How to clean block deck? - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• How to clean block deck? by 92EcoDiesel Jetta on 29 Jul, 2011 06:42
• What's the best way to clean the block surface in preparation for a head gasket install? Bear in mind that the block is in the car so can't put it in a hot tank or parts washer afterwards.
• #1 by CRSMP5 on 29 Jul, 2011 08:27
• i use a die grinder fitted with scotch bright pad...
• #2 by Mark(The Miser)UK on 29 Jul, 2011 10:22
• Quote from: CRSMP5 on 29 Jul, 2011 08:27

  i use a die grinder fitted with scotch bright pad...
  

  
  Scotch brite is too abrasive IMO, use a piece of brass, or mild steel
• #3 by dl_sledding on 29 Jul, 2011 14:41
• Really? Scotch Brite is too abrasive?
  
  CRSMPS, you mean the plasticky, rough pad, not the steel wool, right?  Like this stuff:
  
  
• #4 by theman53 on 29 Jul, 2011 15:56
• On a die grinder he means these
  
  
  
  Not too abrasive if you can get the super fine. Maybe ok with the very fine. But nothing coarser. Even the very fine is capable of radiusing the corners of water passages and making leaks if you aren't careful.
• #5 by Mark(The Miser)UK on 29 Jul, 2011 16:39
• Quote from: dl_sledding on 29 Jul, 2011 14:41

  Really? Scotch Brite is too abrasive?
  
  CRSMPS, you mean the plasticky, rough pad, not the steel wool, right?  Like this stuff:
  
  
  

  I think that plastic is a misnomer, I think that's harder than steel wool. Having said that, the fine scratches will probably help the gasket bond.
• #6 by CRSMP5 on 29 Jul, 2011 19:23
• been using red round ones for 25+ years... even on head surface... if you worry.. do it on block.. then use same pad on head.. it is much more worn in that order.. and simple.. do not sit in 1 area too long.. your just cleaning it up... not decking the block/head.. and honestly.. you would really have to work at it on the block to screw it up...
  
  
• #7 by maxfax on 31 Jul, 2011 03:56
• I'm with ya CRSMPS but, you'd be surprised what those little discs can grind..  That being said I've used them cautiously if I'm going to be using a fiber gasket..   With a MLS, no way!
• #8 by 92EcoDiesel Jetta on 31 Jul, 2011 12:09
• I don't have air tools here or those Scotchbrite pads. I do have a scrap piece of1/2 thick Lexan 4"x8" so I taped a piece of 400 grit wet dry paper to it for a sanding block.
  
  
  
• #9 by 92EcoDiesel Jetta on 31 Jul, 2011 12:11
• 
• #10 by 92EcoDiesel Jetta on 31 Jul, 2011 12:19
• I hope 400 grit is not too coarse. I used WD40 as a lube/cleaner.
  
  before
  
• #11 by 92EcoDiesel Jetta on 31 Jul, 2011 12:25
• Cleaned up really well.
  
  After
  
• #12 by 92EcoDiesel Jetta on 01 Aug, 2011 10:42
• Sorry, it seems I posted the same pics twice, twice! Couldn't see it I was on my phone on the WAP site. Fixed!
• #13 by CRSMP5 on 01 Aug, 2011 20:00
• scotch brite lot less harsh then 400 grit..
  
  how did you clean the head??
• #14 by 92EcoDiesel Jetta on 01 Aug, 2011 21:11
• I used the same 400 grit sanding block on the head after using it on the block.
  
  I've read that cylinder heads on performance engine are finished to RA 50. I did a search for RA 50 and came up with a table of stainless steel surface finish in this thread:
  
  http://www.finishing.com/98/42.shtml
  
  Per the table, RA 50 is around 130 US grit, so the 400 grit I used is not too coarse, but too fine.
  
  I assume you do not want a super smooth surface on the head and block such that the head gasket can slide around against but rather a coarser surface like 130 grit to "bite" into the head gasket. I am just theorizing so forgive me and set me straight if I am wrong.
  
  
  
  

  Quote from: CRSMP5 on 01 Aug, 2011 20:00

  scotch brite lot less harsh then 400 grit..
  
  how did you clean the head??