Zinc Plating Subframe/traiiling arms?

[bradmer]

I'm not the most concerned about salt but just looking for a good amount of protection to cost ratio. I might end up painting everything depending on the cost in the end. Is there a significant difference in weight before and after?

Galvanizing has lead, lead is heavy.

[Vincenze]

You can do Black Zinc Plating too.
You usually have to clean and sand surfaces yourself.

It seems that a zinc-plated layer is much thinner than a painted one. It's easier to scratch it. But you can paint over it.

He says $75 per 150 lb.

[nando]

Galvanizing would could warp parts, but not plating? Not too familiar on the differences.

Yes, definitely. Even thicker steel structures have to account for this. A subframe may have enough strength that it's not an issue, but I can't think of any major series manufacturer that uses galvanizing for suspension parts - I assume for good reason.

As far as zinc plating tanks, I wondered about the availability of large ones (I am used to dealing with galvanizing large structures, 50-100ft peices). But keeping in mind they are probably used to jobs in the tens of thousands, or even millions of dollars - plating a couple car parts is probably not going to be cheap.

It's an interesting idea though. Zinc and cadmium platings are honestly pretty attractive, certainly far more so than galvanizing (expect a thick, rough, uneven surface). Zinc is also one of the main elements used in glavanizing.

But even here in basically the ass crack of nowhere - I found a shop literally a mile down the road that powder coated my parts for a couple hundred bucks, including cleaning, materials and prep. And it's definitely good enough for a subframe - the original was painted, and they still last 30 years without issue.

[jwest11]

Yes, definitely. Even thicker steel structures have to account for this. A subframe may have enough strength that it's not an issue, but I can't think of any major series manufacturer that uses galvanizing for suspension parts - I assume for good reason.

As far as zinc plating tanks, I wondered about the availability of large ones (I am used to dealing with galvanizing large structures, 50-100ft peices). But keeping in mind they are probably used to jobs in the tens of thousands, or even millions of dollars - plating a couple car parts is probably not going to be cheap.

It's an interesting idea though. Zinc and cadmium platings are honestly pretty attractive, certainly far more so than galvanizing (expect a thick, rough, uneven surface). Zinc is also one of the main elements used in glavanizing.

But even here in basically the ass crack of nowhere - I found a shop literally a mile down the road that powder coated my parts for a couple hundred bucks, including cleaning, materials and prep. And it's definitely good enough for a subframe - the original was painted, and they still last 30 years without issue.

So zinc plating will not warp parts right? I think a black zinc would look really good on the suspension components. I have many industrial platers near me in Portland so finding one with a tank big enough won't be an issue. I will look around though to see what the cost is since I imagine many are strictly industrial.

I was quoted $300 alone for a subframe and $500 for brakes. I'll try to find a cheaper place but was also wondering if it would be a good idea to hot tank the parts to be completely stripped instead of sandblasting or will the heat have negative effects? Another reason I am thinking of using chemicals to strip the paint is because those two holes in the middle of the subframe have lots of grime from over the years and I dont know how that would be removed. But now that i think about it, if the paint in there is removed, how would it be painted/coated again to prevent rust...?

[jwest11]

You can do Black Zinc Plating too.
You usually have to clean and sand surfaces yourself.

It seems that a zinc-plated layer is much thinner than a painted one. It's easier to scratch it. But you can paint over it.

He says $75 per 150 lb.

That's a lot cheaper than I was expecting! I would like to not have to do the prep work myself, I have lots of little hardware pieces and it would take forever with my little wire wheel. Hopefully I can find a place that preps too!

[Vincenze]

That's a lot cheaper than I was expecting! I would like to not have to do the prep work myself, I have lots of little hardware pieces and it would take forever with my little wire wheel. Hopefully I can find a place that preps too!

He said he used the company TFC in Portland: http://tfcplating.com

You need a company that does bead blasting.

[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 ...

[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]

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

[e30austin]

there is a reason the factory painted these parts.

paint them.

[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]

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

[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

[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.

[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!