46 BMW 1983 R100RS Repair Panniers & Plastic

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.

Double Latch Cracks

Double Latch Cracks

Mulitple Corner Cracks

Crushed Corner With Multiple Cracks

Single Latch Crack

Single Latch Crack

Some of the cracks have opened up so there is a gap that needs filling.

Latch Cracks Have Open Gaps

Latch Cracks Have Open Gaps

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.

Plast-Aid and Black Acrylic Paint for Tinting

Plast-Aid and Black Acrylic Paint for Tinting

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.

Black Acrylic Model Paint

Black Acrylic Model Paint

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.

Aluminum Screen Patches

Aluminum Screen Patches

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.

Round Dremel Bit for Widening Back of Crack

Round Dremel Bit for Widening Back of Crack

Engraving Dremel Bit for Creating Texture Pattern

Engraving Dremel Bit for Creating Texture Pattern (Not So Good. See Later Bit Choice)

Dremel Engraving Tool #106-A Bit Too Big, #105 Maybe Best Choice

Dremel Engraving Tool #106-A Bit Too Big, #105 Maybe Best Choice

I use some steel picks to help clean out the cracks and to help create the texture pattern.

Pick To Help Create Texture Pattern and Clean Off Excess Plast-aid

Pick To Help Create Texture Pattern and Clean Off Excess Plast-aid

Toothpick End Dimpling Plast-Aid

Toothpick End Dimpling Plast-Aid

The cases are discolored and stained. I use Forever Black to restore the original luster to them.

Forever Black Plastic Restoration

Forever Black Plastic Restoration

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.

Mineral Spirits Loosens Paint Scuffs

Mineral Spirits Loosens Paint Scuffs

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.

Pick Loosens Paint in Textured Area

Pick Loosens Paint in Textured Area

Paint Scuff Removed

Paint Scuff Removed

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.

Inside Crack Edges Opened Up With Cross Grooves

Inside Crack Edges Opened Up With Cross Grooves

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.

Improving Plast-Aid Adhesion Inside Cracks

Improving Plast-Aid Adhesion Inside Cracks

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).

Adding Black Acrylic Paint (2 -8 Drops Depending on Quantity)

Adding Black Acrylic Paint (2 -8 Drops Depending on Quantity)

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.

Mixed Plast-Aid with Acrylic Color

Mixed Plast-Aid with Acrylic Color

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.

Dripping Liquid Plast-aid To Fill Outside Cracks

Dripping Liquid Plast-aid To Fill Outside Cracks

Then I used the Popsicle stick and painted Plast-aid in the grooves on the back of the crack inside the pannier.

Plast-aid Fills Filling Inside Grooves

Plast-aid Fills Filling Inside Grooves

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.

Using Pick to Remove Excess Plast-Aid

Using Pick to Remove Excess Plast-Aid

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.

Aluminum Screen Patches Hooked Together

Aluminum Screen Patches Hooked Together

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.

Aluminum Screen Patch on Inside Reinforces Repair

Aluminum Screen Patch on Inside Reinforces Repair

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. 🙁

Crack Repair-Edges Not Even

Crack Repair-Edges Not Even

Corner Repair-Low Spots and Edges Show

Corner Repair-Low Spots and Edges Show

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.

One Gallon Milk Jug

One Gallon Milk Jug

Textured Plastic at Bottom

Textured Plastic at Bottom

Cutting Out Texture Template

Cutting Out Texture Template

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.

Hand Pressed Milk Jug Texturing

Hand Pressed Milk Jug Texturing

Hand Pressed Milk Jug Texturing

Hand Pressed Milk Jug Texturing

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.

Textured Milk Jug Attached to Blocks

Textured Milk Jug Attached to Blocks

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.

Clamping the Bag with Texturing Blocks

Clamping the Bag with Texturing Blocks

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. 🙁

Better But Crack Edge Still Visible

Better But Crack Edge Still Visible

Not A Good Job Filling Front of Crack

Not A Good Job Filling Front of 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.

Toothpick To Add Plast-aid to Crack and Using End to Add Texturing

Toothpick To Add Plast-aid to Crack and Using End to Add Texturing

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.

Pick To Create Groves for Texturing

Pick To Create Groves for Texturing

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.

Finished Crack Repair-Dimples A Little Too Deep

Finished Crack Repair-Dimples A Little Too Deep

Finished Single Crack Repair-Very Good Match

Finished Single Crack Repair-Very Good Match

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.

