Side cover repair

[steven c]

they  The lower tab on my 77 LeMans side cover  broke, which is what they seem  to do. Has anyone tried using Super Glue and baking soda to make up the part that broke off? Watch a few Youtubes on it and it looks like it would work depending on the plastic. I was thinking of backing it up with some screen to give it some structure.

[Matt Story]

I think a key question is, what type of plastic are they made from?  I don't have a lemans or have ever looked closely at a side cover.  Are these the type of tabs that snap into rubber grommets as is typical on the jap bikes?

I have seen a number of plastic parts where attempted repairs failed, and the chosen glue further complicated subsequent repairs.  You definitely want to get it right the first time.  All that said, I don't find super glue to be very good on pieces with high tensile loads (and small bonding areas) like side cover mounting tabs.  I am more in the camp of chemical bonding, epoxy or fiberglas.  In general, if the bonding area can be maximized, all the better.

[Dirk_S]

I’ve yet to do it on a side cover, but for cracks I’ve had success plastic-welding like Delboy shows in the video below:

https://youtu.be/61iyLarL258

Have you considered Plastex? I think I have some lying around, but if so, I haven’t used it to offer any opinion on it. Seems like it works, though.

https://youtu.be/dIPyDh-1_UI

[guzzisteve]

My quest in the 80's & 90's was to find out what kind of glue works on the regurgitated plastic they use for sidecovers. I was using a Loctite product on making orings up in a kit. I tried it on a cover & it worked great. So, I go to bearing house to get more and the guy says try this other product. Loctite 495 is the best I've found, bonds excellent but isn't cheap. Good Luck.  Not sold at supermarket.

[steven c]

 Well the main problem is I am missing half the tab which has a rubber grommet in it that slides on a pin. So I have to recreate that missing half. I also have read some to use JB weld.

[80CX100]

     I've never done it myself, but I have seen photos of repairs where an appropriate sized washer was layered into the repair to give it some extra strength and backing.

     It may be a tough search, but there have been posts of some very fine repairs; I think Canuck750 may have done a few of those, idk?

     One of my bikes with a missing tab has a very redneck repair done by a po, a tiny hole drilled out of sight and a small zip tie used to secure it in place, it may not be pretty, but I don't have to worry about losing my side cover. fwiw

      Good luck

       Kelly

[guzzisteve]

I have a stick of CRC Minute Mend Epoxy Putty, shape it any way you want, gets rock hard.

[Air-Cooled]

They must be prone to breakage because they make aftermarket fiberglass replicas:

https://www.ebay.com/itm/Moto-Guzzi-Lemans-SIDE-COVER-SET-850-1000-CX100-1447-6250-1447-6350/183755569366?epid=1190320606&hash=item2ac8af78d6:g:Y6UAAOSwdaVcU3DQ

[Wayne Orwig]

I have used superglue and baking soda often. But it can be brittle.
I have repaired side cover broke tabs with a bit of fiberglass cloth and JB weld. That usually works very well.

[Antietam Classic Cycle]

https://www.mgcycle.com/index.php?main_page=product_info&cPath=288&products_id=542
https://www.mgcycle.com/index.php?main_page=product_info&cPath=288&products_id=543

[blackcat]

I have used Plast-Aide on the side cover tabs on my CX without any issues. I didn't get a perfect result but with black side panel covers it's hard to see the imperfections. Mine have only broken in the cold of winter so I've made sure that the tabs have plenty of grease to cut down on the chances of them breaking.

[steven c]

 I really don't want a repo just yet if I can fix this one. I never heard of Plast-aid looks interesting.

[cliffrod]

The Plast Aide reminds me of a silicone mold backing product that Ive used and liked a lot for certain projects.  It was light yellow/butter colored and seemed to had some nominal filament in it. Came as a paste that was firm enough to hold shape and stay in place.  Very strong but it Didn't harden to a completely rigid or brittle state.   I thought it was called Plastex but what ive found online under than name looked different.  Will do some looking and try to find out more info to post.

Whatever you do use, you'll get more durable results by extending the reinforcement on the part.  If you simply try to do a butt joint repair with adhesive, I doubt it will last.

Edit- the product I have used is Plasti Paste by Smooth On.  Smooth On is a major industrial-level professional products company.  Excellent products.  Unless there is a comparable well-recommended auto body-specific professional product, this is what I would use before going with anything off the shelf at the local parts store.  Link https://www.smooth-on.com/product-line/plasti-paste-series/. They may offer a small sample quantity if you ask.

More to consider is what the product you use is engineered in terms of compatibility.  Some adhesives will size/shrink in a way that overwhelms the substrate and the original surface will delaminate when the added product cures.    The new product may have an acid or solvent component to enhance adhesion that damages the substrate. Both are common reasons for failures.

