• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

restoring nuts and bolts

Share this page

S

sp53

Yoda
Country flag
Offline
Does anyone have a method of restoring nuts and bolts back to a somewhat normal color and protection after glass beading? I glass beaded the nuts and bolts for the spring pans on a tr3 and want to put some protection back on them. It seems there was a thread on this sometime back, I can not find it. Perhaps paint or dirty motor oil, but what is the dark kind of stuff that comes on un-galvanized bolts?
George
 
Check with Eastwood they have replating kits.

Don
 
Paint is thick and can create problems with thread clearances but many suspension parts are painted as sub-assemblies or threads masked off. Most bolts and fasteners are zinc or CAD plated and the black finish (if not paint) is usually black phosphate on LBC's. Caswell has do-it-yourself kits (just look for the vendor link on this website). There is a thread about zinc plating in the tool forum. I use their CopyCAD/Zinc kit and then use their blackening acid afterwards if the finish needs to be dark. Hope that helps.

Cheers,
John
 
A while back in one of Classic Motorsports restoration articles they suggested collecting all of the fasteners you want replated and taking them to a local zinc plater. They can do them all for a "lot" charge. As mentioned, the original coating probably would have been zinc. If you want black, be careful what you ask for. If you ask for a phosphate coating you'll get something that is more charcoal grey and rough than what you get by asking for black oxide... which is what you're used to on fasteners. Because Cadmium is toxic, Cad plating is a bit harder to come by these days. If you want parts with a yellow Cad look you could ask for yellow zinc chromate which will have the yellowish appearance you see on some electronic plugs and connectors. All of these coatings should be available at local plating shops. The anodizer I use at work can handle all these coatings and more.
 
I spray all my glass beaded hardware (that I don't powdercoat) with Boeshield T-9. It's an aircraft parts preservative and lubricant that is clear but takes away the whitish finish that beading leaves. I have had great results for both stored parts and ones on the cars. Available at many sources, just look for it. PeterK
 
Hi,
I have been lurking here for the last couple monthsbut since I have been a fastener engineer for the last 27 years I figured it was time to jump in.
On most Triumphs you will see three different finishes. The internal engine parts as well as some other parts that see little weathering (SU screws and some gage screws) are just plain steel with no plating. We rely on the 'natural oiling' to keep them from rusting.
Most of the 'big dirty bolts' used on the chassis and suspension were made with what is called phos & oil. This is what many folks think is black oxide, but the two are very different. If you just ask for phosphate you will get a dry finish that is sort of greyish. All that is done with the phos and oil is to dip those parts into a oil, after which the parts are spun to get off the excess. These parts will have moderate corrosion resistance but over time they will start to rust if they don't get regular British oil misting.
The last group of parts (and the important group) are the plated parts. Most triumphs came with cadmium plating but that is very hard to find now (and expensive). Your best bet is to try an aerospace plater since they still use a lot of cad in airplanes. A good alternative is zinc plating which is much more readily available.
You have to be very carefull with electroplating and high strength bolts (grade 8 or equivalent) that you do not end up getting hydrogen embrittlement. This can cause the bolts to break up to 72 hours after they have been installed. All heat treated bolts should be baked by the plater at 400 degrees after plating to prevent hydrogen failures.
If you call around to different platers you should find one who will process you hardware. You are looking for one that has barrel plating capability. The charge should be about $50 - $75 per lot for either phos & oil or zinc.

Dick
59 TR3
 
Hi Dick,

Welcome to the forum and appreciate your jumping in with some good info. I have updated some info and images showing the procedure and my results with the Caswell Copy CAD/Zinc kit on another thread for anyone who in interested. Plating Thread
I prefer to plate my own parts because it allows me to do it in small batches so I can dis-assemble something, clean the parts and re-assemble all in one day. This way I can keep track of the exact fasteners/parts used. I was also concerned with a plater loosing or damaging parts since some of them are no longer avail.

Cheers,
John
 
What I have done on some batches of odds and ends is to use my trusty soft iron wire and a soft metal tag made from pieces that I cut off some left over patch steel and wire the tags to individual or groups of parts. I stamp a series of ID marks into the tag that matches up with marks that I make in my notes for that part of the car. The tags help keep parts from getting lost and they also help to bulk up the load in the plating barrel so it works better. Here at work we use 50# or so of steel dowel pins to bulk it up. When we get the whole mess back we can easily pick the sample screws from the pins.

If you decide to use a commercial plater you will want to find a smaller shop to work with; and one where some of the employees are car guys. This is a pretty common thing and they understand trying to keep parts right for a restoration. Big shops are just interesting in keeping the production moving and won't want to be bothered by your small order. A small shop that isn't interested in old cars will also manage to mess things up because they don't undestand what you are trying to do. So call up some shops and talk to the folks, you'll get a flavor for their interest and knowledge pretty quick.

Dick
 
[ QUOTE ]
Most of the 'big dirty bolts' used on the chassis and suspension were made with what is called phos & oil. This is what many folks think is black oxide, but the two are very different. If you just ask for phosphate you will get a dry finish that is sort of greyish. All that is done with the phos and oil is to dip those parts into a oil, after which the parts are spun to get off the excess.

[/ QUOTE ]
Dick, any chance you could elaborate just a bit on this particular process? Being a bit of a "closet purist" in my restoration efforts, I'd really like to know more about this! What form of phosphorous (phosphate? or ???), what oil, proportions, etc.

Thanks!
 
