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Head Gasket Copper Coat or Dry?

18K views 19 replies 7 participants last post by  philipswanson 
#1 ·
I am installing a new head gasket. Head was surfaced but not block. Do you guys recommend spraying the block surface with a light coat of Copper Coat for added insurance. Gasket is Cummins and the block looks good with machinists scale on edge with no light coming thru. I did have a previous oil leak but that was with a different head.

Thanks Phil Swanson
95 Bluebird RV
 
#2 ·
How do you spray anything without the over spray getting into things that don't need spraying? Install the gasket dry.
 
#5 ·
i've done plenty of headgaskets with a LOT of the copper coat, and studs and what not, and plenty without...and to my knowledge, neither has blown after i worked on it

so, go for it, or not...whatever you feel like

oh, btw, i sprayed the hg itself...both sides, gently placed onto the block, and then gently place head onto it without scraping it all off
 
#10 ·
I did something different. I copper coated the deck surface, let it dry and put the gasket on the next day, dry. The upper side and head are dry as well. Did it because the block surface was never decked as was the head. I am assuming that the copper coat never interferes with sealing. Hope I am right about that. The car racing guys swear by the stuff on head gaskets and they run 1,000 HP. The racers are saying it reduces both oil and water leaks even on multi layered MLS head gaskets. I have never heard of a single case where Copper Coat caused a leak. Thanks for all the comments, pros and con.

Phil Swanson
95 Bluebird
 
#14 ·
I cut o-rings into the block myself and sprayed the block, HG, and under side of head all with copper coat and didn't mask off anything. Seems ok so far.

I don't think its a good idea to get the stuff on the pistons and cylinder walls. My machinist warned me about getting CC into the rings and clogging them. I sprayed the deck but was careful not to get any on the cylinder walls. Yes, used masking tape and a wiped down the cylinder walls with oil afterwards just to make sure. I did not spray the gasket on either side, only the deck surface. These engines have a habit of seeping oil and coolant from the head to block mating surface.

Phil Swanson
95 Bluebird RV
 
#15 ·
Hope ya ll have good luck with CC on a gasket that your not even suppose to touch with your fingers. The HGs have a uncured film that seals to the head a deck .I use CC on copper head gaskets and some shim style but never on a layered gasket.
 
#18 ·
I sprayed a little just to keep the gasket from sliding. Still going strong.

Heard lots of high HP engine builders use it as well. It's one of those debatable things like retorques.
 
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