Jump to content
SAU Community

Plastic welding/repairs(yamaha R1 fix up....project #1000000056 :D)


Recommended Posts

Due to being ask a number of times on how to repair plastic parts i have decided to post yet another educational DIY thread...rule number 1 is bikes have 2 wheels and fall over quite often :D ....Ok so i have recently bought a Yamaha R1 that has been damaged and the previous owner has tried a DIY job and turned it into a shamozzle,so the first thing we do is remove all the fibreglass/filler and glue that he has applied....we do this by waving a heat gun over it and pry it away with a screwdriver....this as you can see in the pics uncovers holes and cracks all over the place,its really important that we get all the foreign matter out of the way on both inside and outside of the panel to ensure a good clean surface so the weld is nice and strong...today i just cleaned off the rubbish quickly and tomorrow i will blast it over with an orbital to flatten it off to prepare the surface for welding....Before welding we must determine what type of material it is,some straight materials have a marking such as ABS,PP,GF stamped or moulded into them on the underneath side,some are composites such as PA6+PPE ect ect some are even more elaborate and have 3 or 4 composites....and then theres times when there no marking at all this is when we use the "melt it and smell"test or melt it and "feel/vision"test through a soldering iron :D....using these 2 test's to verify the material require experience....nylon is very smooth and shiny melting material and is quite stringy its also quite heavy...where as PP(poly propolene)is light,smooth melting with a dull appearance....ABS feels crackly and dry and GF(glass filled)is even more dry and crumbly and smell bakalite-ish.....You would be amazed at what can be resurrected from death......More on the actual welding tomorrow

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hope you aren't too sore after that one, might take a day or 2 to notice yet and I guess it is a loooooong drive home. On the bright side, tube frame front end is a thing at superlap, right?
    • https://www.facebook.com/share/p/18rmVb1SKB/ 
    • The chart of front pressure to rear pressure (with one being on the x axis and the other being on the y axis) is not a straight line on a typical proportioning valve. At lower pressures there is a straight line with one slope, and at higher pressures that changes to a lower slope. That creates a bend in the line at that pressure, called the knee point. If you do not change the proportionng as the pressure gets higher, you will suffer excessive pressure (at one end of the car or the other, depending on which way you look at the proportioning action) and then get lockups at that end. The HFM BM57, from my memory of previous discussions, is based on the BM57 from a different car (to a Skyline), with a different requirement for the location of the knee point and the distribution of pressure front to rear, and so is not a good choice for an upgrade on a Skyline. Here's a couple of links to some old posts, one from here, one from elsewhere. A lot of it pertains to adjustable prop valves, but the idea is the same. There are plenty of discussions on here about this issue from al the many years of people wanting a cheap/accessible option. https://grassrootsmotorsports.com/forum/grm/learn-me-brake-proportioning-valves/236880/page1/ https://grassrootsmotorsports.com/forum/grm/learn-me-brake-proportioning-valves/236880/page1/  
    • Yeah dunno why johhny posted that here with no context, just post on FB/insta bro where he put it up?  Laine had an off at T4 during Thurs prac, he's ok, car is less than perfect, they are done for the weekend, he can fill in the rest. Bando also binned it like 100m up the road.   
    • I feel there must have been a FB/insta post and the weekend did not start well at all I hope everyone is all okay
×
×
  • Create New...