On 6 Nov, 16:46, Gary Young <garyyou...@gmail.com> wrote:
> On Fri, 06 Nov 2009 15:31:37 +0000, Jobst Brandt wrote: > > I think the explanation of how to do this is simple and effective... and > > not what bicycle experts commonly do. Don't ride a freshly patched > > tube!
> Yes, I agree. However, since we don't have much of a budget for spare > parts, we often run out of tubes and by necessity have to put a newly > patched tube right back in.
> That leads to another question -- is it OK to re-inflate a newly-patched > tube as long as one doesn't ride it?
Yes, as long as the tube is a close fit to the tyre size then you may inflate and ride a well repaired tube.
>> I gather from comments here that it wouldn't be helpful in >> repairing bike tubes, though I am curious WHY it wouldn't be >> helpful.
Because it will most likely generate a slow leak, even one that requires pumping every other day.
> Indeed it may be. You can test your repairs when the rubber has > cooled. You should not do this with cold cure patching.
Bad advice! Of course if you can give a scientific explanation what your favorite process accomplishes, it might be slightly more believable. My experience arose from replacing patches on poorly patched tubes of riders who learned how to boot, patch, and re-tube tubulars at tire patch classes I gave. Subsequently clincher repairs became necessary when tubulars went out of use.
> Preparation time is otherwise similar. It may be worthwhile to note > that the cold cure rubber solution may be sensitive to shelf life > and to check manufacturers date codes.
Cooled? Don't heat inner tubes when patching. Use REMA the best patches available and put them in place as described in the FAQ. Sheldon Brown did not put all that information in the FAQ for naught.
>> At the community bike shop, we're going to start using the solvent >> recommended by Andrew Muzi and others. (Plus refresher training.)
I don't know what the solvent is supposed to do, but sand paper and REMA patch cement work well enough to make patch removal highly difficult. As I said, a domed patch gets that way from not being uniformly adhering to the inner tube.
Gary Young wrote: >>>>> I volunteer at a community bike shop where we give away bikes >>>>> and do repairs for the needy. We've had some problems with >>>>> sending out bikes with newly patched tubes and then having them >>>>> come back to us a little while later with leaks. Maybe a >>>>> refresher course in patching technique is in order for our >>>>> volunteers is in order, but I was also wondering if this device >>>>> might be of help:
>>>>> That page claims the patch would be cured in five minutes -- >>>>> true? >>>> Not true! I posted my experience with the REMA patch >>>> representative at InterBike two years ago who was unaware of the >>>> purpose of installation of his product. He was not aware of why >>>> sandpaper is used to CLEAN the tube at the puncture and was >>>> unaware of applying the patch before the rubber cement is fully >>>> dry, having never heard of van der Waals forces and how adhesives >>>> work. >>>> After applying a patch to a tube he had as demonstrator, >>>> following the wide spread mis-beliefs installing the patch and >>>> not removing the cellophane, he handed me the "perfectly patched >>>> example" from which I instantly pulled off the patch and handed >>>> it to him to his amazement. >>> Yes, but the machine at the link above applies pressure and heat >>> to the patch and tube: >>> "Automatic setting repairs inner tube punctures in just five >>> minutes. >>> * Large 6" throat makes it easy to apply heat sealed patches to >>> any size inner tube * Snap-type thermostat reaches curing >>> temperature quickly * Includes two curing heads: round head for >>> small punctures and an oval head for longer tears * Manual setting >>> allows longer application of heat if necessary" >>> I gather from comments here that it wouldn't be helpful in >>> repairing bike tubes, though I am curious WHY it wouldn't be >>> helpful. >>> At the community bike shop, we're going to start using the solvent >>> recommended by Andrew Muzi and others. (Plus refresher training.) >> That's old automobile technology and does not make a patch that is >> permanently held, not readily removable. >> Those who have tried to remove a well cured REMA parch can recall >> that they are not manually removable. Of course most REMA patches >> are not well cured because they are applied to dried up rubber >> cement. >>>> I'm sure he never heard of what is in the following FAQ item:
>> I think the explanation of how to do this is simple and >> effective... and not what bicycle experts commonly do. Don't ride >> a freshly patched tube! > Yes, I agree. However, since we don't have much of a budget for > spare parts, we often run out of tubes and by necessity have to put > a newly patched tube right back in. > That leads to another question -- is it OK to re-inflate a > newly-patched tube as long as one doesn't ride it? >> The test of placing a common cardboard business card between tube >> and tread ought to make that apparent.
