bag latch broken (plastic)

[cliffh]

Well, upon return from a great 1,400 mile ride, this is what I found. At least all the plastic is there. I haven't had time to remove the bag yet and have no idea how to do it.
Does anyone know how difficult this is to remove for repair? I want to reinforce the piece with fiberglass from the inside.

 

[mikesim]

It's not difficult but it is time consuming. I would stitch it back together with a plastic welder from the inside, and then solvent weld the crack with the proper plastic solvent. The lids are poly-carbonate but I'm not sure of the housing. When you get the housing of the plastic material it is made of will be coded on the housing. For example, poly-carbonate is coded >PC<. The plastic solvent weld supplier can help you select the best product. Once that is done, reinforcement with a thin layer of fiberglass woven roving will finish the job. It looks like you just pop riveted the latch to the housing with no backing reinforcement. Be sure to use a metal backing plate to comeplete the repair. If the other side has been installed the same way, nip the cracks in the bud and reinforce it before it cracks. Also, make sure you get the proper pop-rivet. Measure the thickness of all the items you will be joining and make sure that the pop rivet you select falls into the "grip range" of the rivet. Excessive clamping force will also create a similar failure mode.

Good luck!

Mike

 

[cliffh]

Well, I've repaired the latch damage on my right bag. I went an easier route, I think. I used 2 layers of modeling plywood, each with 4 layers in the wood, to make a support for the damaged plastic. I bent the plywood piece by steaming the wood and using a tourniquet to hold into place on a 3 lb coffee can to dry. The final piece ended up being 5 1/2" long, so I believe it has good support. I roughed up the underside of the plastic surrounding the damage and used a liberal amount of JB Weld to secure it in place. I then replaced the damaged plastic pieces, again with JB Weld and used a spray paint made for plastic to coat. Then secured the latch with wood screws. I think was much easier than removing a lot of pieces to repair and I still ended up with a solid mount.

Thanks for your advice Mike. I'm sure that was the "right way" , but I believe this will work just fine.

 

[Sunny]

Holly Moly ... i would like to see the wood part too... man that looks so good ...

 

[cliffh]

Holly Moly ... i would like to see the wood part too... man that looks so good ...

Thanks. I should have taken some pictures, but.....
Anyhow, the wood piece has to be sized and shaped to be able to fit into the hole made by the broken parts. The final piece ended up being about 5 1/2" long and an inch wide. The side toward the outside remained straight, while the inside part was curved on each end to fit. The whole piece needed to be steamed and bent to fit the arch of the bag, much more than you might think. I used a 2" wood screw temporarily in the middle of the piece to hold and handle the wood piece while fitting and installing. It took many in and outs to get the final shape. You could probably do the same thing with 3 or 4 tongue depressors. The use of wood made using wood screws possible and avoided the problems associated with pop rivets. No disassembly of the bag was required doing the repair this way.
Clif

 

[ADK Jim]

Thanks. I should have taken some pictures, but.....
Anyhow, the wood piece has to be sized and shaped to be able to fit into the hole made by the broken parts. The final piece ended up being about 5 1/2" long and an inch wide. The side toward the outside remained straight, while the inside part was curved on each end to fit. The whole piece needed to be steamed and bent to fit the arch of the bag, much more than you might think. I used a 2" wood screw temporarily in the middle of the piece to hold and handle the wood piece while fitting and installing. It took many in and outs to get the final shape. You could probably do the same thing with 3 or 4 tongue depressors. The use of wood made using wood screws possible and avoided the problems associated with pop rivets. No disassembly of the bag was required doing the repair th

Well, I've repaired the latch damage on my right bag. I went an easier route, I think. I used 2 layers of modeling plywood, each with 4 layers in the wood, to make a support for the damaged plastic. I bent the plywood piece by steaming the wood and using a tourniquet to hold into place on a 3 lb coffee can to dry. The final piece ended up being 5 1/2" long, so I believe it has good support. I roughed up the underside of the plastic surrounding the damage and used a liberal amount of JB Weld to secure it in place. I then replaced the damaged plastic pieces, again with JB Weld and used a spray paint made for plastic to coat. Then secured the latch with wood screws. I think was much easier than removing a lot of pieces to repair and I still ended up with a solid mount.

