S65 Valve Cover Replacement, HydroDip, Repaint?

[SAMM3Y]

Originally Posted by Jonzny

Can't you just paint these with a rattle can using high temp paint?
Assuming you can use paint stripper to strip the old coating

Yep thought about that too.. but good paint, primer and stripper would run you atleast $50 and the need to bead blast off the crud twice and spend a bunch of time doing it cuz sand paper would never get it done well enough. This way it gets done professionally and stands a chance.. and for $200 all in, to me it's a no brainer.. saves a smelly kitchen oven too..

[Jonzny]

Originally Posted by SAMM3Y

Yep thought about that too.. but good paint, primer and stripper would run you atleast $50 and the need to bead blast off the crud twice and spend a bunch of time doing it cuz sand paper would never get it done well enough. This way it gets done professionally and stands a chance.. and for $200 all in, to me it's a no brainer.. saves a smelly kitchen oven too..

I mean I don't need it to be perfect. Just want the flaking gone.
Hell i'd probably leave it primer gray. Think it still needs to bake?

[SAMM3Y]

Originally Posted by Jonzny

I mean I don't need it to be perfect. Just want the flaking gone.
Hell i'd probably leave it primer gray. Think it still needs to bake?

Magnesium is a porous alloy so you'll need to bake off the oil that has penetrated the covers to give the paint a chance to stick. If you can control your bbq temp pretty accurately you could use that.. 350 for an hour should do it... I'd do it twice with a bead blast in between.

[Jonzny]

Originally Posted by SAMM3Y

Magnesium is a porous alloy so you'll need to bake off the oil that has penetrated the covers to give the paint a chance to stick.If you can control your bbq temp pretty accurately you could use that.. 350 for an hour should do it... I'd do it twice with a bead blast in between.

Ah okay. Didn't know that, thanks!

[delirium330]

I just replaced my valve covers (with new OEM ones) and associated gaskets, oil separators, spark plugs tubes, bolts, etc.

I've got the existing covers and other than a bit of flaking as discussed in this thread, they are in fine condition. 65k miles on them as originals on my car and ready to be powder coated and prepped for use on another S65. Thoughts on what you think I should sell them for and the best place to try and sell them? Suppose I'll get a post on this forum to start...

[BayE30]

Originally Posted by delirium330

I just replaced my valve covers (with new OEM ones) and associated gaskets, oil separators, spark plugs tubes, bolts, etc.

I've got the existing covers and other than a bit of flaking as discussed in this thread, they are in fine condition. 65k miles on them as originals on my car and ready to be powder coated and prepped for use on another S65. Thoughts on what you think I should sell them for and the best place to try and sell them? Suppose I'll get a post on this forum to start...

usually see them go for around $300/pair. refinishing them cost about $80/each.

[delirium330]

Originally Posted by SFCM3

usually see them go for around $300/pair. refinishing them cost about $80/each.

Thanks, I just posted them in the forum sales area.

[IamFODI]

Originally Posted by deansbimmer

The coating flakes off of the gasket groove leaving a poor surface for the new gasket to seal to, = poor seal quality and oil leaks soon after unless you fill the groove with sillycone to assist the seal.

Dean, thanks for the info you've provided in this thread.

I'm going to pull my valve covers soon and I have no idea what I'll find. If I'm reading you right, you seem to be suggesting that I can use a bit of sealant (I'll be using the BMW-specified Drei Bond 1209) to fill in any gaps left by flaking coating. Is that correct? If so, any thoughts on how long that'd last, assuming it's done right?

[deansbimmer]

Originally Posted by IamFODI

I'm going to pull my valve covers soon and I have no idea what I'll find. If I'm reading you right, you seem to be suggesting that I can use a bit of sealant (I'll be using the BMW-specified Drei Bond 1209) to fill in any gaps left by flaking coating. Is that correct? If so, any thoughts on how long that'd last, assuming it's done right?

If you're removing a used cover then you will have flaking and pitted sealing grooves. Need to run a small bead inside the entire perimeter of the sealing groove before fitting the gasket. That will seal any irregularities in the sealing surface. The covers must be absolutely clean and oil free and you need to scrape the loose/corroded magnesium free to create a solid bed for the sealant. When you think the cover is clean...clean it again. Soap and water. Final wipe down in the groove with lacquer thinner.

I hate using silicone where it's not supposed to go, but this is the only way to prolong a leak free seal on these covers.

[IamFODI]

Originally Posted by deansbimmer

If you're removing a used cover then you will have flaking and pitted sealing grooves. Need to run a small bead inside the entire perimeter of the sealing groove before fitting the gasket. That will seal any irregularities in the sealing surface. The covers must be absolutely clean and oil free and you need to scrape the loose/corroded magnesium free to create a solid bed for the sealant. When you think the cover is clean...clean it again. Soap and water. Final wipe down in the groove with lacquer thinner.

