Engine Paint q

[Brett Dikeman]

On Jul 4, 2005, at 11:00 AM, n-engelbert at terrans.net wrote:

> I'll be getting my 3b block back from the machine shop this  
> weekend, and
> I'd like to paint it prior to putting the engine back together.  I  
> realize
> that I'll need high temp paint, and I had been thinking either  
> black for
> the factory look, or white, so that I can find leaks once it's running
> again.  BUT, my dad suggested to me that I could paint it LA3A,  
> mars red,
> to match the car that it's going into and to detect leaks.

I'd go black.  Red, yellow, etc look boy-racer-ish and rather bad  
within a few years unless they're kept completely clean and the paint  
was applied very well.

POR-15 makes what they call Hardnose paint; it is a 2-part,  
isocyanate paint that is extremely tough.  You MUST prep the metal;  
loose/heavy rust should be mechanically removed, then the whole  
surface should be sprayed with their "Metal Ready", which eats the  
rust and then leaves a light galvanized coating.  Then, you can apply  
or spray the paint. It has its own thinner, but I think you can thin  
it with Xylene.

As an isocyanate, the vapors are quite bad for you to breathe.   
Supplied-air hood/respirator is recommended/required for spraying,  
with some sort of cartridge respirator (not sure what kind) for  
painting and LOTS of ventilation.  Skin exposure should be kept to an  
absolute minimum(ie long sleeve/pants).  It will take about 2 days to  
fully cure, depending on temperature and humidity.  In short, it's  
probably best to have someone else put the stuff on if you are  
painting something sizeable; any shop which does classic cars or  
restorations should be familiar with POR-15 products etc...and  
painting a bare block should be a walk in the park.

The only other real choice in terms of durability is powdercoating.   
Skip the 'engine paint' sold in stores; I used the 'Duplicolor' stuff  
one lister suggested on my calipers (black, thank you much), and it  
lasted all of about 4 months before they were completely, totally  
covered in rust- and that was WITH two coats primer and flat-black  
topcoat.  Now I use POR-15's high-temp paint (not 2-part, just a  
variant of their regular stuff).  I honestly haven't looked to see  
how well it has held up...maybe I'll take a peek tomorrow.

By the way, if your block was bead-blasted or sandblasted, you need  
to have it professionally cleaned inside and out, and change the oil  
almost immediately; the glass bits are supposedly especially  
problematic.

HTH!
Brett
-- 
"They that give up essential liberty to obtain temporary
safety deserve neither liberty nor safety." - Ben Franklin
http://www.users.cloud9.net/~brett/