Painting Engine Block and transmission HELP???????

[FireballV8]

Hi

I want to paint my engine and trans, both are out of the car. Last time I did a car I used Bill Hirsch paint and I didn't like it.

I went to my local paint store and they said to use epoxy primer on the bare metal & cast iron. Then go over it with acrylic urethane single stage with hardner. My question is do primers resist the heat? I was told before to spray acrylic urethane on bare metal without any hardner. Which way is correct? Please help.

Also this store sells glassurit paints and told me this urethane would be there UNO brand, is this any good?

Thanks

[Guest stude8]

Never spray any kind of paint on "Bare" metal if you expect it to stay there very long. Always prep the metal with the Phosphoric Acid solutions like those that Dupont and Ditzler sell. Once prepped then use a good primer, unfortunately the good Zinc Chromate stuff like MDP1538 that I always had good luck with was banned by EPA, apparently too many kids were eating it instead of applying it to the ferrous metal they were supposed to.

Think about it, your engine should normally not get over 212 degrees F except for the exhaust manifolds so most urethanes will survive that fine. I don't like hardener mixes because they invariably tend to chip from stones and the like. Good old Dulux enamel stays flexible and holds up for the long run better.

Stude8

[Guest imported_PackardV8]

surfaces to be painted MUST BE IMMACULATE. Spray with DuPont Centari acrylic enamel no hardenerdirectly onto the bare block. NO PRIMER. This is the DD recommendation. I used Renshed MAson acrylic enamel (1975 stock) and it holds up and sticks just fine. The DD should be even better.

DISCLAIMER: It works just fine on cast iron. I have no idea well it holds up on Al. Never tried it on Al.

[DizzyDale]

Dear Fireball,The UNO brand has to be somebodys cheaper line of product,should be fine.I always use Bill Hirschs engine enamels on ANTISEPTIC bare blocks and transmission cases and have NEVER had any problems.diz

[Bhigdog]

Bill Hirsch engine enamels on bare steel work fine. The castings must be completly degreased. Oils and grease hide in all the little sand pits in the rough castings. The castings must be scrubbed clean or better yet boiled out. If not completly clean no paint will adhere correctly.

[FireballV8]

Packardv8

What is DD?

So I am correct about the no primer?

Doesn't the Bill Hirsch paint get stained with coolant? Mine was a lighter color and it sure did.

thanks for all the help, please let me know I need to paint this weekend.

thanks

[Guest Indiana_Truck]

I have painted a few engines with the epoxy primer and single stage on top of that and they have all held up real well for years. You will always have a spot or two that you will need to touch up no matter what you use but I would go with the epoxy on the bare metal no matter what. Paint will not hold on to bare steel. It should take the heat unless they have messed it up from what it was to much.

Bob

[Guest imported_PackardV8]

DD = DuPont.

I use NO primer. Mix up some DuPont centari acrylic enamael and spray the block, heads any of the engine u want to. Call DuPont customer service (its a 1-800 number, find it on the net or something ) and ask them. If they tell u any different pls let me know. I called DuPont customer service about 5 years ago and a man about 50 years old told me NO primer, mix up the Centari and spray it just like u would a fender but NO primer.

[Rich Niezabitowski]

I have used it succesfully on aluminum transmissions and other parts after priming with Variprime. If you don't use a primer it will not stick at all. I have not tried it on an aluminum block so I can't comment.

[FireballV8]

Packardv8

The local PPG store owner told me the same thing, NO primer and this is what I've done in the past with no problems.

Thanks for the help

[Guest bkazmer]

Your engine, even with an unpressurized cooling system, can certainly get over 212 F - if the engine weren't hotter than the coolant, there would be no heat transferred to the coolant!

[Charles2]

About ten years ago, I overhauled the 300 ci six in my 83 F-150. The inside was pretty clean. I scrubbed the inside and outside of the block and head with solvent, rinsed the outside with toluol and sprayed them with spray-can engine enamel from Pep Boys, no primer. After 85,000 miles, the paint is still there; no signs of peeling or heat deterioration. This paint job has lasted longer than the original. More recently, I have done rebuilds/restorations after hot-tanking and heat-cleaning. On those, I have used phosphoric acid metal prep and then spray can primer and enamel. This has held up pretty well thus far but it is really too soon to be making predicitions. Mostly though, I never bothered painting the routine rebuilds I've done; not a good idea for restorations however!