Brutus: The CB550F Cafe/Gravel Runner Build

Discussion in 'Some Assembly Required' started by JB2, Nov 11, 2015.

  1. JagLite

    JagLite Long timer

    Joined:
    Jun 17, 2010
    Oddometer:
    4,571
    Location:
    Anchorage Alaska
    The advantage of fiberglass is that you can use just about anything to make a form.
    I used blue board rigid insulation to make the gas tank on my street tracker.
    There is a thread on here for using sheet rock mud and I have seen paper mache used too.

    But I really got a kick seeing this guys work:
    http://www.autoblog.com/2008/05/30/lithuanian-builds-car-from-polyurethane-foam/

    Yeah, it's a car but the same technique could easily be done on a bike.
    Maybe tape cardboard together as a base, mix and pour the foam, cut and sand to shape.
    Then cover with paint to seal the foam, put on mold release and start the layup.

    You could pull a female mold from that but if it is a one-off build I just put 2 or 3 layers of cloth and epoxy at the same time and let it harden.
    Then I pull out the mold and do the rest of the lamination's on the inside.

    It is the outside surface that needs to be perfect and that really shows the difference between high quality and... uh, a good attempt.

    My street tracker tank:

    [​IMG]

    During final fairing:

    [​IMG]
    #81
    oregonsurveyor, JB2, Foxed101 and 2 others like this.
  2. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Jag, I really, I mean really like your gas tank. There are almost no limitations to building in glass except your imagination. The link to the Lithuanian build was also cool. I noticed he used a contour gauge. I've always built by feel and sight which you can get by with on a motorcycle but probably not a car. I'm almost compelled to make something in glass for Brutus but I'm sticking to metal on this build. However, Nuggets got me to re-thinking the Yamaha project so much so that I'm selling off all the bobber parts. When I start it I'm thinking seriously about all glass bodywork more in line of a cafe'-ish track-day bike. Who knows? The one thing for sure is, with all the ideas floating around on this forum, that I'll probably change my mind a few more times before it actually gets built! :thumb
    #82
    JagLite and nuggets like this.
  3. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Well it got up to the mid-40's the past few days so I was able to get a head start on the welding projects in my semi-comfortable shop the last few evenings. I first clamped the sleeve to the main part of the rear fender. I flip it over to weld up the old upper mounting holes and the wiring hole.

    [​IMG]

    Working from right to left each weld got a little better. You can see I had to touch up a few pinholes. Not so pretty but they finish off nicely. The heat setting would have preferred "A.75" but I played with the wire speed and got it to weld pretty good on "B". Once I figured out what the Asian metal liked the button-welds went smoothly.

    [​IMG]

    And here they are finished off.

    [​IMG]

    As fate would have it the tail lamp needed to be about a half of an inch higher on the fender to be near level. Sliding it up would have meant a very think spacer for the license plate bracket to clear the lip around the edge of the fender. So I cut another half inch off the tip before welding. Maybe I should have checked Ichiban Moto for a source on an adjustable fender too? :lol3

    [​IMG]

    After the final trim I tack welded the tip from the topside...

    [​IMG]

    ... then button-welded the sleeve from the underside. Note the penetration from the first three holes I welded. It is just a little warm on "B". Someday soon a tig will be in order.

    [​IMG]

    After tacking I started welding in 1" segments allowing the metal to first cool. Then I ground each weld so I could hammer and dolly the sheet metal deformation before the next weld. You have to take your time with this stuff or it will warp. As you can see it's the same learning curve on welding the gap as it was welding the holes. Not quite as nice as I like but...

    [​IMG]

    ... after getting the hang of how to stitch the gap with this little Lincoln I laid a bunch of connecting welds that looked like this.

    [​IMG]

    After the seam was entirely welded I very carefully finished grinding the welds. You can take too much off. If you don't keep the previous welds ground and dollied you'll end up with some wavy-assed fenders and piss-thin sheet metal.

