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Author Topic: Fixing those cracked side covers  (Read 2780 times)

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Offline tennesseebreeze

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Fixing those cracked side covers
« on: November 18, 2014, 06:04:11 am »
I'm going to share my best kept material secret here and tell you how I fixed my cracked side covers. The covers on my '73 cb500 build had been cracked in a few places and one of the posts that hold them to the frame had been broken completely off. The p.o. had used hot glue to stick it back on. They had filled the cracks with hot glue as well. It took some doing, but I removed the hot glue and used an adhesive method that an old carpenter had taught me.

What you do is use baking soda and super glue in combination to produce an exceedingly tough fix. The baking soda acts as a catalyst for the glue, both thickening it and creating a matrix of sorts. You can build up layers of the material by first dropping the baking soda onto the back side of the side cover on the place that needs repairing. You can tap the cover with your finger to spread the soda evenly. Then you drip the super glue onto the baking soda and it absorbs it and hardens quickly. There are different thicknesses of super glue available and the thin stuff absorbs into the soda easier. I had the thick stuff but dripped it from a little of a height so gravity would aid in the glue penetrating into the soda. You can repeat the process and build up the material as thick as you like. The result is a structural fix that is tougher than the surrounding material. If you end up sanding the piece be careful, it does send off some pretty noxious gases.   
'79 CB750F, '73 CB500K2, '78 CB400A, '71 CL100

Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #1 on: November 18, 2014, 06:10:29 am »
This is a new fix for me,I imagine if I would do this I'd use the thicker 'gel' type super glue.That super glue eats up paint,etc. if it runs down onto it. How's it holding up for you ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline tennesseebreeze

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Re: Fixing those cracked side covers
« Reply #2 on: November 18, 2014, 06:15:45 am »
Like I said the thick stuff has a hard time absorbing into the soda, so my solution would be use the gel stuff first without the soda to seal up the crack, then a layer of soda and some of the thinner stuff. It's holding up really well and seems to adhere to the plastic much more readily than something like JB Weld or other epoxies. The great thing about it too is that the glue pretty much goes where there is soda, so if you are careful, it can be a very clean fix.
'79 CB750F, '73 CB500K2, '78 CB400A, '71 CL100

Offline tennesseebreeze

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Re: Fixing those cracked side covers
« Reply #3 on: November 18, 2014, 06:26:09 am »
You can also do the reverse. Put super glue down and catalyze it quickly by sprinkling the baking soda on top of it. Then just blow away the excess powder.
'79 CB750F, '73 CB500K2, '78 CB400A, '71 CL100

Offline evanphi

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Re: Fixing those cracked side covers
« Reply #4 on: November 18, 2014, 06:57:03 am »
I had just heard of this trick recently a well! Works great!
--Evan

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Offline strynboen

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Re: Fixing those cracked side covers
« Reply #5 on: November 18, 2014, 08:16:51 am »
i use lego..put soms block (in a color fit )in a glass and fill some acetone in..it melts and can be filled in as glue or fill holes ..then it harden for some days and the plastic can be vorked onn

chain gards vork fine..and other soft plastic types can be fixed.. sidecovers on my 500 t...vas a easy fix.


.tryed some hard plastic on my yamaha dt..it dont work vell on that..i just can pull it off...so dont vork on all types
i kan not speak english/but trying!!
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Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #6 on: November 18, 2014, 09:32:21 am »
You can also do the reverse. Put super glue down and catalyze it quickly by sprinkling the baking soda on top of it. Then just blow away the excess powder.

Does the baking soda kind of attract/absorb the thin/light super glue so it doesn't tend to run down the work ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline 70CB750

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Re: Fixing those cracked side covers
« Reply #7 on: November 18, 2014, 09:57:49 am »
I have a sidecover to fix, I will try it.

Offline Maurice

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Re: Fixing those cracked side covers
« Reply #8 on: November 18, 2014, 10:08:27 am »
i use lego..put soms block (in a color fit )in a glass and fill some acetone in..it melts and can be filled in as glue or fill holes ..then it harden for some days and the plastic can be vorked onn

chain gards vork fine..and other soft plastic types can be fixed.. sidecovers on my 500 t...vas a easy fix.


.tryed some hard plastic on my yamaha dt..it dont work vell on that..i just can pull it off...so dont vork on all types

This.

