To jump straight to the 2018 update click here.
Due to some of the trouble we had with tubes during the 2016 expedition, I was forced to look at how we repair tubes from scratch. Over the years I have refined my technique & gear used, but last year in the Great Sandy Desert with tubes & then tube repairs failing there had to be something wrong, seriously wrong with both the tubes, materials & maybe how I was dealing with them. It was a puzzle, some of these problems we had seen before but never to this degree i.e. multiple times a day. To illustrate how tube repairs effected our expedition, I expected about half-a-dozen flat tyres in total as the entire group had Bias tyres fitted. Turned out I was right, we had only 4 fair dinkum punctured tyres from stakes, but we had 20 flat tyres! Below are the figures;
2016 Off-Track Expedition (Website Report 2016 Expedition Tyre Report )
- 20 flat tyres in total
- 9 tubes just split in the sidewall, nothing through the tyre
- 4 tube repairs split under the patch
- 4 staked tyres – perfectly normal & expected when off-track
- 2 flat tyres – unknown causes, not investigated (vehicle left trip midway due to major mechanical issue)
- 1 slow leak that was not investigated (second vehicle left trip midway due to suspected major mechanical issue)
Anyone at this point who thinks that fitting tubeless tyres would solve the problem obviously has no experience in long term remote area work travelling off-track where no roads or tracks exist. I suggest they learn a bit more about tyres, tyre construction & working for weeks without a track or road at all then join the "discussion".
As I mentioned in the Expedition tyre & tube report I spent a lot of time thinking about what happened & what to do about it. A mate of mine in the tyre industry from Perth did some ringing around to ask experienced tyre industry fellas about our problems & so did I. Ultimately, we found out a few things but nobody had seen or heard of the problems we had in regard to 4WD tyres. I did get a few snippets of information via Rema Tip-Top but not from the technical department as expected! These little workshop gems confirmed what I had already been thinking. So to cut a long story much shorter these are the things I came up with to try & solve our tube problems, they are in order of importance. Two already have solutions. No.3 is the brain teaser & what this report is actually about.
Problems
- Tiny tube splits in sidewall for no apparent reason; our theory is that the cheap tubes have quite an amount of recycled tyre rubber in them (this we know), this makes them quite hard & almost brittle. Put these tubes under great stretching/stress while at low pressure and the tubes split in the sidewall area where the stretching is the worst. Only use quality tubes, no cheap thin rubbish. This has boiled down to using only tubes from the major tyre manufacturers; Toyo, Bridgestone, Sumitomo, Michelin etc - Don’t skimp on quality, there are no excuses. ------ Using quality tubes normally gets rid of problem No.1. Once again look at the 2016 Expedition report.
- Cheap thin tubes do not always take glue very well; this leads to problems within hours at low pressure sometimes. -------- Using quality tubes gets rid of problem No.2. Once again look at the 2016 Expedition report.
- Tubes splitting underneath a repair patch; Use a thicker patch that won’t stretch & allow the tube to split. This will require a bit of experimentation with different patches & glues.
Before we get started I’ll just to throw some light on the legal aspect of tube repair, quite simply there doesn’t seem to be any. There is no reference to tubes in the Australian Standards for Tyre Repair, there is no repair sheet with the boxes of tube patches, (unlike the tyre patches which have a specification sheet included). There are no notes on tube repair in Rema Tip-Top's book-like catalogue which has their repair requirements for tyres etc. I also can’t remember any tube repair references in the Tyre & Rim Association Manual, but I may be wrong there. So, it looks like tube repair is much like temporary tyre repair, Rafferty’s rules so to speak.
Now to the good stuff;
Testing different patches & glues on tubes to see if the tubes will split underneath the repair at low pressures while 4WDing on various surfaces. The following are the different things we have tried. Read on to find out what happened in the bush with these tests. Some of this is ongoing.