    [​IMG]

    At this point I've also welded in the lower sleeve that will support the lower mount on the new tail lamp. After some more hammer and dolly work I then planish sanded the fender with 24 grit paper on an orbital sander. I could have almost metal finished it... but not quite. It'll need a coat of mud to get the final flaws out of it, but not much. Also note I've drilled the new wiring hole and the upper mounting hole. Since the screws are made to fit on a radius and, I might still put a thin spacer under the gasket, I won't drill the bottom two holes until it's almost ready to paint. I want to avoid having to slot holes to make the bottom screws line up. The back of the LP bracket either needs a shallow relief cut in it for the fender lip or I need to make a spacer. I'll sleep on it. :D

    [​IMG]

    And here it is back on Brutus with the tail lamp being held on by one screw. The days of mocking up the fenders with duct tape are finally over. :thumb From the side...

    [​IMG]

    ... and from the rear.

    [​IMG]

    Just as I envisioned it so the rear fender is now ready for body and paint. Tomorrow I'll weld up the front fender then both fenders and the new side covers will head to the basement for the final touches. The gas tank will need the least amount of work so it will stay on the bike until the other four pieces are ready for paint. That way if I get another night or two in the shop I can start setting the valves and cam-chain tensioner, change the oil and filter and various other mechanical maintenance items.

    This is the first time I've used the copper weld-through primer. I despised the old heavy-zinc coating we used to use. Our technicians at the shop told me I'd really like the new copper primer. It cuts down a lot of spatter and BB's you get from a mig and provides that extra edge against corrosion. I'm sold. I won't weld sheet metal without it now.

    Front fender next...

    Stay tuned.
    #83
  4. Foxed101

    Foxed101 Monkeywrench

    Joined:
    Aug 1, 2015
    Oddometer:
    387
    Location:
    Holland
    Very nice job!:thumb

    Decided on a colour yet?
    #84
  5. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Foxed101, Thanks and yes I've decided on a paint scheme. The tank and both fenders will be medium olive-green metallic with a traditional white scallop on each side of the tank. The side covers will be black. I'll use gold and black accent stripes bordering the white scallops with OEM badges and gold "Super Sport" scripts on the side covers(think '65 Nova). It will be a blend of a factory Honda look with British influences. It's a mid-70's bike with an early-60's splash. I'm shooting everything in single-stage Imron. No clear-coat. Good clear-coats and the extensive use of them didn't come about until the early 60's. Manufacturers didn't start using clear-coat until the 70's. I'm going full-on old-school with this bike. :thumb
    #85
    JagLite and nuggets like this.
  6. Foxed101

    Foxed101 Monkeywrench

    Joined:
    Aug 1, 2015
    Oddometer:
    387
    Location:
    Holland
    Good on you! Taking a theme and then carrying it through untill the world ends.

    You probably know that after the Apocalypse :devildog
    the only thing running will be cockroaches and Honda's.

    Bet yours will outrun em all:happay
    #86
    JagLite and JB2 like this.
  7. nuggets

    nuggets It's all my fault...

    Joined:
    Jul 13, 2010
    Oddometer:
    2,710
    Location:
    Virgina
    JB2, thanks again for explaining the how and why of what you are doing.
    #87
    JagLite and JB2 like this.
  8. waylongway

    waylongway madmax

    Joined:
    Dec 16, 2009
    Oddometer:
    3,079
    Location:
    NorCal

    Nice job JB2....!!

    Maybe it's the angle of the pic...? But to me ...:y0!It looks like the light could go up a touch and make the License plate match the flow of the finder.....?