[LowRyter]

My body shop guy uses a 2 part plastic repair.  It's probably stronger than the original plastic and you shape, sculpt and sand. 

I have posted photos here and listed the product for the plastic repair on my Greenie.   Sorry, just can't find it.

[john fish]

My body shop guy uses a 2 part plastic repair.  It's probably stronger than the original plastic and you shape, sculpt and sand. 

I have posted photos here and listed the product for the plastic repair on my Greenie.   Sorry, just can't find it.

Is this it, John?

https://www.amazon.com/dp/B01IBOK7FE?psc=1&ref=ppx_pop_dt_b_product_details

[steven c]

 Whatever I use I was planning to put some mesh behind it joining the two.

[blackcat]

Whatever I use I was planning to put some mesh behind it joining the two.

The piece that broke on my side panel cover was lost, so what you are seeing above is just the plastic patch with no mesh and it's been in place for two years as a daily rider in NYC where the roads are less than stellar. But the mesh certainly won't hurt. 

[bigbikerrick]

I "made" the same tab on my Cal II s sidecover. Guzzi plastic is ABS on all I have seen. You can buy abs pipe at home depot,and cut a piece that is close to the missing tab, shape with a dremel,and use  abs glue to attach it. You can also grind the abs to make "abs sawdust" ,mix with the glue and make a thick abs past for filling in holes, etc.  Mine came out stronger than new, and with the rubber grommett in place , and painted,you could not tell it was repaired.
  If you dont feel like taking it on, you can mail me the side cover,and I will be happy to repair it for you for free. I also do  a bit of plastic welding,and have the correct "rod" for abs, etc.
Rick.

[bigbikerrick]

Here is a good video...Polyvance is the company I buy all my plastic welding stuff from. They have great videos and instructions on basic plastic repair on their website.
Rick

https://www.polyvance.com/Fairing-Tab-Repair/

[LowRyter]

Is this it, John?

https://www.amazon.com/dp/B01IBOK7FE?psc=1&ref=ppx_pop_dt_b_product_details

Nope.  I posted some photos of my Greenie side covers and starter cover.  I think the guy used a two part 3M product that he also uses for car bumper covers.  I'm guessing the JB Weld work. 

I posted here and on V11 Lemans but I could guess it was 2+ years ago.

Found it:

here is the work done on the panels on my Greenie.  My body guy Dusty (Central Customs in OKC)  uses 3M 04247 two part filler epoxy + adhesion promoter.  He filled, bonded and sanded.  Since he knew I didn't want to paint it, he was limited to working on the backside only. 
 
I gave him the paint recipe using the candy paints from House of Kolor and may go that route in future.

https://wildguzzi.com/forum/index.php?topic=90273.0

He also glued the left side fairing on my Ducati SS after I hit road debris.   He actually didn't charge me but of course I gave him a tip.  OTOH, the Greenie was fragile, I wanted a pro to do it.  I'd hate to try to paint it.  The light colored adhesive blends OK.

[steven c]

 I'm going to give the J B Weld a shot.

[Matt Story]

Guzzi plastic is ABS on all I have seen.
Rick.

If true, another option would be to 3D print an repair tab in ABS.  Design into it a generous glue flange and chemically bond it.  There are special cements made expressly for bonding ABS to itself.  It's very possible the resulting repair would be stronger than original. 

[Canuck750]

I have repaired one before and I placed a big thin washer with the same ID as the original hole behind the cover and used a plastic epoxy to bind the washer on the back side and join the break on the front.

[Kiwi_Roy]

I have done quite a few repairs on plastic faring etc, I like to use a thin aluminium sheet and drill it like a Swiss cheese so its about as stiff as the plastic then glue it to the plastic with JBW.

[Testarossa]

I like to use a thin aluminium sheet and drill it like a Swiss cheese so its about as stiff as the plastic then glue it to the plastic with JBW.

This. Aluminum-reinforced JB Weld is cheap and easy, and can be ground and sanded to shape. On a fairing tab use soft aluminum bar stock, bent and ground to shape  with an oversize extension to glue to the backside of the fairing. Slather the alu with JB Weld, put a sandwich baggy over it and clamp to cure.

[ozarquebus]

A cheap strong repair I have found for hard polyester and polycarbonate plastics is using regular fiberglass cloth impregnated with the common twin tube  kit epoxy. Build up as needed. Pretty much the same as "e-glass". Good rough backside surface prep and clean with 100%  alcohol while still gel state. It is not pretty but ok if hidden. Can be shaped and sanded down when cured. Does not stick well to polyethylenes or pliable thermoplastics, though.

[wymple]

I'm going to give the J B Weld a shot.

Bear in mind that regular slow curing JB Weld is far superior to the quick stuff.

[steven c]

Work in progress