- Toyo brand new tube
- Pinprick hole patched with normal tube patch
- An amount of low pressure as well as normal off-road pressure
The first thing I wanted to test was if a good quality tube would split under a normal tube repair patch. I knew they would as it had happened over the years during previous expeditions, but never enough to think it was anything more than a poor repair done by myself. Getting into Kalgoorlie late in the 2016 season I arranged for a new box of Toyo tubes to be delivered from my Perth contact. All went as planned, I picked them up and then stripped all 4 of my tyres & fitted brand new Toyo tubes, spotlessly clean tubes & tyres, talc in the right place, the usual procedures. I was quite impressed with Toyo’s during the most recent expedition. However, I went a bit further, on the rear left tube I made a pinprick hole in the sidewall of the tube & repaired it with a No.4 round tube patch & tube glue, exactly like we do in the bush all the time.
Kalgoorlie tube experiment September 2016 – pinprick hole in new Toyo tube sidewall
I chose the rear left as it does the hardest work being on the rear axle with the most weight and due to road camber the left has more weight thrown its way most of the time. Normally in my case while driving I favour the right (drivers side), so the left cops the worst of the bumps as well.
The last trip for the year had soft sand in quite a few places so I would have pressures right down during the coming few weeks to see if a result was possible, namely trying to see if the good quality tube would split under the patch. Later on with only a day or two left in the trip and the worst of the sand completed I had the time one afternoon to pull the experimental tube & see how things were going. I was quite surprised to find that the Toyo tube had indeed begun to split under the patch. The patch was well bonded but it was very easy to feel that the tube's tiny pinprick puncture was now a split maybe an inch long. So there you go, my theory about the tube patches being too elastic seemed proved with a simple test over less than 3 weeks. I replaced it with a new tube and put it back together. We finished the season & headed home. Later in the workshop at home I cut the repaired section out so I could see it properly from the "inside". The patch was well bonded, but it couldn’t stop the tube from stretching enough at low pressure to split further.
Test repair on new tube – tube patch & tube glue
When you fold the patch forward a little you can see the split underneath.
Test repair on new tube – tube patch & tube glue
Split underneath from the tiniest pinprick
Test repair on new tube – tube patch & tube glue
Have a look at the shape of the test patch, it’s no longer round after stretching with the
sidewall of the Radial tyre. I find this very interesting.
- Toyo brand new tubes in All Steel Radial tyres
- Pinprick hole patched with UP10 - small rubber only tyre patches
- One patch done with "Vulc Fluid" tube glue
- Other patch done with "BL Cement" tyre glue
- Both fitted to rear for off-road tours & bitumen highway work
Moving on with my plans to find a solution to the "tube repair splitting problem" I once again fitted a new set of Toyo tubes for the first couple of commercial trips in 2017. This time I was trying tyre patches on tubes. Because these are tyre patches I also had to try both types of glue that Rema Tip-Top produce, the one for tube patches & the "blue glue" for tyre repairs. I wasn’t sure what would be best so I would try both. Once again I purposely damaged brand new tubes & repaired them. This time I did the same thing as before, just the tiniest pinprick in the sidewall. Both tubes were repaired the same way with Liquid Buffer & scotchbrite, which is the best way I have found lately. However this time I used UP10 patches which are a small square rubber only patch designed for nail holes in tyres. These UP10 patches are much less elastic than the standard tube patches and I was hoping they would hold the tube at low pressure & stop the splitting problem. As usual with working outside the box so to speak, there is only one way to find out.......give it a go!
Pinprick hole in sidewall of new Toyo tube – splinter pick from my pocketknife.
A closer look at how small the pinprick hole is – I used the same tool to put a hole
in the test repair in Kalgoorlie in September 2016
UP10 on new Toyo tube using Rema tube glue (clear stuff in green tin/tube)
UP10 on another new Toyo tube using Rema tyre glue (the blue glue)
After the first trip was finished we spent some time in Alice Springs late in May 2017 and I pulled both tyres apart to inspect the patches & see how things were going, (good fun this desert work isn’t it). I was pleased to find that both patches were sound and I couldn’t feel any change in the tube under the patch. Another good sign was that both types of glue look like they are doing really well. I intend to check both at the end of the second trip if there are no failures during the Anne Beadell & Connie Sue Highways trip.
Experimental UP10 tyre patch on sidewall of tube using Rema Tube Glue
So far it looks sound & the tube feels good underneath, (not splitting).