I hate using silicone where it's not supposed to go, but this is the only way to prolong a leak free seal on these covers.

Awesome. Thanks, Dean!

[CHE///MIST3]

Originally Posted by deansbimmer

If you're removing a used cover then you will have flaking and pitted sealing grooves. Need to run a small bead inside the entire perimeter of the sealing groove before fitting the gasket. That will seal any irregularities in the sealing surface. The covers must be absolutely clean and oil free and you need to scrape the loose/corroded magnesium free to create a solid bed for the sealant. When you think the cover is clean...clean it again. Soap and water. Final wipe down in the groove with lacquer thinner.

I hate using silicone where it's not supposed to go, but this is the only way to prolong a leak free seal on these covers.

I've read that some people cook-off the oil from the covers...and while I do have access to a 350F oven I worry that certain components in the valve cover will get warped or damaged at that temperature. Would you feel confident that careful and thorough de-greasing is sufficient to provide a good surface for coating?
GM

[deansbimmer]

Don't try to DIY bake them. You probably won't get them hot enough long enough to do any good. Clean them in several stages. Brake clean>Soap and water>strip coating/sealing grooves>Dawn dish soap and water>Final surface prep for coating with lacquer thinner or Prep-solv. You can substitute Dawn dish soap with a proper degreaser.

In our shop we use this, but Dawn will work in a pinch:
https://www.amazon.com/Extreme-Aircr...ay&sr=8-1&th=1

[CHE///MIST3]

Originally Posted by deansbimmer

Don't try to DIY bake them. You probably won't get them hot enough long enough to do any good. Clean them in several stages. Brake clean>Soap and water>strip coating/sealing grooves>Dawn dish soap and water>Final surface prep for coating with lacquer thinner or Prep-solv. You can substitute Dawn dish soap with a proper degreaser.

In our shop we use this, but Dawn will work in a pinch:
https://www.amazon.com/Extreme-Aircr...ay&sr=8-1&th=1

Thanks ! I'm going this route as I'd like to keep my otherwise perfectly fine valve covers...and I can always get warranty replacement gaskets and bolts from FCP if I run into leaking again down the road.
GM

[2bits]

Acetone is also a kick ass degreaser.

[CHE///MIST3]

Originally Posted by 2bits

Acetone is also a kick ass degreaser.

Definitely, and it's a good last minute wipe down also before painting due to its high vapor pressure.

I measured something in the range of 190-200 F on the surface of the valve covers with my temp gun. I'm going to try using a single stage automotive urethane, airbrushed thinly on. It'll have a nice, glossy finish and should last well..I hope!

GM

[GORDON.M3]

Non-Chlorinated brake cleaner does wonders before paint. Acetone works but I can source brake cleaner in tubs for a lot cheaper

[Eflynn46]

Hi guys,has anyone tried polishing the magnesium valve covers?i used to polish bike frames and wheels as a side gig,i would def like to see my s65 with some highly polished valve covers,if anyone knows where i can get a teat set i will defs do the work and see how they come out, thanks

[deansbimmer]

Originally Posted by Eflynn46

Hi guys,has anyone tried polishing the magnesium valve covers?i used to polish bike frames and wheels as a side gig,i would def like to see my s65 with some highly polished valve covers,if anyone knows where i can get a teat set i will defs do the work and see how they come out, thanks

Not gonna work. It's not like stainless or aluminum. The magnesium will turn grey and oxidize again before you're even done polishing the rest of the cover. If you did manage to polish it you'd still need to clear coat it- and then you're back in the same boat with bubbling and peeling problems.

[Zero Signal]

Surprised no one has made aluminum valve covers that also addresses the oil cap problem too

[Eflynn46]

Originally Posted by deansbimmer

Not gonna work. It's not like stainless or aluminum. The magnesium will turn grey and oxidize again before you're even done polishing the rest of the cover. If you did manage to polish it you'd still need to clear coat it- and then you're back in the same boat with bubbling and peeling problems.

Thanks for your insight,it saved me alot of time and a little money

[Eflynn46]

Originally Posted by Zero Signal

Surprised no one has made aluminum valve covers that also addresses the oil cap problem too

Lets find someone that can make them custom and group buy?cant get polished aluminum valve covers off my brain

[deansbimmer]

Originally Posted by Zero Signal

Surprised no one has made aluminum valve covers that also addresses the oil cap problem too

Not surprising at all. Sounds cool but they would need to cost a fortune due to the required complexity of the part. Most owners can't fathom spending $1200 for a new OEM set- no way people will line up for a set that costs over twice or even three times that.

There's no inherent problem with the oil cap design. The cap's gasket wears out and caps need to be replaced occasionally to ensure a good seal.