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Discussion Topic:
Paint head gaskets?
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spqr67 |
11-21-2012 @ 2:10 PM
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Member
Posts: 43
Joined: Jul 2012
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I read that applying some ceramic (engine) paint to both sides of head gaskets before installing is a good way to seal them. They would be wet when placed on the block. Thoughts on this? Michael
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alanwoodieman |
11-21-2012 @ 2:52 PM
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Senior
Posts: 868
Joined: Oct 2009
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I use copper coat spray gasket coating, it seals small fissures in the cast iron and also acts as a lubricant to allow the head gasket to move around when torquing the head bolts.
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Stroker |
11-21-2012 @ 2:57 PM
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I agree with Alan, in the Fifties, there was a dedicated product called "Copsilloy", that was designed to do just what he describes. As you noted, the idea is to install the heads before the coating dries, as the heads move around a bit when being initially torqued.
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supereal |
11-21-2012 @ 6:09 PM
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Before you install the heads, have them resurfaced by a good machine shop. Inspect the block deck (surface)for any nicks or other things that can interfere with the head gaskets. We have used the copper bearing spray, but dry gaskets will be fine if the mating surfaces are correctly prepared. No paint.
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trjford8 |
11-21-2012 @ 6:29 PM
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I agree on the copper spray. Years ago (early 60's) I had a 33 Ch*^y that needed a rod replaced. I replaced the rod , but could not find a head gasket for the early 6 cylinder. I used the original head gasket and sprayed it with copper spray. It ran for many years with the old gasket. It was still running good when I sold the car to buy my first Model T ford.
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spqr67 |
11-21-2012 @ 8:38 PM
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Good stuff! Im on a bit of a budget so I have a set of non copper gaskets. Still suggest painting them? Do copper gaskets really make that big of a difference?
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Oldad |
11-21-2012 @ 8:56 PM
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New Member
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I agree with Supereal that the heads should be surfaced by a good machine shop, preferably ground or milled and not surfaced on a belt sander. If the heads are not flat you are destined for grief no matter what gasket or coating used. While the heads are at the shop inquire about getting them pressure tested. Copper is a better heat conductor but for street use you should be OK with a quality gasket. As noted before a quality coating will allow the heads to move when tightened. Follow the recommended pattern for torqueing and do it in several steps. Good luck.
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supereal |
11-22-2012 @ 11:42 AM
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Either steel or copper gaskets are fine if you follow my suggestions above. If you have aluminum heads, steel is a better choice to reduce the electrolysis which can firmly bond the gaskets and the heads to the block. A secret to getting a lasting seal is to replace all the studs (or bolts, if a later type). Most old studs are weak, due to heat cycles and erosion from the places that are "wet". This allows complete and full torque without having one snap. (Been there, done that). Be sure to use a good non-hardening sealer on all the block ends.
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spqr67 |
11-22-2012 @ 12:56 PM
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Member
Posts: 43
Joined: Jul 2012
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Thanks super. I do have a new set of studs as well as ceramic sealer for the threads. Will copper spray work on steel gaskets?
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Stroker |
11-22-2012 @ 2:09 PM
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Senior
Posts: 1460
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The original idea of copper gaskets was because annealed copper is quite soft, and will deform enough to fill-in the defects present when changing gaskets without machining a fresh surface on the block deck and heads. These usually had an asbestos "cushioning" layer sandwiched between the copper sheet layers. The steel gaskets are supplied on the assumption that the block deck and head surfaces are machined "true". Any high-temperature paint will allow for slight movement during torquing, and I personally don't believe it has to be copper, nor do I believe it is actually necessary on a properly prepared head/block assembly. Your previously referenced ceramic block paint should function as a temporary sliding surface just as well as copper, or white lead, or any other slow drying brush-on/spray-on films. What Super was saying is that if everything is properly prepped through appropriate machining operations, and you follow proper torquing procedures, you really don't need any coatings. The idea of allowing the surfaces to "creep" really goes back to the old copper asbestos gaskets that were designed to be used as replacement gaskets when no block preparation was done, and the gasket was expected to "flow" into the low points, voids, fissures, etc. In theory, if we had "optically flat" surfaces that didn't squirm-around, we wouldn't need gaskets at all.
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