Inspected 20th May 2017.........I’ll check again after the next trip
Well, turns out I didn’t need to specifically pull the experimental tubes for inspection. My "luck" was in and both rear tyres had punctures late in the second trip.......most folks would shy away from saying that was lucky, but I’m a little bit different as you may realise by now if you have read through much of our website.
The left rear picked up a small sidewall stake while on an old set of wheel-tracks detouring off the Connie Sue Highway (we have Aboriginal permissions for these). Repairing the tyre that afternoon I had a close look & feel of the experimental UP10 patch and tube underneath it. No sign of splitting at all & the glue looked in very good condition. I was a happy camper, literally. Just to continue the experiment I repaired the staked tube with another UP10 and the same glue as the experiment. Thought I may as well see what happens.
Experimental patch UP10 & Tube Glue after almost 2 tours – in great condition.
Inspected 21st June 2017 on the Connie Sue Highway
The second flat tyre (rear right) was a problem we have seen before quite a few times. The All Steel Radial Tyres we were using were a set that had done an expedition a couple of years earlier on a customer vehicle. So, they had the usual "cuts & bruises" from cross-country bushbashing. I had inspected these tyres pretty well before fitting them but during these two commercial trips I actually had the pressures lower than I normally would because of this tube experiment. This put more strain on those minor tyre cuts and so one of them had got bigger & deeper and gone through the tyre eventually rubbing a small hole in the tube. Result, one slow leak. Simply one of the hazards of using "veteran tyres" instead of brand new ones every time you go bush. (If we used new tyres for every trip we’d go broke buying tyres!).
Anyway, the experimental patch was fine & the glue was in terrific order. I couldn’t feel any splitting of the tube under the patch either, so things were looking good. So far the test was working very well. The small tube hole was repaired the same way again as the experimental patch to keep things neat.
This is the tube showing the imprint & scarring from the old tyre damage. This
happens now & again if you use tyres that have done some very hard work. (The experimental
patch was fine on this tube so I was pretty chuffed. Inspected 23rd June 2017)
Both tubes made it back home to NSW after those two commercial trips in May & June 2017. I pulled them out of the All Steel Radials, inspected them, found them to be both in excellent order & so fitted both into Bias tyres for the upcoming off-track expedition and the final tour of the season. I kept both on the rear axle so they would be doing the most work. This would help to force a result, and we did get results from both tubes, read on.
UP10 & Tube Glue in excellent order after two tours in the western deserts
Inspected July 12th 2017 after 11,350 kms
UP10 & BL Cement Tyre Glue in excellent order after two tours in the western deserts
Inspected July 12th 2017 after 11,350 kms
The off-track expedition was for 28 days looking for explorer sites and waterholes. We covered about 650kms off-track & had a really good time. On day 25 the right rear developed a slow leak. I couldn’t be sure what the cause was immediately so I changed the wheel and we carried on. That afternoon I pulled it apart to get an answer......the experimental patch was the problem, the tube had split underneath and just come out from the edge of the patch, only just, but that is all it takes! This was the patch that the tube glue was used on, an interesting result. So, we had an outcome after two tours and pretty much a full expedition.
UP10 & Tube Glue failure near end of Expedition (3rd trip), with the tube inflated you can
see the tiny hole on the edge of the patch, the tube has split underneath.
19th August 2017 after 16,230 kms
UP10 & Tube Glue experiment
Arrow indicates the crease where the split has come out under the patch
This is the UP10 patch with tube glue after two tours and almost a full expedition. You can see
where the tube has split underneath the patch from stress and just begun to creep out under
the edge of the patch. A new patch is sitting there for size comparison, (not a bad effort considering what
happened last year to kick all of this experiment off).
While the tube glue patch had failed the other patch with tyre glue was still inflated and causing no trouble at all. I was keen to see what it was doing but decided to leave it alone until the end of the expedition, which at the time was only 3-4 more days. Maybe it would fail before then or maybe it was in excellent condition and completely different to the tube glue version, who knew?
