Sandblasting Opinions Requested

[lockedlex]

I have a painted valve cover from another car that I'm going to media blast myself. If anyone has any experience, would love some input:

1) The Valve Cover is Magnesium
2) My plan is to use Soda (medium grade) for the cover inside and outside. If that doesn't work, I'm going to use medium Glass bead for the outside and might leave the inside as is.
3) If I can't get rid of the paint on the outside with Soda, I will switch to Glass Bead, with Aluminum Oxide as a final last resort.
4) I intend to use Zinc Chromate primer with a flat black wrinkle coat spray paint in the end for the outside. I don't plan to paint the inside.

There are NO oil baffles on the valve covers, it's just a single piece.

My one concern is using glass beads on the inside and possibly having some "embedded" that might work itself loose later one (since Mg is so soft?). As I understand, Soda pretty much disintegrates/washes off.

Can I blast the edges that the gaskets sit inside or would that risk creating leaks? Those gasket seats are also painted the the paint is bubbling in various places in various degrees already.

Does this sound about right or would you have other experienced suggestions?

Thanks!

 

[Devbot]

For what purpose? Just use a stripper - they make gentle/noncaustic stuff for metals like magnesium.

 

[WeakSauz]

Honestly would just use a stripper, such as Citru-Strip.

The valve covers are just oily and grimey right?

Soak them in citru-strip over night and hit them with a pressure washer. They will look like new

 

[DreadPirateJon]

I powder coated the 5vz covers with a wrinkle red. Ended up looking nice, if a little like Honda colors. Because these are baffled I cleaned them by hand first with a mix of a dremel and just scotch bright.

My experiences sand blasting other things is just to mask off any surfaces you dont want hit with painters tape. On tip for masking is to us the flat side of a razor to pull over the painters tape at the edge you want to cut it at. Kinda like when you are using a crayon to see indented writing on a piece of paper. That will make a nice clean edge.

 

[19963.4lsr5]

I bead blasted my valve covers and intake when I rebuilt the engine.


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[lockedlex]

Thanks, so +1 for bead blasting.

I've already tried the paint stripper option, but it's not working. It's painted from the factory and just doesn't seem to want to come off.

So it's OK to blast the tunnel that the valve cover gaskets sits on to remove paint there? No chance of it leaking if I'm bead blasting it? Should I maybe put a thin layer of RTV to be safe?

 

[dmppdx]

Thanks, so +1 for bead blasting.

I've already tried the paint stripper option, but it's not working. It's painted from the factory and just doesn't seem to want to come off.

So it's OK to blast the tunnel that the valve cover gaskets sits on to remove paint there? No chance of it leaking if I'm bead blasting it? Should I maybe put a thin layer of RTV to be safe?

Often, the paint used for things like valve covers and other automotive parts won't come off using normal paint stripper. If you get some Aircraft Stripper, that normally works since that normally dissolves any paint or epoxy, but I think its way more toxic so use more care with it.

 

[jbtvt]

Gasket seat is painted? Weird. I've blasted tire beads with glass and they didn't leak after so wouldn't think it'd be a problem to blast. Yes, would avoid blasting inside with anything harder than soda or walnut shells. If DCM stripper won't take it off I doubt those will though.

 

[lockedlex]

Often, the paint used for things like valve covers and other automotive parts won't come off using normal paint stripper. If you get some Aircraft Stripper, that normally works since that normally dissolves any paint or epoxy, but I think its way more toxic so use more care with it.

Yeah, already tried aircraft stripper, (without DCM since it doesn't seem readily available in Cali) and it basically didn't work, plus was really concerned about the toxicity, smell (even with PPE on).

 

[lockedlex]

Gasket seat is painted? Weird. I've blasted tire beads with glass and they didn't leak after so wouldn't think it'd be a problem to blast. Yes, would avoid blasting inside with anything harder than soda or walnut shells. If DCM stripper won't take it off I doubt those will though.

Yes, I'm not a fan of what they did. It was painted from the factory, here's an example. Last time I opened it up, about 8 years ago, It was already peeling and I took a light sanding block but didn't really go to far into the seat/groove.

Good to know that beadblasting should be OK if needed. My plan is to try with Soda first... see how far that gets me for the outside and then go harsher if needed.. all the way to maybe an alum oxide or black beauty (?).

For the inside, I might just stop at "good enough" for fear of getting anything embedded, possibly messing up the Mg (?), or ripping of parts of the gasket groove seat. Worst case, I can just RTV it with whatever paint might be left.

 

[19963.4lsr5]

My VCs were aluminum. They cleaned up nice.

Only thing I’d do different is id soak them in acetone for a few weeks to remove the oil coking in the baffling.

I clear coated the VC’s. They eventually yellowed.


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