I found out today that the machine shop that is rebuilding my 364 sandblasted the engine, then threw some kind of Red Oxide primer on it because they didn't want it to rust due to the humidity coming from their hot tank. They were also going to coat over that with Seymour's Alumi Blast. The problem is the Alumi Blast is not rated for heat above 200 degrees and I can't find any info that shows the red oxide is either. I'd rather use Duplicolor Cast Coat Aluminum on the block, heads, etc. and their metalcast paints on the brackets and accessory items, but Duplicolor techs tell me that if I put an engine enamel over anything but their engine enamel primer it won't hold up. Do I need to have the machine shop sandblast again and go with Duplicolor's advice? Not sure what to do, but I want to do it right the first time. I have to make a decision within the next two days. Any advice is much appreciated. Thanks in advance! Joe
People have been using red-oxide for years on engine rebuilds. It actually works well in the valley and the heads to reduce oil build up/sludge.
sand blast it clean. Consider using caliper paint for your engine if it comes in a color you want to use. Caliper paint can be sprayed or put on with a brush and it levels great. Most caliper paints are humidity curing urethane and you wont need a primer so lifting will be far less likely to occur. Urethane is incredibly durable too so then engine will look great for many years to come.
I don't know much about red oxide. What is it's heat resistant properties and can you put any brand primer over it? I was told not to mix brands. thanks for your input!
I agree that I should do it the right way. I'll have to look into the caliper paint. I don't want anything I have to heat cure as this will be sitting without being run for a little while. Do I even really need a primer or can I go Duplicolor engine enamel right on the engine? I've also heard people say that the sprays aren't as good as the Hirsch paints, but not sure what to believe.
Well you'd figure caliper paint would hold up to some abuse. One round of bleeding bubbled the "caliper paint " right off. They were cured for over 1 month on brand new properly prepped calipers. Didn't touch the single stage black on the nearby ch***is parts.
Sandblast???? I would just hot tank it or if it's the kinder, gentler hot tank or won't remove the paint, then I'd use stripper and a car wash or lauqer thinner
I would not use "any" red oxide primer for internal protection. Thats not the proper paint to use. USE the glyptal paint, it looks like red oxide, but has outstanding properties. http://www.glyptal.com/1201tech001.pdf
Can I use any brand engine enamel on top of the glyptal as my final coat? Looking for an aluminum/silver color.
We are talking about the outside of the engine, not the inside, right ? If so, strip off that primer and do it right with epoxy primer and your favorite catalyzed enamel. Our machine guy thinks he is doing us a favor by painting our blocks, but we have to take a cup brush on a grinder and clean it all off when we get it back from him. If done right your paint will last for years and be easy to maintain. Don
Etch primer adheres to the bare casting real well. A careful sand and COB (2 pak) comes next. Did the engine in my 35 in 1K without etch and it is lifting n oil pan edges.I'd strip it back and start again to be safe.
I'm still suprised a machine shop sand blasted an engine. My old shop teacher made it very clear never to blast anything you can't get a brush at to clean it. A buddy had some heads reworked that were blasted, went thru 4 water pumps before he installed the last one and sold the truck. Hot tank will get everything off and leave clean, bare metal. Blasting will leave blast media in the water jackets where it will eventually take out the water pump and forever contaminate your cooling system. I may be wrong, do whatever floats your boat.
Oh boy, lots of misconceptions and bad info being thrown around. First, I wouldn't sandblast engine parts, esp. if they are already ***embled. Sand gets everywhere, even places you wouldn't guess. Masking doesn't insure it doesn't get where you don't want it. Why take a chance? Red oxide. What is it? In the good old days, it meant red/brown lacquer primer. Now, it is just a color of primer, or even a 'rat rod' finish color. Primer comes in many variations nowadays, urethane, epoxy, etch. Engine paint. You could use it, but you dont' have to. Just about any modern paint system will work on an engine, except lacquer. Single stage uro, BC/CC, Imron, acrylic enamel (but use hardener, please!). spray bombs will work, but not as well as a good catalysed paint. You do't specifically need hi-heat paint. Any paint will burn off near the headers, though, eventually. Similarly, most modern primers will work as well, just stay away from lacquer. Etch, epoxy, both work well. Rough cast parts really don't even need primer, but it helps coverage and color hold out. Sheet metal parts need the primer. Just be sure your engine parts are CLEAN! No rust, oil, grease, or moisture! CLEAN, CLEAN, CLEAN!
I questioned in my mind the statement they "sandblasted " the block too. No one I know of does that to an engine. I think what he meant to say was that thay tumbled the engine with shot and got it to bare metal. Our machine shop does that, and the block comes out like the day it was made. So much better than the old hot tanking did, even inside hard to reach places like water p***ages. Go back to your machinist and ask them exactly what their process was for clarification. Don
Have them strip it back down once all machine work is done, so they don't have to "worry about rust". If they are actually sand blasting your block, go get it now!
Sorry. To clarify, they hot tanked the block, heads, etc. and only sandblasted the small accessory parts that they said they could blow compressed air through to clean out. I'm going for a bright aluminum color for most of the engine and thought that the duplicolor engine enamel was going to be fine, but after reading some of your suggestions I'm definitely having second thoughts on that. I'm attaching a photo of the parts that the machine shop sandblasted and primed with the "red oxide" primer. They insist that this primer should be good enough.
If you're going with the rattlecan duplicolor engine enamel, don't worry about it. Just spray it and put it all together. Use the clear coat cause it really holds it together. Keep another can or 2 handy for touch-up, cause the parts that aren't as strong will flake or chip off. TP
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