A lot of times these plastics are ABS, so using acetone, or ABS glue from the hardware store (which is nothing other than acetone + dissolved ABS) results in a perfect bond.

I've re-made cover a cover spigot like this on my NT650 by molding an existing one with silicone, then "glued" the "new" spigot back onto the cover. Still holding to this day, despite the vibratory nature of the bike.

Offline tennesseebreeze

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Re: Fixing those cracked side covers
« Reply #9 on: November 18, 2014, 11:14:34 am »
You can also do the reverse. Put super glue down and catalyze it quickly by sprinkling the baking soda on top of it. Then just blow away the excess powder.

Does the baking soda kind of attract/absorb the thin/light super glue so it doesn't tend to run down the work ?

Exactly. If you apply it drop by drop you can control it well.
'79 CB750F, '73 CB500K2, '78 CB400A, '71 CL100

Offline Head

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Re: Fixing those cracked side covers
« Reply #10 on: May 06, 2016, 11:53:12 am »
I was reading this, I have been using Plast-Aid, Works very nice as it bonds the plastic together. Plast-Aid.com.
« Last Edit: May 06, 2016, 02:27:10 pm by Head »
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
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Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #11 on: May 06, 2016, 12:14:18 pm »
I was reading this, I have been using Plast-Aid, Works very nice as it bond the plastic together. Plast-Aid.com.

That looks like good stuff,have you tried using it to fill pit marks in steel or aluminum? will it bond to a fork tube and then be able to be sanded ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline BobbyR

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Re: Fixing those cracked side covers
« Reply #12 on: May 06, 2016, 02:12:00 pm »
I was reading this, I have been using Plast-Aid, Works very nice as it bond the plastic together. Plast-Aid.com.

That looks like good stuff,have you tried using it to fill pit marks in steel or aluminum? will it bond to a fork tube and then be able to be sanded ?
For a fork tube you clean the defects complety and then put straight crazy glue into the defect. Let it harden overnight. You can wet sand the fork using ATF and very fine paper in a shoeshine motion. You should  finish with Mothers chrome polish.  Old time wrenches will tell you if you run your fingernail over the fork and you feel a defect, you will get a leak.

@Tennessee, that is a very clever solution with the baking soda.
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Offline Head

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Re: Fixing those cracked side covers
« Reply #13 on: May 06, 2016, 02:31:29 pm »
I have not try tried or even thought about doing any thing with metal. That thought is making me think now!
 
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
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Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #14 on: May 06, 2016, 06:21:49 pm »
I was reading this, I have been using Plast-Aid, Works very nice as it bond the plastic together. Plast-Aid.com.

That looks like good stuff,have you tried using it to fill pit marks in steel or aluminum? will it bond to a fork tube and then be able to be sanded ?
For a fork tube you clean the defects complety and then put straight crazy glue into the defect. Let it harden overnight. You can wet sand the fork using ATF and very fine paper in a shoeshine motion. You should  finish with Mothers chrome polish.  Old time wrenches will tell you if you run your fingernail over the fork and you feel a defect, you will get a leak.

@Tennessee, that is a very clever solution with the baking soda.

Thanks Bobby  :) !
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline b52bombardier1

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Re: Fixing those cracked side covers
« Reply #15 on: May 06, 2016, 07:20:48 pm »
  My 72 Honda CL100 had a large crack in a side cover that I fixed using a strategically placed layer or two of fiberglass on the backside.  This not only fixes the crack but strengthens the entire piece against future breaks . . . invisibly to anybody but you. 

  And almost any automotive fiberglass repair kit will have plenty of extra material to strengthen the cover on the opposite side of the bike and that next bike that we are all looking for.

Rick
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1972 Candy Yellow CL100 K2
1972 Candy Jet Green Honda CB500
1973 Mighty Green ST90 K0
1974 Mars Orange CT90 K5
1975 Topaz Orange ST90 K2
1976 Shiny Orange CT90
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Offline nvr2old

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Re: Fixing those cracked side covers
« Reply #16 on: May 29, 2016, 10:42:53 am »
I've repaired plastic side covers with great success with 2-part epoxy found at any hardware store.  Groove out the cracks with a dremel or sandpaper. apply to both sides, wait 15 minutes and sand smooth.  Simple, permanent repair.
'76 CB550F-'72 XL250-'82 MB5-'82 CX500 Turbo-'77 naked Goldwing-'75 CB400F cafe'-'79 Suzuki GS1000S..hey, it's a Wes Cooley..