We finished the expedition at Tjukayirla Roadhouse on the Great Central Road on time as planned with no real vehicle trouble and no more flat tyres. It had been a good trip. Once we had cleaned radiators and done all of the vehicle jobs for customers that needed to be done I decided to have a look at the remaining tube experiment. The UP10 & tyre glue. I was very curious as to how it had coped. I stripped the tyre from the split rim and pulled the rust band & tube out. Everything looked OK at first glance. I ran a finger over the experimental patch feeling for the tube splitting underneath, and it had, bugger. The split wasn’t as large as the other tube glue job, it wasn’t near the edge of the patch, but it was getting there. So, we had results from both.
I kept that experimental tube out and destroyed it by cutting out the patch for comparison with the other patch that failed. I fitted another new Bridgestone tube in that rear left tyre.
UP10 patch with BL Cement (tyre glue) after two tours & a full expedition off-track.
It looks good on that side....
UP10 & Tyre Glue – you can see that the tube has split (but not as much as the Tube Glue UP10 patch).
A pretty good result but we still haven’t solved the stretching issue.
New patch sitting there for size comparison.
Tjukayirla Roadhouse W.A. 23rd August 2017
- It was obvious that off-road pressures and travel didn’t have the same effect on the tubes as the off-track work. We had covered the entire Anne Beadell & Connie Sue plus a trip around the dog fence in the Coober Pedy area, something like 5,000kms off-road, and the tubes couldn’t care less even though I had them down in pressure. (I’ll include a picture of the tyres at those exact pressures to show you exactly what was going on). It wasn’t until the off-track got going that the real stress on the tube began. I find this very interesting. It must have something to do with the frequency of movement of the tyre & tube I suppose. Maybe the tube stays stretched for longer when the speeds are around 10kms/hr instead of 30-70kms/hr.
- It was tube glue that failed first, at first glance you would think that tube glue would work best on tubes regardless. Not so it seems. The workshop gems from Rem Tip-Top also indicated that tube glue would be better. More food for thought I guess, but results in the field are hard to go past for accuracy.
- The UP10 patches didn’t stop the tubes from stretching entirely. The next step would be to try a full blown tyre patch and see what happened. Now do you use Radial patches or Bias patches? What glue do you try? Looks like the experiment will continue.......
- Bridgestone brand new tube in Bias tyre (14 ply)
- Small sidewall hole patched with Bias No.3 reinforced tyre patch
- BL Cement tyre glue used in this instance
- Small amount of off-track, off-road tour & bitumen highway work
I fitted a new Bridgestone tube to the failed experimental tyre (UP10 & tube glue). I had other new Toyo’s but thought I would make it obvious in case I switched, rotated wheels before I got home. As luck would have it the very next day I got a stake in that same tyre (rear right) I had just put that new tube in. So, I thought I’d keep the experiment going by using a Bias patch with tyre glue to repair the hole. It was only a 3mm puncture in the tube so I put a No.3 Bias patch on the tube and used BL Cement tyre glue to bond it on with. It went on well and inflated without incident. We’ll see what happens this time.
Putting Bias tyre patch onto a tube, not a normal thing but we are experimenting with low pressure stress
on tubes. We are trying to stop the tube from splitting under the patch.
Hunt Oil Road 20th August 2017
Connie & I after the expedition went out for another 10 days between trips and while having a couple of days off at Skull Springs near Nullagine I noticed one morning that the left rear had a slow leak. I guess my "luck" was still in! Anyway, I pulled the tyre and found the remains of a self-tapping screw burrowed into the shoulder of the tyre. It had been there for some time by the look of the tyre but only recently rubbed the tube enough to create a very small hole. Such is life. So, continuing the experiment I repaired the tube with a small Bias tyre patch and used BL Cement tyre glue. That means that both rear tyres had tubes with the same repair.
Bias reinforced tyre patch put on tube with BL Cement tyre glue. We’ll see how this goes.
We still had another 18 day tour to do before heading home so if the Bias patches were completely inappropriate we should know within a few weeks.
