200 has made it flat how long do you need to sand with the others? Is it just a few passes.or should I really work it?


Cheers Stevo.

 

[steveo3002]

yeah a few passes , i dont really think you need to go to 4000

 

[pedrobedro]

I get Mirka abrasives from the local supplier and they last well and don't clog too much. I don't think I ever used anything finer than 2000 grit wet, how bad is the finish to need that much before polishing and how many coats has it had for it not to be back to bare metal with all that DA work ?

 

[Jack155Q4]

I am only using 3 and 4K as I was advised to by the detailers on the detailing world forum. They said it will make bringing up the shine much easier with the compounds.

http://www.polishedbliss.co.uk/acatalog/mirka-abralon-sanding-discs-cat11.html

There are 3 coats on the car and then the original paint. No amount of sanding I have done has caused me to go through it. As I say, the discs I am using just stop any noticeable cutting after hardly any use! High speed, low speed, pressure, no pressure. I don't see where I can get it wrong but I must be.

So, once I have used the 1200 to get it dead flat I shall just being using anything higher to prepare it for compound and polish.

 

[steveo3002]

going over the 1200 with 1500 and 2000 would make polishing easy

make sure its super super clean while you sand it , you dont want to be having a lump of grit on the paper , rinse and wipe it over every few passes , and change the water often

 

[Jack155Q4]

Yes I have suffered with some lumps of grit in the paper. I need to be more careful. I am using a spray bottle for wetting the surface at the moment but it doesn't exactly rinse the paper which is where I was going wrong.

 

[steveo3002]

have a bucket and keep washing the paper , then use a sponge or squeezy bottle to make a trickle of water over where youre rubbing , so its a constant flow