Working with ABS plastic

Discussion in 'The Garage' started by Andyvh1959, Sep 30, 2021.

  1. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    Done some ABS plastic fabrication and heat/solvent welding/bonding in the past, which lead me to my current project. I'm modding a late 70's Pacifico Shadow fairing to mount on my Kawasaki VN1600 cruiser. My project also uses a gauge set from a VN1700 Vaquero (which is not a plug and play conversion). I fabbed up ABS sheet stock into panels I'm bonding into the fairing to mount the gauge set. This is an in process pic of the development. That entire gauge panel above the two vents is the fabrication to mount the gauge set into the fairing, so it has a ways to go before it is complete:
    Gauges.JPG

    ABS sheet stock is easy to work, form, bend (with some heat), heat weld and solvent bond. I have a glass jar full of ABS chips and shavings that I've dissolved in Acetone. This creates an ABS slurry that I can use to fill gaps, create fillets in joints, reinforce panels. Since many motorcycle plastic panels are ABS its easy to modify/repair with some heat welding and or ABS plumbing cement (which is mostly Acetone). A friend of mine had some crash damage on the lowers on his Star Venture Royale. Some cracks, busted off mount bracket, even a ground down rounded edge. I was able to make all the repairs with Acetone, some heat welding and some ABS slurry, paint matched up quite well with Duplicolor spray cans.
    #1
    MacG, Dan V., Ozarkroadrunner and 5 others like this.
  2. DerekS

    DerekS Been here awhile

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    I really like working with plastic too. Quick and much easier than any other material to get good results, paint or not. My work is generally not as courageous as yours though!
    #2
  3. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    Had I not done a similar fairing on a buddy's bike back in 2016, and other plastic repairs/mods I've learned to do over the past five years I wouldn't have tackled this one. What I have found is large thin cardboard sheet stock is the way to make templates and fitments before moving to fabricating the ABS. Also, in this case because everything involves profiles and shapes in various planes, everything has to start from a center line (like tile work on a floor or wall). Establish the center line first, than measure and fit from there. What I also do is make the template from the center line to one side, then flip that side to duplicate the other side of the centerline. Then I get the consistent shapes to make it look even and centered.

    I don't have a picture of what that fairing looks like unmodified. But the inner side of the stock fairing looks much like a Vertter, or fairings typical to that era. Aftermarket fairings in the mid/late 70s were universal in that they had no gauges installed into them, and any stereo setup of that time was an add on package up where the gauges locate on my modded fairing. The VN1700 gauge panel is all electronic, lightweight, slim, and retro looking enough to fit into the looks of the Pacifico Shadow fairing. I much prefer the gauges up high and near my line of sight, versus the fuel tank mounted "traditional" cruiser speedo/gauges.
    #3
  4. Hay Ewe

    Hay Ewe Just a Wannabe

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    Interesting.
    If I was to make a template / buck out of sheet aluminum or steel, and then got a sheet of ABS plastic, could I heat with at hot air gun and so it softens and then follows the contours / shape of the template / buck?
    Thanks
    #4
  5. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    Should be able to do that. I made a buck from OSB and thin plywood, onto which I clamped or screwed the sheet stock to bend it to shape. Then I set the buck with the sheet stock on it in the oven set at 350F for about ten minutes, just enough to get the ABS to set without flowing. Then out of the oven to cool and the sheet stock took the form of the buck, to form the arch of the cover piece I fabbed to go over the top of the face panel and gauge set. To get the look I wanted, I formed three pieces; the cover itself is made from 1/8" ABS sheet, and two strips of 3/16" ABS, all bonded/solvent welded together to get a 1/2" thick edge to give the impression of heft, but only 1/8 thick over the gauges. Came out well:
    Fairing 3.JPG Fairing 4.JPG
    Some "localized" shaping I did with a heat gun or even a micro butane torch, just enough to heat the ABS to bend and then hold the bent shape after cooling. I have to do some detail work on the LH and RH ends of the cover panel to blend it over the gauge panel. Once I have that done the entire gauge panel will be solvent bonded into the fairing and all the edges of the gauge panel will be filled with ABS slurry, so when done the gauge panel will look like it was molded into the fairing from day one. Then I can blend the gauge panel onto the lower brow panel with a radius to make it look like one molded product.

    Here's what the inside of the stock Pacifico fairing looked like when I started to modify it: Fairing 5.jpg
    The VN1700 gauge set fit in the area on top with a few mods, then I started fabbing the various ABS material to build a "brow" extension above the vent openings, and then the vertical gauge mounting panel.
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    rick danger, nostep and Hay Ewe like this.
  6. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    In the view that shows the gauges I've drawn circles where the midrange/tweeter speakers will mount, which are about 3" diameter. The larger speakers will mount below in the area ahead of the fork legs. The stereo receiver/amp will mount below the gauge panel. I'm designing a ball mount that will clip to the center of the brow above the gauges so I can mount a Garmin Nuvi 2757 gps when I want to use a gps.
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  7. markk53

    markk53 jack of all trades... Super Supporter

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    ABS is really nice to work with, glues easily with the plumber's glue and welding (we used a wood burner and ABS scraps when gluing up bike panels).

    I didn't like the lollipop tail light on my XSR 700. I got a good buy on some used parts including a rear fender. I cut off the mount hump and filled the hole. I got a scrap cut out from a Honda bumper (where they fit the fog lamps) and some ABS plumber glue I had. I ground and sanded the hole in the fender, shaped the piece of plastic, then glued it in. After drying another couple layers of ABS glue were added to make sure it was a secure fill. Then I drilled and fitted the new tail light.

    Fender 1.JPG taillight.jpg

    Attached Files:

    #7
  8. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    That fender mod looks good. Proof that a lot that can be done with ABS.

    I have a glass jar in the shop in which I soak ABS scraps, strips, grindings, cuttings in Acetone. It makes a nice slurry that works great for bonding ABS pieces together, forming fillets, filling gaps. I prep the areas to join by roughing up the surfaces, then wipe them with ABS solvent cement, then apply the ABS slurry to do the bonding work. It flows well if there is enough acetone in the slurry, but can start to set quickly, so I work in layers of slurry laid onto each other. They all bond together into one solid shape.

    Friend of mine dumped his Yamaha Venture Royal Star and damaged the LH lower of the fairing. I was able to fix the cracks, add slurry behind them to reinforce the repairs, applied ABS slurry to some areas scraped flat which I shaped after the slurry fully set. On a rounded edge that had been ground flat I applied ABS rod stock that I bonded in place and filled with slurry to blend it in. After some sanding and paint it came out looking like a factory panel.
    #8