- Tools For the Job
- Removing Paint Scuffs
- Filling and Reinforcing Cracks
- Repairing the Repair and Matching the Texture on the Outside
- Fixing A Broken Lid Latch
- Repair Missing Ring on Retaining Straps
- Replacing Sealing Gasket in the Lid
- Adding Some Shine
- Two Keys Aren’t Enough 🙁
In 1983, the R100RS came with BMW branded panniers, or saddle bags. These have a number of cracks and a broken lid hinge. While I’m waiting for some fork parts to come, I started to repair the panniers.
I’ve come across a product, Plast-aid, and the headquarters for the company is in Estes Park, here in Colorado. I’ve visited the factory and spend a couple hours talking with the owner, Randy Amen. I wrote a blog about my visit and how I used it to fix the wiring bulk head connector on a Windjammer fairing. You can read more about the product on the Plast-aid web page. I also used it to fix a crack in the fairing on my R1150-RS and a broken turn signal housing and it worked very well.
Tools For the Job
The panniers are made of a plastic that Plast-aid adheres to, and I suspect it’s ABS. As you can see below, there are some significant cracks.
Some of the cracks have opened up so there is a gap that needs filling.
Plast-aid comes in two parts. The kit includes a plastic mixing cup made from a plastic it won’t stick to. The cup is identical to the ones you get with cough syrup. I use the eye dropper to add the liquid catalyst to the white powder so I can closely control the consistency.
It can also be colored by adding artist acrylic paint to the mixture. I got a small bottle from Hobby Lobby for painting miniature military figures.
To strengthen the repair, I use aluminum screen patches available at most hardware stores. It’s stronger than fiber glass and can be shaped easily.
I used a Dremel tool and several bits. I use the rounded bit to route out the back of the crack and to cut intersecting grooves across the crack. The sharp pointed bit was my first choice to create the rough texture on the front of the plastic. It was too pointed. In another attempt, I used a #106 engraving bit which is a little wider than I’d like. On my next pannier crack repair project, I’ll try the #105 bit which is pretty small.
I use some steel picks to help clean out the cracks and to help create the texture pattern.
The cases are discolored and stained. I use Forever Black to restore the original luster to them.
Removing Paint Scuffs
There are some white paint scuffs and smudges on the bags. I use mineral spirits and a blue shop towel and rub hard to remove the them.
And when it still won’t come off, I use the pick to loosen it. It comes off easier after it’s been soaked with mineral spirits.
Filling and Reinforcing Cracks
I use brake cleaner to clean the area around the cracks and inside the cracks where they have opened up so the surface is clean and any wax, road grime and oil are removed. I use the rounded bit and route out the back side of the cracks inside the pannier. I cut grooves that cross the crack at right angles. I will fill all the grooves with Plast-aid. The right angle grooves will act as ribs that help keep the crack from opening up again. I also cut a groove at the end off the crack to relieve stress at the tip of the crack so it will stop extending.
I use a small paint brush to paint some of the Plast-aid liquid inside the cracks. It softens the existing plastic and promotes better adhesion inside the crack.
Once I have one crack prepared, I mix up some Plast-aid. I pour some of the white powder into the mixing cup. I use the eye dropper to add the liquid until it has soaked the white powder and there is a little liquid on top of the granules. I add a couple drops of the acrylic paint (2 to 8 drops depending on how much Plast-aid I am mixing up).
Then I use a Popsicle stick to mix it up until the acrylic paint has completely dissolved. If it doesn’t seem black enough, I add a couple more drops of the acrylic paint until it’s nice an black.
I filled in the cracks from the front. I used a small coffee stirrer, but later, I found that a round tooth pick that had the sharp end broken off was more precise and minimized the amount of Plast-aid that ended up on the outside of the crack.
Then I used the Popsicle stick and painted Plast-aid in the grooves on the back of the crack inside the pannier.
The problem with this approach, is the edges of the crack don’t want to stay even and I ended up with a high edge and excess Plast-aid creating a high ridge. I used the pick to smooth down the high ridge and scrape the excess away from the edge of the crack before the Plast-aid hardened. I had about 10 minutes per batch before it hard.
To reinforce the repair, I hooked two screen patches together and mixed up another batch of Plast-aid and stuck on the inside of the pannier over the two cracks.
I had to hold the screen in place with a couple Popsicle sticks until the Plast-aid stiffened up enough to hold the screen to the case.
However, when everything dried, I still had one edge of the crack higher than the other, so the repair is quite visible. And, the corner repair had a very uneven surface. I wanted the repair to be as invisible as possible, so this wasn’t what I wanted. 🙁
Repairing the Repair and Matching the Texture on the Outside
I decided to sand down the high edge and to get them even. And, I had to fill in the low spots on the corner with more Plast-aid. This means the texture on the outside is lost which makes the repair even more visible. I started thinking about how to recreate the texture. I suddenly thought of the plastic one gallon milk jugs. They have textured plastic at the bottom, and are made from a plastic Plast-aid doesn’t stick to.
