In the garage blow out

[Timothy Keith-Lucas]

Thank you for the coaching, MV8. Right now I'm building a bead breaker powered by a 1/4 inch impact driver.

[panamericano]

Nice wheels.  Looks like MV8's bead cleaning suggestion may be helpful.  You may be lucky that the old tire blew up.  At such high pressure, I would have worried about the old magnesium just as much.

[MV8]

Work fine in a drill. Use fine/blue.

https://www.ebay.com/itm/404104712901?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D290432%2C290494%26meid%3D11b5c7a9729b49a884dc8c5e1d707b62%26pid%3D101875%26rk%3D4%26rkt%3D4%26sd%3D256787830586%26itm%3D404104712901%26pmt%3D1%26noa%3D0%26pg%3D2332490%26algv%3DSimVIDwebV4WithCtxRankerV1ECPM&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A40410471290111b5c7a9729b49a884dc8c5e1d707b62|enc%3AAQAKAAABEHpsrQN%2BfAdDZYpPJGYWcJeM%2B7kOu0qCwhwpE0jI5WLZbLunKqjjv17aqA5FlcDVyvSFenRBY8aBUq%2FPJfsTBjvsyJZaZLA6rAzH2%2Fa2MXa47nyhPiAb7nZKrf7rBTERoAvjcBLd9SbNoGr6iRLQAR648Pe0BjG%2FIvLhAgMc03VdQeG4KZWlcDDRJQhjSS6iBX4TKCT8XvnSeXGy2eO3956ju51VPBoQxzQ8HWJRFnMGXyOM1hwmkXi3WehnJixlqv%2B2cfrJxJ73QJNfFXvP%2BZDOc8qGds9YqugU6HHLyCfJd5z35QKszTS%2FxSIKh2077mk44pAUzgp%2F4g8ekgFq4dpAVp0jryLZUJ5iyV5moU%2BR|ampid%3APL_CLK|clp%3A2332490&itmmeta=01K2MMFVE9M3FB38E7ZZ7R3BGD

[theDreamer]

Modern magnesium does not age well. This fact is even more prominent for magnesium items exposed to the elements and subjected to numerous heat cycles, high G forces and shock loads for example; automotive, motorcycle and aircraft wheels. That is why Porsche recommends that owners of their GT3 RS models should replace the wheels every 10 years or 40,000 miles whichever comes first.

Older magnesium wheels are even more suspect. Most vintage racers won’t use real mags but rather opt for a similar looking, almost as light modern alloy rims. I’ve seen the aftermath of old mags that have broken under race conditions. Some sanctioning bodies require wheels to be date coded and/or tested to prevent use of wheels that are suffering from material degradation.

NO! Magnesium wheels CANNOT be magnaflux tested because this method is only suitable for ferromagnetic materials. Instead, dye penetrant inspection, X-Ray or other non-destructive testing methods must be used for magnesium wheels.

Sorry but just like your old, over inflated tire your wheels are time bombs. I would not use them for anything other than static display.

As for mounting tires in your garage here is one trick I learned years ago. After the tire is on the rim and positioned correctly, (alignment dot on tire over the valve stem) wrap a tie down around the center of the tire and tighten it. This is done to draw the center inward and get the tire beads set in or very near the wheel rim lips. Apply air pressure and once the tire beads are sealing, (and before they pop into place) release the tie down.

Also, leave the valve core out of the valve stem while you are inflating to seat the tire bead. You can force more air under greater pressure into the tire with the core out. Once the beads seat then place the core into the stem and inflate to proper pressure. (Yes, many people over inflate and let the tires sit for a period to ensure the beads have seated all the way around. BUT, do not leave it overinflated for days. A new tire should take no more than an hour or so to fully seat onto a cleaned wheel rim.)

Edited August 15 by theDreamer

[Timothy Keith-Lucas]

Thank you, Dreamer. I'm getting a short course in tire care.  Right now (with a day out for volunteer stuff) I'm working on a bead breaker.  I'll be back soon.

 

Many thanks to the several forum members who have contributed to my education. I really appreciate your patience and the wisdom you impart. I started in on a Seven as a step up from 60 years overhauling and maintaining small motorcycles.  Some of those skills transfer well to the Seven, but a lot do not.

[IamScotticus]

15 hours ago, theDreamer said:

After the tire is on the rim and positioned correctly, (alignment dot on tire over the valve stem)

Could have two dots. A red and yellow,  IIRC, one is for valve stem and the other is for a balance high side?

[theDreamer]

Back in the 60’s and into the 70’s when I was working in a service station I only remember tires having white dots. The one on the outside sidewall was to be aligned with the valve stem. If there was one on the inside it was an inspection stamp or so I was told.

Sometime after I left the auto trade they decided to make things more complicated by introducing colours. I believe you are correct; yellow is for the valve stem but red is for the high spot and it take priority over yellow. But not all rims have balance marks. So that’s why I say use the yellow to align with valve stem. If you do not know where the wheel's balance point is you can end up with more weights then you need. My Caterham had a poor tire tech back in 2004 (date code on tires). One wheel had two strips of weights almost directly across from each other and on another wheel one long strip. Neither of those should have happened.

[panamericano]

Most run of the mill tire shops pay no heed to the dots, which is odd, since the shop is wasting money on weights.  I've even asked a couple times and had them look at me like a dummy.  Mostly Discount Tire.