    Other wise .....Love it....:crash
    #88
  9. DiggerD

    DiggerD DougFir from SuperDuke Days

    Joined:
    Mar 14, 2013
    Oddometer:
    2,110
    Location:
    Mid Wet Or A Gun
    I first saw the poly foam used as form material back in the 60's.
    A neighbor gear head made a hood scope for his car.
    Mixed a patch of poly foam and poured it right on his hood, with the hood still on his car.
    Shaped it the way he wanted, glassed it up, then cut the hole in the metal from the bottom side.
    I keep looking at that AJS tracker.....my kind of bike I never had...got a XRR...maybe I need another stable mate for it...
    #89
    JagLite likes this.
  10. JagLite

    JagLite Long timer

    Joined:
    Jun 17, 2010
    Oddometer:
    4,571
    Location:
    Anchorage Alaska
    Excellent demonstration of how much work goes into something so simple as bobbing the fender for it to look good.
    Seems that most people just cut it off and call it done.
    And then wonder why nobody else thinks it looks good. :fpalm

    There are always many "bobber/cafe'/tracker/scrambler/chopper" bikes on CL where the butcher just hacked away on what he kept and then bolted on a tank from another bike (that doesn't fit the frame at all of course) and made a plywood seat and thinks it is worth thousands more than it did before.

    There is a lot involved in making a bike look right and much of it is subtle small things, like a fender lip.

    Good job! :thumb
    #90
    Tim_Tom and nuggets like this.
  11. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Wow, hey guys I worked in the shop all day and missed out.

    Foxed101, Yeah I started by chopping and painting the neighborhood kids' Stingrays when I was less than 10. I learned a lot from my pop and most of it old school. He worked in lead when he did bodywork. Early 60's bikes were the first ones I remember stealing my soul. It's hard not to go back to your roots, progress be damned! :D If the world passes me up then so be it because they're probably going the wrong way anyway. If I last as long as the cockroaches and the Hondas Brutus might well me the fastest but I doubt it. That's okay too. :thumb

    Nuggets, thanks it's added a whole new perspective to building a bike by being able to follow each other's threads. Most of what I post here is basic stuff and everybody has their own set of rules for how things should be done. If posting mine helps someone then that's cool too. Sometimes I think I post too much detail? :lol3

    Waylongway, Yes it's part optical illusion and part not. I can't slide the bracket any further up on the fender because the LP bracket hits on it. To do so would mean about a 3/4" spacer because the Honda fender is flat across the middle section. There's a small relief already formed into the back of the bracket to allow for a fender with a lip on it. I would like to kick up the angle of the light just a hair more and I think I can do that with a wedge shaped spacer cut from black poly sheeting. I had thought about buying this lamp without the bracket and under-sling the license plate but decided I liked this look better. If I think about it I'll snap a photo with the bracket slid up so you can see what I mean. It's still not painted so you never know... I may toss that lamp and use my original idea. Can't never tell. :lol3

    Jag, Thanks and I agree. Somewhere I have a picture of the first Honda Scrambler I bobbed. I did just cut the desired amount off but I also put nice smooth radiuses at both ends of the front fender and the tip of the rear fender. Come to think of it it looks similar to what I'm building now only but I was only 13 then. SHEESH! Where does time go? :hmmmmm I'm trying to maintain that factory look and you're right, details like keeping the lip intact insures the changes look almost stock. I was going for subtle. BTW, where are the Tiny Techs? :lol3

    DiggerD, I haven't worked with a lot of foam. It seems that most everything I've built has been on a covered wire form. I hadn't planned on doing any glass work on this bike but Jag's gas tank got me to thinking about doing small headlamp fairing in glass. I could just buy a Buell Cyclone piece. It looks like it would fit but making it would be more fun. :1drink

    Publishing photos now. Update in a few...
    #91
    JagLite likes this.
  12. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    The front fender goes nearly the same as the rear with the addition of a few lessons learned. The 1/4" holes I had punched in the rear sleeves were too big for the thickness of the Asian steel and the range settings on the welder. I went with smaller holes on the button-welds and a narrower gap on the seam. That's a Roper-Witney hand punch. One of my favorite old school tools. It's been in service for over thirty years now.

