Paint question for Jack [or anyone else wise]

[JPSmit]

Jack, not too long ago, someone was asking about painting his engine (he was looking for high heat engine paint in green as I recall)

I seem to remember you saying you didn't prime your engine before you painted it-

Any reason?

TIA
JP

 

[jlaird]

No reason at all, I just never have nor have seen it done.

Now that does not say it is wrong to do so. I just never have and I have painted quite a few. Have never had the paint come loose either, shrug.

What you other guys say, is a good question.

 

[Shealey]

If you prime it, use a acid based or self etching primer. Watch the mil thickness if you prime. There is alot of heat and expansion and contraction working against the adhesion. Engine paint works fine without priming. It's soft and durable as well as heat resistant. If your going to use a custom color you may want to prime first to increase adhesion. You may want to also use a flex additive to help with the adhesion, expansion and contraction.

 

[jlaird]

Ahhhh, makes sense to me. Always wondered why I did it that way.

 

[John Loftus]

The Hirsche engine enamel instructions said that no primer is needed for the block and head (because they are porous). Just make sure it is clean of grease and oils. For all the smooth metal parts such as valve cover, side access panels, oil pan, etc. use a primer.

Here's the page with the instructions:

https://hirschauto.com/engine.htm

 

[JPSmit]

For all the smooth metal parts such as valve cover, side access panels, oil pan, etc. use a primer.

Here's the page with the instructions:

https://hirschauto.com/engine.htm

That's pretty much what I've been doing - thanks for the confirmation