Topic: How to repair cracked sidecovers

[Raul CB750K1]

A friend of mine showed me the results of a trick he was told. I was so amazed but hoped never to need to put it to the test.

Unfortunately I have had to do it before I would have ever wanted, as I dropped my bike a couple of weeks ago.

Obviously you need to pick up every single chip and piece of the cracked part and compose the jigsaw. Just use a little drop of loctite to hold everything into place

[Raul CB750K1]

From the inside, cover the crack with loctite and quickly cover the glue with baking soda -I learnt this trick in this forum- Please note that in this example, there is a part where the blinker stem attaches to, so the plastic must be flat. In that point, a big amount of material is not desirable.

[Raul CB750K1]

Now is where the unusual part comes. You will need a discarded sidecover of the same material and some acetone, but not the one to clean nail polish, but the industrial type -bought mine in a paint shop-. Cut some little pieces of the old sidecover and put them in a closed recipient with the acetone, just enough to cover the pieces. Don't worry about the paint, just let it soak for some hours or even one day. The acetone will dissolve the plastic and leave a messy goo.

We will use this goo to glue the crack. The acetone will eat through the sidecover-to-be-repaired, melting the plastic together. It takes a couple of days -even more- to fully cure, as the acetone from the outside evaporates quickly while inside dries slowly. Look at the pictures how the colour of the glue changes as it dries. Also, make sure the part to be glued is flat, as the goo tends to slip.

[Raul CB750K1]

See these pictures to notice the change in color with the passing hours/days -just put some goo there even if not needed, to check how hard it stuck. Impossible to remove it with an x-acto knife, it just melted with the plastic as if it was the same.

The reason to cover the whole crack with loctite -super-glue- is to avoid the acetone to go past the crack and ruin the paint in the other side of the crack.

[Raul CB750K1]

And finally, to touch up the paint, just used the closest match in nail polish I found at a Dollar Tree -well, the spanish equivalent-. Be aware that nail polish have solvent, so if you paint over your paint, it will eat it up in seconds, so no chance to wipe it out.

[Spikeybike]

welcome back raul, this is a nice trick , haven't heard the baking soda version though .... whats that all about

[Ecosse]

welcome back raul, this is a nice trick , haven't heard the baking soda version though .... whats that all about

+1  

what if you wanted to repaint/finish the "pretty" side, could you goop it and sand it down for filler etc...?

oh yeah, thanks for the tip!

[Raul CB750K1]

I think I read about the baking soda from Terry in Australia. The idea is to pour some baking soda over the liquid super-glue. It reacts and form a hard compound that reinforces the union. i used it first in a battery cover from my TV remote -you know, they spend more time on the floor than on the couch. In the inside, with a knife, I cut the edges slightly at an angle, in such a way that when both parts are put together there is a slight groove instead of a hairline crack. Glue the parts together as usual, and then, pour superglue over the groove and baking soda over it. It will dry in seconds, blow the excess away and you are done. In fact, next time the remote fell, it broke at a different place, not at the repaired crack.

About using the acetone-plastic to repair the "pretty side", I think you can do it, but painters will surely have better options such as filler and the like, that you can sand and smooth out. This is intended to be a cheap solution, that reinforces the piece from the inside if you can live with a cracked cover instead of having it painted -or before you have it painted-

[mystic_1]

I think it was Industrial Cafe who had a thread about modifying a seat cowl using the acetone-and-shavings technique.  He had problems with the edges of his repair when the part was heated in the sun several days after repair.  He was getting a ridge where the edge of the repair was.  Don't remember how it turned out but I think his theory was that the inside wasn't completely dry.  So, one might consider building up a repair like this in layers allowing several days drying time between them. 

mystic_1

[MoTo-BunnY]

I 'rebuilt' the badly cracked corner of my side cover using that 5 ton, two part epoxy that comes in those double syringe thingies?  I soaked a strip of fiberglass cloth with the epoxy and also put it generously over the afflicted area, then applied the patch (after I had cleaned the area well with alcohol solvent). It's rock hard now and the fiberglass really reinforces the multiple cracked area nicely. I could have even sanded it down smooth, like you would with fiberglass, but I didn't bother given that it's all hidden.

I'm sure the super glue and soda tricks works great but I don't know if I would trust it on such a broken up area, as shown in the first pictures of this post? Breaks that bad are repaired much stronger with a reinforcement backing material along with the glue, in my opinion.



(by the way, the odd  reddish tint is from the piece of cardboard I prepped the patch on - the epoxy picked up some of the dye, otherwise it would all be beige)