MOTOBRICK.COM
TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: KCinSB on July 12, 2016, 11:42:01 PM
-
I got a pair of the slim "City Cases" for my K1100RS, and they fit the Z brackets fine. They both need some TLC, but one is cracked pretty badly on the back side near the mount lug. Has anyone had experience getting cracked luggage Plastic Welded?
-
Has anyone had experience getting cracked luggage Plastic Welded?
I haven't. I repair mine with fibreglass cloth and epoxy resin.
-
They can be plastic welded but you need to know what type of plastic. Apparently with the right rods you can do it yourself with a soldering iron or a torch. Lots of info and tips on the net.
Regards Martin.
-
HF has a plastic welder pretty cheap. Anybody had any success with it? I have two complete sets of cases to sell -- 1 system and 1 city -- but they have cracks. I used 2 part epoxy and fiberglass a couple years ago but although it appears to adhere well at first, it begins to separate after a time and a couple years later you can just peel it off. I thought I'd prepped the surface but either I didn't or West Systems epoxy doesn't or I didn't do it right.
What I did was cut the cloth, lay it out with epoxy on a separate surface, brush out a layer of epoxy on the surface, wait till tacky, the press the cloth onto the surface. Like I said...good for maybe a couple years, then fail. Plastic welding would be much better if someone could demonstrate that it works.
I got a small sheet of similar ABS at a boat maker in Annapolis....for welding you'd probably need to source it for someplace like that.
Laitch, how long has your epoxy patch job been good for?
-
This Youtube channel, Delboy's Garage, has a good video on plastic welding and lots of other good tips as well.
https://www.youtube.com/watch?v=k7GRNvPSf7k&list=PLRS52UHF-Mflmn-VRdUf3xF7MDFU83TMN&index=28
I am going to try it myself as soon as the bike is out of customs (it has been eight weeks now and I am going crazy waiting for it :musicboohoo: )
-
Laitch, how long has your epoxy patch job been good for?
Three years and counting. My method differs from yours. I pour what I believe is enough epoxy into a foil-lined pan being used to soak all the fiberglass strips that I'll need. After the surface is sanded, the strips are soaked in the epoxy/hardener mixture until they are saturated then lifted to allow excess to runoff and laid up on the clean, prepped surface. I need to work swiftly to soak and lay up all the strips before the epoxy mixture hardens. Usually there's some wasted epoxy. Cleanup is with acetone.
I've used JB Weld for corner bashes. Now that my retaining system using water heater hose pieces seems to work, I'll probably be doing less repair.
-
Plastic welding specialist did a set of mine & you could hardly see the places where it had been repaired. He told me that using the right type of rods and correct heat & method for each material was the key.
Apparently he sees lots of repairs to this type of plastic that do not hold, mostly with Araldite and epoxy resins / glues. He said it made his job harder because you have to thoroughly clean all the glue off before you can do the job properly. His charge was just $25 - so I was well pleased. Wish I had taken before & after photos.
-
Plastic welding is easy. I've done a few repairs of cracks in plastic parts like my wife's cellphone cover and the fender of my Moto Guzzi. I used a standard soldering iron with a large 700 degree F tip. The large tip made sure there was lots of thermal inertia and wouldn't cool down quickly. There's no more trick than to melt the plastic either side of the crack so it flows together. You're trying to melt about 2/3 of the way through, not all the way. Then any voids can be filled with sprue from plastic of a similar type to the base material.
-
Yes, it is quite easy to do with a soldering iron, and I have done repairs on less visible parts and on various other things (a gas filler cap for my forklift yesterday) around my shed.
Check the type of plastic by the number on the bottom of the container and choose a type that is the same to use as the sacrificial filler... you will get lots of smoke too, so sacrificial takes on new meaning!
-
I talked to the guy that did the resto on my Wife's Highlander headlights and bumpers while here. He said about the same. Do it yourself, it's not hard. I may try, but would prefer a "Pro" as since this cracked once, likely a repair would not be as strong in the same area of stress.
-
For ABS plastic I use to use ABS cement and ABS shavings mixed in to make a slurry. Worked well but was runny, making it difficult to work with sometimes. Especially if you couldn't lay the repair flat.
Loctite has a plastic repair that comes in a two part tube like epoxy. It's for ABS, doesn't run and I've found it to be very strong and easy to work with. I get it at Orchard Supply Hardware and it's about $6.00 for the package. I love the stuff. :2thumbup:
For large cracks you could use your sheet of ABS and butter the repair with the Loctite and have a very solid repair.