Topic: How would you repair cracks on sidecovers?

[mazingerzeca]

Hello all.
I have a crack on the right sidecover of my 78' cb 750. Is the charasteristic crack on these covers, close one of the attachments and goes to the center of the cover. I've repaired some other covers with epoxy (the generic one), but I could not find a specific one for this kind of plastics so I used generic Araldit. I went to marine shops and so on but nothing. Do you know any brand to repair these covers with the necessary resistance for putting on and off the covers on the bike? Thank you.

[mazingerzeca]

The two components epoxy used on other covers.

[mick750F]

   This has been covered a few times, most recently at this thread... http://www.sohc4.us/forums/index.php?topic=17664.0 ...The baking soda and superglue method works very well.

Mike

[paxtonpony]

I used fiberglass on mine.  I taped the outside to hold everything in place then ran fiberglass on the inside.  You can buy fiberglass kits at wal-mart.  I wouldn't worry about skill level because it's going to be on the inside and noone will see it anyway.  I'll post pics of my project when I get home.  I accidentally ran over mine (long story) and it was in 30+ pieces.  Having never worked with fiberglass or bondo I was a little worried how it would turn out.  It actually came out realy good.  Had to tell something happened to it.

[ttr400]

I'll second the baking soda and super glue....works like a charm.

Kevin

[mazingerzeca]

I'll second the baking soda and super glue....works like a charm.

Kevin

I think I'll try this. And will be less visible.

[TwoTired]

Here's a CB550 cover I repaired with hobby shop epoxy in the very early eighties.  It's still good!

Baking soda is a good filler but is not as strong and the parent glue.  Today, I would use thin CA (watery type) to wick into the crack.  Then I would run a bead of thick viscous CA to bridge the crack, and then squirt it with accelerator.  Of course, clean the bonding surface first.

Then I would get new grommets for the frame to keep side cover cracking at bay.  They are cheaper than side covers.

Cheers,

[kghost]

Personall I shave an old sidecover down into MEK.

After it melts I use the resultant goop to repair the side cover.

[TwoTired]

Personall I shave an old sidecover down into MEK.

After it melts I use the resultant goop to repair the side cover.

That's a good repair process.  But, MEK will probably attack the paint and the decals.  If you are committed to repaint, though...

Cheers,

[mazingerzeca]

Hello. Thanks for fast replies.
Sorry for my ignorance, but what is CA and MEK?
Cheers.

[TwoTired]

CA =  Cyanoacrylate glue.  Also, called super glue.  Get this at a hobby shop with a reasonable turnover.  CA has a shelf life of about 6 Months. Then it slowly hardens (thickens) in the bottle.
A good Hobby shop will have several viscosities.

MEK= Methyl Ethyl Ketone  = solvent found in hardware stores.

Cheers,

[drlarryw]

Being a simpleton, I gravitate toward simple fixes. [like molasses to clean out the gas tank].  With cracked sidecovers, I've had luck with a product called, fittingly, "GOOP". It comes in a squeeze tube, I apply generously to the inside of the sidecover [after making sure of alignment].  It dries very strong and remains flexible, allowing it to bend with the cover.  I've sanded and painted the sidecovers with either textured or "hammer finish" paints and they look great!
Larry of Simpleville

[kghost]

Personall I shave an old sidecover down into MEK.

After it melts I use the resultant goop to repair the side cover.

That's a good repair process.  But, MEK will probably attack the paint and the decals.  If you are committed to repaint, though...

Cheers,

I just use the resultant goop.

I stop drill and use some additional holes depending on the severity of the crack

Just lay it in with a small paint brush. Build up the layers as the solvent flashes off.

[slarty-bart-farst]

Get a bowel of water ready. Cut and bend a piece of perforated steel mesh or make your own by drilling loads of holes in a piece of steel plate say 1/32 or 1mm, heat it up to just goin blue place the side pannel of a flat surface upside down. place heated steel behind the crack n press so melted plastic comes through the holes then shift the whole lot into the cold water quick. Job done.....is v strong mines lasted 30 years!!!

