Glueing tubulars [the tubular thread]

Everything about building wheels, glueing tubs, etc.
Wadl
Posts: 39
Joined: Thu Sep 06, 2012 7:37 pm

by Wadl

I'm reading this thread and I am wondering how does the cement glue works ?? You put a couple layer in there, let it dry and mount the tire... why letting it dry up ?

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atakaoka
Posts: 80
Joined: Tue Aug 07, 2012 2:29 am
Location: Ibiuna-SP-Brazil

by atakaoka

sungod wrote:depending on which tyres you are going for, you may not need to stretch them

fwiw i've found i can fit veloflex carbon fine without stretching, i think others reported the same



same whith Vittoria EVO CX ll.
cycling,a great individual sport,were you can't reach anything,whithout group effort.

by Weenie


fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

Wadl wrote:I'm reading this thread and I am wondering how does the cement glue works ?? You put a couple layer in there, let it dry and mount the tire... why letting it dry up ?


Rim cement is a contact adhesive so letting layers cure is standard procedure for this type of adhesive.
The first layers of cement are left to cure as these serve as a foundation/anchor point for the last layer.
The final layer is only left to dry for a number of minutes (depending on the manufacturer's instructions) so it can be handle without smearing cement all over.

From a gluing POV this is not a problem as the cement will still contain plenty of solvents/agents (whatever) to reactivate the underlying layers so it all bonds together.

Ciao, ;)
Being a snob is an expensive hobby.

sungod
Posts: 1497
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

just de-glued my first wheel with the glue remover that fdegrove mentions here...

viewtopic.php?f=3&t=72309&start=2460#p939436

it was the second tyre mounted on the same glue, both removals had left the entire layer of basetape latex behind, so now it really had to be stripped, i was wondering how it'd handle the latex

i used about half the tube to coat the glue/latex, returned about 6 hours later to find the glue/latex had swollen considerably, at first i tried a cloth but then found it easier/faster to run (nitrile gloved) fingers along and scrape it off

the latex had made the glop quite resilient, i think glue alone would just turn to sticky jelly and come off better with a cloth

perhaps because of the latex, there was still fair bit of softened but tenacious glue left, i used another quarter of the tube to recoat it, and waited about 30 minutes, then it came off ok

had to do a few passes with paper towel and petrol to clean up the sides and eliminate any remaining stickiness

overall, it was far quicker and less messy job than the last rim i cleaned, the schwalbe glue remover is well worth it!

btw on the new tyre i've scraped off the latex, it was one that had a coat of glue on, i found scraping off the glued latex was *much* easier than doing it on a tyre with just the original latex

Rich.H
Posts: 96
Joined: Mon Mar 10, 2008 6:48 pm
Location: South Derbyshire, UK

by Rich.H

Ok, I know I am at risk of asking a daft question but I want to check my understanding is not subject to some kind of international translation.....

When removing Mastik glue from carbon rims "household" petrol / diesel is often recommended.

I assume this is straight forward automotive fuel as available from my local Shell filling station?

Many thanks

Rich

fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

I assume this is straight forward automotive fuel as available from my local Shell filling station?


Yes. Keep in mind though that you'll be paying more for car fuel than you'd pay for heater fuel.
What I often use is called lamp oil which is cheaper but quite similar to regular diesel fuel.

Ciao, ;)
Being a snob is an expensive hobby.

Rich.H
Posts: 96
Joined: Mon Mar 10, 2008 6:48 pm
Location: South Derbyshire, UK

by Rich.H

Many thanks - just the clarity i was looking.


Rich

zedliang
Posts: 5
Joined: Wed Mar 16, 2011 2:49 am

by zedliang

Hi guys,

I need some advice since it is the first time I glued tubulars. I followed the general suggestions on this thread to use 2 coats each on rim and tire with 24 hours of drying time in-between, followed by a wet coat on the rim and mount. Ok, so after about 1000km my front tire is still nicely glued on, but on my rear wheel there is black sticky glue showing up on the rim-tire area. It seems like the glue is contaminated and no longer holding. It is strange since both front and rear were done the exact same way. The front has some little beads of glue in the same area but they are yellow and dry, unlike the rear which looks black and "wet".

I deflated the tire and tried to push off the tire, and I noticed that the good glue bond seems further inwards (means I have to push more to see it).

Maybe it is a dumb question, but is it safe to carry on riding it? and why does this black stuff occur?

Thanks,
Zed

zedliang
Posts: 5
Joined: Wed Mar 16, 2011 2:49 am

by zedliang

Also, if I pull off the tire, there is already some of the bad black stuff on the edge of the rim and base tape...how do I clean the base tape? and I am not looking forward to removing the glue on the rim.

Geoff
Posts: 5097
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

First off, what glue were you using? What tires and rims? It would probably help us to see a pic of both, too.

I have never seen an adverse reaction between a basetape glue and rim cement before, nor have I ever seen a cement react to a rim before. The fact that it is only occurring on one wheel implies to me that it wasn't something environmental. Accordingly, I suspect that the rim or basetape may have been contaminated with something before you mounted it.

Turning to what the 'black stuff' could be, it could be whatever contaminated your glue job (grease, oil, etc.) or, it could just be dirt or grime adhered to your glue. If the latter, you can clean-up the mess with a clean rag with a bit of thinner on it. Just be sure to clean the rim well before you ride it.

zedliang
Posts: 5
Joined: Wed Mar 16, 2011 2:49 am

by zedliang

Oh I forgot. I'm using mastik one on zipp 404 rims and vittoria corsa evo cx tires.

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atakaoka
Posts: 80
Joined: Tue Aug 07, 2012 2:29 am
Location: Ibiuna-SP-Brazil

by atakaoka

I believe that is a problem whith heat on the rear rim melting the glue,because I have the same problem.and I use brakes a lot.
cycling,a great individual sport,were you can't reach anything,whithout group effort.

Geoff
Posts: 5097
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

Ok, I have definitely never seen at with Matstik 1 and Vittoria. I still think that this is a contamination issue... ( I don't think this is an 'over-heating' issue, as this is the rear wheel, not the front wheel).

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

Chain lube. I find it on rear rims all the time. it gets flung off when riding. Solution is less lube/more wiping.

fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

That plus a rim that wasn't thoroughly degreased prior to put the cement on perhaps.

Hard to tell from a distance anyhow.

Ciao, ;)
Being a snob is an expensive hobby.

by Weenie


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