Andy,
No problem. The process for the phos & oil finsish is a dip process that creates a chemical conversion coating made up of zinc phosphate. This is pretty much an industrial process, the chemicals are pretty nasty. I just ran a quick Google search and I didn't see any of these chemicals for sale in small quantities. If you want to sound like you know what you are talking about you can ask for parts to be finished to Chrysler spec PS80 or GM 6035M.

The oil that is added can really be any kind of oil that you want to use. Most often it is a medium viscosity oil with some additional rust inhibitors. We have actuaaly shipped parts that were dipped into Johnson wax to reduce the friction. The different oils don't look at all different, the only way you tell them apart would be to do a chemical analysis.

Dick
 
Hi Dick and Andy yes I am having trouble locally locating a product for protecting and darkening up these bolts. Perhaps I am asking for too much. What I am looking for is a product that I can easily buy and put on at home. I called our one local platting shop and when I told him over the phone what I was doing he wanted 130.00. I told him I just wanted black oil/oxide for about ten pounds of bolts and he went into this big description about types of metal and if the car metal was English it is different steel. Anybody know an easy and cheap way to just put them back to almost unprotected dark steel for maybe to last 20 years.

George
 
It sounds to me like he gave you a price and a story because he simply didn't want to handle the parts for you.

This would be a poor substitute for the industrial process but you could consider thoroughly degreasing the fasteners and washing/soaking them in some generic phosphoric acid (Ospho, OxiSolve, Metal Ready, etc.). The phosphoric acid will leave the fasteners free of rust and zinc. You could then buy the "gun blue" products from a source like Birchwood Casey (gun shops may have this). After applying those chemicals the fasteners will be darker but probably not as nice looking a professional black oxide and oil. What do you say Dick?
 
I agree that that shop doesn't want to mess with a bunch of 'odd' parts. He is right in that some types of steel with certain heat treatments don't take color well. The blanket statement about British steel is total BS though. Just like the US has regular low carbon steel along with a host of alloys, so do the British and they end up using the steel that will get the job done at the lowest material cost, just like the US.
The phosphoric acid dip will put a phosphate etch (I'm not sure of what phaosphate chemistry though) onto the surface of the parts. After that you will find that the gun blue substances will not work on that surface because they will not have an 'active' surface on the steel to react with.

My sugestion here is to go to Brownells, which is a gunsmith supply company.
https://www.brownells.com/aspx/NS/Store/AdvancedSearch.aspx

They sell the same industrial chemicals that the plating shop would use, but in small volumes for shop use. I looked through the 'metal coloring' section and found several products that will do the trick. You are looking for "Parkerizing" with a blackening process added.
https://www.brownells.com/aspx/NS/Store/P...ATE+PARKERIZING

https://www.brownells.com/aspx/NS/Store/AdvancedSearch.aspx

Brownells is a great place to find odd tools and chemicals; gunsmiths are a lot like old car nuts, they have a lot of weird bits and pieces that they work on.

One nice thing about doing this at home is that if you have a highly heat treated part that won't take color very well you can try some different things to it to get it to work, and the regular shop can't take the time to do that.

Dick
 
I copied the following from the Healey list a few years back about blackening tools. I haven't tried it yet but it sounds like an interesting, lowcost technique.

---------

As to blackening, the technique of using Birchwood Casey Gun Blueing works
great. I have done all of the original blackened fasteners on my BN1 plus my
tools, one other tool kit and I'm about to do a third tool kit. You cannot
tell the difference between the blackening that I have done as compared to
NOS fasteners or some of the very original tools in my kit. In fact we
compared my blackened tools to a fellow club members who had his done
professionally and the only difference was that his cost more than four times
as much. There is however a technique required to achieve these results
which I will attempt to explain...

First of all follow the directions given on the label for the Birchwood Casey
Gun Blueing which is a cold process. Now the secret is that after the parts
are nice and black and rinsed clean with cold water they will immediately
"flash rust". What I do next is to place the parts in a metal pan on a hot
plate (low heat) and spray them with white lithium grease all over using a
small acid brush to coat them all over with the grease and then let them cook
for thirty minutes. The grease will bake into the metal somewhat and when
the parts have cooled all you do is wipe them clean with an old rag and
toothbrush. Do this in a well ventilated area and DO NOT let the grease get
so hot that it starts to smoke! Resulting parts are nothing less than
fantastic.

As you can see there is no need to apply the gun bluing hot, which is not the
recommended procedure of the manufacturer anyway. There is a hot blueing
process but once again I believe that it is poisonous and best left to
professionals All I can say is that this system was taught to me by a
professional restorer in Los Angeles who has worked in a few of the better
restoration shops. Total cost of the gun blueing, hot plate, metal pan,
lithium grease etc... was about $20.00 at any Wal-Mart store.

Cheers

Curt Arndt
 
That process will give a good dark color. One key is too make sure that there is no oil or grease at all on the parts. Use some brake cleaner and wear gloves to keep your greasy skin off them.
I am not a big fan of the blackening or blueing because it has really poor rust resistance unless the parts are kept oiled (well, since these are gong to be on a British car I guess we meet that requirement). The phosphating process is microscopicly porous and the oil can penetrate into that surface and give you much better rust resistance and also generally better surface lubrication. As an interesting aside; many years ago I worked for Dana grinding ring and pinion gears for 4wd axles. One of the processes that we put all of the small 'side gears'on the spider through was a phosphating dip. I asked one of the supervisors about it and he told me that it was to keep them from galling going around sharp corners under load.
 
Back
Top