Chiefdams Posted January 9, 2016 Share Posted January 9, 2016 Yestarday i saw that the hull of my kingsong was cracked. Have you the same problem? Link to comment Share on other sites More sharing options...
Jason McNeil Posted January 9, 2016 Share Posted January 9, 2016 5 hours ago, Chiefdams said: Yestarday i saw that the hull of my kingsong was cracked. Have you the same problem? Is that white powder snow? As the below video demonstrates, the plastic is incredibly durable but can become brittle in cold temperatures. Did it take an impact? Link to comment Share on other sites More sharing options...
Chiefdams Posted January 9, 2016 Author Share Posted January 9, 2016 No the white is volvo lifepaint https://www.youtube.com/watch?v=CfWzeGlaFvI. I saw your video long time ago and when i discovered the cracks i remember it. No cold temperature in France this year on Paris, and no special crash recently. Link to comment Share on other sites More sharing options...
Keith Posted January 10, 2016 Share Posted January 10, 2016 Wow, I've never seen that before - it would have to be a Volvo product wouldn't it ;-). However, I cringed when I saw it being sprayed on the cycle helmet in the video, golden rule is that helmets should never be sprayed as the paint solvents can degrade and weaken the helmet - I guess that would go for the shell of an EUC as well? Do you still have the can? If so is it solvent or water based? The V.O.C. label (circular label on the can) will be green or blue if the product is low in organics and orange or red if high, I would be concerned for its impact on plastics if it is orange or red. Link to comment Share on other sites More sharing options...
Chiefdams Posted January 10, 2016 Author Share Posted January 10, 2016 The can is orange. You think it can be crack the hull where I Didn t paint it. I painted all my wheel except at this place. And after one week I cleaned it because I Didn t like the effect. Link to comment Share on other sites More sharing options...
Gimlet Posted January 10, 2016 Share Posted January 10, 2016 What did you clean the paint off with? Was it a solvent based paint remover? Link to comment Share on other sites More sharing options...
Keith Posted January 10, 2016 Share Posted January 10, 2016 Good point @Gimlet. Although the KS video shows impressive strength, a "pure" plastic (I.e. Without reinforcement like carbon or glass fibre.) can be prone to fatigue cracking in the same way that metal fatigues. Like metal, once a crack starts it will rapidly propagate through the material, even through areas that are thicker or tougher. However, something has to start it, it could simply be repeated stresses over time with a fatigue focus point (as with the square window edges of the Comet airliner and repeated cabin pressurisation) but if a solvent gets into the plastic and weakens the structure that would make an easy starting point for cracking. Once started it will travel easily even through stronger material that hasn't been subject to solvents. Link to comment Share on other sites More sharing options...
Chiefdams Posted January 10, 2016 Author Share Posted January 10, 2016 White spirit substitute. Ecological version without solvant. Link to comment Share on other sites More sharing options...
Keith Posted January 10, 2016 Share Posted January 10, 2016 2 hours ago, Chiefdams said: White spirit substitute. Ecological version without solvant. So designed to dissolve or soften oil based paints even when they are dry (I.e. Plasticised) so quite capable of penetrating plastics. Please don't get me wrong here, as an owner of a KS14C myself what you have found is concerning as it may indicate that there is a weakness in the design (I.e. that vibration or repetitive flexing of the case might cause cracking to occur, the colder climates in winter Europe might make the case brittle?) The problem is that the paint and solvent you have used, at the very least, muddies the waters. It will only be possible to know there is a problem if we see more cases with the same problem. Having said that quite a number of people including @Jason McNeil have got quite high mileages on theirs without seeing this problem, which does suggest yours is not behaving typically? Link to comment Share on other sites More sharing options...
Chiefdams Posted January 10, 2016 Author Share Posted January 10, 2016 Do you think there is a method to stop cracks like injecting epoxy? Link to comment Share on other sites More sharing options...
dmethvin Posted January 10, 2016 Share Posted January 10, 2016 48 minutes ago, Chiefdams said: Do you think there is a method to stop cracks like injecting epoxy? The way you usually stop cracks in metal is to drill or grind out the end of the crack to stop the stress point and then fill it. Most EUC plastic shells are too thin to "fill" anything though. You might be able to reinforce it from the back side via fiberglass mesh and something like JB Weld? Maybe you can get them to send you new shells, they're relatively light and cheap compared to the other parts. Link to comment Share on other sites More sharing options...
Chiefdams Posted January 12, 2016 Author Share Posted January 12, 2016 I contacted albedo by phone and they confirmed me that this spray can be apply on plastic.It s write on the spray ! On their site we find: Albedo100 Light Metallic is appropriate for use on wheels on pushchairs, bicycles, gates, letter boxes, kayaks, tools, metal, painted surfaces, pavements, fences, nylon textiles, bicycle-helmets, etc. Link to comment Share on other sites More sharing options...
Tomek Posted January 12, 2016 Share Posted January 12, 2016 I've glued my wheel shell with success by using a thick mix of acetone and scraps of ABS, applied in several layers (it's basically liquid ABS, but it shrinks a bit as it dries) Link to comment Share on other sites More sharing options...
Mistagear Posted January 15, 2016 Share Posted January 15, 2016 I have a couple of "early" 18" KS cases which have cracked around the mounting holes. Apparently the material used since the KS video was released is different and superior to the originals. Have been repairing by plastic welding into the cracks and reinforcing the areas using aluminium plates on the inside to spread the load over a larger area. Not totally convinced the problem is solely due to the earlier plastic material and suspect there is a small design problem which contributes to the fault. My cases do get a fair beating but so far the aluminium plates have worked reasonably well. At first I tried minor repairs which only temporarily fixed the problem, wasn't until I was serious about the extent of repair before there was improvement. My advice would be to go hard and fix it the first time. Link to comment Share on other sites More sharing options...
Mistagear Posted January 17, 2016 Share Posted January 17, 2016 Here's a recent repair on a cracked 18" case. I grind out the back surface to give room to fit an aluminium plate where once was only plastic. I use a construction adhesive to bond the two. Then turn to the outside of the mounting point and recess washers into the surface of the plastic using a dye grinder. This also helps to increase contact surface area around each mounting bolt. Inner side Link to comment Share on other sites More sharing options...
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