Zinc Plating Subframe/traiiling arms?

[RegardsDavid_17]

I thought that the parts were originally e-coated? That's generally what high volume manufacturers use, probably going to have a hard time finding someone to do individual parts, and I'm not sure how well they protect against corrosion. IMO painting is the way to go and I'd agree with 15Michaeljoseph's process except I'd just sandblast everything, mostly because it's fun. Chemically treat any rusted areas until the metal is perfectly clean then hit it with a gnarly epoxy primer.

I think this guy is good at this

[E30 Wagen]

I thought that the parts were originally e-coated? That's generally what high volume manufacturers use, probably going to have a hard time finding someone to do individual parts, and I'm not sure how well they protect against corrosion. IMO painting is the way to go and I'd agree with 15Michaeljoseph's process except I'd just sandblast everything, mostly because it's fun. Chemically treat any rusted areas until the metal is perfectly clean then hit it with a gnarly epoxy primer.

[15Michaeljoseph]

I appreciate the quick how to! Great idea for those drip holes, never thought of that. Will definitely reference this post if I decide to paint everything myself.

I have had really good luck with Eastwood's products for doing my bodywork. For what I mentioned above, I used Eastwoods primer, rust encapsulator paint, and that internal frame coating with the flexible hose. Well worth the money... They also sell a brushable seam sealer for dressing panel repairs and that stuff is absolutely amazing imo. I think paint is the way to go. Plus, unlike paying for powder coating, you get to do all the prep and process yourself... I'm very particular so I actually preferred doing it all myself this way even if powder coating is accepted as "better" than paint. Happy to help if you've got any questions about what worked for me! Sent from my moto g(6) using Tapatalk

[e30davie]

You are overthinking it mate, its lasted 30 odd years painted..

Paint it black and put it back.

[jwest11]

I really think OP should paint/powder coat. From March to June I did an OCD+ subframe/arms/underbodywork job on my daily e30, and ended up painting my subframe. The car is my daily, and has been through 33 years of New England winters (although it is/ has been always garaged and washed frequently) so the subframe and arms were crusty in spots. Mechanically stripped the rusty areas with wire wheels, leaving some areas where the factory paint was very well adhered, and then cleaned it all very well with acetone. Any areas that had some light pitting left behind from the rust got a light coat of rust reformer, then two coats of rust encapsulate paint. After that, I sanded and 2k primed everything, and then went through several cans of high solids chassis paint over it. Inside those hollow areas/ drip holes, I shot some internal frame coat spray with a flexible wand spray tip. Once it was all back in the car, I hit everything I could reach with some heavy duty cosmoline wax spray. Long story short, I feel confident in the paint and the process didn't really break the bank... Though I hope to have a second car sooner than later so I can keep the old girl off of the salty winter roads. Sent from my moto g(6) using Tapatalk

I appreciate the quick how to! Great idea for those drip holes, never thought of that. Will definitely reference this post if I decide to paint everything myself.

[jwest11]

if you are in the Portland, OR area, as you mentioned in a previous post, give these folks a try. i use them for all my media blasting and powder coating needs. they are good folks, reasonably priced, and have a fair turn around time. it goes without saying, but you will have to give them a completely disassembled trailing arm and subframe, in order for them to do the job.

Quality Sand Blasting and Powder Coating
12805 SE Carpenter Drive #100
503.722.2335

Thanks for the suggestion! I'll look into them. Yep, everything will be disassembled before hand.

[jwest11]

I agree with this paint or powder. The powder quotes you gave also sound ridiculous. At that price you could buy a reinforced, camber kit installed and powder coated subframe from some of the people that do it. One of the places that powder coats calipers near me strips them, coats them and rebuilds them for your quote.

Leaning that way, just can't stop thinking how sick a plated subframe would look. I'm glad someone else thinks the prices are high, I will definitely shop around for a good place!

[Tzantushka]

Agree with paint if powdercoat is too pricey for you.
Easy DIY, lots of options - I would stick to epoxy or specific chassis paint.
As with all painting preparation is key.

Zinc plating is sacrificial, so over time it will lose its protection.
Especially with alkaline/acidic based cleaners and salt.

[15Michaeljoseph]

I really think OP should paint/powder coat. From March to June I did an OCD+ subframe/arms/underbodywork job on my daily e30, and ended up painting my subframe. The car is my daily, and has been through 33 years of New England winters (although it is/ has been always garaged and washed frequently) so the subframe and arms were crusty in spots. Mechanically stripped the rusty areas with wire wheels, leaving some areas where the factory paint was very well adhered, and then cleaned it all very well with acetone. Any areas that had some light pitting left behind from the rust got a light coat of rust reformer, then two coats of rust encapsulate paint. After that, I sanded and 2k primed everything, and then went through several cans of high solids chassis paint over it. Inside those hollow areas/ drip holes, I shot some internal frame coat spray with a flexible wand spray tip. Once it was all back in the car, I hit everything I could reach with some heavy duty cosmoline wax spray. Long story short, I feel confident in the paint and the process didn't really break the bank... Though I hope to have a second car sooner than later so I can keep the old girl off of the salty winter roads. Sent from my moto g(6) using Tapatalk

[e30austin]

if you are in the Portland, OR area, as you mentioned in a previous post, give these folks a try. i use them for all my media blasting and powder coating needs. they are good folks, reasonably priced, and have a fair turn around time. it goes without saying, but you will have to give them a completely disassembled trailing arm and subframe, in order for them to do the job.

Quality Sand Blasting and Powder Coating
12805 SE Carpenter Drive #100
503.722.2335

[Shangsta]

there is a reason the factory painted these parts.

paint them.

I agree with this paint or powder. The powder quotes you gave also sound ridiculous. At that price you could buy a reinforced, camber kit installed and powder coated subframe from some of the people that do it. One of the places that powder coats calipers near me strips them, coats them and rebuilds them for your quote.

[e30austin]

there is a reason the factory painted these parts.

paint them.

[D.Martijn]

You are thinking about black oxide which is a much cheaper and much less effective coating than zinc - and why you see the corrosion so quickly. Black zinc is just a regular clear zinc bath followed up by a black chromate coating to give it the dark color - yellow zinc is similar using a yellow chromate bath.

Zinc coatings do take paint well so it would be an easy option to paint anything.


I think a clear or yellow zinc subframe and trailing arms would look great underneath a car.



MJ

Oh I never heard of black zinc plating, looks like I mixed it up with black oxide like you mentioned. (not a native English speaker :) )
I would paint it, just to have some extra bit of protection.. but to each their own ofc

[mjweimer]

I would zinc/cad plate the parts and then ideally get them powder coated. Or use a paint if that's a cheaper option.

If I'm not mistaken black zinc plating is just blackening the part? If you ever used a black socket head bolt on something outdoors, they start to rust pretty quickly ...

You are thinking about black oxide which is a much cheaper and much less effective coating than zinc - and why you see the corrosion so quickly. Black zinc is just a regular clear zinc bath followed up by a black chromate coating to give it the dark color - yellow zinc is similar using a yellow chromate bath.

Zinc coatings do take paint well so it would be an easy option to paint anything.


I think a clear or yellow zinc subframe and trailing arms would look great underneath a car.



MJ

[D.Martijn]

I would zinc/cad plate the parts and then ideally get them powder coated. Or use a paint if that's a cheaper option.

If I'm not mistaken black zinc plating is just blackening the part? If you ever used a black socket head bolt on something outdoors, they start to rust pretty quickly ...