Have you tried this?
As I explained, a freshly patched tube is diagonally massaged by the bias ply of the tire when it rolls under load, hence the business card test that shreds the card into fine confetti. This action loosens the patch from the tube in its center where air pressure can get between patch and tube through the puncture... while it is being massaged.
As I explained previously, REMA patches have a perforation across the center of the cellophane backing for a good reason that the original REMA engineers recognized. The perforation is there to enable the user to break the cellophane cover and peel it from its center to its edge. If this is tried in reverse, the patch will peel off.
Once peeled, the patch can cure and adhere to the point of not being removable, while freshly applied patches separate easily as the designers of the cellophane cover knew.
>>> I think the explanation of how to do this is simple and >>> effective... and not what bicycle experts commonly do. Don't ride >>> a freshly patched tube! >> Yes, I agree. However, since we don't have much of a budget for >> spare parts, we often run out of tubes and by necessity have to put >> a newly patched tube right back in. >> That leads to another question -- is it OK to re-inflate a >> newly-patched tube as long as one doesn't ride it? > Yes, as long as the tube is a close fit to the tyre size then you > may inflate and ride a well repaired tube.
We don't ride no closely fitting tubes, not that close because that will cause a wrinkle and pinch flats on assembly. For this reason, tubes should be slightly undersized so that tubes stretch to fill the tire casing both in the major and minor diameter. Of course this was all well known back in olden times when we patched car tire tubes and this was well understood. -- Jobst Brandt
On 6 Nov, 19:21, Jobst Brandt <jbra...@sonic.net> wrote:
> As I explained, a freshly patched tube is diagonally massaged by the > bias ply of the tire when it rolls under load, hence the business card > test that shreds the card into fine confetti. This action loosens the > patch from the tube in its center where air pressure can get between > patch and tube through the puncture... while it is being massaged.
Only when you use too much rubber solution and leave it wet. The tube must be cleaned (with naptha) it then may be roughened with a fine abrasive only if the dust is brushed clear with a clean brush. The thinnest smear of rubber solution left to dry. You have easily a half hour open joint time in which to apply the patch. This is documented for many contact adhesives of which rubber cement in a bicycle puncture kit is just one. Apply centre of patch first, spread out and burnish from the centr out. The pressure applied during burnishing is an armful on a few sq mm.
> As I explained previously, REMA patches have a perforation across the > center of the cellophane backing for a good reason that the original > REMA engineers recognized. The perforation is there to enable the > user to break the cellophane cover and peel it from its center to its > edge. If this is tried in reverse, the patch will peel off.
No the cellophane peels when sufficient burnishing has been performed.
> Once peeled, the patch can cure and adhere to the point of not being > removable, while freshly applied patches separate easily as the > designers of the cellophane cover knew.
If the rubber solution is dry before closure of the joint, then there is no solvent to evaporate. And it wont fully evaporate through the patch or tube in 24hrs if assembled wet.
>>>> I volunteer at a community bike shop where we give away bikes and >>>> do repairs for the needy. We've had some problems with sending >>>> out bikes with newly patched tubes and then having them come back >>>> to us a little while later with leaks. Maybe a refresher course >>>> in patching technique is in order for our volunteers is in order, >>>> but I was also wondering if this device might be of help:
>>>> That page claims the patch would be cured in five minutes -- true?
>>> Not true! I posted my experience with the REMA patch >>> representative at InterBike two years ago who was unaware of the >>> purpose of installation of his product. He was not aware of why >>> sandpaper is used to CLEAN the tube at the puncture and was unaware >>> of applying the patch before the rubber cement is fully dry, having >>> never heard of van der Waals forces and how adhesives work.
>>> After applying a patch to a tube he had as demonstrator, following >>> the wide spread mis-beliefs installing the patch and not removing >>> the cellophane, he handed me the "perfectly patched example" from >>> which I instantly pulled off the patch and handed it to him to his >>> amazement.
>> Yes, but the machine at the link above applies pressure and heat to >> the patch and tube:
>> "Automatic setting repairs inner tube punctures in just five >> minutes.
