I was doing some late-night web surfing and came across this old Subaru TSB on proper surface prep during head gasket jobs: http:/
(Link to the 3M Roloc Bristle "White" Disc: https:/ www.bescaredracing.com/ sti/ tsb/ cylinder_head_gasket.pdf / or https:/ www.amazon.com/ Scotch-Brite-Quick-Change-Attachment-Aluminum-Diameter/ dp/ B000FW4LDU /)
At least from an OEM, I was a bit surprised to see these discs as an "approved" method of prepping the engine block and/or the cylinder head for re-sealing. I have always used plastic razors and gasket remover.
trav, mattd, clineberger and others -- any thoughts? www.amazon.com/ gp/ product/ B01MSU3PYQ/ ref=ox_sc_act_title_2?smid=A1Y3PCPH3CY53X&psc=1