Puncture Repair

[David Brown]

Not having had a spare for 12 years, I wonder if I'm pushing my luck by just carrying an aerosol can (can I test if it still works?). 

Have been looking at alternatives. Has anyone tried Stopn'Go which pushes a mushroom plug into the tyre? Do the CO2 canisters properly re-inflate the tyre?  

Also see a product called Slime which appears to be put in through the  valve stem but is water soluble so can be washed out to allow a repair. Some respondents claim tyre companies won't repair tyres that have had foam inserted, no matter what kind it is. 

As have some longer trips arranged I don't want to empt fate. 

[Jonathan Kay]

There are some proprietary products in the archives with firm adherents.

I carry a spare.

Jonathan

PS: Would you like a tool tube for the aerosol can etc?

[Mort]

Holts Tyreweld is is water soluble, and can be bought from Halfords with your 10% club discount.  I carry this in the MX5, which doesn't have the option of a spare, but I carry a spare on the Seven to mitigate against tyre wall tears which Tyreweld won't fix.

[Ian B]

I've used one of these on several occasions with success. Sold ont he continent as permanent repair kits for cars, although in the UK many are marketed as "temporary" or "emergency" repair kits.

I've had one last for many thousand miles until the tyre go down to the wear bars when it was scrapped.

They don't coat the inside of the rims with gunk (that the tyre fitters hate) like the aerosol cans do.

[ScottR400D]

Most after puncture sealants are water based and can be washed out. The problem for a tyre fitter is that it's messy (ever tried to get water out of a tyre?!) and you need a few days in a warm place to dry the tyre before repair which makes things impractical sometimes. 

I was in the tyre business for some years and did quite a bit of research on these sealants. The results were patchy to say the least.

I was reminded of that when we had a puncture in my wife's SLK last year. MB supply a sealant which is pumped in by the compressor that also reinflates the tyre.  It appeared to work but the tyre was deflated again after about 25 miles so we needed to be recovered home. 

Since then I've equipped my daily, the SLK and my 7 with a similar kit to that shown above, plus a cheap set of long nose and normal pliers and side cutters. Also a cheap compressor/pressure gauge. Having played with these things quite a bit over the years I'm confident I could temporarily repair a good % of the tread injuries I'm likely to get. 

Not as good a solution as having a spare but none of our cars have one. In some ways the 7 is the bigger risk. The other cars have TPMS which will give me a warning before any damage is done running under inflated. I'm not sure how the seven will behave. How easy is it to tell if you have a tyre running at, say, 10psi if you're just cruising along?

[Ian B]

On 15" not very easy!

[David Brown]

Thanks all. Reckoned that the mushrooms looked  better solution than the "string" mentioned. Anyone tried the small gas cylinders for re-inflating?

[pikeyboy]

I don't drive my 7 on the road much but went to the linc's L7 club meet about 2yrs ago.  On the way there i clipped some wood in the road which must have nicked the valve stem.  Having not realised what had happened it gave me a slow puncture it turned out I couldn't repair, i don't have a spare but almost managed to limp home using different garage tyre inflators. I ended up having to get a lift home and going back to collect it on the trailer that night.

[ScottR400D]

I'm sure the mushroom plugs are fine but the sticky strings have been around for decades and have a very strong record. They're also good if the puncture isn't clean and straight through and you can double them up for the rare larger injury. 

Bear in mind that any of these should be regarded as temporary repairs only. 

[DJ.]

I have the stop'ngo mushroom kit and have used it once. It was pretty straightforward to used and sealed well for a couple of thousand miles until I replaced the tyre due to wear.

[thompster]

I've used the strings that Ian linked to on runflats twice and kept them in until the tyres needed replacing.  Very easy and worked a treat.  I would have had 'proper' repairs done but all tyre fitters incorrectly believe you can't repair a runflat.

[PeterM]

Cheers Ian @ #4; just ordered some. The 'gunk' approach has never appealed and a recommend by a fellow 7-er is worth its weight in gold 

[Ian B]

:-)

[Wrightpayne]

I'm about to get some too - also spotted the basic Ring tyre inflator is just over £11 at Screwfix. 