>> * Large 6" throat makes it easy to apply heat sealed patches to any >> size inner tube * Snap-type thermostat reaches curing temperature >> quickly * Includes two curing heads: round head for small punctures >> and an oval head for longer tears * Manual setting allows longer >> application of heat if necessary"
>> I gather from comments here that it wouldn't be helpful in repairing >> bike tubes, though I am curious WHY it wouldn't be helpful.
>> At the community bike shop, we're going to start using the solvent >> recommended by Andrew Muzi and others. (Plus refresher training.)
>That's old automobile technology and does not make a patch that is >permanently held, not readily removable.
> >> I gather from comments here that it wouldn't be helpful in > >> repairing bike tubes, though I am curious WHY it wouldn't be > >> helpful.
> Because it will most likely generate a slow leak, even one that > requires pumping every other day.
> > Indeed it may be. You can test your repairs when the rubber has > > cooled. You should not do this with cold cure patching.
> Bad advice! Of course if you can give a scientific explanation what > your favorite process accomplishes, it might be slightly more > believable. My experience arose from replacing patches on poorly > patched tubes of riders who learned how to boot, patch, and re-tube > tubulars at tire patch classes I gave. Subsequently clincher repairs > became necessary when tubulars went out of use.
> > Preparation time is otherwise similar. It may be worthwhile to note > > that the cold cure rubber solution may be sensitive to shelf life > > and to check manufacturers date codes.
> Cooled? Don't heat inner tubes when patching. Use REMA the best > patches available and put them in place as described in the FAQ. > Sheldon Brown did not put all that information in the FAQ for naught.
> >> At the community bike shop, we're going to start using the solvent > >> recommended by Andrew Muzi and others. (Plus refresher training.)
> I don't know what the solvent is supposed to do, but sand paper and > REMA patch cement work well enough to make patch removal highly > difficult. As I said, a domed patch gets that way from not being > uniformly adhering to the inner tube.
It seems you're up to your old tricks of misattributation again. Your responses are garbled. They do not follow.
The use of a solvent such as naptha will remove the grease and dust and prepare the rubber by partially disolving the surface. Repeated application of naptha is as least as good as cleaning with a alcohol and using a fine abrasive followed by clearing the dust with a clean (use solvent and cloth) brush. Even if you insist on using an abrasive for preparation you should use the solvent first to keep the abrasive free from the grease on the tube. To not do so means you will recontaminate the tube with the grease now on the abrasive.
As far as domed patches go, it doesnt matter. The advice for larger tubes is to cut a circular hole to surround the puncture. I have done this for a bicycle tube when using a large thick patch. A pair of pointed nail scissors will do the trick and are also useful when you want to cut small patches from a larger one.
On Fri, 06 Nov 2009 19:21:47 +0000, Jobst Brandt wrote: > Gary Young wrote:
>>>>>> I volunteer at a community bike shop where we give away bikes and >>>>>> do repairs for the needy. We've had some problems with sending out >>>>>> bikes with newly patched tubes and then having them come back to us >>>>>> a little while later with leaks. Maybe a refresher course in >>>>>> patching technique is in order for our volunteers is in order, but >>>>>> I was also wondering if this device might be of help:
>>>>>> That page claims the patch would be cured in five minutes -- true?
>>>>> Not true! I posted my experience with the REMA patch representative >>>>> at InterBike two years ago who was unaware of the purpose of >>>>> installation of his product. He was not aware of why sandpaper is >>>>> used to CLEAN the tube at the puncture and was unaware of applying >>>>> the patch before the rubber cement is fully dry, having never heard >>>>> of van der Waals forces and how adhesives work.
>>>>> After applying a patch to a tube he had as demonstrator, following >>>>> the wide spread mis-beliefs installing the patch and not removing >>>>> the cellophane, he handed me the "perfectly patched example" from >>>>> which I instantly pulled off the patch and handed it to him to his >>>>> amazement.
>>>> Yes, but the machine at the link above applies pressure and heat to >>>> the patch and tube:
>>>> "Automatic setting repairs inner tube punctures in just five minutes.
>>>> * Large 6" throat makes it easy to apply heat sealed patches to any >>>> size inner tube * Snap-type thermostat reaches curing temperature >>>> quickly * Includes two curing heads: round head for small punctures >>>> and an oval head for longer tears * Manual setting allows longer >>>> application of heat if necessary"
>>>> I gather from comments here that it wouldn't be helpful in repairing >>>> bike tubes, though I am curious WHY it wouldn't be helpful.
