BMW K bikes (Bricks)


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1Back to top Go down    fairing repair on Tue Dec 01, 2015 6:14 pm

1990k75

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So, wondering about the best way to repair minor damage to the K75 fairing...

It's fiberglass - but not mat, just 'rovings' ?

Let's see if I can upload a pic...


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

2Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 6:24 pm

1990k75

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OK, so the pic worked - yay!

Now, is it realistic to repair this in place - or should I go through the whole process of removing that part? Question

And, what's the best way to repair this? - crazy glue, resin, JB weld... & then body filler & much sandpaper?

I'm sure many of you have been through this before, so bring on the wisdom.

Cheers, Lorne & Joanie


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

3Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 6:38 pm

Point-Seven-five

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The fairing is made from bulk molding compound. It is a mix of glass strands in a putty of resin and filler material, probably talc. It is put in a mold and heated which causes the resin molecules to crosslink and thus, solidify. It's how the agitator in your washing machine is made.

As far as repair, I would straighten things as much as possible and saturate the fractures with Polyester resin. Rough shape with 80 grit front and back. Reinforce with a couple layers of resin and fiberglass mat applied to the back side. Fill the surface imperfections on the front side with a polyester based filler. Rough shape with 80 grit and final shape with 150. fill scratches with a filler sanded with 220 followed by 320.

Prime and paint.


__________________________________________________
Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

4Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 6:41 pm

Point-Seven-five

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No way you'll make a decent repair with the part on the bike. you will be working with some messy stuff and need to get at the back of the part. It really isn't all that hard to remove that part. about 10 screws and a couple 6mm bolts hold it on. You can leave the main fairing and the radiator grille.


__________________________________________________
Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

5Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 6:50 pm

92KK 84WW Olaf

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Lorne, that panel comes off very easy. So much nicer to be able to repair it inside in the comfort of home with a beer on the table.

From memory........I have done it so often and when you get used to it only takes about 10 minutes.

1. Open the left side storage box and you see 2 screws to front, 2 on left and also1 each side of the lock mechanism. Take them all out. There is a metal support frame with 4 crosshead screws but you can leave it in place.

2. Bottom of the leg panel, not far from your left toe when its on the footrest there is another screw. Out with that one too.

3. You can now lift out the storage box and the left leg panel. The 2 screws between the box and leg panel often stay in but the box and leg panel will come out together

4. Under the storage box there should be a closure piece about a foot long, closing space between the fairing and the gas tank. Three screws in this. Out them too.

5. At the rear of that panel there is also a closure panel, about 6 x 3 inches, closes the gap between theside of fairing vent panel you want to remove and the air box. 2 screws and off with this too.

6. Now at last you can remove this panel, its got 2 screws at the front, when you look at the radiator straight on, from the front you will see a screw top and bottom facing toward the forks. Out with them.
You now need a 10mm socket and from where your left leg would be there are 2 mountings, with 10mm bolts and various washers. Out with the bolts, hold on to the damaged panel as these are the last 2 fixings.

Now you can assess it but I figure get a spare and sort it out, they are cheap as mostget damaged at some point.

For me its filler such as Isopon, wet and dry rub down, primer, more wet and dry, paint etc. They are made of fiberglass and have a bit of weight.

The little downward leg on those vent panels on my RT were painted black. I think that's a very good idea as they get scuffed and it saves repainting the whole panel. In that location its not easy to see the quality of the painting so it can cover up a less than perfect repair.

Now to do the job you need :-c: Surprised-o:


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

6Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 8:00 pm

robmack

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This should be repairable using techniques developed for repairing boat hulls. Look up the books that are published by Gougeon Brothers, Inc., the firm that makes West System Epoxy. Specifically the book entitled "002-550: Fiberglass Boat Repair & Maintenance", in Chapter 4 "Repairing Damaged Skins", it shows the techniques you're going to use on this repair.


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Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

7Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 8:09 pm

1990k75

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@Point-Seven-five wrote:No way you'll make a decent repair with the part on the bike. you will be working with some messy stuff and need to get at the back of the part. It really isn't all that hard to remove that part. about 10 screws and a couple 6mm bolts hold it on. You can leave the main fairing and the radiator grille.

Yeah, that's what I was expecting... Crying or Very sad

Well, at least the garage is heated... Smile

Wifey Joanie will be thrilled that I'm in the garage & not at the bar (haven't been to a bar in the last 4 years LOL)

Guess I'll begin the fairing dismantling...


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

8Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 8:18 pm

1990k75

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Thanks Olaf & Robmack, I'll try to do a good job & post pics...

Now that I have the paint in hand thanks to Point-Seven-five, nothing to do but bite the bullet & get that fairing piece off Laughing


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

9Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 8:51 pm

92KK 84WW Olaf

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Give a thought to a little black paint in the damaged area to avoid repainting the entire of the red panel. Black is good for hiding the road dirt too.


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

10Back to top Go down    Re: fairing repair on Tue Dec 01, 2015 10:14 pm

indian036

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@92KK 84WW Olaf wrote:Lorne, that panel comes off very easy. So much nicer to be able to repair it inside in the comfort of home with a beer on the table.