Offline Head

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Re: Fixing those cracked side covers
« Reply #17 on: December 02, 2016, 06:48:18 pm »
I was reading this post and for and update, Using the PLAS-TEX I was able to 2 make new posts on 2 side covers and it works just like original. 4 posts total.
Head
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
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Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #18 on: December 05, 2016, 08:21:12 am »
I was reading this post and for and update, Using the PLAS-TEX I was able to 2 make new posts on 2 side covers and it works just like original. 4 posts total.
Head

Do you have any pics ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline Head

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Re: Fixing those cracked side covers
« Reply #19 on: December 05, 2016, 10:01:09 am »
Not yet, I'll try to get some and post.
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
NOTICE Due to current financial restraints the
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Offline strynboen

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Re: Fixing those cracked side covers
« Reply #20 on: December 06, 2016, 03:41:04 am »
fiber glass,,is so damed heavy..and often not melt to the plastic..so it loosen after some time
i kan not speak english/but trying!!
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Offline Head

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Re: Fixing those cracked side covers
« Reply #21 on: January 06, 2017, 05:20:52 pm »
Here is a pic of my first try making a new post for a side cover,as strong as new! This is now a piece of the side cover not glued together. The next 2 pic's show the area of the back side of the cover 1st ,what is in white is the4 area that was not there,2nd showing the front side after finishing and some paint. Strong like new.
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
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Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #22 on: January 07, 2017, 10:23:19 am »
Those sidecovers look good,Plast-aid ? Did you need to rough-up all the orig. ABS quite a bit for it to bond well ?
What types of 'Prep' did you do to the orig. sidecovers ? I like it  8)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline Head

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Re: Fixing those cracked side covers
« Reply #23 on: January 11, 2017, 11:49:18 am »
I just lightly sanded, Mixed some plast-aid up to the consistency that I wanted and then put a tiny bit of the liquid on the side cover to get the surface ready then form a pillar and pressed and formed it. Let it dry, then formed with a rasps and sand paper. For filling cracks I use a Dremel to slightly valley out the crack. Then use a clean tube, From spray cans such as Brake Clean to get the liquid just in the crack to soften the area and trying not to get to over flow past the crack Next I used a larger tube from a Windex bottle that was pushed into the powder and tapped it with my finger so the powder would fall from the tube in to the crack only so as not to have it all over the surrounding surface. Let it set up and do it again till it was level or slightly above the surface and rasp, sand till I like it. Look at Plast-aid.com for so more info. It takes some getting used to to get the consistency right. I hope this helps with out pic's It is hard trying to explain with just words some times. If I can I'll try to post some pic's of the procedure. I also did a repair of a cb900f side cover that was broke in half, came out nice and solid.
1970x2,71,72,74,75K's,75F-FO-750ss, 2 x 75 GL1000, 77 GL1000,  3x 1981 CB900F, 74 550,  1966 CL77 305, 1967 CL77 305, 1974 MX360 Yamerhamer, 1983 CB1100F RED
NOTICE Due to current financial restraints the
Light at the end of the tunnel will be turned off until further notice!! sohc member#1522

Offline grcamna2

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Re: Fixing those cracked side covers
« Reply #24 on: January 12, 2017, 09:05:49 am »
I just lightly sanded, Mixed some plast-aid up to the consistency that I wanted and then put a tiny bit of the liquid on the side cover to get the surface ready then form a pillar and pressed and formed it. Let it dry, then formed with a rasps and sand paper. For filling cracks I use a Dremel to slightly valley out the crack. Then use a clean tube, From spray cans such as Brake Clean to get the liquid just in the crack to soften the area and trying not to get to over flow past the crack Next I used a larger tube from a Windex bottle that was pushed into the powder and tapped it with my finger so the powder would fall from the tube in to the crack only so as not to have it all over the surrounding surface. Let it set up and do it again till it was level or slightly above the surface and rasp, sand till I like it. Look at Plast-aid.com for so more info. It takes some getting used to to get the consistency right. I hope this helps with out pic's It is hard trying to explain with just words some times. If I can I'll try to post some pic's of the procedure. I also did a repair of a cb900f side cover that was broke in half, came out nice and solid.

Yes,
Thanks for the explanation/procedures.  ;)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

 

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