>>>> At the community bike shop, we're going to start using the solvent >>>> recommended by Andrew Muzi and others. (Plus refresher training.)
>>> That's old automobile technology and does not make a patch that is >>> permanently held, not readily removable.
>>> Those who have tried to remove a well cured REMA parch can recall that >>> they are not manually removable. Of course most REMA patches are not >>> well cured because they are applied to dried up rubber cement.
>>>>> I'm sure he never heard of what is in the following FAQ item:
>>> I think the explanation of how to do this is simple and effective... >>> and not what bicycle experts commonly do. Don't ride a freshly >>> patched tube!
>> Yes, I agree. However, since we don't have much of a budget for spare >> parts, we often run out of tubes and by necessity have to put a newly >> patched tube right back in.
>> That leads to another question -- is it OK to re-inflate a >> newly-patched tube as long as one doesn't ride it?
>>> The test of placing a common cardboard business card between tube >>> and tread ought to make that apparent.
> Have you tried this?
> As I explained, a freshly patched tube is diagonally massaged by the > bias ply of the tire when it rolls under load, hence the business card > test that shreds the card into fine confetti. This action loosens the > patch from the tube in its center where air pressure can get between > patch and tube through the puncture... while it is being massaged.
I haven't tried this for myself, but I have no reason to doubt you on that score. My question, though, was whether merely inflating the tire will tend to cause liftoff of the patch if the bike is not ridden until the patch has cured. The fact that you attribute the problem to the massaging that takes place when the tire is under load leads me to think that inflating the tire but not applying a load would not cause problems. However, I'd like to be sure that's so.
> As I explained previously, REMA patches have a perforation across the > center of the cellophane backing for a good reason that the original > REMA engineers recognized. The perforation is there to enable the user > to break the cellophane cover and peel it from its center to its edge. > If this is tried in reverse, the patch will peel off.
> Once peeled, the patch can cure and adhere to the point of not being > removable, while freshly applied patches separate easily as the > designers of the cellophane cover knew.
> someone in the UK wrote: >>> I gather from comments here that it wouldn't be helpful in >>> repairing bike tubes, though I am curious WHY it wouldn't be >>> helpful. Jobst Brandt wrote: > Because it will most likely generate a slow leak, even one that > requires pumping every other day. >> Indeed it may be. You can test your repairs when the rubber has >> cooled. You should not do this with cold cure patching. > Bad advice! Of course if you can give a scientific explanation what > your favorite process accomplishes, it might be slightly more > believable. My experience arose from replacing patches on poorly > patched tubes of riders who learned how to boot, patch, and re-tube > tubulars at tire patch classes I gave. Subsequently clincher repairs > became necessary when tubulars went out of use. >> Preparation time is otherwise similar. It may be worthwhile to note >> that the cold cure rubber solution may be sensitive to shelf life >> and to check manufacturers date codes. > Cooled? Don't heat inner tubes when patching. Use REMA the best > patches available and put them in place as described in the FAQ. > Sheldon Brown did not put all that information in the FAQ for naught. >>> At the community bike shop, we're going to start using the solvent >>> recommended by Andrew Muzi and others. (Plus refresher training.) > I don't know what the solvent is supposed to do, but sand paper and > REMA patch cement work well enough to make patch removal highly > difficult. As I said, a domed patch gets that way from not being > uniformly adhering to the inner tube.
We don't disagree on the concepts but a solvent wipe will remove much more contamination much more quickly and I believe more thoroughly than an abrasive technique. Which is why car/moto tire shops use Tech patch buffer. A clean cloth will be completely blackened with a quick wipe over a couple square inches of the typical bicycle tube.