    [​IMG]

    You can see the huge difference in penetration between the front and rear fenders. This is just right. The larger holes in the rear fender meant you had to stay on the throttle longer to fill in the weld and it was a tad too hot. The smaller hole meant I could get the hole filled and off the throttle pretty quick with perfect penetration. Note also the gap on the seam is half that of the rear fender. Still learning what it takes to get a nice welds out of the Lincoln.

    [​IMG]

    Here it is tacked and ready for stitch-welding.

    [​IMG]

    After welding and finishing it looks much the same as the rear only with a lot less detail work required on the weld seam.

    [​IMG]

    And here it is mounted on the bike with the holes for the lower brace drilled and OEM hardware installed. The brace sets right over the seam. Technically I could paint it without mud work because it just does not show... but I won't leave it unfinished. :D Details.

    [​IMG]

    Now it looks like a Super Sport. Who would put full fenders on a bike called a Super Sport anyway? Here's a shot with both fenders installed and back far enough you can make your own decision on the rear light. Now that I can look at the photo from further away I'm convinced a thin wedged spacer is in order. What ever I can get with that I'll stick with. I might even leave it just like this. The extra 1/2" I took off before welding helped a bunch.

    [​IMG]

    There's a COLD winter blast coming in for the next week or so. All the sheet-metal that gets painted is ready for the next stage; prep and paint. I'll probably tear it back down tomorrow and move the skins to the basement. The only metal-fab work left to do is the rear seat pan. The next warm day will see that project getting some attention. I've moved the '71 BSA frame to the basement also so there's at least a couple of weeks worth of work that I can do in a warm space. YEE HAW! :D

    Stay tuned.
    #92
  13. oregonsurveyor

    oregonsurveyor Been here awhile

    Joined:
    Mar 14, 2014
    Oddometer:
    244
    Location:
    Oregon
    JB2, you do NOT post too much detail.
    #93
  14. JagLite

    JagLite Long timer

    Joined:
    Jun 17, 2010
    Oddometer:
    4,571
    Location:
    Anchorage Alaska
    The Tint Techs are waiting for parts...


    Again :becca :dirtdog
    #94
    JB2 likes this.
  15. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Jag, you could loan them out if they're bored. I have a frame to strip with lots of labor intensive prep work needed before I can bead blast it. Plus the swingarm bolt is seized... I could use the help. :D
    #95
    JagLite likes this.
  16. JagLite

    JagLite Long timer

    Joined:
    Jun 17, 2010
    Oddometer:
    4,571
    Location:
    Anchorage Alaska
    I will pass on your request but I warn you, they don't work cheap.

    You might be able to find a local team willing to work by the hour for typical non-skilled labor intensive projects.

    :lol3
    #96
    JB2 likes this.
  17. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    72,336
    Location:
    Alexandria, VA
    Wow, nice! Looks far better than mine, and I see why. The slight gap allowing a clean weld. I butted mine right up before welding. :shog
    #97
  18. JB2

    JB2 Dirt Of The Earth

    Joined:
    Jan 4, 2008
    Oddometer:
    969
    Location:
    Edge of The Great Plains
    Jim, The rule of thumb on butt-welding is to leave the gap of the wire you're using to weld with between the two pieces of metal. For welding with a sleeve they recommend leaving the thickness of the metal you're welding between the two pieces of metal. I got carried away on the rear fender and left too big of a gap but corrected on the front and got the results I desired. I really like your scrambler, BTW. You've got good welds and even if they're aren't pretty you finished them off with bondo. I'm doing the same also so who would ever know or care, right? :lol3

    Keep on Scramblin' on! :thumb
    #98
    JimVonBaden likes this.
  19. nuggets

    nuggets It's all my fault...

    Joined:
    Jul 13, 2010
    Oddometer:
    2,710
    Location:
    Virgina
    :ear:lurk

    :dirtdog
    #99
    waylongway likes this.
  20. waylongway

    waylongway madmax

    Joined:
    Dec 16, 2009
    Oddometer:
    3,079
    Location:
    NorCal
    :dirtdog

    :ear :lurk
    nuggets likes this.