The idea I had was to put a light coat of Plast-aid over the sanded area and the press the textured milk jug strips into it and emboss the pattern. Here is the result on the double cracks next to the latch and the large corner cracks.
Much better, but there I still need to work on these to get them to blend in better.
Another Texture Technique
I decided to work on the other pannier. It has a number of single cracks that aren’t as bad as the ones I just worked on. I made up some small blocks of wood that would cover the length of the cracks and used silicone seal to stick the milk jug textured plastic to them.
I applied the Plast-aid to the inside and outside of the crack. I put a block over the Plast-aid on the inside and outside and the clamped them and waited for the Plast-aid to dry.
The result was better, but on the front, the edges of the crack were still a bit uneven, and when I was cleaning up some of the excess Plast-aid on the front of one crack, I managed to remove some from inside the crack. 🙁
Yet Another Texturing Technique
I sanded out the high edge and mixed up a small amount of Plast-aid. I applied it with a broken off round toothpick and then used the edge of the toothpick to gently dimple the Plast-aid when it had stiffened up.
Then, I used the pick and carved some small grooves in the hardened Plast-aid. I also tapped the sharp end of the pick forcefully to create some stippling.
Then, I used 1000 wet/dry sand paper to smooth off the roughness, followed by 1500 grit and then 2000 grit. This is the result. It looks very close to the original texturing and the line of the crack is not easily seen, although it’s there if you look very closely, and the dimples are a little too deep.
A Third Texturing Technique
Another technique I used was the Dremel Tool with the sharp engraving tip. I tried this on the first case after I sanded out more of the rough spots and I needed to texture larger areas on the outside of the pannier I ran it on the lowest speed and randomly cut grooves and curlicues. I also tapped the tip into the plastic to create some small dimples. This works pretty well, but you have to be careful to not get too deep a dimple. When I was done with the Dremel tool, I sanded the area with 1000 wet/dry paper followed by 2000 grit. The result is pretty close to the original texturing.
In this repair, the dimples are too deep. I’ll fill these in with Plast-aid and redo them.
Dremel Engraving Tool 105 or 106
I looked up engraving tools and found the #105 and #106 bits that don’t have a sharp end, but a rounded ball. I picked up the #106, but I think the smaller #105 would be even better.
NOTE: Dremel has several size engraving bits, #105, #106 and #107. #105 is the smallest and I think the better choice for this technique. The #106 I choose is a bit to large, even though it’s a small bit.
Here is the final result for the double crack under the latch and the crushed corner. It’s a closer match to the texture that the previous try with the sharp end engraving tool.
Summary of Crack Repair Techniques
Due to the thin ABS plastic used in the panniers, it’s not easy to keep the edges even when repairing the cracks. Using a larger wood plate with the textured milk jug plastic may help keep both edges of the crack at the same height. I have some other bags that have cracks and I’ll try this and see how it works
The Plast-aid is very strong and with the black acrylic paint, blends very closely with the existing color of the panniers. For a single crack, I don’t think the aluminum screen reinforcement is necessary. Where there are several cracks close together, or where a corner has been crushed, the screen provides a very strong repair.
Using a broken off round toothpick to apply Plast-aid to the front side of a crack controls the application well. You can make Plast-aid more runny by adding more liquid, but it is not a thin liquid, so I have to press it into the crack with the tip of the toothpick. By slightly blunting the sharp end, it can be used to create dimples and grooves in Plast-aid when it is still soft. I think this is a good way to try and create the texture effect on small areas of Plast-aid on the front of the pannier.
The pick is very handy for removing excess Plast-aid on the front of the pannier. It kind of works for making dimples and grooves in sanded down plastic, but it takes a lot of force to cut a groove and you have to be careful you don’t create a long straight line which is hard to do when pressing down hard.
The #105 Dremel engraving bit is likely the best choice. The #106 worked, but I think the dimples and grooves are a bit too wide. The technique I used was to run the Dremel tool at its lowest speed and the lightly move it back and forth, up and down and on alternating 45 degree angles going from left to right. The rotation of the bit causes the tool to skip over the plastic and hop about. This makes the nicks, grooves and dimples more random. The marks made have sharp edges. I used the rounded end of a pick and burnished the area I put grooves and dimples in and this helps round the edges a bit making them more like the original texture. I use 1000 wet/dry to smooth the dimpled area followed by 1500 and then 2000 grit so the surface is smooth. Last, I use Forever Black to bring back the luster of the sanded plastic and Plast-aid.