(bicycle service time to patch costs too much in comparison to our cheap inner tubes)
> > someone in the UK wrote: > >>> I gather from comments here that it wouldn't be helpful in > >>> repairing bike tubes, though I am curious WHY it wouldn't be > >>> helpful. > Jobst Brandt wrote: > > Because it will most likely generate a slow leak, even one that > > requires pumping every other day. > >> Indeed it may be. You can test your repairs when the rubber has > >> cooled. You should not do this with cold cure patching. > > Bad advice! Of course if you can give a scientific explanation what > > your favorite process accomplishes, it might be slightly more > > believable. My experience arose from replacing patches on poorly > > patched tubes of riders who learned how to boot, patch, and re-tube > > tubulars at tire patch classes I gave. Subsequently clincher repairs > > became necessary when tubulars went out of use. > >> Preparation time is otherwise similar. It may be worthwhile to note > >> that the cold cure rubber solution may be sensitive to shelf life > >> and to check manufacturers date codes. > > Cooled? Don't heat inner tubes when patching. Use REMA the best > > patches available and put them in place as described in the FAQ. > > Sheldon Brown did not put all that information in the FAQ for naught. > >>> At the community bike shop, we're going to start using the solvent > >>> recommended by Andrew Muzi and others. (Plus refresher training.) > > I don't know what the solvent is supposed to do, but sand paper and > > REMA patch cement work well enough to make patch removal highly > > difficult. As I said, a domed patch gets that way from not being > > uniformly adhering to the inner tube.
> We don't disagree on the concepts but a solvent wipe will > remove much more contamination much more quickly and I > believe more thoroughly than an abrasive technique. Which is > why car/moto tire shops use Tech patch buffer. A clean cloth > will be completely blackened with a quick wipe over a couple > square inches of the typical bicycle tube.
> (bicycle service time to patch costs too much in comparison > to our cheap inner tubes)
Absolutely right - from a job costing standpoint, but a little of the amateur's time spent patching his own rotation of inner tubes has a couple of benefits. It keeps you practiced for if and when you must patch in the field, doesn't let those road hazards get the better of you, and "experienced" serviceable components lend anthropomorphic character to the overall apparatus.
On 6 Nov, 21:44, Gary Young <garyyou...@gmail.com> wrote:
> I haven't tried this for myself, but I have no reason to doubt you on > that score. My question, though, was whether merely inflating the tire > will tend to cause liftoff of the patch if the bike is not ridden until > the patch has cured. The fact that you attribute the problem to the > massaging that takes place when the tire is under load leads me to think > that inflating the tire but not applying a load would not cause problems. > However, I'd like to be sure that's so.
As the solvent treatment can't possibly remove the various ridges and protrusions on most tubes, which by Murphy's Law will occur within the area of a patch, I don't understand how folks can assert that it's the method of choice.
I'll continue to use a sanding or abrasive wheel in a Dremel tool. A few seconds of effort and one has a nicely matte area ready to receive the vulcanizing fluid.
On 6 Nov, 23:47, art.shap...@unisys.com (Arthur Shapiro) wrote:
> As the solvent treatment can't possibly remove the various ridges and > protrusions on most tubes, which by Murphy's Law will occur within the area of > a patch, I don't understand how folks can assert that it's the method of > choice.
> I'll continue to use a sanding or abrasive wheel in a Dremel tool. A few > seconds of effort and one has a nicely matte area ready to receive the > vulcanizing fluid.
> Art
Always bought Vredstein / Raleigh when I could. No moulding seams and a good tough butyl tube. I'm predominantly on tubs and there's no seams on them either. Even on the tubes I have with seams, Michelin I think, they are so thin that the greasy finish is more of a problem so degreasing has a higher prominence. It's easier to wipe naptha over a tube than mess about with a small piece of abrasive when on the road.
Andrew Muzi wrote: >>>> I gather from comments here that it wouldn't be helpful in >>>> repairing bike tubes, though I am curious WHY it wouldn't be >>>> helpful. >> Because it will most likely generate a slow leak, even one that >> requires pumping every other day. >>> Indeed it may be. You can test your repairs when the rubber has >>> cooled. You should not do this with cold cure patching. >> Bad advice! Of course if you can give a scientific explanation >> what your favorite process accomplishes, it might be slightly more >> believable. My experience arose from replacing patches on poorly >> patched tubes of riders who learned how to boot, patch, and re-tube >> tubulars at tire patch classes I gave. Subsequently clincher >> repairs became necessary when tubulars went out of use. >>> Preparation time is otherwise similar. It may be worthwhile to >>> note that the cold cure rubber solution may be sensitive to shelf >>> life and to check manufacturers date codes. >> Cooled? Don't heat inner tubes when patching. Use REMA the best >> patches available and put them in place as described in the FAQ. >> Sheldon Brown did not put all that information in the FAQ for >> naught. >>>> At the community bike shop, we're going to start using the >>>> solvent recommended by Andrew Muzi and others. (Plus refresher >>>> training.) >> I don't know what the solvent is supposed to do, but sand paper and >> REMA patch cement work well enough to make patch removal highly >> difficult. As I said, a domed patch gets that way from not being >> uniformly adhering to the inner tube. > We don't disagree on the concepts but a solvent wipe will remove > much more contamination much more quickly and I believe more > thoroughly than an abrasive technique. Which is why car/moto tire > shops use Tech patch buffer. A clean cloth will be completely > blackened with a quick wipe over a couple square inches of the > typical bicycle tube.
