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Kirkham Motorsports

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Old 05-29-2020, 09:46 AM
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Default Any magnesium wheel gurus in here?

I'm having a fit getting some tires on a set of old magnesium Halibrands (I think *EDIT* 7.5" front 9.5" rear).

I brought them to a local shop to put 4 new tires on (BF Goodrich Radial T/A - same tire and size as what was on previously).

He puts the new tires on, and tells me when I picked them up, "its strange, the wheels/tires aren't meant for tubes, but the tires all had tubes in them."

I shrug it off, go home and put them back on the car. A couple days later one is low, and won't hold air. Back to the shop, reseat the egde, took extra care to get a clean seal. Still wont hold air. Back to the shop. Finally, "Found the leak, the wheel has an internal crack forming."

Ok. Maybe thats why PO had tubes in all 4?... but the other 3 seem to be holding fine...

Any tips on fixing the wheel up to hold air? Tried some epoxy over the visible crack, but that didn't seem to help. So we are thinking, back to running a tube just in this one wheel (its a front). Car isn't really driven enough or long distance that this should be an issue. The issue, 'normal' automotive tubes don't seem to have the valve 'clocked' right. It doesn't reach the stem hole in the wheel. Obviously whatever tubes were in prior fit well enough. But it was so long we don't know what they were, the shop has tossed the old tubes by now.

So i have really 2 questions.

1) Does any one know what type/make/model tube would have been used on a Halibrand that would fit i guess the "non-typical" valve location. And a source to get another one.

or

2) Any tip or advice on how to seal the porous internal face of the wheel to make it reasonably airtight? Is it even possible? I keep reading murmurs of various "epoxies" or "enamel" tricks on old hot rod forums, but no specifics, and I can't find any indication on what or how exactly to approach that.

My mechanic who I trust reasonably well, has exhausted his own knowledge on the matter, and has apparently called every wheel shop in town, receiving the same answer from each. "Magnesium? We're not touching them."

Have any of your encountered/successfully dealt with this issue? I'm happy for any advice.

Last edited by MD427; 05-29-2020 at 01:24 PM..
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Old 05-29-2020, 10:34 AM
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Originally Posted by MD427 View Post
Any tip or advice...
Welding magnesium is a little tricky. If it catches on fire, it's going to be a really bad day and burn until the wheel is ashes. No promises, but I remember some threads on this place. https://www.rimpro.com/ Give them a call and see if they can fix it -- finding a local welder that will tackle magnesium, and do it right, is going to be harder than you think. And if they won't do it, they'll know who will.
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Old 05-29-2020, 11:23 AM
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In 1969, I replaced the Goodyear racing tires on CSX-2286 with 60 Series tubeless tires, the hot tire at the time for the street. My tires had tubes in them and I replaced the tubes with new ones, so back then it was not a problem as tubeless tires were just coming to the market. Otherwise, I would have run into the problem that now faces you. I would first check with Coker tire and see if they have any suggestions as they make a lot of the old tires. Also, check out on Amazon PREMIUM SERVICE GR13/14/15 Automotive Tire Inner Tube TR13 Valve Stem Automotive. I don't know what size tires you have put on, but the site gives you a lot of tubes for various 15 inch size tires. See, if you can find out who makes these tubes and talk to them as to the proper size for your tires. As I remember, we had to go a little over sized on the tube because 60 aspect ratio was also new and lower than conventional size tires of the time. You do not want to go UNDERSIZED on the tube.

Bill K
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Old 05-29-2020, 11:41 AM
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Coker sells tubes and should have what you need. Make sure to let them know that the tube is for a radial tire.
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Old 05-29-2020, 12:02 PM
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patrickt: So you are saying I shouldn't just get out my "Jr. Welder" kit and go for broke?

bkozlow and bcrumpley: Thank you both for the suggestions i will pursue those avenues.


