Jump to content


Photo

Cutting And Polishing Fresh Clear Coat


  • Please log in to reply
7 replies to this topic

#1 danie garry

danie garry

    I love BMW minis

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 2,254 posts
  • Location: malmo
  • Local Club: IMOC-Irish Mini Owners Club

Posted 08 June 2019 - 09:05 AM

Hi all, having a little trouble with some paint work I've just finished
Clear coated about 10 days ago, sanded out any runs and orange peel with 2000 grit paper wet and then I've used indasa compound on a white foam pad but it really doesn't seem to be taking the 2000 grit scratches out of the paint work
Any tips or suggestions on what I've messed up, not long enough with the polisher and compound or?? I tested a patch with indasa polish on an orange pad and 3m rossa on a black pad and the shine is there but there's still sanding scratches

Thanks in advance

#2 bluedragon

bluedragon

    Mini Mad

  • Members
  • PipPipPipPip
  • 186 posts

Posted 08 June 2019 - 10:15 AM

I'm not familiar with Indasa compound, but for this type of work at least 2 and often 3 grades of compound are needed. 

 

First, a heavy cut compound designed to remove sanding scratches. This will often leave the finish looking hazy, so follow up with a light cutting compound. For some product lines or color schemes, this is enough, but usually it's best to finish with a fine polishing compound.

 

If the use of heavy cut still leaves clear sanding scratches visible, it's possible that you had contaminants on your sanding paper or perhaps tried to stretch an old sheet of paper a bit too far. Try just removing these with fresh paper and clean lubricant (water with a bit of soap) and then polish again.

 

 

Dave



#3 Steve220

Steve220

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,897 posts
  • Location: Shropshire
  • Local Club: RAF Mini Club

Posted 08 June 2019 - 10:23 AM

You'll need to get down to 3000 (maybe 5000) and use a cutting pad with 3M finesse it. It'll then need refining with a polish pad and a chosen light cut compound. What's your paint thickness?

Edited by Steve220, 08 June 2019 - 10:23 AM.


#4 Ben_O

Ben_O

    Mill Road Garage

  • Paint Doctor
  • PipPipPipPipPipPipPipPipPipPip
  • 8,515 posts
  • Location: Isle of Wight

Posted 08 June 2019 - 10:46 AM

How long did you polish for?

 

If sanding with just 2000, you need to polish for a lot longer with a reasonably course compound to remove the scratches.

Keep topping up on compound and keep going and they will slowly polish out. You really want to aim for the panel to become warm from the polishing.

 

I would recommend polishing up in sections so that you can really concentrate the polishing on each section, say 5"x5" sections at a time.

 

If the scratches are really deep, then it could be contaminated sandpaper. Even the smallest piece of grit on the paper can leave deep scratches which will be very hard to polish out.

You could also be using too much pressure when sanding which will cause quite deep scratches.

 

You can work to progressively finer papers but you will probably find that if the scratches left from the 2000 are due to heavy sanding or contaminated paper, then the finer grades just won't touch it.

 

Are you using plain water with the 2000? I find that a drop of car shampoo in the water helps ease friction and keep soaking the paper constantly to avoid the area drying up too much.

 

Good luck

Ben



#5 And again

And again

    Learner Driver

  • TMF+ Member
  • PipPip
  • 24 posts
  • Location: Durham

Posted 08 June 2019 - 11:17 PM

Same as paint doctor said but don't use bucket of water use a garden spray type so you know you're not contaminating you're panel,personally I like to use farcela G3 and white foam pad keep adding touch of water to panel as well as compound when you get a panel right loosely mask it to stop it getting splattered with compound,slow speed keep moving it will come good.

#6 [email protected]

[email protected]

    Learner Driver

  • Noobies
  • PipPip
  • 24 posts
  • Location: scotland

Posted 10 June 2019 - 02:23 PM

to be honest i know a lot of people think it is a good idea to give the paint or clear a long cure time prior to flat and polish.

 

But when the paint gets too hard it is much harder to bring up after flatting, it is better to do it sooner than later, and if any flatting marks do re-appear after a week or two, they are much easier to deal with. Than starting from scratch excuse the pun  O_O

 

Funnily enough i an encountering this problem today on a series 2 landrover we are doing at the moment, the panels have been sitting around painted for about 8 days, ambient temps have been quite high, the paint is very hard, i would say it is taking twice as long as normal. i should have done them 5 days ago really.

 

Above suggestions about moving up a few grades of paper may well help, or as Ben mentions some nice soapy water in a squirty bottle and make sure the panel is scrupulously clean, before any flatting. and doing a small area at a time, if your sweeping across an entire panel you will never get them out no bigger than ten inches square at a time.

 

Farecla's new 360 compound is very good 

 

the darker the colour the harder the job will be.


Edited by [email protected], 10 June 2019 - 02:25 PM.


#7 Daz1968

Daz1968

    Camshaft & Stage Two Head

  • Members
  • PipPipPipPipPipPipPipPip
  • 1,921 posts
  • Location: Dudley

Posted 13 June 2019 - 11:01 PM

I have had good results going from 3m p2000 by hand, sanded one direction only using a rubber pad, then used p3000 and p4000 abralon discs followed by p6000 3m trizact on my da with a foam interface pad I always use a hand sprayer with fresh water, then I found it needed very little compounding to finish. I found this easier and more controllable than using coarse compounds. I understand the da makes a difference as to much orbit can cause pigtails but my electric Mirka sander seemed ok with 5mm orbit, some recommend 2.5 orbit for colour sanding.
I found 2k paint very hard to polish and the finer sanding made a massive difference just ensure all previous sanding marks are removed at each stage and clean properly before going to next grade. But I am no expert at this.
If you are doing it all by hand then use each finer grade at 90 degrees to the previous it’s easier to see when all scratches are gone.

Edited by Daz1968, 13 June 2019 - 11:01 PM.


#8 danie garry

danie garry

    I love BMW minis

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 2,254 posts
  • Location: malmo
  • Local Club: IMOC-Irish Mini Owners Club

Posted 15 July 2019 - 09:55 AM

thanks for all the advice, ended up going with 3000 and polishing a little longer and was getting some good results but with a few places that i wasnt happy with i decided to rub the whole car down again and re-do the clear coat over the weekend. much better result too so maybe a quick run with 2000 and 3000 wet and a polish and it's good to go!

 

thanks again guys!






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

Mini Spares