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.
Car body repair kits should provide the necessary materials.
I didn't think of auto body repair kits, that's worth checking.
Spike <aero.spike@mail.com> wrote:
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
Spike <aero.spike@mail.com> wrote:
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!
On 28/12/2023 20:07, bob prohaska wrote:
Spike <aero.spike@mail.com> wrote: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
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.
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.
It would help a lot to know what the plastic is [...] so far,Flames can give clues ...
nobody's offered a clue.
bob prohaska wrote:
It would help a lot to know what the plastic is [...] so far,Flames can give clues ...
nobody's offered a clue.
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification>
bob prohaska wrote:
It would help a lot to know what the plastic is [...] so far,Flames can give clues ...
nobody's offered a clue.
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic -Identification>
bob prohaska wrote:
It would help a lot to know what the plastic is [...] so far,Flames can give clues ...
nobody's offered a clue.
<https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification>
In uk.rec.motorcycles wessie <willnotwork@tesco.net> wrote:
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
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
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.
At least here in the USA. We neither repair nor recycle 8-(
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.
Spike <aero.spike@mail.com> wrote:
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.
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