Valve cover powder coating

I'd say soda blast over sand blast, https://www.easycomposites.co.uk/soft-yellow-filleting-filling-wax is the type of wax used to completely seal the baffles.

 

Sodium bicarbonate (baking soda) is water soluble and rinses off with water so no particulate left from the blast media and is gentler on the aluminum since sand might cut too hard/pit the cast aluminum

 

I use soda on things I don't want to etch.

 

For prep to powder coat, soda should work fine. Does the powder coater not offer blasting/prep?

 

how about dry-ice blasting?
would that clean up the VC and make 'em shiny like new
has anybody tried that type of blasting on this part?

do you have some pics of these black spots?
i am curious to see and compare

 

I had a terrible experience with a sand-blasted upper intake manifold where some blasting media clung to internal areas even after being pressured and the water hose washed.

That media later came out and was sucked into the intake and firing chamber.

 

My experience has been that a top-notch powder coater will tell you if there are any problem areas requiring attention before they coat and bake.

I also have worked with a powder coater that will prebake parts in a kiln to burn off any grease or impurities before finally coating and baking.

 

I AM the powder coater. Been doing it for a couple decades at home. It's not rocket science, but there are tricks.

When you fab a lot of your own parts, nothing's better than just getting done making a new part and then giving it a once over with the blaster and PCing it. 30 minutes later it's ready to install. No waiting days for paint to dry.

 

Just to reiterate, sand blasting a metal part is the optimum way to prep something for PC. Just like sanding a part before painting, the PC will have more surface area to adhere to and will last longer. You can totally PC a smooth polished part and in some cases it's desired for a certain effect. But where you want ultimate durability you need to etch. Soda doesn't etch which is the whole reason to use it for delicate things. It's more for encapsulation of dirt and grease and removal. Chemicals don't etch (limited exceptions). A lot of times using chemicals can have adverse results in the PC adhesion. A second thing the blasting does is it cleans and dries out the metal. When you pull a thoroughly blasted part out with rubber gloves and wipe it with acetone it's about as clean and accepting of paint or coating as it ever will be. You gotta clean it after blasting. If you leave crap on it and PC it, it's gonna get trapped, make the PC bubble and then it will fall off.
It's all about the prep.

If something's oil stained after blasting, it's advisable to stick it in the oven at a temp higher than the PC cure temp to 'cook' off the entrapped oil. If you don't the PC will lift

 

can you do an acid soak?
i believe that is what my powdercoater said they did to remove the surface rust on the lower fuel tank shield before powdering it
not entirely sure they did any other prep to it

 

Paint on the block, that's it.

 

Yeah I imagine for something with rust that would be fine. You definitely need to get down to bare virgin metal. Now the question you'd have to ask them is what did they do to cancel out the acid? Usually a soap and baking soda bath will neutralize the acid and you can then paint or coat. I guess that's the thing with Ospho a lot of people don't get. You need to get it off there before you do anything else.

 

yeah, the first place i had that thing powdered it only lasted a few years before it started flaking off and re-rusting
so i tried another powder shop that cost twice as much lmao... but it definitely looks badass under there!

 

Something like that, I wouldn't be surprised. That's why I will never pay to have a frame PCed. At least with paint I can fix it. Once you get a chip in PC you're done.

 

I PC small parts. Brackets, engine parts, some suspension parts. I don't think I would even do calipers just because there's so many ways that can go wrong and end up looking like crap. If I want bright shiny red ones I'll just buy them.

 

So I got adventurous today and removed the baffles from one cover.

Just for the record, those aren't rivets afterall. They are aluminum posts that were sonically deformed just like I originally thought. There is no hole underneath, just more aluminum. I haven't decided what I'm going to do exactly yet. Mainly concerned with the type of screw to be used. I like the idea of tacking the edge of every screw just to make sure they don't come out. So the screws will need to be SS ideally. There's enough meat there to use a 1/4-20 screw, but if I can find maybe a #10 with a really wide head that would be better. Whatever it ends up being, I'll need to pick up some 'plug' taps to make some short holed threads. All I seem to have is taper taps. Also need to find replacement plugs for the vent on the top side.



A picture of the top. They looked a lot more "black" when they had just come out of the hot tank. Still you can see that darker buildup. Blasting will take care of that. I'll probably just use my fine media.

 

those seals are stuck in there good!

 

If anyone knows who sells a really nice billet oil fill screw cap fill me in

 

I'll have to get the dimensions on this plug so I can shove a new one in right before PC.

 

Whoa!