[IamScotticus]

I could forgive that as long as they hand thread my nuts

[MV8]

Fear not. This is not a race car or being used as a race car. You can reuse your mag wheels if the corrosion is not too deep and you should treat the cleaned wheel with alumniprep33 followed by alodine (both available at aircraft spruce and also used for aluminum alloys). Unlike aluminum which forms an effective oxide layer to protect itself, magnesium's oxide is not as effective. Aircraft parts are often magnesium and without life limits but the chems are toxic and they must be maintained. Deep corrosion is the reason for failure (just as it can be for other materials) and will make a part scrap. If you are not going to make maintaining them a priority (like 90% of the population), switch to aluminum alloy or steel now.

Unfortunately, shops are in a hurry but you are not. Since you do not have a big compressor to rapidly dump air through the valve stem and also have a valve on the compressor hose, install the valve stem and bring it up slow. Rapid means the beads don't need to be up against the rim when you start as the rapid increase will push the beads out toward the rim. In emergencies, they pour flammable liquid into the tire and ignite it to seat the beads (don't do this please). Again, with this size tire and appropriate rim width, it won't be an issue to slowly increase the tire pressure. They make dump tanks with a ball valve instead of an end fitting to press a valve core but still need a clip-on end that will stay connected. It isn't necessary. You should not need more than 20 psi to seat with the valve core installed.    

Edited August 16 by MV8

[Timothy Keith-Lucas]

Thank you, MV8.  I will clean and polish up each rim in turn.  I have not seen anything but surface corrosion so far, despite the wheels being over 60 years of age.

 

Actually, I do have a compressor capable of a very rapid dump; it sits at 60 gallons of 175 psi air.  It's biggest problem is that it shatters the glass beads in my blast cabinet, resulting in silicon dust which is basically a hazardous material. So far, I've had no problem getting the bead to seat. It's getting it to unseat that is the challenge.

 

You've gone to a lot of trouble to coach me.  I really appreciate that.

 

--Tim.

[Timothy Keith-Lucas]

Amen, IamScotticus. Aside from the PITA of cross threading a stud, do you want to place a bet on how many air wrenches deliver the right torque for the stud? I bought a Jeep that had oversized tires torqued to 200 ft lbs., a miserable case of "It's bigger so we should put it on really tight."  My rant, but I doubt many tire shops understand that they are aiming at the elastic range of the stud, not "tighter is better."

[Timothy Keith-Lucas]

Perhaps the final word....

The air gun on the end of my air system didn't supply enough air fast enough to seat the bead on my wheels, despite having 60 gallons of 175 psi available, due to friction loss. A very simple rig of scrap 3/8" air hose, a ball valve, and some fittings solved that problem.

[wdb]

I tried to post a "funny" video of the starting fluid method of seating a tire bead, but it didn't work. Anyway congratulations on getting it done!

Edited August 19 by wdb

[Timothy Keith-Lucas]

More bang for your buck! Use enough and it might remove the tire from the rim for you. Reminds me of the time I tossed a can of starter fluid into my burn barrel....

[pethier]

I don't think I have ever seen "the stamped steel version" that looks like a MiniLite.

[Timothy Keith-Lucas]

Time to rant. I rotated the tires on my Miata yesterday. The generally very good local mechanics shop had mounted them when new. Not even my air wrench would loosen them. They were on so tightly that I sheared a socket adaptor when trying to loosen them with a breaker bar and extension. Someone simply does not understand torque/elastic range/plastic range when it comes to lug nuts. Fifty years ago a truck tire bouncing down the Interstate killed the wife of one of my colleagues. I wonder how many of those YouTube flying tire incidents are the product of lug nuts being over torqued. 

[MV8]

That comes from the shop not using torque sticks and the air pressure set to high. Sticks are color coded for the torque spec. Assuming it wasn't deliberate, all it takes is one moron without enough supervision.

 

You can always stop and take it back to the shop to have them loosen the lugs and torque to a spec.

Edited October 15 by MV8

[wdb]

I had the same experience a year ago at a Mercedes Benz dealership. I needed a breaker bar and a 3-foot piece of pipe to loosen the lug bolts. 

[pethier]

I no longer have my Ford Fusion, but I did have an issue with the dealer.  There were several submodels of Fusion.  Some, like mine, were supposed to have the lugnuts at 100 foot pounds, and others at 150.  I often after the dealer had the car found that the lugs were damned tight.  I suspect that the tech failed to pay attention to the submodel of Fusion and the diameter of the studs and tightened to 150 instead of 100.

 

Now I have traded the Fusion for an F-150 and the knuckleheads take the air out of my tires.  I have load-range-E tires on the truck because I tow a Seven or a Cayman (and recently a friend's Corvette) in my enclosed trailer.  The tires I got for the truck to replace the darn CAR TIRES that were on it are Cooper load-range-E terrain tires.  Even with the full-load 80 PSI in them the tread is squirmy.  After an oil change, I went to pick up my trailer.  In a bit of flukey wind, the rig with empty trailer was all over the road.  I stopped to check the pressures:  36 PSI!  They sent me a survey email and I sent back an email that they had better not deflate my tires if they wanted me to send in a favorable survey.  They have promised to not do this again.  Do you know how long it takes to get tires this big from 36 to 80 with a domestic-size compressor?

Edited October 15 by pethier