Best repair of a crack in black rooftop cargo boxes a la Thule/Yakima etc? (1 Viewer)

[e9999]

Got myself an older Thule cargo box for either the roof rack or a trailer. There is a crack near one of the attachment points. I want to fix that before using it.
It seems like the material might be ABS, but not positive.
Anybody has experience with fixing those?
Somebody mentioned ABS patch kits from the hardware store but not sure what those are and how well they work.
I imagine some sort of epoxy patch might possibly work too but maybe too rigid since I think these boxes are flexing a fair amount.
I'd put some sort of metal plate or mesh in there as reinforcement too.
Or fiberglass? but that's also pretty rigid I think.
The wall is pretty smooth and not sure how well compound would attach to it.
The stitching kits for stud guns are cool but I don't have a stud gun and I think the material is way too thin.
Thoughts?

 

[e9999]

ah, watched a bunch of plastic welding vids on youtube. Very easy. One neat trick was to melt some copper wire in the plastic to bridge the crack. I'm thinking to cut some excess plastic somewhere from the box to use as filler. Put the wires in and then melt some ABS into the crack with a soldering iron. Then slather everything with some as of yet unidentified goop with fiberglass or metal mesh. Looks doable.

dang, maybe should have put this thread in the Tools and Fab forum...

 

[rusty_tlc]

Go to youtube and search "fairing repair". The two wheel crowd has been fixing ABS plastic for a long time.

 

[e9999]

yes, I saw quite a few vids on that. Seems like they are mostly using plastic welding rather than chemical bonding.

 

[skidplate]

I've used "Goop" for plastic with great success. I'd slather some mesh on the inside of the repair with it. If the area is clean I don't see why it wouldn't stick. My .02

 

[e9999]

well, the Goop I've used is the shoe type stuff. It did not seem like it would have much structural strength. Yours must be different.

I've read some interesting stuff where some folks make their own bonding agent by dissolving abs in acetone.

 

[kbahus]

I have used Wurth brand 2-part plastic weld epoxy for the repair of multiple cargo boxes, they are all still going strong years later and it's a great product. I have also used Loctite brand plastic weld which I believe I purchased from Wal-Mart with good success as well.

 

[rusty_tlc]

yes, I saw quite a few vids on that. Seems like they are mostly using plastic welding rather than chemical bonding.

There might be a reason for that, just sayin......

Why would you not want to use a weld to repair the damage rather than glue it?

If you really want to glue it try a solvent based glue, like ABS cement found in the plumbing department at the home stores. The correct solvent will melt the base plastic, then you join the pieces then wait for the solvent to evaporate. Test the solvent of a different area first so you don't contaminate the area you want to repair. Just pick a inconspicuous edge or something.

 

[mtbdad]

Go buy some bongo glass, super cheap easy to use will keep water out as well..

 

[Whistler74]

I had some similar repairs to do in a Yakima box. It's ABS. I used Crazy glue to put it together, then some thin ABS sheet scraps that I moulded with a heat gun. These were glued to the inside with hello ABS plumbing cement. Still holding a few years later.

 

[e9999]

good idea on the heat gun if I could find some abs sheets.


Dan, the material looks too thin to me to weld. It's surprisingly thin in fact, probably for weight. And given the location I'd really want to build it up quite a bit to be safe.

 

[rusty_tlc]

good idea on the heat gun if I could find some abs sheets.


Dan, the material looks too thin to me to weld. It's surprisingly thin in fact, probably for weight. And given the location I'd really want to build it up quite a bit to be safe.

Get a soldering iron with temp control, it's like welding sheet metal; low heat small sections at a time. Just do a dot move a few inches do a dot, move a few inches, etc.

ABS is pretty common, lots of plastic jugs are made from it. I think most of the Motorcycle guys use antifreeze jugs.

 

[brownbear]

Get a flat piece (thin) of similar material. Rough it up on the inside with some 40 grit. And rough up the patch. Clean it with acetone, quick wipe only as it might melt the plastic a bit. Then use plumbing glue forays pipes. Put it on with some tape and let it dry. On the top side you can use a urethane 2 part bumper repair type crack filler. Afterwards you could lightly sand the top and hit with some plastic paint to hide it.

That's how I would fix it.

 

[RufusTheDufus]

I used Plasti Mend to fix our Thule box a few times. I was happy with the results. I repaired a 6" diamater crushed corner with the stuff. I made a mold with spray foam off of a friend's box and then built a new corner out of Plasti-Mend for my box.

Search the RV community for tank repair solutions for other options.

 

[mrbigboy]

http://www.fiberfix.com/

 

[FJ40_Nut]

I successfully repaired my Thule with PVC pipe cleaner and glue. My crack was about 5 inches long on the bottom.