Any magnesium wheel gurus in here?

[xb-60]

With respect, why attempt to repair Mg wheels? Most of us have replicas, not original Cobras, and aluminium alloy wheels can be made to look like authentic vintage Mg wheels, so why not err on the side of safety and stick with aluminium alloy wheels?

nota bene...a 275/60 x 15 tyre weighs around 30lb / 14kg, and a 15" x 9.5" aluminium alloy wheel is only around 15lb / 7kg

That said, I understand the desire to go as "authentic" as possible in certain areas.....but if safety is a concern....

Cheers, and stay safe!
Glen

[my427cobra]

Disclaimer: I am not an expert. You need to speak to the “right” Cobra experts of the period. People like Lynn Park. Fran Kress, JL Henderson and others whose names will be referred to you by these people and people on this forum.

Now, I did research the period Halibrand wheels for the Goodyear tire history I wrote for SAAC a couple of years ago and learned a lot about the original Halibrand magnesium wheels.

Before I go into that, we need to know more about the wheels you have.

You say you have “a set of old Halibrand magnesium wheels”.

You have to be more specific than that. Old as in 1965 or 1966? Which style Halibrand? You’re sure they’re Halibrand.

In any case, “old” is not good when talking magnesium wheels. Age embrittlement, stress cracks (visible and invisible), and corrosion are your enemies.

Halibrand, as good a manufacturer as they were, did not have the modern metallurgy technology in the 1960’s we have today.

Age embrittlement can take place with a wheel just sitting on a shelf for years. Add heat, UV, ozone, corrosion and stress and you have a cocktail for disaster.

OK, lots of guys are running period magnesium Halibrands in vintage racing, but as you have read in the previous posts they are carefully and meticulously maintained.

Running old, unknown magnesium wheels (one which already has a crack) on the street is probably not a good idea, earning on the side of caution and safety.

The Dow coatings, mentioned in previous posts, applied to the magnesium wheels were intended as corrosion protection (not air sealing) and had a limited life. Simply reapplying a “new” coating of the Dow coating (or other coating) without being assured of the internal condition of the casting (corrosion and stress cracks) will only mask an impending problem.

Now regarding mounting, bead sealing and inner tubes.

Keep in mind that those 1960’s ish Halibrand magnesium wheels were intended for racing due to their light weight. Racing tires were replaced frequently and any sign of wheel damage relegated the wheel to the scrapheap. Lots of broken/cracked Halibrand magnesium wheels hanging in garages as garage art (mine included).

And the period Goodyear racing tires were intended to have tubes to insure sealing and to keep the light weight tires/beads on the rims. (it is a challenge to find modern tubes with valve stems that line up well with the old Halibrands but the previous posts here about the tubes may help).

And, regarding the bead sealing. Not all bead sealing lubricants/sealers are created equal and some can quickly promote corrosion on magnesium and aluminum wheels. (ask me how I know LOL)

The period expert on tire/tubes would be JL Henderson, (Shelby’s Goodyear Racing Tire manager for 46 years now retired). He would be a wealth of information.

Most tire/wheel stores will be of no help. Contacting a high end (Ferrari or restoration shop etc) dealer to get a tire mounting recommendation (relative to bead sealing compounds that do not cause corrosion) might help or of course a Goodyear Racing distributor like Roger Kraus will be a big help regarding tubes.

And I wouldn’t even broach the subject of welding repairs of cracks etc without a very thorough crack and corrosion inspection and finding a very competent (aerospace or racing) weld shop with experience in magnesium repair. No fireworks wanted here. Epoxy repairs will just hide/promote corrosion

So, OK, lots of guys back in the old days ran magnesium wheels on the street. But keep in mind performance upgrades of the day were passing fancies and short lived. They weren’t running a magnesium wheel for 60 years, or 60 months and probably not even 60 weeks.

So proceed with a great deal of caution.

Unless your car is intended for high end concors shows or museums, or carefully maintained vintage race cars, running ”old” magnesium wheels on a street car may not be prudent.

Lots of very nice modern (aluminum and some as mentioned magnesium) reproductions out there.

That’s my 10 cents worth.

Cheers
Greg

[xb-60]

I'm certainly no expert either, however Greg has way more information and knowledge on the subject of old mag. wheels than I do. Safety should always come first, particularly when the subject is Cobras.

My 1 cent worth

Cheers,
Glen

[1985 CCX]

Greg is right safety 1st.
I never repaired any wheels, crack check yes. My feeling is cracked wheels should be repaired by a qualified individual, which will be at great cost.
Best rule if cracked = wall art!

Last, they are a wheel that requires PM, Lynn and Fran gave me the tools on that which I have shared. Oil Oil Oil and look at them to be sure they are good.
If cracked you will lose air. If not they may seep but will hold over time.
If you dont want the headache buy alloy!

Oiled and not pretty, Mags on AC#1085

[grodavidson]

Read all of the above, doesn't appear to have any recent feedback.

Bought my Contemporary Classic locally in 2013. Car was built in 1984, the previous owner contracted a complete rebuild in 1992-1993. When I got it the tires constantly leaked down. Had Yokohama tires that were showing signs of dry rot/cracking, so I had them replaced with BFG TA's by a local mechanic/hot rod shop while the car was there for an overall go-through. Back in 2013 vehicle inspection in NJ was done every two years, but any new purchase had to be re-inspected. On my purchase in 2013 the owner and I drove to "his guy", and looking at records I saw that the only miles put on the car since it's previous inspection exactly equalled the distance from the shop to his home, then back to the shop for inspection after my purchase! That's why I wanted to have the car gone through. That shop had my car for 2 years, 2 months, and 28 days. I had finally had enough and took it out of there.