Residual solvent and damage to the tube make adhering poorer than sand paper method. The thought of chemicals appeals to many users, especially because it takes less work.
> (bicycle service time to patch costs too much in comparison to our > cheap inner tubes)
I wasn't contending cost but performance and experience with failed and secure patches.
> Andrew Muzi wrote: > >>>> I gather from comments here that it wouldn't be helpful in > >>>> repairing bike tubes, though I am curious WHY it wouldn't be > >>>> helpful. > >> Because it will most likely generate a slow leak, even one that > >> requires pumping every other day. > >>> Indeed it may be. You can test your repairs when the rubber has > >>> cooled. You should not do this with cold cure patching. > >> Bad advice! Of course if you can give a scientific explanation > >> what your favorite process accomplishes, it might be slightly more > >> believable. My experience arose from replacing patches on poorly > >> patched tubes of riders who learned how to boot, patch, and re-tube > >> tubulars at tire patch classes I gave. Subsequently clincher > >> repairs became necessary when tubulars went out of use. > >>> Preparation time is otherwise similar. It may be worthwhile to > >>> note that the cold cure rubber solution may be sensitive to shelf > >>> life and to check manufacturers date codes. > >> Cooled? Don't heat inner tubes when patching. Use REMA the best > >> patches available and put them in place as described in the FAQ. > >> Sheldon Brown did not put all that information in the FAQ for > >> naught. > >>>> At the community bike shop, we're going to start using the > >>>> solvent recommended by Andrew Muzi and others. (Plus refresher > >>>> training.) > >> I don't know what the solvent is supposed to do, but sand paper and > >> REMA patch cement work well enough to make patch removal highly > >> difficult. As I said, a domed patch gets that way from not being > >> uniformly adhering to the inner tube. > > We don't disagree on the concepts but a solvent wipe will remove > > much more contamination much more quickly and I believe more > > thoroughly than an abrasive technique. Which is why car/moto tire > > shops use Tech patch buffer. A clean cloth will be completely > > blackened with a quick wipe over a couple square inches of the > > typical bicycle tube.
> Residual solvent and damage to the tube make adhering poorer than sand > paper method. The thought of chemicals appeals to many users, > especially because it takes less work.
> > (bicycle service time to patch costs too much in comparison to our > > cheap inner tubes)
> I wasn't contending cost but performance and experience with failed > and secure patches.
> Jobst Brandt
The softening of the rubber's surface by naptha encourages bonding with the rubber solvent. This works with all tube rubber. Wipe it, leave it to dry, rub a little more naptha, look for evidence of solution of rubber. The patch rubber solution will likely use a combination of naptha and acetone, using the same to prepare the tube can only encourage adhesion for it wets the tube and its evaporation through the solution will draw the solution tighter to the tube. It is not a contaminant but an aid to adhesion. Pre-wetting a surface which will draw the wetting agent into the substrate or where the wetting agent can evaporate through the cement is basic adhesives application. If you had failures, they were not due to using my described method, you must have used it wrong.