Well, we got through the last off-road tour of some 2,310 kms along Len’s roads and another uneventful run on the bitumen of about 3,000 kms to get home. Once home I then had a trip to Victoria so another 1,200 kms of bitumen got added to the tally, both tubes in the rear tyres with the Bias experimental patches never missed a beat. I haven’t pulled them out yet but as the tyres are still up, I’ll take that as a good sign. However, from what we have learnt over time & confirmed with this experiment we know that a serious test won’t occur until we are back doing off-track work deep in the western deserts.
Current Conclusions
OK so we have got some results and have drawn a few further conclusions, now, we have to see what happens. We now know the following;
- There is a vast difference between off-road touring & off-track bush-bashing when it comes to stress on tubes & tyres.
- This difference in stress due to road conditions, or lack of them more accurately, will lead me to change my tube repair patch selection to specifically fit the type of travelling the tyre & tube will be doing. By the way, I will still use tube patches in the tread area regardless because the tread area doesn’t stretch & bulge. It is relatively stable in comparison so there isn’t the need for heavier non-stretch "tube patches" in the tread area. (I can’t remember a tube tread patch ever failing).
- UP10 patches are fine for off-road tube repairs, but will not survive off-track work for long periods, although they are far better than the standard tube patch.
- At the moment it looks like BL Cement tyre glue is better for bonding tyre patches to tubes. We’ll try again next year & see if the result is the same in regard to glue longevity.
- Full blown tyre patches seem to be needed for off-track work on sidewall tube repairs. More on this as the experiment continues.
Next year I will continue the experiment. If both Bridgestone tubes with the Bias patch repairs look healthy when I’m fitting up tyres for 2018 I will use them in the rear the same as I did this year.
This thing has turned into a real can of worms hasn’t it?
As seen above I had two tubes with Bias tyre patches instead of normal tube patches. Both of these "test tubes" (pardon the pun), looked fine when I inspected them before the 2018 season kicked off. They were fitted into a set of older All Steel Radials for the first two trips of our commercial year.
Remember the original intent of this experiment job. We are investigating the third point as mentioned above (Page 1 & 2);
- Tubes splitting underneath a repair patch; Use a thicker patch that won’t stretch & allow the tube to split. This will require a bit of experimentation with different patches & glues.
So we left home to start the 2018 touring season with both rear tubes previously repaired with Bias tyre patches during 2017. Running on the bitumen was no problem at all, no surprises there as the pressures are up and the tyres & tubes don’t flex much at all particularly as I run highway pressures very high, higher than on the data plate on the vehicle most of the time.
Got a result pretty quickly after getting onto the dirt, we were going north past Mt Conner heading for the Rock when an alarm went off and I stopped to change a slow leaking tyre on the rear. I immediately thought about the experiment but of course it was possible it was caused by something else entirely, you never know until you strip it all off the rim and have a good look.
Slow leak in rear right which had an experimentally repaired tube,
very curious to know the cause......Early May 2018 near Mt Conner.
That same afternoon after we got everyone settled in at Yulara I began the repair on that slow leak. Pretty easy to find, the Bias patch had "broken" and cut the tube. So this tube repair had covered about 2 off-road tours, some off-track and roughly 6000-7000 kms of highway travel. So the No.03 Bias patch had done a bit of work and probably shouldn’t be labelled as any sort of failure, just not an ideal repair.
In another life I was an aircraft mechanic so I’m very familiar with stress on materials but I’ll admit I didn’t think a rubber plied repair patch would act as it did – very interesting. At a glance it seemed that the Bias tyre patches are designed to flex only one way, this isn’t a surprise as they are for repairing tyres not tubes. This was a No.03 Bias patch which is the smallest Bias patch that Rema produce. As it doesn’t have as many plies & isn’t as strong as the larger patches may explain why it lasted as long as it did. The other tube has a larger Bias patch bonded on. Not much sense talking about this further so I waited to see what the second Bias repair did.
So once again we have a result that we can gain quite a lot out of, much the same as all of the things we have done since starting this little adventure, so to speak. Keep in mind that I still had one more tube repaired in the same way on the vehicle. Perhaps this failure was a one off, time would tell (and it did).
The No.03 patch has broken along the edge of the ply in the patch -
Yulara Resort May 2018.
Early in July the other rear tyre developed a slow leak along the Anne Beadell Highway. No trouble as the pressure monitors let me know what was happening & I could pull up and get the jack under the axle well before the tyre was flat. I really like pressure monitors!
