Cracked Givi hard luggage

[bob prohaska]

Find where the far ends of the cracks are, and drill small ?crack stopper?
holes there. Then use fibreglass matting and a suitable adhesive inside the
case to reinforce the cracked area.

The notion of "suitable adhesive" is what's stopping me. I don't know what
Givi cases were made of ~20 years ago, but they are injection molded and
most moldable platics are tricky to glue. ABS and PVC are glue-able, but
need different glues. Polypropylene and polyethylene (polythene on your
side of the pond) are close to un-glueable AFAIK.

Car body repair kits should provide the necessary materials.

I didn't think of auto body repair kits, that's worth checking.

Thanks for writing!

bob prohaska

[Andy Burns]

Post by bob prohaska
I didn't think of auto body repair kits, that's worth checking.

is it a thermoplastic (i.e. melty)?

if so, then either the red-hot staples, and/or plastic stir welding,
done on the inside ...

[wessie]

Post by bob prohaska

Find where the far ends of the cracks are, and drill small ?crack
stopper? holes there. Then use fibreglass matting and a suitable
adhesive inside the case to reinforce the cracked area.

The notion of "suitable adhesive" is what's stopping me. I don't know
what Givi cases were made of ~20 years ago, but they are injection
molded and most moldable platics are tricky to glue. ABS and PVC are
glue-able, but need different glues. Polypropylene and polyethylene
(polythene on your side of the pond) are close to un-glueable AFAIK.

Car body repair kits should provide the necessary materials.

I didn't think of auto body repair kits, that's worth checking.
Thanks for writing!
bob prohaska

the kit I used was sold by motor factors, made by Plastic Padding but I
can't find it now. The brand is still a thing, so you might find something
in your land.

[Bruce Horrocks]

Post by bob prohaska

Find where the far ends of the cracks are, and drill small ?crack stopper?
holes there. Then use fibreglass matting and a suitable adhesive inside the
case to reinforce the cracked area.

The notion of "suitable adhesive" is what's stopping me. I don't know what
Givi cases were made of ~20 years ago, but they are injection molded and
most moldable platics are tricky to glue. ABS and PVC are glue-able, but
need different glues. Polypropylene and polyethylene (polythene on your
side of the pond) are close to un-glueable AFAIK.

Car body repair kits should provide the necessary materials.

I didn't think of auto body repair kits, that's worth checking.
Thanks for writing!

There are a couple of options that might work.

Firstly this stuff <https://www.ebay.co.uk/itm/164971020409> and use it
to glue a reinforcing plate on. A cheap steel ruler (cut to length and
roughened with a file to help the glue grip) would provide a thin but
strong plate.

The seller offers advice if you send in a picture of the damage.
Wouldn't do any harm to get his opinion.

Alternatively there is "plastic welding". Lots of videos on Youtube
covering car bumper repair and the like. If the Givi is a waxy plastic
that is typically hard to glue then plastic welding a patch over the top
might be the answer.

[bob prohaska]

Post by bob prohaska

Find where the far ends of the cracks are, and drill small ?crack stopper?
holes there. Then use fibreglass matting and a suitable adhesive inside the
case to reinforce the cracked area.

The notion of "suitable adhesive" is what's stopping me. I don't know what
Givi cases were made of ~20 years ago, but they are injection molded and
most moldable platics are tricky to glue. ABS and PVC are glue-able, but
need different glues. Polypropylene and polyethylene (polythene on your
side of the pond) are close to un-glueable AFAIK.

Car body repair kits should provide the necessary materials.

I didn't think of auto body repair kits, that's worth checking.

I think at the end of the day, things usually crack or break at the
weakest/most stressed point and a glued joint is usually weaker than the
original. At best the glue will provide a mechanical bond, not a chemical
one on moulded plastic so some kind of patch is essential, maybe some thin
aluminium on both sides with pop rivets?

It would help a lot to know what the plastic is. I've written to
GiviUSA but probably won't get an answer till well into the new
year, if then. Somewhere I got the idea that Givi cases were made
of ABS, which can be glued very well using solvents. If that's
true, a sheet of ABS affixed with solvent cement might be a
fairly good repair. I posted in large part hoping somebody
on these lists might know. So far, nobody's offered a clue.

Thanks for writing,

bob prohaska

[wessie]

Post by bob prohaska
It would help a lot to know what the plastic is. I've written to
GiviUSA but probably won't get an answer till well into the new
year, if then. Somewhere I got the idea that Givi cases were made
of ABS, which can be glued very well using solvents. If that's
true, a sheet of ABS affixed with solvent cement might be a
fairly good repair. I posted in large part hoping somebody
on these lists might know. So far, nobody's offered a clue.

I looked on my Givi E21 box but could not see a mark

Just dug out the E33 map storage box. Had to remove the maps but it is
clearly marked as recycle code 7 ABS in a roundel in the middle of the
base. The case was bought when I had my first VFR750 in 1993/94

[bob prohaska]

Post by wessie
Just dug out the E33 map storage box. Had to remove the maps but it is
clearly marked as recycle code 7 ABS in a roundel in the middle of the
base. The case was bought when I had my first VFR750 in 1993/94

Sure enough. With enough light the same shows up in the bottom
of my case. ABS glue is readily available for pipe, if I can soak
some fiberglass cloth with it there's hope.

Thank you very much for the needed investigative inspiration!

bob prohaska

[wessie]

Post by bob prohaska

Post by wessie
Just dug out the E33 map storage box. Had to remove the maps but it is
clearly marked as recycle code 7 ABS in a roundel in the middle of the
base. The case was bought when I had my first VFR750 in 1993/94

Sure enough. With enough light the same shows up in the bottom
of my case. ABS glue is readily available for pipe, if I can soak
some fiberglass cloth with it there's hope.
Thank you very much for the needed investigative inspiration!
bob prohaska

it's weird that the E21 cases bought in 2015 just have a date code in the
same roundel. No evidence of a recycling code or material ID.

