Erat

iTrader: (5)

You have to understand that plating is just a layer of metal placed on top of another layer of metal. The junk they put on these bolts is actual trash. And keep in mind that when to metals are very close together you get galvanic corrosion. That's why the bracket still looks good and the bolts, not so much.

I work in the plating / anodizing / coating business. We will take hardware that is already factory coated exactly like what you have, strip them, and recoat them with our process for our customers. Because it's that much better, but costs a lot more. Plus we have our own blend of spices like PTFE coating and what not.

So the plating that may or may be there is hardly clinging to the surface as it is and it doesn't take much to knock it off or dissolve it away.


You can buy this hardware (nuts and bolts) on mcmaster for basically nothing too.

Bajingo

I get that I really do, just didn't expect my bolt cleaning to turn into new bolts or re-plating, it's mildly annoying.

any idea on the ballpark for re-plating the ~100 random bolts and random brackets a miata has? I'm pretty convinced I'm going to try and diy the re-plating but I still want to call the professionals on Monday, if it's <$250 it's a way better deal than doing it myself or buying new.

Erat

iTrader: (5)

I can promise that it will not be cheap. We are a pretty big company, i don't know min-lot fees for every process we have, but i know it's more than $250. Smaller job shops will be a lot less.

All you can do is call and ask.

Godless Commie

iTrader: (2)

I just go to a local plating business anytime I need something nickel or chrome plated.
They charge me less than $5 for a couple handfuls of parts I give them, like all bushing sleeves for my delrin bushings.
I think I paid about that much for all the bolts for a Miata, too.

Bajingo

I've been digging all over for pricing found one mail in place that looks like it would be about $250 all said and done but that was their minimum that covers up to 100lb. Hearing $5 makes me hope one of the local places will do it at nice reasonable prices. I'll update after I talk to them.

dan91

The big thing with bolt coatings is that they have a huge effect on thread friction. If you change the coating and don't compensate with a different tightening torque to match, you run the risk of breaking the bolt head off or having the bolt not tight enough and working loose. The problem is, you would need to know the K factor for both the original coating that the torque spec assumes, and the new K factor after recoating to compensate appropriately.

Torque = K factor x bolt diameter x clamp force. Clamp force is material strength x cross sectional area x safety margin to account for variables, usually something like 0.6 or 0.7.

A small change in K factor, like going from a phosphate coating with a K of 0.15, to a zinc coating with a K of 0.2, is a very large percentage difference (0.2/0.15 = 1.333. Your bolt stretch just dropped 1/3 if you use the same torque). That change can be greater than the margin of safety built into the torque spec.

dan91

How much are new bolts from Mazda?

Bajingo

Not to sound silly but none of these bolts are ones that require a specific torque in my mind, or at least I have zero intention of using a torque wrench on them. If we were talking cam, Rod, flywheel, or main bolts I'd just buy new in a heart beat. But water pump and accessories? I'm sure they'll be fine. Although I do have a minor worry of new coating being too thick and making everything difficult to put together, that was on my list of things to ask the coating people about.

Main reason I'm opposed to buying new is because I expect it to be a pita to go through each bolt and order it I expect price to be silly too. Quick look shows the 3 waterpump pulley bolts at ~$7 the single t-stat housing bolt at ~$3

technicalninja

The reason Godless Commie's plating is so cheap is where he lives...
Here in the USA metal plating is considered one of the biggest polluters and there is butt-loads of regulations and red tape...
Almost all of the refinishers have gone out of business and it's now damned expensive.
Only economically viable route is to do it yourself IMO.
This will take some experimentation to get your process up to your level of expectations.

I've never heard of a problem with replating factory stuff with regards to torque value.
Nothing external on a Miata engine is that critical anyways.
I have found that changing all of the fasteners to show quality high end hardware is usually cheaper than have the stock stuff replated.
This is the reason for the post regarding the POR 15. It will work pretty good and be inexpensive...

Erat

iTrader: (5)

You'd be surprised how easy it is to remove heavy metals out of a waste stream.
Really isn't even that expensive too, if you're smart about it.

Bajingo

I'm definitely going to buy/build myself a re-plating kit regardless of what I do,seems too useful to ignore. The por is still on the table but everything I've heard about how annoying it is to apply has it pretty low on my list. I might just buy everything new I do have plenty of time to do it, it just seems so boring/time consuming to get done.

One of the old plating companies in my area is a Superfund site which I found interesting.

Godless Commie

iTrader: (2)

That, and the fact that I never go to places that do custom work. Too expensive.
There is a pretty big business chrome plating plumbing fixtures by the thousands not too far from me. They take my stuff and add them in the line whenever I ask them nicely. Since they have no protocol to bill walk in customers for retail work, whoever is in charge there just pockets the money. Win win.
I made a point of checking this thing with the company management. They are cool with the fact that someone is making couple extra bucks on the side. It is not worth their time to generate paperwork for the trivial amount of work they do for me.
I do the same thing for laser cutting, sheet metal bending, etc. I had custom front frame rails cut and bent for a Miata at a huge plant, and they made me pay about 10 bucks.

Bajingo

This is what I'm hoping for.

paNX2K&SE-R

iTrader: (8)

What is the preferred place to buy said hardware, Is McMaster?

I love por15 and have used it in the past but never for this purpose. What's the best method, dipping or brushing?

Efini~FC3S

iTrader: (4)

Where’s a JeffBucc when you need one...?