Thanks for your advice Mike. I'm sure that was the "right way" , but I believe this will work just fine

 

[ADK Jim]

Cliff:
I just got an email from the forum saying I should see what is happening and I hope I am not too late to help. I've had the similar problem (exactly) on a cross country trip and I might be able to give you some additional thoughts and things that what worked for me. 1.) The plastic is bondable/repairable with the black ABS/PVC glue (see attached picture) which you can get at any hardware store or Lowes, etc. 2.) The problem is probably caused by one or two things - maybe both. The plastic (all our plastic on our "old" NT's) is becoming brittle from sunlight and age and therefore is weakened. Additional problem is if you mabye over stuffing the panniers with the pressure and rattling down the road, this can cause vibration on your modified latch mechanism that was "popped riveted" through the pannier black mating frame. There is no strength there. I understood what you did with your piece of plywood and I did a similar repair but instead of the plywood, I used pieces of formed (curved) aluminum which were about 1/8" thick. There is a neat tool you can make many repairs on your bike along with the PVC glue that is like a soldering gun but instead of the tips used for soldering, has a variety of staples that get heated and melt into the plastic to form mechanical bonds that will strengthen the bonds of the adhesive (available on Amazon - Plastic Welder Kit - about $20). I hope this is of some help. If you have any questions, PM me. Jim

 

[cliffh]

Cliff:
I just got an email from the forum saying I should see what is happening and I hope I am not too late to help. I've had the similar problem (exactly) on a cross country trip and I might be able to give you some additional thoughts and things that what worked for me. 1.) The plastic is bondable/repairable with the black ABS/PVC glue (see attached picture) which you can get at any hardware store or Lowes, etc. 2.) The problem is probably caused by one or two things - maybe both. The plastic (all our plastic on our "old" NT's) is becoming brittle from sunlight and age and therefore is weakened. Additional problem is if you mabye over stuffing the panniers with the pressure and rattling down the road, this can cause vibration on your modified latch mechanism that was "popped riveted" through the pannier black mating frame. There is no strength there. I understood what you did with your piece of plywood and I did a similar repair but instead of the plywood, I used pieces of formed (curved) aluminum which were about 1/8" thick. There is a neat tool you can make many repairs on your bike along with the PVC glue that is like a soldering gun but instead of the tips used for soldering, has a variety of staples that get heated and melt into the plastic to form mechanical bonds that will strengthen the bonds of the adhesive (available on Amazon - Plastic Welder Kit - about $20). I hope this is of some help. If you have any questions, PM me. Jim

Thanks for the info. I'll keep that in mind. BTW, I'm pretty sure about the cause. The little spring that returns something in the factory latch came off causing the latch to go to the closed position. I did not realize it and kept trying to close the bag. Dumb I know, but that's what I did I'm not going to bother to try to reinstall the spring at this time as I'm happy with my repair.

 

[Tuchango]

Has anyone applied the same glue used for emblems instead of rivets or screws to attach external aftermarket latches?

 

[mikesim]

Has anyone applied the same glue used for emblems instead of rivets or screws to attach external aftermarket latches?

I played around with 3M trim tape to work out the positioning of the latches but it wasn't strong enough to hold them in place when shutting the lids. I doubt that 3M trim adhesive would be any better as they don't seem to have enough strength when used in a shear application

Mike

 

[Tuchango]

Got some of this and I’ve been messing around with rivets on practice sheets of plastic.

Reluctant to pull the trigger on either of them got some of this and I’ve been messing around with rivets on practice sheets of plastic.

After seeing some of the plastics break
With screws and rivets or bolts, and not having a full of an understanding of how the glue might affect the plastic, I’m still delaying things. The stock clips are starting to show where in both sides I think I have a little time, but you never know.

 

[mikesim]

Based upon what I have seen, I don't think that the trim adhesive will work well for this application. If you want to see how the adhesive affects the plastic, take a small dab of the adhesive on the inside of the pannier lid and housing. If it does ugly things, at least they are on the inside and not visible. To minimize the likelihood of the plastic cracking it is essential that you spread the clamping forces over a broad area by using a backing plate on the inside of the pannier and housing. Instead of pop rivets, you may want to consider machine screws with nylock nuts. The nylock nuts will prevent loosening due to vibration and will allow you to snug the latch down "just enough" to keep the latch securely in place.

Mike