The drill screams!
I took in a Pinarello Dogma 65.1 frame from a customer.
Apparently it had been repainted,
and in the image above you can see the caliper brake mounting holes,
but they're currently sealed over — whether the paint was applied over the masking tape
or for some other reason, the holes are blocked
(though there are holes on the inside).
During the frame repainting, the front derailleur bracket was removed.
When they tried to re-attach it with epoxy adhesive
and drive in a stainless steel mandrel (shaft) blind rivet,
it broke partway through, and they want me to fix it.
You can see scuff marks on the frame in the image above.
But those same marks were already present in the photos the customer sent with their letter.
This is the upper left rivet.
↑And the lower right looks like this.
There are two blind rivets that need to be removed.
The customer tried removing them, but
the mandrel part was abnormally hard
and they couldn't manage it.
Both the mandrel and rivet body are stainless steel.
There's no center dimple for drilling, so
I mounted a carbide bit on a rotary tool
and set up a drill guide,
Then fitted a carbide drill bit to it,
and machined away until the mandrel could drop inside the frame.
↑This is the drill guide.
Even though it's stainless steel, I was worried the machining debris
might stick to the power meter's wake-up magnet,
so I masked it just in case — and sure enough, it did stick to the magnet.
I collected the bits of the broken rivet that broke at maximum pull.
The two ring-shaped pieces are the outer portion,
and the remaining mandrel
is the inner part that I dropped inside the frame.
This was actually the trickiest part and what required the most care.
Even after removing all the rivets, the epoxy was still holding,
so the front derailleur bracket was loose like a wobbly tooth but wouldn't come off.
I was nervous the whole time — what if the bracket pulled away and tore a hole in the frame? —
but I carefully peeled it off, and here's the result in the image above.
The duct tape is applied over the masking tape, so
there's no damage to the frame's paint.
The customer didn't ask me to fill the scratches on the bracket,
but I applied metal putty anyway,
then sanded it smooth,
sprayed on primer,
and let it dry.
The customer gave me black spray paint too,
but the paint had a coarse texture
and it was hard to apply smoothly.
I paid attention to distance, spraying technique,
humidity, and other conditions, but it still wasn't easy.
↑This is the third coat. I forgot to photograph the in-between,
but after applying about five coats total, it finally looked smooth.
I attached the front derailleur bracket to the frame with epoxy adhesive
and, before it dried, drove in
the blind rivets the customer had provided.
But pulling in the mandrel required far more force than I've ever experienced,
and when I finally broke it off,
there was no way to avoid scratching the bracket.
I had protected the frame, but
not the bracket.
The customer provided five blind rivets for four mounting holes.
The rivets themselves set correctly,
so I'm returning one unused.
But the epoxy needs drying time, so there's no going back.
If I'd had four or more extra rivets,
I would have reset everything and started over.
I masked off the bracket area
and painted over it.
The paint has dried.
I asked the customer, "Would you prefer if the rivet heads were silver instead of black?"
They said black was fine, so the job is done.
I took in a Pinarello Dogma 65.1 frame from a customer.
Apparently it had been repainted,
and in the image above you can see the caliper brake mounting holes,
but they're currently sealed over — whether the paint was applied over the masking tape
or for some other reason, the holes are blocked
(though there are holes on the inside).
During the frame repainting, the front derailleur bracket was removed.
When they tried to re-attach it with epoxy adhesive
and drive in a stainless steel mandrel (shaft) blind rivet,
it broke partway through, and they want me to fix it.
You can see scuff marks on the frame in the image above.
But those same marks were already present in the photos the customer sent with their letter.
This is the upper left rivet.
↑And the lower right looks like this.
There are two blind rivets that need to be removed.
The customer tried removing them, but
the mandrel part was abnormally hard
and they couldn't manage it.
Both the mandrel and rivet body are stainless steel.
There's no center dimple for drilling, so
I mounted a carbide bit on a rotary tool
and set up a drill guide,
Then fitted a carbide drill bit to it,
and machined away until the mandrel could drop inside the frame.
↑This is the drill guide.
Even though it's stainless steel, I was worried the machining debris
might stick to the power meter's wake-up magnet,
so I masked it just in case — and sure enough, it did stick to the magnet.
I collected the bits of the broken rivet that broke at maximum pull.
The two ring-shaped pieces are the outer portion,
and the remaining mandrel
is the inner part that I dropped inside the frame.
This was actually the trickiest part and what required the most care.
Even after removing all the rivets, the epoxy was still holding,
so the front derailleur bracket was loose like a wobbly tooth but wouldn't come off.
I was nervous the whole time — what if the bracket pulled away and tore a hole in the frame? —
but I carefully peeled it off, and here's the result in the image above.
The duct tape is applied over the masking tape, so
there's no damage to the frame's paint.
The customer didn't ask me to fill the scratches on the bracket,
but I applied metal putty anyway,
then sanded it smooth,
sprayed on primer,
and let it dry.
The customer gave me black spray paint too,
but the paint had a coarse texture
and it was hard to apply smoothly.
I paid attention to distance, spraying technique,
humidity, and other conditions, but it still wasn't easy.
↑This is the third coat. I forgot to photograph the in-between,
but after applying about five coats total, it finally looked smooth.
I attached the front derailleur bracket to the frame with epoxy adhesive
and, before it dried, drove in
the blind rivets the customer had provided.
But pulling in the mandrel required far more force than I've ever experienced,
and when I finally broke it off,
there was no way to avoid scratching the bracket.
I had protected the frame, but
not the bracket.
The customer provided five blind rivets for four mounting holes.
The rivets themselves set correctly,
so I'm returning one unused.
But the epoxy needs drying time, so there's no going back.
If I'd had four or more extra rivets,
I would have reset everything and started over.
I masked off the bracket area
and painted over it.
The paint has dried.
I asked the customer, "Would you prefer if the rivet heads were silver instead of black?"
They said black was fine, so the job is done.