[c_kyle]

   This has been covered a few times, most recently at this thread... http://www.sohc4.us/forums/index.php?topic=17664.0 ...The baking soda and superglue method works very well.

Mike

http://www.sohc4.us/gallery/v/members/personal/Wulfshrunting/SideCoverRepair_Ready/

Here's a link to my gallery; I've added the pics of my repaired side cover.  I used a plastic welder and a baking soda/super glue concoction.  Here are the steps:

Clean the hell out of the side cover with Dawn.

Sand about 1" on each side of the crack, both front and back.

Drill small hole at end of crack, approximately 1/16" (basically, smaller diameter than the welding rod).

Clean the side cover with alcohol.

Feather (bevel) the edge of the crack (I did both sides).

Fold aluminum foil into a 1" strip, and tape it to the front of the side cover, covering the crack.

Weld the back side of the cover with the plastic welder.

Remove the aluminum foil and clean the side cover with alcohol.

Pour the baking soda into the front side of the crack.

Pour super glue on top of the baking soda.

Smooth over with a razor blade.

Sand, sand, sand.

[aptech77]

Careful.......MEK is BAD, BAD, STUFF..............

[paxtonpony]

OK here's the pics.  I forgot to take a pic before I glassed it all back together but you can tell from the picture it was busted into ALOT of pieces.





Here's the back.  I know, it's some really crappy glass work but I haven't played with the stuff in probably 15 years.





Here's what it looks like after bondo and a rattle can paint job.  Not bad considering I haven't messed with bondo in 15 years either.  Came out really good after I wet sanded and polished it.  I was a little worried when I started because black shows every flaw but I'm really happy and proud of my work.

[Bob Wessner]

An impressive transformation, nice work.

[medic09]

Nice.

Wanna do mine? 

[GNXFan]

That really turned out well considering where you started. Great job!

[mazingerzeca]

Here's what it looks like after bondo and a rattle can paint job.  Not bad considering I haven't messed with bondo in 15 years either.  Came out really good after I wet sanded and polished it.  I was a little worried when I started because black shows every flaw but I'm really happy and proud of my work.

Nice job. Even if broken like a chinese Ming Dinasty bass it can be repaired with fiberglass. I will try a less ambitious job, with Baking soda and Cyanochrilate adhesive.
Cheers.

[paxtonpony]

Thanks guys!  I'm pretty proud of my finished product.  Was almost funny when it happened.  I had just goten a right side cover (bought the bike with only a left side) off of e-bay for 20 and was getting ready to paint it when I broke the left side.  I had the cover off while I was working on the electrics and I scooted it underneath the bike to make sure I didn't step on it and break it.  Well, I went to move the bike, brought it off the center stand and totally forgot the cover was under there.  In hind sight, I think I would have made out much better had I stepped on it.
Either way, it turned out well.  I'm still amazed at how good it came out because I had (have) no skill at doing any form of body work.

[paxtonpony]

Damn, not even a week passed and the damn thing blew off on the highway.  Didn't even know it till I got home.  Luckily I found it not far from where I started, better yet it's still in one piece.  A little scuffed and a few chips but better than I expected.  I need to figure out a way to pin these damn things in so they don't blow off again.

[TwoTired]

Replace the frame grommets and they will hold your cover on.

Cheers,

[Terry in Australia]

Nice Job Paxty, you're a natural body man, that sidecover looks great.

Only problem with adding all that fibreglass, bondo, metal, flywire etc etc, is that it also adds extra weight, so it's more likely that it'll fall off again, so you'll either damage it, or lose it completely.

I gave all those other methods the arrse after discovering the "super-glue and baking soda" method, it's the best, full stop. It's so strong that the cover might break again on either side of the repair, but the repair will stay put, and it's lighter than the parent material and can be "wet rubbed" back to the surrounding material so it looks "OEM" on both sides.

Anyone who says it's not the best, hasn't tried it. Cheers, Terry.