I just swung by the shop, and saw the wheel in person again... spray bottle test shows at least a dozen (no exaggeration!) pinhole leaks. Ugh.
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Old 05-29-2020, 12:42 PM
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how about several coats of concrete sealer ( on the inside of the rim) to seal the pores ?
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Old 05-29-2020, 03:33 PM
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Ok I run mags on two cars. Magnesium is porous to a degree.
I oil my mags in two stages. The oil penetrates and seals the magnesium.
Second my mags have tractor type valve stems, they need to be snug or they leak to.
Third mag is tricky to weld. It can be done. If the crack is visible find someone with experience to repair.
If the crack appears to possibly be a seam from the molds you may be ok with the above.

Best of luck
BTW running bias tires on mags no tubes and no air losses. 👍🏻
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Old 05-30-2020, 01:59 AM
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1985 ccx, did you buy the mags from crosthwaite and gardiner? Went down and bought a diff case from them and saw the mag wheels, they let me watch as they machined a wheel. They are beautiful wheels and the way they coat them is impressive.
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Old 05-30-2020, 06:59 AM
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Quote:
Originally Posted by feadam View Post
1985 ccx, did you buy the mags from crosthwaite and gardiner? Went down and bought a diff case from them and saw the mag wheels, they let me watch as they machined a wheel. They are beautiful wheels and the way they coat them is impressive.
I bought my Mags from C&G. Very nice wheels. They are finishing with a very nice black chromate which is air impermeable
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Old 05-30-2020, 08:07 AM
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the manager walked me through the shop to show me all the neat stuff they had, the black chromate was nice, i know aircraft wheels used a zinc chromate but the black looks a ton nicer.
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Old 05-30-2020, 08:11 AM
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Quote:
Originally Posted by MD427 View Post
I'm having a fit getting some tires on a set of old magnesium Halibrands (I think *EDIT* 7.5" front 9.5" rear).

I brought them to a local shop to put 4 new tires on (BF Goodrich Radial T/A - same tire and size as what was on previously).

He puts the new tires on, and tells me when I picked them up, "its strange, the wheels/tires aren't meant for tubes, but the tires all had tubes in them."

I shrug it off, go home and put them back on the car. A couple days later one is low, and won't hold air. Back to the shop, reseat the egde, took extra care to get a clean seal. Still wont hold air. Back to the shop. Finally, "Found the leak, the wheel has an internal crack forming."

Ok. Maybe thats why PO had tubes in all 4?... but the other 3 seem to be holding fine...

Any tips on fixing the wheel up to hold air? Tried some epoxy over the visible crack, but that didn't seem to help. So we are thinking, back to running a tube just in this one wheel (its a front). Car isn't really driven enough or long distance that this should be an issue. The issue, 'normal' automotive tubes don't seem to have the valve 'clocked' right. It doesn't reach the stem hole in the wheel. Obviously whatever tubes were in prior fit well enough. But it was so long we don't know what they were, the shop has tossed the old tubes by now.

So i have really 2 questions.

1) Does any one know what type/make/model tube would have been used on a Halibrand that would fit i guess the "non-typical" valve location. And a source to get another one.

or

2) Any tip or advice on how to seal the porous internal face of the wheel to make it reasonably airtight? Is it even possible? I keep reading murmurs of various "epoxies" or "enamel" tricks on old hot rod forums, but no specifics, and I can't find any indication on what or how exactly to approach that.

My mechanic who I trust reasonably well, has exhausted his own knowledge on the matter, and has apparently called every wheel shop in town, receiving the same answer from each. "Magnesium? We're not touching them."

Have any of your encountered/successfully dealt with this issue? I'm happy for any advice.
The only problem I have with using tubes in the the tires is risk o explosion of the tube when it deteriorates and it cause more damage than you can shake a stick at. There are many wheel repair outfits that can see to repair your wheel vs running a tube.
Just my humble opinion.
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Old 05-30-2020, 09:51 AM
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Trust me, when I say there are VERY FEW places that will work on Real alloymagnesium wheels in the country and do a job I would trust my life to. I would suggest you give Aircraft Spruce a call (877-477-7823) and see who they recommend or could steer you in the right direction in the aviation industry. It will not be cheap!! That crack must be addressed if you plan to use that rim!