Now to do the job you need :-c: Surprised-o:
Lots of good advice here, Lorne, but one thing to consider before you start - check the clearance behind where the repair will be done, especially at the leading edge, to ensure you don't build it up too thick to go back to where it should be on reassembly.

Also, a modification to Olaf's advice:
:-c:Surprised-o:

Bill


__________________________________________________
1985 K100RT VIN 0028991 My original Very Happy (Historic rego)
1985 K100RT VIN 0029036 BOB the Blue Old Bike (Historic rego)
1990 K100LT VIN 0190452 Work in progress
1984 K100RT VIN 0023022 Work needing lots of progress

1986 K100RT VIN 0090542 Work needing lots and lots of progress
1993 K1100LT VIN 0183046 Work in progress
1993 K75S VIN 0213045 Newest toy, slightly non-original
    

11Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 1:41 am

1990k75

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Got it off Smile


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

12Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 1:45 am

1990k75

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And as you can see, took Indian's advice... Beer drinker


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

13Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 3:17 am

charlie99

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some advice if I can add

the material of the fairing is quite prone to breakages in the same place ...even after repairs of sorts (blame flexing )

cut away a lot of the broken material and try to file off some of the thickness on the affected area ....build up the repair in layers that over lay the old stuff with a good amount of extra fiberglass matt that covers a greater area of the good part of the fairing as well .

else you will have cracks appearing around the repair

just what I have experienced

good luck


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cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

14Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 7:45 am

Dai

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One addition to Robmack's link: where it shows scraping the crack out with a pointed tool, use a small rotary ball in the end of a Dremel or similar. It makes for a much more even slot for the filler and unlike the pointed tool, you don't have to put pressure on as the rotary ball will do all the cutting for you. Trust me (or maybe not!) - it does make life easier.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

15Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 5:16 pm

1990k75

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Thanks guys for the added info, I will reinforce with some cloth... Smile


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

16Back to top Go down    Re: fairing repair on Wed Dec 02, 2015 5:22 pm

92KK 84WW Olaf

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You need to watch too in case it overheats so after about a minute apply a teaspoon of PolarIce to the Dremel Operator to reduce the temperature.


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

17Back to top Go down    Re: fairing repair on Thu Apr 21, 2016 11:52 pm

1990k75

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Totally copped out on this one. Winter was dragging on & I was spending a lot of time on the couch... Smile

Took the panel to a local auto-body shop and threw money at them - re-installed the panel (thank you my digital camera) & now ready to ride, as soon as the last snow (yes, still snow here on my birthday April 20th) leaves the driveway Laughing

Thanks to everyone for the help

Cheers, Lorne & Joanie cheers


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

18Back to top Go down    Re: fairing repair on Fri Apr 22, 2016 5:57 am

92KK 84WW Olaf

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Excellent move and probably not a very expensive one.

Glad to see you are sorted, now for a photo?


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

19Back to top Go down    Re: fairing repair on Mon Apr 25, 2016 3:19 pm

Point-Seven-five

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Just did a repair to the same part on my K75RT. Bike got knocked over in the garage and the crash bar broke a 3" x 6" chunk out of the panel right in front of the vents.

Here's how I repaired it:

1. Trimmed the fibres back to where it could get the chunk positioned properly in the panel. Then I used cyanoacrilate glue to hold it securely in place.

2.With the chunk positioned, I carefully scratched up the back side of the panel with 80 grit.

3. After a second dose of C/A glue. I used my Dremel with a wire wheel to clean out the seam for the application of Bondo to make the seam level with the surface of the panel. I carefully sanded the bondo for an even surface.

4. I used a lightweight fiberglass tape 2" wide that I got from a hobby shop. R/C airplane guys use the tape for airplane repairs. I cut 5-6 pieces to make three layers on the back side of the seam between chunk and panel. I put the glass down with polyester resin and a 1" chip brush. Paint the surface with the resin then lay the fitted pieces of glass in place so the fibers are running in different directions. Press down and work the resin into the glass with the brush.

5. With the back side cured the panel is now strong enough to do the cosmetic work on the front. Clean out the seam with the wire wheel in the dremel and fill with bondo. Sand the Bondo, prime, and use a spot putty for minor defects.

6. Paint with base coat and take to a collision shop for the clear coat.

Total time to make the repair was about 4 hours over two days. I didn't stop to take photos. Can't post them here anyway.


__________________________________________________
Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

20Back to top Go down    Re: fairing repair on Mon Apr 25, 2016 10:11 pm

1990k75

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Good work Point-Seven-five, I went right to step 6 LOL.

Our bikes must be drinking in the garage, they keep falling down... Laughing


__________________________________________________
Past bikes - Yamaha YL-1, Honda XL-125, 1967 BSA 650 Lightning

Current - 1990 K75RT (in drydock) & 1995 K75RT VIN # (I'll get back with that)

Who sez I'm too old to ride?
    

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