Took it to a different shop, a really talented fabricator. Everyone there said it was the best repro Cobra they had ever seen. He went over the car completely, made a few safety upgrades re:rear heim joints, fabbed a better enclosed fan shroud and installed a more efficient fan & fan motor. Asked him to look at the wheel leak-down. He removed the new tires, installed new valve stems, remounted tires. I still have air leak down. Only one wheel (RR) holds indefinitely. LF and LR are "OK", lose a couple lbs/week. RF loses 4-5lbs in a day and can be nearly flat in 3 weeks of winter sitting.

Hope there will be some new input re:this subject on this thread. I'm confused as to how to proceed with any repair. Surely thought there would just be some sort of common sealer applied to the inside of the wheels to solve this problem, but apparently not. I have not done, or had done by someone reputable, an inspection of the wheels with the tires off. I was just chalking it up to the porosity of magnesium and certainly was not thinking about anything like cracking. Furthermore I have no idea how to establish that the wheels are actually Halibrands vs. aftermarket knockoffs. Just have the "Halibrand" raised lettering in the spoke casting on the spinners. Also have no idea of their age.

As I've tried to say I have no idea of how to proceed (as locally as possible) with a remediation for this problem. Any advice appreciated.

[1985 CCX]

Post pictures
Then we can possibly help

[MD427]

I will follow up on this. As one of my pet peeves on web forums is coming across a question that someone had similar to my own, and never chimes in with what worked! Lol.
......

I decided first order of business was to get a tube in the tire so the car could at the least be rolled around the shop/garage. I contacted Coker Tire and asked them about. tubes. He recommended a size immediately ("225/235R14/15 Radial Tube | TR13 Offset Rubber Stem" ). I mentioned that we had previous fitment issues and wasn't sure about the provenance of the wheel. He assured me that TR13 would be correct if the wheel was "right". Happy to say that nailed the problem on the first try, shop had no issue fitting the tube. Assured me construction of these tubes is sufficiently sturdy to run with modern radial tires.

So there you go GT40 style Halibrand wheels (front) take TR13 tubes from Coker Tire.

With that out of the way, I wasn't flying high with confidence on the shop after working with them for some time. So I asked around and found someone who came really highly recommended to me from a trusted source. Further away but bit the bullet and shipped the car on flatbed to the new shop. New mechanic pointed out a couple things after looking the car over.
Summary:
1) Claimed work to fix the leak hadn't been done. No sealant, no epoxy, no nothing, so of course it still leaked.
2) There is no "crack" or damage, at least visible to the discerning naked eye.
3) There is some porosity causing pinhole air leaks. Properly coating that should fix, has yet to be attempted.

As far as the wheels they seem otherwise sound. So I'll probably run them for a while longer, at least. The other 3 still are holding air without issue.

Someone asked what I know of the wheels history the truth is not much. They are Magnesium, they appear to be real Halibrand by any marking I can see. No idea of date of manufacture. Wheels came on a Contemporary Classics build.

1985 CCX, can you elaborate please on your oil treating process, I may attempt that next go-around.

[1985 CCX]

I can...... I'll abreviate so if I miss an apparent detail let me know if I sound crazy. Note, I run no tubes with bias tires.

Step 1:
Clean the rims with a nylon brush so it does not hurt the surface, brass may work too. I then set up a trash can with a bag in it with a coulple small wood straps so wheel sits above trash cans, if tires are on you dont need the straps.

Step 2:
Have penatrating oil, I used WD40 and soak the one side of the wheel and let sit. After about 60-75 minutes flip over and repeat. Do this twice to get pen oil into all areas of exposed Mag.

Step 3:
Wipe with rags to a dull oiled finish. Now use a gun oil, as it does not fling and it sticks like the hammers of hell. I used Lucas I think last but there are several brands and I am not sure brand matters. Probably like everything else made i one spot then repackaged for each product offering?
Use liberal amounts and apply with a small paint brush, wet with heavy coat and let sit to absorb into mag taking advantage of pouroisty of the metal.
Flip over and do the other side, again do this twice however I let sit overnight on this step as its the final round.

Once completed rag wipe and leave shiny, it dulls with brake dust and road dirt. I used to do this every year but it does seem that every other now works as the rims seem to be soaked.
On the green car I only have one wheel that slowly loses air, say over a couple weeks. On the gold car the rears never lose air and one front say monthly with one say bi-monthly. To note when I say lose air its like 4-6lbs not flat, over the winter they may lose all air however with monthly pass by its never an issue. Its not too hard to keep up and also keep in mind I rarley drive in the rain so the oil really does bond and stay put. If they need a touch up I do this while on the car.

The idea is fill the metal rim and then let stand. Seems to work for Lynn (gave me info) and a few other on the left coast. I know John B has a plating that can be done which is very correct and is a sacrificial coating that also needs repop over time. I think if I remember this was like the original wheels.

Hope I helped versus confused......

PS, I also use the metal valve stems which do have rubber seals. Sometime tightening helps as I know I lose air that way too. I always torque lightly as I dont want to crack wheel.

PSS for the astute these are my old spinners as now I have a more correct looking plated steel versions.

[MKS427]

I remember reading a post on magnesium wheels here on Club Cobra a while ago. Someone said, you have to keep the wheels oiled to prevent leaks, because they are porous. They even recommended a specific type of oil, but I cannot remember what it is. I've had no luck searching posts here on CC lately.

[MKS427]

Today, search is working.
maintenance of magnesium wheels

[CompClassics]

Here is a great link to the care of magnesium wheels.....

https://www.jalopyjournal.com/forum/...l-care.639065/

[MD427]

Gibbs! I have a couple cans of that in my garage. Next time the tires come off, will try an application of it.

[1985 CCX]

You can do an application with tires on too.