bike i'm working on has a craks in the fairing, top right above the headlight/windshield junction where the mirror mounts. recommendations for repair? i've been told that epoxy for ABS was da stuff. links to sources would be nice.
I used JB weld on the fairing mounts wit good results. With the JB you have to be sure to try an work it early to get it smooth, before it sets up. The JB hardened like a rock, but was hidden from view. I rounded out all the edges so there where no stress risors, or places that fatique cracks where likely to occur. Typically these are areas that have abrubt surface contours, or sharp angles. A contour piece of plastic that matches the fairing contour may help lay the repair medium on nice, kind of like a squeegy to work into those crevises. Just a thought.
I fixed a stress crack with fiberglass which worked real well. Came out very strong and was easy to sand smooth for painting. vtrider
I drill holes at the end of the crack to prevent it from going any farther. Then I take a small piece of ABS plastic and slip it into my dremel, turn it to the fastest setting and then "weld" the crack on both sides. Once that's done you just sand it down, give it a touch of paint and you are set.
+1 on the plastex Over the course of several years & 'hobby' repairs/paint jobs on bikes, I've used various epoxies/glues & heat-welding. IMO, plastex beats them all for effort, effectiveness, and strength - with very little additional finishing work required to prep for paint. Seems pricey for the amount of material, but a little goes a loooong way since there's very little waste.
another + 1 on the Plastex. Used it on the fairing of my wife's F650 and it worked great - becomes one with the original plastic (and smells REALLY nasty, must be super toxic!). It's the only product I know that was specifically made for the purpose of putting fairings back together. I got mine from Whitehorse Press/gear. I've used alot of epoxy in my other hobby, wooden boatbuilding, and wouldn't expect most clear epoxies to truly bond to plastic - it may bond to some types, temporarily, but generally epoxy works best when it can penetrate into porous materials and form a mechanical bond - IMHO it isn't the best thing for making a chemical bond, for that some strong solvents need to be involved. On the other hand I've seen JBweld do miracles - Steverino used my stash of JB weld to put his front brake reservoir back together after a close encounter with a deer in WV a couple years ago, and it held!
<BR>That Plastex product, that's the one at all the bike shows isn't it? The product I've seen at the shows is a cyanoacrylate adhesive (super glue) and glass bead filler powder. Head on over to a women's nail shop and pick some up. Heck, make an appointment and show up with your fairing. CA and glass bead powder filler are what's used to fill nails. Or go to a hobby shop, there are many different types of CA adhesives, primer, and filler powder. Some CA is flexible and works on cloth. - Jim<BR><BR>
Except neither component is cyanoacrylate or glass beads..... The filler is an extremely fine plastic powder, and the solvent smells similar to MEK, but different & shtankier - and yes, very pungent when curing. Definitely a 'chemical weld' solvent bonding rather than just a glue. Thing about epoxies, especially very hard ones like JB weld - trying to finish-sand them is difficult at best, and they're also fairly brittle so flexing/vibration will tend to crack the repair over time. The plastex seems to make a thorough homogenoeous bond, and you only need to make a small chamfer (vee) along the crack & use a very small amount to get a seamless repair that is at least as strong as the surrounding plastic (vs. a generous amount of feathering & beading on the back-side which you generally need to do to get a decently strong bond w/ epoxy). Trust us - for plastic it's hands-down the best stuff (of the options listed here, and in my experience).
<BR> Oh, CyanoAcrylate adhesive, and Acrylic plastic powder (often with glass filler for strength) is the product I've seen at the show, so it wasn't Plastex brand then? The products I've seen like this 'go off' too quickly to be a solvent bond. And the "stink" is the CA primer coated onto the filler. And will dissolve abs/pvc. But your experience is that the product is pure solvent bondable plastic? And bonded with MEK or acetone or something like it? How do the volatiles (VOCs) get out of the mix so quickly? Is Plastex your product Kerry? How does the product get the volatiles out so quickly? - Jim<BR><BR>
Not 'mine' as in I make it or sell it, but yes - Plastex is the stuff I'm describing. I couldn't tell you chemically how it works, only that it does work better than anything I've ever used - fast cure, but not immediate (30~60min, IIRC). The repair looks/sands just like ABS & seems to be just as strong as unbroken plastic (assuming careful chamfering/filling). I've used cyanoacrylate gel before also (strong 'industrial' stuff), and it works pretty well - but it's still a 'glue', and a brittle one at that.
<BR> In thin sheets, and if portioned correctly, 2-part fiberglass resin cracks like brickle too. The fiber cloth is the strength not the resin. And in the case of the powder filler, the filler is the strength. If you need to make a repair and run out of Plastex, prep a piece of cracked ABS and take it to the nail shop. Then stop at the beauty supply and pick up some powder and glue. All different colors. There is some UV cured gel in that market now. It's sold as surfboard 'ding repair' at inflated prices. Comes with a little UV LED 'curing light' in sort of a keyfob light package. You can make temporary fillings with it too, heh heh. And those prices are a little more inflated. - Jim<BR><BR>