Once again that afternoon I pulled it apart to see what had happened & bingo we had another result! Once again the Bias patch had cracked along the edge of the plies inside the patch and eventually damaged the tube. So we can say with some certainty that the Bias patches won’t handle being flexed the opposite way for long periods of time. However it is best to remember that this repair had completed about four off-road tours, some off-track and a fair bit of highway work, say about 10,000 kms. Not a bad effort to be honest.
As I said above I won’t call this any sort of failure. Best thought of as not the best alternative but will easily get you out of trouble. Looks like I’m still looking for a long term solution for the problem of tubes splitting under repair patches, the initial problem that began all of this mucking about 2 years ago.
Once again the Bias patch has "broken" along the ply ends due to flexing the wrong way
because of being bonded to a tube – Anne Beadell Highway July 2018.
Opening up the break you can see how the edges have eventually cut the tube
underneath - Anne Beadell Highway - July 2018.
Now we know Bias patches are designed to flex this way
(which is how they work inside a tyre).
Unfortunately Bias patches are not made to flex this way
and will eventually fail as we have found in 2018.
It was worth a try, necessity being the mother of invention etc.
Oh well, I can’t rely on Bias tyre patches to repair tubes as the patches are not designed to flex in the opposite direction, as we have just proved. I’ll be honest & say I didn’t expect this to happen. Of course I was hoping for a sound long term repair for tubes for both off-road & off-track travel. A repair that would eliminate splitting under patches, oh well can’t win them all. I’ll try Radial tyre patches and see how they go but suspect the result will be the same, but we won’t know unless we try it.
So the reality is pretty simple, I haven’t yet found a patch I can use on a tube that will last a very long time & handle every type of travel & pressure situation. However for normal travellers, say one good sized off-road trip and highway travel, most of these experiments we have tried will work perfectly. However for what Connie & I require there are still a few things to try.
The next step in trying to solve this problem (and you must remember only the smallest percentage of 4WDers will ever see this problem actually happen) was to go ahead and try a different brand of repair material. If Rema TipTop don’t produce anything that fits the bill then we have to try elsewhere. So in this case our mate from Perth who owns a tyre shop suggested Tech products from the USA, our mate uses them all them time in conjunction with Rema gear and didn’t have a bad word to say about Tech from his perspective. So having been supplied with various patches and the correct glues mid-way through 2018 we had a few chances to try out this new stuff during the rest of our commercial season.
The Tech brand Multi-purpose patches are the next effort to try a patch on a tube that will hopefully stop the tube stretching while at low pressure, this being the thing that causes splitting under repairs patches as far as I’m concerned & the ultimate goal with all of this fiddling about with different tube repairs. As the Multi-purpose patch is designed for tyres it should go some way towards ticking the boxes we have.
In early August we began our 2018 off-track expedition, it was a pretty quiet run for tyres on the whole. I think in three weeks we only had 5 flat tyres and not all of them were punctures. My one & only punctured tyre while off-track was caused by a tiny tread stake which is perfectly normal for Bias tyres while bush-bashing in the desert. I repaired it with a Tech MP-2 tyre patch as shown in the image below. We’ll have to see how this patches goes but at the moment there have been no issues, again time & miles will tell.
Tech MP-2 tyre patch applied in the field to a tube while off-track
Great Victoria Desert - August 2018.
Looking at the sectional view of a Tech MP-2 tyre patch, you can
clearly see there is a single ply of nylon or polyester cord within the
patch. This is good news, we may have found a patch strong enough to resist stretching
but pliable enough not to crack when used "incorrectly" so to speak.
Home - January 2019.
2019 should be the year we find a solution to our major tube repair problem. I can only hope we do, but along the way I have learnt a great deal more about repair & tube repair in particular. There is nothing wrong with evidence from practical trials & tests. That is how our civilisation got to this point. Theory as usual is a good start but has little to do with the actual results especially when we are dealing with such a basic thing as tyres & tubes. We’ll see how the next experiment goes this season when we get back into the bush and start lowering those tyre pressures.
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