Dan O wrote: > On Nov 6, 1:48 pm, AMuzi <a...@yellowjersey.org> wrote: >>> someone in the UK wrote: >>>>> I gather from comments here that it wouldn't be helpful in >>>>> repairing bike tubes, though I am curious WHY it wouldn't be >>>>> helpful. >> Jobst Brandt wrote: >>> Because it will most likely generate a slow leak, even one that >>> requires pumping every other day. >>>> Indeed it may be. You can test your repairs when the rubber has >>>> cooled. You should not do this with cold cure patching. >>> Bad advice! Of course if you can give a scientific explanation what >>> your favorite process accomplishes, it might be slightly more >>> believable. My experience arose from replacing patches on poorly >>> patched tubes of riders who learned how to boot, patch, and re-tube >>> tubulars at tire patch classes I gave. Subsequently clincher repairs >>> became necessary when tubulars went out of use. >>>> Preparation time is otherwise similar. It may be worthwhile to note >>>> that the cold cure rubber solution may be sensitive to shelf life >>>> and to check manufacturers date codes. >>> Cooled? Don't heat inner tubes when patching. Use REMA the best >>> patches available and put them in place as described in the FAQ. >>> Sheldon Brown did not put all that information in the FAQ for naught. >>>>> At the community bike shop, we're going to start using the solvent >>>>> recommended by Andrew Muzi and others. (Plus refresher training.) >>> I don't know what the solvent is supposed to do, but sand paper and >>> REMA patch cement work well enough to make patch removal highly >>> difficult. As I said, a domed patch gets that way from not being >>> uniformly adhering to the inner tube. >> We don't disagree on the concepts but a solvent wipe will >> remove much more contamination much more quickly and I >> believe more thoroughly than an abrasive technique. Which is >> why car/moto tire shops use Tech patch buffer. A clean cloth >> will be completely blackened with a quick wipe over a couple >> square inches of the typical bicycle tube.
>> (bicycle service time to patch costs too much in comparison >> to our cheap inner tubes)
> Absolutely right - from a job costing standpoint, but a little of the > amateur's time spent patching his own rotation of inner tubes has a > couple of benefits. It keeps you practiced for if and when you must > patch in the field, doesn't let those road hazards get the better of > you, and "experienced" serviceable components lend anthropomorphic > character to the overall apparatus.
In the OPs situation a solvent wipe seems sensible and probably also for the guy who carries patched tubes on the road and patches them later at home.
> ...a solvent wipe will > remove much more contamination much more quickly and I > believe more thoroughly than an abrasive technique. Which is > why car/moto tire shops use Tech patch buffer. A clean cloth > will be completely blackened with a quick wipe over a couple > square inches of the typical bicycle tube.
What solvent do you use? I tried oldfangled brake cleaner the other day, and it seemed to work but the cancer was a buzzkill.
> AMuzi wrote: >> ...a solvent wipe will >> remove much more contamination much more quickly and I >> believe more thoroughly than an abrasive technique. Which is >> why car/moto tire shops use Tech patch buffer. A clean cloth >> will be completely blackened with a quick wipe over a couple >> square inches of the typical bicycle tube. Chalo wrote: > What solvent do you use? I tried oldfangled brake cleaner the other > day, and it seemed to work but the cancer was a buzzkill.
On 7 Nov, 06:38, AMuzi <a...@yellowjersey.org> wrote:
> > AMuzi wrote: > >> ...a solvent wipe will > >> remove much more contamination much more quickly and I > >> believe more thoroughly than an abrasive technique. Which is > >> why car/moto tire shops use Tech patch buffer. A clean cloth > >> will be completely blackened with a quick wipe over a couple > >> square inches of the typical bicycle tube. > Chalo wrote: > > What solvent do you use? I tried oldfangled brake cleaner the other > > day, and it seemed to work but the cancer was a buzzkill.
7. Center the patch over the injury on the inside of the tire and outline an area 1/4” larger than the patch to define the area to be mechanically buffed. 8. Using liquid buffer/cleaner and an innerliner scraper, thoroughly clean the outlined area, removing all mold lubricants, dirt, and debris. 9. Using a low speed buffer, mechanically buff the outlined area to an even velvety textured finish. Be careful not to buff through the innerliner and expose the fabric portion of the tire. Vacuum away any buffing debris. 10.Apply a thin coat of chemical vulcanizing cement to the prepared area of the innerliner using the brush applicator in a stippling motion. Allow the cement to dry thoroughly before installing the repair unit. 11. Remove the protective backing from the patch. 12.Place it on the innerliner centered over the insert. 13.Press out any trapped air. 14.Using a roller stitcher, stitch the patch down firmly to the innerliner by working from the center outward.
For tube repair you either "keyhole the ends of a cut" or cut out a round hole. Small punctures of a tube which have not made significant injury to the tyre casing dont need any cutting out, usually. There are projectiles which may cause greater interior damage, I suggest the best tactic here is to pedal hard for exit cover.
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