Ian

[Hampshire West AR]

I have used the kit Ian recommends.  My only reservation would be if you were involved in an accident with one that had been left in as a "permanent" repair and the tyre had blown out due to the temporary fix.  I suppose you could argue thatyou have just repaired it, but not sure you would be believed.

On the issue of runflats I understood that Michelin recommend one repair only before scrapping the tyre. Most tyre dealers don't want to repair them because they are a pain inthe neck to get off and on the rims.

Nick

[ScottR400D]

I'm a little out of touch but Michelin were the first manufacturer of RFTs to approve their repair about 10 years ago or so. The only reason they recommend only one repair is concern that the tyre might have run out of useful runflat capability (50 miles at 50mph) after two injuries. 

It's a fair assumption but if you were able to make sure that the injured tyre didn't run at very low pressure, e.g. below 1 bar, there are no technical reasons why a RFT can't be repaired as much as any other tyre. A good reason to carry a mini compressor, as most punctures let the tyre down reasonably slowly.  

As for reluctance of tyre dealers, that's much more to do with the desire to sell a new tyre. The tyre changer in my garage is about 10 years old and it will easily handle RFTs, even on asymmetric rims, so I find it hard to believe that tyre dealers don't have the right kit.  

Btw, minimising or avoiding running flat applies to non RFTs even more, of course. 

[thompster]

My understanding of the rules is that the British Standard puncture repair requires an inspection of the inside of the tyre. so by default a repair applied from the outside doesn't meet BS.  But as a few of us have said they work just as well as the mushroom-type pulled through from the inside.

Scott - you're spot on. For runflats, the tread part of the tyre is essentially identical to a non-runflat, only the sidewall is different so there is no practical difference in puncture-repairability. RFTs only have a certain run-flat life (e.g. 50 miles) so if a tyre has been run flat and started to delaminate its a bin job - hence the BS internal inspection requirement. Sadly my experience of tyre fitters is that they don't know very much about the products they're fitting.

[ScottR400D]

Your understanding is correct. I would argue that an internally applied 'mushroom' is technically better than the externally applied ones in that the 'head' or patch is bigger and is bonded properly to the liner, which doesn't happen with the external ones. 

But there's no doubt that in many cases, especially with a simple straight through puncture, the external ones will work well, but an inspection is always worthwhile.

Any tyre will be ruined by being run flat. At the risk of teaching grannies to suck eggs, when the pressure is very low the upper sidewall contacts the lower and as the diameters are different there is a rubbing action when in contact with the road, which destroys the sidewall. It's easily spotted from inside, evidenced by the rubber crumb created. 

There also the risk of internal damage caused by whatever punctured the tyre. I've seen tread punctures where the penetrating object has cut into the shoulder or sidewall from the inside. Not visible from the outside but can be very dangerous if externally repaired and left as is. 

In my experience many tyre fitters know what's what but are motivated, if not incentivised, to sell a new tyre. It's easier, quicker and usually more profitable.

 

[Ian B]

I would argue that an internally applied 'mushroom' is technically better than the externally applied ones in that the 'head' or patch is bigger and is bonded properly to the liner, which doesn't happen with the external ones. 

I would argue that the way the loop of "liquorice" is inserted, and twisted, before the tool is removed on the externally applied ones creates a similar, if not larger "mushroom" inside the tyre.

Also the strips are very sticky and do include a bonding agent to help them bond properly to the tyre.

[ScottR400D]

The head of an internally inserted plug and patch will typically be 40-45mm diameter. (Some designed for very small injuries are maybe 20mm but the most common are the larger ones. 

The face of them is uncured rubber which chemically vulcanises into the butyl liner of the tyre, after that has been cleaned and mechanically buffed. 

The sticky string doesn't bond to the liner at all, if it touches it. I agree they bond well into the injury and that's often enough, which is why I said the internally applied patches are only technically better. Perhaps 'theoretically' would have been a better word to use. 

 

[Wrightpayne]

Personally, I'd only see the string repair as a get me home / finish the journey with a view to sorting properly at the earliest opportunity. Anything to avoid having to be trailered home!

Popped to screwfix today and got the slightly better tyre inflator with built in LED lights for £16 so can also repair punctures in the dark :-)

Ian