Finished Single Crack Repair-Blends in Pretty Well

Finished Single Crack Repair-Blends in Pretty Well

Finished Crack Repair On Crushed Corner

Finished Crack Repair On Crushed Corner

In this repair, the dimples are too deep. I’ll fill these in with Plast-aid and redo them.

Crack Repair But Dremel Dimples are Too Deep

Crack Repair But Dremel Dimples are Too Deep

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.

Dremel Engraving Tool #106-A Bit Too Big

Dremel Engraving Tool #106-A Bit Too Big

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.

Double Latch Crack Final Repair

Double Latch Crack Final Repair

Crushed Corner Final Repair

Crushed Corner Final Repair

Crushed Corner Final Repair

Crushed Corner Final Repair

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.

Original Lock Mechanism Hinge Plate Riveted to Latch Casting

Original Lock Mechanism Hinge Plate Riveted to Latch Casting

Lock Mechanism with Broken Top Plate on Latch Casting

Lock Mechanism with Broken Top Plate on Latch Casting

Latch Casting Missing Top Plate To Secure Lock Mechanism

Latch Casting Missing Top Plate To Secure Lock 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.

Lock Mechanism Pins In Hinge Slots of Latch Casting

Lock Mechanism Pins In Hinge Slots of Latch Casting

Lock Mechanism Slides Into Hinge Pin Slots of Latch Casting

Lock Mechanism Slides Into Hinge Pin Slots of Latch Casting

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.

Using Evaporated Milk Can Lid For New Top Plate

Using Evaporated Milk Can Lid For New Top Plate

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.

Rough Cut of Lock Mechanism Hinge Pin Top Plate Patch

Rough Cut of Lock Mechanism Hinge Pin Top Plate Patch

Final Top Plate Patch for Lock Mechanism Hinge Pins

Final Top Plate Patch for Lock Mechanism Hinge Pins

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.

JB Weld Applied to Lock Mechanism Hinge Plate

JB Weld Applied to Lock Mechanism Hinge Plate

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.

Propping Bag Open so Gravity is My Friend

Propping Bag Open so Gravity is My Friend

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.

Top Plate Patch In Place on top of JB Weld

Top Plate Patch In Place on top of JB Weld

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.

JB Weld Over Top  of Metal Plate To Strengthen It, But Not on Hinge Boss

JB Weld Over Top of Metal Plate To Strengthen It, But Not on Hinge Boss

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.

Original Metal Loop for Fastening Two Retaining Straps Together

Original Metal Loop for Fastening Two 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.

Strap Pulled Through Washer With Excess Making a Tab & Glued Together

Strap Pulled Through Washer With Excess Making a Tab & Glued Together

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.

Insert Washer Through Ring

Insert Washer Through Ring

Slide Original Ring Behind Loop to Secure the Retaining Straps

Slide Original Ring Behind Loop to Secure the Retaining Straps

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.

Screen Door Gasket - 0.125 Inch Diameter

Screen Door Gasket – 0.125 Inch Diameter

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.

Gasket Inserted into Groove

Gasket Inserted into Groove

Seating Gasket In Groove With Screw Driver Blade

Seating Window Screen Spline In Groove With Screw Driver Blade

Adding Some Shine

I spray on some Aerospace Protectant 303 and then mount the panniers.  Much improved.

Aerospace Protectant 303

Aerospace Protectant 303

Panniers Mounted

Panniers Mounted

Panniers Mounted

Panniers Mounted

Panniers Mounted

Panniers Mounted

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.

Pannier #1 Latch Locks Use Key #069

Pannier #1 Latch Locks Use Key #069

Pannier #1 Bag-to-Frame Lock Uses Key #059

Pannier #1 Bag-to-Frame Lock Uses Key #059

Pannier #2 Latch Locks Use Key #054

Pannier #2 Latch Locks Use Key #054

Pannier #2 Bag-to-Frame Lock Uses Key #049

Pannier #2 Bag-to-Frame Lock Uses Key #049

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).

3 thoughts on “46 BMW 1983 R100RS Repair Panniers & Plastic

  1. Good job! I had my 84 R80RT in storage for several years and lost track of all but one ignition key. I did get a folding blank from a local dealer and had a copy cut. My bags had the 042 code and I got one key from a shop in San Diego and one from Dunbar’s in New England. The bike is being shipped to me from WA to CO and should be here next week.

Leave a Reply

Your email address will not be published. Required fields are marked *