Bill K
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Old 05-30-2020, 11:04 AM
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No, mine are from two sources
Fran Kress
Lynn Park

Think I have three different castings in my FIA and one in Kidney bean.
Mags are great just require more attention
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Old 05-30-2020, 11:27 AM
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I was serious regarding a sealer. Do a google search for: "sealing porous metals" or similar.
Do you know any machinists or foundry worker or engineer ?
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Old 05-30-2020, 02:15 PM
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I seal with gun oil

Last edited by 1985 CCX; 06-01-2020 at 05:13 AM..
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Old 05-30-2020, 04:46 PM
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Quote:
Originally Posted by bkozlow View Post
That crack must be addressed if you plan to use that rim!

Bill K
I don't like the idea of having cracks in your wheels, even if you do have safety tubes in there.
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Old 05-31-2020, 04:23 PM
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Google magnesium wheel repair and refinishing. There's a company down south that specialize in Campagnolo mags but also has done Halibrands. I talked to them a few years ago about mine. I had a scare a few years ago with my son in the Cobra and we were on a long stretch and i opened it up no problem until i got to the driveway home and the tire just went down to the rim. Turns out it wasn't the rim but the Billboard was dry rot on the inside of the rim! If it happened a few minutes earlier we might not have been able to survive it. I always use Gibbs on my Halibrands especially the backside of the rims. It really helps seal the magnesium.
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Old 06-01-2020, 11:28 AM
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Quote:
Originally Posted by MOTORHEAD View Post
I was serious regarding a sealer. Do a google search for: "sealing porous metals" or similar.
Do you know any machinists or foundry worker or engineer ?
I'll investigate that route. Now that I've seen the wheel, the extent of the problem is more concerning. There were over a dozen pinhole leaks clustered around different spots on the wheel. 3 areas on the back side, 1 on the face. I'm not sure about a sealant being adequate due to the dispersed nature of the problem. It might be worth a shot.

At least, now it does not appear to be an actual crack, which on one hand is good. But on the other it is clearly oxidized pretty thin in a few spots, so it may not be long for the world anyway.
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Old 06-01-2020, 12:31 PM
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First, you have to determine what exactly caused the leak, crack, corrosion, etc?
Second, when Halibrand delivered the magnesium wheels they were “pickled” with a protective diechromate process made by DOW chemicals to protect the magnesium’s exposed surfaces from corrosion. This protective coating is the ONLY thing that will protect the magnesium properly. You can paint over the magnesium but only if it has had the DOW process done prior to painting. If you paint directly over the magnesium the wheels will rapidly corrode, sometimes without any clue that it is happening but it is. The corrosion takes place between the paint and the surface of the magnesium where a moisture layer starts. The only way you will catch this corrosion is when it breaks through the paint as a white powdery material but this does not always happen. This is the reason for the common misconception that magnesium wheels rot from the inside out. Magnesium needs oxygen and humidity to start the corrosion process. If the DOW process is left unpainted it will eventually need to be redone as it is only a primer for paint and when left exposed it will deteriorate.
You can oil the wheels as suggested above but it still leaves the magnesium exposed, even the smallest pores can start the corrosion process. There is a spray penetrant made by Gibbs that penetrates down to a very small hole diameter but it’s still not 100% protected.
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Old 09-14-2020, 10:22 PM
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If it is a casting leak due to a crack, then the wheels needs to be properly cleaned, and welded, then dressed off and re-chromated. If the leaking is due to porosity in the casting then the process id different. For slow leakage find a company that specializes in casting impregnation. The wheel would need to be cleaned with and acid bath, rehromated , then impregnated, but check with the impregnation company as they may impregnate before the chromate.
When we were still sand casting wheels we would impregnate castings after polishing to stop porisity leaks. The sealer was clear and you could not tell it had been done. the wheel was cleaned and placed into a sealed tank. Next a high vacuum was pulled, and the sealer was then introduced, after which it was pressurized . After a time the sealer was drained and the wheel removed.
If the wheel has a crack anywhere in the center disc of the wheel , please replace the wheel and do not weld on the spoke section for safety reasons.
we currently make one-off cast and forged magnesium wheel for vintage race cars.
scott
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