If you are installing a solid copper head gasket I suggest that the best sealant is "Hylomar Blue" in a spray can
I have had very good luck with aluminum paint
Copper Coat. I've used it many times on all kinds of different head gaskets and it always works well. I also make darn sure the head bolt threads are clean and coated with anti-seize compound to help achieve uniform torque readings. Any one can achieve good results replacing head gaskets any one of a number of ways. Just have to make sure the mating surfaces are clean, flat, free of flaws, and properly torqued.
I think Les is talking SOLID COPPER, I totally agree with him. Les did you make your own or find a supplier? Last solid copper gasket I used was in the Navy years ago, anneal and reuse. KGB
These are new. Being CNC water jet cut from soft annealed solid copper.
I'm not interested in arguing about sealants. Just stating the results of many years of industrial experience. Others are welcome to have different opinions
We use Hylomar Blue on the solid head gasket on our Gemsa race engine. Works great. We had to O-ring the block and use a custom made solid gasket because the .130" over bore left only about 1/4" between the cylinders. No leaks with the Hylomar.
Since an engine rebuilder friend suggested Hylomar I've used it with never a failure.
That goes for using head gaskets a second time as well if they looked good.