Prepping head prior to painting

[smittykid]

I just purchased a 5.5:1 high comp. head from Snyder's. I'm sending the short block out to the folks in Skokie, Il. for a rebuild. I checked with them and they use the same paint that Snyder's sells. I want to paint the head before I get the block back. I think I know what to do regarding prepping and painting the head, but I wanted to double check with you guys first. Thanks in advance, Smitty

[Mitch]

Hi Smit,
Make sure you skim cut the new head as most seem to have a little twist. I usually spray a new head with brake kleen and paint, no primer needed.
this works for me, others skin the cat differently

[Mitch]

P.S. buy extra paint for the future as not all batches are the same exact match, even from the same supplier

[smittykid]

Hi Smit,
Make sure you skim cut the new head as most seem to have a little twist. I usually spray a new head with brake kleen and paint, no primer needed.
this works for me, others skin the cat differently

Ok, I'm showing my ignorance here-What do you mean "skim cut" and how can I tell if it needs it?

[Mitch]

it's called milling which will give you a flat surface on the head where it mates to the block. usually .010 usually gets it right
It shouldn't need to be done on a new head but they have been coming through with a tiny twist

[Big hammer]

Your NOT showing your ( a word I don't like) your asking and learning, thats why there's a forum ! No dumb questions !
Learning that's smart :-)

[Mitch]

Right on BH i should have said that but was concentrating on my answer
THANK YOU

[tbirdtbird]

Captndan and I like to do what Mitch does, and then we treat the metal with Ospho (phosphoric acid) and let it sun dry, and then use the paint of your choice. Do not wash Ospho off. If you ever want the paint off, you'll have to sandblast if off. The Ospho etches the iron and gives a hell of a bond, especially at the seam area, which always likes to rust up/peel back

[JB-OB]

I won't be critical of our Host's mechanical ability, but when it comes to paint.....

Ask any successful painter of houses, cars or boats, they ALL use a primer to act as a 'glue' to hold the top coat to the surface to covered.

After all the effort to scrub, scrape, clean & pickle the metal, without a base coat of epoxy primer, you've wasted your time.

[Mitch]

Love Ya Jimbo

See ya at high noon with primer, and paint in hand for my tires

[Rowdy]

JB-OB, what primer do you recomend for engines? The only time I used primer on engine parts it was a disaster. Primer/paint bubbled off in the warmer areas of the engine. Mechanicly and electricly I am pretty good, paint and I mix like oil and water most of the time. Rod

[CarlG]

Why not send the head along with the block and have it installed (& painted) by the engine builder.

[Mitch]

Good idea Carl & milled

[CarlG]

Actually, that's what I did, and he did have to mill it about .010

[BILL WILLIAMSON]

Scrub it with T.S.P. which etches the surface for better adhesion. NO primer needed.
By the way, skin a CAT from the rear to the front!
Dad Shine

[tbirdtbird]

in 40 yrs we have never used primer on a block. with good prep not needed. don't wanna reduce heat transfer any more than u have to

we have a booth here and have painted a whole lot of cars over the years.
the quality of your paint brand helps, too

[JB-OB]

Rowdy,

For all my cleaned & prepped bare metal I always start with PPG DP-LF 90 Black epoxy primer, especially under to be painted black items. Why would anyone use lite gray primer under a black top coat when the first stone chip looks the size of a man hole cover ??

For my engine block, in the car, I mixed the epoxy as recommended and brushed it. Following day brushed it green and that was 20 years ago in a typical Model A engine compartment with the common leaks & drips. No peeling yet.

I have no advice on skinning cats or dogs......

[BNCHIEF]

Bill is an old cat skinner? Also what we call dozer operators in the oil patch.

[Captndan]

Without another thought send the head with the block. Checked, milled, assembled, and painted. Done.

[BILL WILLIAMSON]

Bill is an old cat skinner? Also what we call dozer operators in the oil patch.

YEP, Chief, I could tell you about all my escapades, with a Caterpillar-22--LOL---I actually pulled a 15 Ft tandem disc with it!!!---Uncle "Pappy" threatened to BURY me, with his D-8 Caterpillar, with a DOZER blade, as he was digging a GARBAGE PIT!!!
Bill Stillscared

[BNCHIEF]

I knew an old catskinner if you made him mad he would damage your truck or cut a tire with the blade positioning your truck on a drilling rig site. We called him killdozer.