Fixing A Broken Lid Latch
One of the lid latches comes off the bag. Upon inspection I see there is a plate riveted on top of the lock mechanism hinge pins. That’s what’s missing on the broken latch. It’s easy to see when I separate the latch from the locking mechanism.
The locking assembly has pins that slide into grooves in the latch casting. The locking assembly slides into the latch casting grooves from the bottom and then rotates in its slot in the latch casting when the latch is opened and closed.
I need some metal to replace the lost plate. I use the top from an evaporated milk can and cut out a shim with my utility knife.
I use a Dremel tool with a small grinding cylinder to square up the edges and to size the shim to fit on top of the hinge housing. I cut out a small notch with the utility knife so it fits around the rectangular pin on the casting.
I use JB Weld to glue the piece on top of the casting. Rather than remove the latch base plate from the bag by drilling out the rivets, I make the repair with the latch and lock mechanism assembled on the base plate. There is just enough room to put the metal shim on top of the hinge pin casting using long needle nose pliers.
I mix up some JB Weld and apply it to the top of the lock hinge pin casting.
Then I assemble the lock mechanism into the latch mechanism and insert that into the grooves in the base plate that hold the latch mechanism. I carefully arrange the lock mechanism so it’s hinge pins just engage in their slots in the base plate. I find that gravity holda the pieces just the right way if I prop the case open with a Popsicle stick.
I use long needle nose pliers and a coffee stirring stick to maneuver the metal patch on top of the lock hinge pin casting. After the seventh try, I get it aligned correctly. I press down on the metal patch with the coffee stir stick.
Then I use the stir stick to smear some more JB Weld on top of the metal plate to strengthen it. I have to be careful to keep it off the hinge pin boss in the hinge pin casting so the hinge pins will rotate smoothly after the JB Weld hardens.
Then next day is the moment of truth. The latch works smoothly and closes the lid snugly. 🙂
Repair Missing Ring on Retaining Straps
The retaining straps are pretty tired, and if I can find the right elastic material, I’ll replace them. One strap is missing the metal ring that is used to secure the top and bottom retaining straps together.
I find a washer that just slips inside the metal loop. I slide the retaining strap through the center hole and make a loop around the washer leaving a little extra material at the end. I use “Goop” to glue the retaining strap together and clamp it until it drys.
Now, I can push the washer through the other metal loop and then slide the metal loop back behind the the tab of retaining strap to secure it.
It’s not pretty, but works nicely.
Replacing Sealing Gasket in the Lid
I tested the panniers for water tightness with my garden hose. When I opened them, there is water inside. I replace the worn gasket material with 0.125 inch window screen spline I found at Home Depot.
I use a pick to get the old gasket out and then insert the screen spline into the groove. I use a fat screw driver blade to seat the spline all the way to the bottom of the groove.
Adding Some Shine
I spray on some Aerospace Protectant 303 and then mount the panniers. Much improved.
Two Keys Aren’t Enough 🙁
I have two keys. Each key has a different number stamped on them, “069” and “049”. I tried all the locks and find that the “069” key works in the latch locks of pannier #1 but not in the bag-to-frame mounting lock. On the other bag, pannier #2, the “049” key works in the bag-to-frame mounting lock but not the latch locks. It looks like the groove is more narrow on the “049” key.
In doing some Google searching, it looks like it was typical to have two keys, one for the lid latch lock and one for the bag-to-frame lock. That explains why the 049 key worked on the bag-to-frame latch, but only on one of them. The other bag-to-frame latch looks like it may have been replaced. But, I guess I don’t have the key that fits that lock.
The lock mechanism is supposed to have a key code stamped on them some place. After a lot of looking around, I found it on the edge of the lock mechanism. I find multiple codes are used on these panniers: “069”, “049”, “059”, and “054”. Now I have the mystery solved. The latch locks marked “069” are the latch locks on pannier #1 and they use the “069” key. Pannier #1 has the “054” lock for the bag-to-frame lock and I don’t have that key. Likewise, pannier #2 latch locks are marked “059”, and I don’t have that key, while the bag-to-frame lock is marked “049” and works with the “049” key.
Whewww. I’m sure that some lock mechanisms have been replaced, but only the “069” and “049” keys survived. Very interesting. Bummer. 🙁
I posted a note to the Micapeak Airheads forum about this and learn that the latch locks are no longer available, but, Larry Stonestreet, owner of Stoner’s Beemer Stash [[email protected]; 951-813-1704] has the “054” and “059” keys. So, I will order them from him and then I should be able to lock both bags — using four keys. A PITA, but oh well. I’ll color code them with red dots on the left side keys (port side) and green on the right side (starboard side).