Author Topic: Block Painting (Read 6601 times)

subsonic · « **on:** January 06, 2008, 04:09:14 pm »

I am going to paint my block before it all gets put together. I figure I can wing it, but would love to hear from you that have already done it.

The block has been run through the cleaning tank at the machine shop. I was planning on going over it with a wire brush to get any stuck on, flakey crap off.

Does anyone have any prep tips or tricks that they feel like sharing?

Any tips on sealing off parts of the block that need to be kept paint free?

Paint application? Did anyone prime, or just go straight to color? Thinners or hardeners used?

What have you used for paint application?

Drying /curing. Just air dry at room temp?

Type of paint. Needs to be durable and be able to take the heat.
I was thinking of one of the John Deere greens. I am guessing that the same paint that is used on the tractor blocks will be OK for our blocks.
Comments?

Turbinepowered · « **Reply #1 on:** January 07, 2008, 12:00:28 am »

I haven't done a block yet, but I did recently paint a set of manifolds, the valve cover and the oil pan of my Fox.

I bought that Dupli-Color stuff that you can get in a FLAPS type place. Says it's rated for 500F, comes in a variety of colors, seems durable enough, and was easy to spray on. Two light coats ten minutes apart, another ten minutes then a middling-wet coat. Let it all dry and you're done, handleable in three hours.

I masked everything off with painter's tape, since it's designed to come off surfaces without leaving a lot of tacky residue behind. It's the blue stuff you can buy in the paint department of places like Home Depot or Lowe's or ACE (I love ACE, lots of esoteric little things, but that's a digression).

I used petroleum jelly to mask things like bolt threads and heads.

jimfoo · « **Reply #2 on:** January 07, 2008, 09:30:58 am »

Not sure if you are painting the head as well, but if you are, you will need to use an acid etch primer as paint doesn't stick to Al very well. Priming the block will help as long as the primer can take the heat.

zukgod1 · « **Reply #3 on:** January 07, 2008, 03:16:32 pm »

I just painted the block I just got back from the machine shop.

I used a ceramic based gloss black. Dont know how long it will last.
I have used this paint in the past as well on other blocks. I even painted a set of SBC heads, it burned a bit just above the exhaust ports but the rest held up well.
I think it's a Krylon paint.

subsonic · « **Reply #4 on:** January 07, 2008, 04:04:04 pm »

I have seen the ceramic paint before. Would that hold the heat in the block, as well as reflect heat from the engine compartment?

silvertdi · « **Reply #5 on:** January 08, 2008, 05:52:53 pm »

Many years ago when I worked in an auto parts store (20 yrs ago), folks would come in and buy auto body paint to use on their engine block. They particularly liked Imron by 3M. Pretty toxic paint, but extremely durable. They may have something better nowadays. When I build my motor I'd like to paint (powdercoat) it wrinkle finish black...kinda like the new Harley Davidson engines. I think that would look pretty sharp...especially with a few chrome bits like the valve cover, timing cover, etc.

subsonic · « **Reply #6 on:** January 08, 2008, 07:54:06 pm »

That would look cool.

Don't cha have to bake on the powder coat to set it? Man you are going to need a BIG oven :wink:

jtanguay · « **Reply #7 on:** January 09, 2008, 05:39:51 am »

Quote from: "subsonic"

That would look cool.

Don't cha have to bake on the powder coat to set it? Man you are going to need a BIG oven :wink:

i bet the bare block would fit inside a nice fair sized oven. if not there are infrared heaters that'll do the job :wink:

jimfoo · « **Reply #8 on:** January 09, 2008, 07:09:47 am »

Quote from: "subsonic"

Type of paint. Needs to be durable and be able to take the heat.
I was thinking of one of the John Deere greens. I am guessing that the same paint that is used on the tractor blocks will be OK for our blocks.
Comments?

I think a John Deer green is a great color, though I may be a bit biased is it is almost an exact match for the original Rover block color. Then again Rovers started as sort of an agricultural vehicle with a tractor like engine.

subsonic · « **Reply #9 on:** January 09, 2008, 04:25:44 pm »

Just as a bragging point, who was there first? The rover has been around a looong time.

jimfoo · « **Reply #10 on:** January 09, 2008, 05:13:15 pm »

1948, though the engines were robins egg blue for a while.

Krazy · « **Reply #11 on:** February 03, 2008, 07:11:01 pm »

I like Caterpillar Yellow. I think all Clatterpillars should be painted Yellow.

jtanguay · « **Reply #12 on:** February 03, 2008, 07:55:50 pm »

Quote from: "Krazy"

I like Caterpillar Yellow. I think all Clatterpillars should be painted Yellow.

yea i like the yellow too myself...

AdAm84 · « **Reply #13 on:** February 10, 2008, 01:49:27 pm »

When I painted the block for my Jeep(sorry Jimfoo) :lol: I used plasticote semi-gloss black and ford (unfortunatly) red for accents. I primed everything first with engine block primer. Makes a huge difference. Needs less paint in the end. And I used POR-20 Black for the headers. No problems on either after 3500 mi. Biggest thing is to prep. it. Use lots of Brake cleen. lol

BlackTieTD · « **Reply #14 on:** February 15, 2008, 01:35:58 am »

I'm not sure what the thermal conductivity is of these types of coatings or if the manufacturers would give up this information or even know the values themselves.

The thermal conductivity of aluminum is typically between 120 and 250 W/m*K depending on alloy/temperature. Steel is a lot worse, like 15 to 30 W/m*K. Grey cast iron is around 70.

If you are able to get thermal conductivity data for the coating in question, and find that the values are lower than those for aluminum and steel, then the coating will likely hinder the heat dissipation abilities of whatever it is you are coating.

There is a reason heads are aluminum and its not just weight. Have fun.

Author Topic: Block Painting (Read 6601 times)

AdAm84