[bob prohaska]

Post by wessie
it's weird that the E21 cases bought in 2015 just have a date
code in the
same roundel. No evidence of a recycling code or material ID.

Perhaps it's tacit acknowledgement that plastics are seldom
actually recycled. The main target of the markings was packaging
for merchandise, mostly food and beverage products. Marking
end products so they can be recycled is noble but futile.

At least here in the USA. We neither repair nor recycle 8-(

On a brighter note, it looks like I can buy a small swatch
of fiberglass cloth and a few ounces of ABS pipe cement for
less than $15. If it works, great. If it fails, it was cheap.
It turns out both of my E38 cases are cracking at the mount
lugs, so a workable fix has considerable benefit.

Thanks very much for your help!

bob prohaska

[Turby]

Post by bob prohaska
At least here in the USA. We neither repair nor recycle 8-(

Speak for your own locale. (A red state, I assume.)

Here in SoCal, we have 3 bins - black for trash, green for organic waste
(including weeds and food stuff,) and blue bins for recyclables. That
includes plastic containers and styrofoam, along with metal, glass, and
paper. The only thing we don't recycle but should are plastic bags,
because China canceled the contract.

[Andy Burns]

It would help a lot to know what the plastic is [...] so far,
nobody's offered a clue.

Flames can give clues ...

<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification>

[wessie]

Post by Andy Burns

It would help a lot to know what the plastic is [...] so far,
nobody's offered a clue.

Flames can give clues ...
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic
-Identification>

excellent idea - burn it and buy another one

[chrisnd @ukrm]

Post by Andy Burns

It would help a lot to know what the plastic is [...] so far,
nobody's offered a clue.

Flames can give clues ...
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification>

That is so UKRM!
:-)

Chris

[Mark Olson]

Post by Andy Burns

It would help a lot to know what the plastic is [...] so far,
nobody's offered a clue.

Flames can give clues ...
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification>

I was going to suggest putting a flame to it as a possible means
of identification.

Nominative determinism to the rescue!

(Rt Hon J. Cleverly notwithstanding)

[bob prohaska]

Find where the far ends of the cracks are, and drill small ?crack stopper?
holes there. Then use fibreglass matting and a suitable adhesive inside the
case to reinforce the cracked area.

I managed to get some 4" wide fiberglass ribbon and a small can of
cement for ABS pipe. The cement is basically ABS resin dissolved in
acetone. It seems to stick quite well to the case and soaks nicely
into the glass cloth, so that part of the project looks promising.

On close inspection the cracks are much longer than I realized,
extending from the bottom front of the case where the cleats screw
on forward and upward a couple inches toward the corners.
That seems rather bad.

Does anybody have suggestions for a reasonable stop drill size?
My first guess would be no smaller than the case thickness, up
to maybe five or ten times thickness, say somewhere between
one and six millimeters. Does anybody have a better-substantiated
approach to the sizing a stop drill hole?

Thanks to all for writing!

bob prohaska

[Spike]

Post by bob prohaska

Find where the far ends of the cracks are, and drill small ?crack stopper?
holes there. Then use fibreglass matting and a suitable adhesive inside the
case to reinforce the cracked area.

I managed to get some 4" wide fiberglass ribbon and a small can of
cement for ABS pipe. The cement is basically ABS resin dissolved in
acetone. It seems to stick quite well to the case and soaks nicely
into the glass cloth, so that part of the project looks promising.
On close inspection the cracks are much longer than I realized,
extending from the bottom front of the case where the cleats screw
on forward and upward a couple inches toward the corners.
That seems rather bad.
Does anybody have suggestions for a reasonable stop drill size?
My first guess would be no smaller than the case thickness, up
to maybe five or ten times thickness, say somewhere between
one and six millimeters. Does anybody have a better-substantiated
approach to the sizing a stop drill hole?
Thanks to all for writing!
bob prohaska

For a crack stopper, I’d suggest a 2mm drill, and a problem you might have
is that the through-thickness crack front might not be square across the
thickness. You’ll need to examine each crack to ascertain where the ends of
each crack is both inside and outside, and then drill along the crack
front, which might not be square to the local surfaces. This is to avoid
drilling larger holes than needed.

Another thing you might consider is to epoxy short pieces of steel across
the ends of each crack, before applying the glass-fibre matting, whether or
not you drill crack-stopper holes. If doing this, clean the steel strip
with alcohol before applying the epoxy and avoid handling the bonding
surface. Apply pressure until the epoxy sets.

HTH

[bob prohaska]

For a crack stopper, I?d suggest a 2mm drill, and a problem you might have
is that the through-thickness crack front might not be square across the
thickness. You?ll need to examine each crack to ascertain where the ends of
each crack is both inside and outside, and then drill along the crack
front, which might not be square to the local surfaces. This is to avoid
drilling larger holes than needed.

There's enough material for 5-10 mm holes, but I'll look more carefully
to see if the crack inclination can be discerned.

Another thing you might consider is to epoxy short pieces of steel across
the ends of each crack, before applying the glass-fibre matting, whether or
not you drill crack-stopper holes. If doing this, clean the steel strip
with alcohol before applying the epoxy and avoid handling the bonding
surface. Apply pressure until the epoxy sets.

I wonder if using a small screw, washers and nut clamping the ends of
the cracks flat might have a similar effect. That's easier to do,
looks aren't a huge issue. Flatness near the crack ends might be
as the cracks follow the curve from the bottom of the case to the
corners. The end area might not be entirely flat.

Thanks for writing!

bob prohaska