This turned out to be a real pain in the butt. Can anyone think of why you would rivet an aluminum bracket onto a carbon fiber frame using steel rivets?

The cast bracket was not sealed on so in wet conditions it would seep between the br

On 9/27/2023 6:16 PM, Tom Kunich wrote:
> This turned out to be a real pain in the butt. Can anyone think of why you would rivet an aluminum bracket onto a carbon fiber frame using steel rivets?
>
> The cast bracket was not sealed on so in wet conditions it would seep between the br

Because a smaller steel rivet does the job of a larger
aluminum rivet and a smaller hole is desirable in carbon
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971

On Wednesday, September 27, 2023 at 5:14:22 PM UTC-7, AMuzi wrote:
> On 9/27/2023 6:16 PM, Tom Kunich wrote:
> > This turned out to be a real pain in the butt. Can anyone think of why you would rivet an aluminum bracket onto a carbon fiber frame using steel rivets?
> >
> > The cast bracket was not sealed on so in wet conditions it would seep between the br
>
> Because a smaller steel rivet does the job of a larger
> aluminum rivet and a smaller hole is desirable in carbon
> --
> Andrew Muzi
> a...@yellowjersey.org
> Open every day since 1 April, 1971
This problem does not occur if the braze on bracket is properly placed and glue on with carbon fiber.

On 9/28/2023 10:12 AM, Tom Kunich wrote:
> On Wednesday, September 27, 2023 at 5:14:22 PM UTC-7, AMuzi wrote:
>> On 9/27/2023 6:16 PM, Tom Kunich wrote:
>>> This turned out to be a real pain in the butt. Can anyone think of why you would rivet an aluminum bracket onto a carbon fiber frame using steel rivets?
>>>
>>> The cast bracket was not sealed on so in wet conditions it would seep between the br
>>
>> Because a smaller steel rivet does the job of a larger
>> aluminum rivet and a smaller hole is desirable in carbon

> This problem does not occur if the braze on bracket is properly placed and glue on with carbon fiber.

Nope. Adhesives are insufficient for the forces on a FD
mount. As you will soon prove with Gorilla Glue. Do report
back on that BTW.

Hence screws or later rivets besides a bonding agent.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971

On 9/28/2023 8:29 AM, AMuzi wrote:

<snip>

> Nope. Adhesives are insufficient for the forces on a FD mount. As you
> will soon prove with Gorilla Glue. Do report back on that BTW.
>
> Hence screws or later rivets besides a bonding agent.

He was just going to fill the holes where the rivets were with Gorilla
Glue, not hold on the new FD.

Because of the way original Gorilla Glue foams up and expands in all
directions, it is not be the best option for filling holes because the
hardened glob will eventually fall off into the seat tube and will need
to be removed by removing the bottom bracket. Epoxy would be a better
option to fill the holes, or Gorilla Glue Clear.

--
“If you are not an expert on a subject, then your opinions about it
really do matter less than the opinions of experts. It's not
indoctrination nor elitism. It's just that you don't know as much as
they do about the subject.”—Tin Foil Awards

On Thu, 28 Sep 2023 11:33:12 -0700, sms <scharf.steven@geemail.com>
wrote:

>On 9/28/2023 8:29 AM, AMuzi wrote:
>
><snip>
>
>> Nope. Adhesives are insufficient for the forces on a FD mount. As you
>> will soon prove with Gorilla Glue. Do report back on that BTW.
>>
>> Hence screws or later rivets besides a bonding agent.

>He was just going to fill the holes where the rivets were with Gorilla
>Glue, not hold on the new FD.

The origianal Gorilla Glue is polyurethane adhesive:
<https://www.gorillatough.com/product/original-gorilla-glue/>
The glue expands up to 3x as it cures. Much of the expansion is due
to microscopic gas bubbles. It is not recommended for gap filling,
which is what's needed to prevent voids that will eventually fill with
water. The specs section in the above URL indicate that it is NOT
recommended for gap filling. To prevent bubbles and foam, epoxies,
silicones and urethanes require mixing and curing in a vacuum chamber.

"Degassing Materials"
<https://www.crosslinktech.com/support/tips-and-tricks/degassing-materials.html>
"Although most, if not all, suppliers of formulated Epoxy and
Polyurethane materials manufacture products under vacuum."

"How to produce bubble free epoxy and polyurethane products"
<https://www.youtube.com/watch?v=G_tMHyFVDAM>

"Degas Urethane"
<https://www.youtube.com/watch?v=t2Lm3v6TtoI>

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Thursday, September 28, 2023 at 8:12:48 AM UTC-7, Tom Kunich wrote:
> On Wednesday, September 27, 2023 at 5:14:22 PM UTC-7, AMuzi wrote:
> > On 9/27/2023 6:16 PM, Tom Kunich wrote:
> > > This turned out to be a real pain in the butt. Can anyone think of why you would rivet an aluminum bracket onto a carbon fiber frame using steel rivets?
> > >
> > > The cast bracket was not sealed on so in wet conditions it would seep between the br
> >
> > Because a smaller steel rivet does the job of a larger
> > aluminum rivet and a smaller hole is desirable in carbon
> > --
> > Andrew Muzi
> > a...@yellowjersey.org
> > Open every day since 1 April, 1971
> This problem does not occur if the braze on bracket is properly placed and glue on with carbon fiber.

This is a bit indecipherable. I mean in the manner of the Trek braze-on mount