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Nice job on the rear fender so far! You always make it look so easy! I really can’t wait to see you work your magic on the rest of the bike glass!! 8) 8)
 
Gdcast: I think you're right that for smaller stuff like a tank or a headlight, a papier maché mold would do the job, but like you say for bigger things one would probably better make a stiffer fiberglass mold. Thank's for the link, one more thing I need to learn... :roll: :lol:

Half Link: Thanks buddy! :) Making fiberglass fenders isn't very difficult you know. :wink: But today I made a mess whit the foam!! :lol: A little feeling inside me told me to apply a little, let it set for a while and do it in stages like that. Did I do that? No. :roll: Should I have? You bet! :lol: I applied to much to start with and when the foam started to expand half of it didn't stay on the bike and fell on the floor. Well, it fell onto the garbage bag I had laid out but I'd much rather have it stay on the bike.

Here's photo proof, "and that's when I used some explicit language, your honour." :mrgreen:
Fogskum1.jpg


Here's a pic the fender B.M. (before mess).
Bakskrm3.jpg


I cut it roughly to the shape I'm looking for, but it's possible that I'll change the lines a little when I start shaping the rest of the bike if they need to curve differently to work with the overall look. The small cardboard box in the front by the chainstays is there to make it possible to go in from under the fender when bolting on the bike stand. There's a hole cut in the fender where the box is attached.

Now it's time to apply some more foam and hope it stays where it's supposed to. :)
 
When I made the block of foam to make the headlight shape from, I used a cardboard cylinder that I filled with foam. I noticed that when the foam has cured, it sticks like crazy to the cardboard so I thought that I might have some trouble removing a cardboard form from the body of the bike without risking having pieces of foam pulled out. I also have a hunch that the foam takes longer to cure all the way through if it's covered from too many sides. I had some thoughts about just taping pieces of cardboard to the underside of the tubes, acting like a support floor while the foam cured, but I got lazy and decided to try without. :roll:

Here's what it looks like now:
Fogskum2.jpg


Ain't it a beauty!? :lol:

I ran out of foam, got to buy some more tomorrow. Haven't quite gotten the feel for excactly how much it expands yet. In the picture it has stopped expanding, but it's hard to tell when you apply it, how much to use. I've read on the can that it expands about 160%, but before I get a natural feel for it's behavior I'll have to do some trial and error.

In the picture you might also see a plastic tube that I've taped to the top tube of the frame. That's there to make it possible to run the electrical wires from the head light to the rear light through the frame.

Anyway, when all foam is in place and has cured properly, I'll use a hack-saw blade and a knife to roughly shape the body of the bike, and then sanding paper to get it to the shape it's meant to be, keeping in mind that the fiberglass will add to it as well.

I'll post more photos after I've filled the rest of the frame with foam and started shaping it. :)
 
Oh, and I've noticed that the foam doesn't stick to garbage bags, so maybe that could be cut up and taped to be used for support for some shapes. After the foam has cured enough to hold it's shape the plastic support could be removed letting more air get in contact with the foam while it cures all the way through. Just a thought... :)
 
It's always a treat whenever you post progression-pics! 8)
I admire your choice of trying out new materials and develop different skills as you go along and follow your original design. I like this bike even without the glasfibre. The skelleton has some really nice curves... But I'm sure you have the vision to create another stunner.
 
Thanks buddy! Nice to hear that you like the progress so far! :)
Yeah, the lines on the frame itself are such that I think it would look nice with bare tubes. When I had finished welding the frame for this bike I almost wanted to make another one, a "no glass"-version with larger tube diameters to make it stiffer by itself. Maybe someday I'll build one like that, we'll see. All I know now is that after this one's done I have a cruiser and a ladies bike to build next in line, and one more that I'd like to try building and learning to ride, one different from everything I've built so far. More of that later... :wink:
 
Thanks Gold Street! :D
I guess that could work! It doesn't seem to stick to packing tape. Only thing is that it takes long for it to cure when air doesn't get to it. Maybe that would work great with 2 component foam? Never tried that. I think deorman's suggestion could also work. Thanks for the tip! :)

One side note, it's probably best to not spray this kind of foam indoors with bad ventilation. Lot's of really nasty stuff in it. It doesn't smell much, but it's things in it that's not healthy to inhale. Better use a mask while working with it.

Today's tuesday! :D But I won't work much on the bike because today there's a guy at the university workshop that'll instruct us on how the cnc lathe works.
 
Very fun and interesting at the same time ., can hardly wait to see the end result !
 
I have to laugh, this looks so messy but SO MUCH FUN!!!!! You are dead on, I have worked with this foam before and the more air it has the better. I like the way you are putting it on in layers as it will dry more evenly and faster than in just one big clump. What a great idea!! Easy to shape, easy to sand and if you need to fill anything in it just takes the squirt of the can!

See, I’m telling you!! Access to the CNC machine means that production Galtbachen bikes are coming soon!! :shock: :D

Keep up the good work Buddy!!
 
Half Link said:
See, I’m telling you!! Access to the CNC machine means that production Galtbachen bikes are coming soon!! :shock: :D

I agree, I get first dibs on dealership in South America!! :lol: :lol: :lol:
I´d be the number one buyer!!! 8)
 
Thanks guys! :D

Let me just say that the CNC lathe is not exactly under my command just yet... :lol: But it's interresting to see what would be possible to make with it, and now I've got some sort of basic idea of that and making hubs could very well be one use for it! So far I'm more drawn to learning to use the "regular" lathes and mills and all the other machines they've got in the workshop. :) Did I mention that they also have a five axis CNC...uh..beast? I don't know how to run that one either! :D
Good to know I've got the american dealerships covered! :mrgreen:

The blob in the middle of my room is slowly transforming.
Fogskum3.jpg


Thanks again for the kind words everybody!
 
Looking good.

Are you going to dissolve the foam after it is laid up. I believe you can dissolve it with MEK or Gasoline.
 
Thanks! :D

cman: My plan is to leave the foam inside the fiberglass body. I was thinking a little about different alternatives before I started building, and what I hope to achieve by making the foam a part of the core of the construction is that it'll both add some strength when it's sandwiched between the fiberglass, and also prevent the body of the bike to act like a resonance chamber like it probably would if it was hollow. Thanks for the tips, good to know things like that when hatching new ideas! :)

Hoeha: You've got it right, I'm shaping the foam core of the bike in my room with a hacksaw-blade in one hand and the vacuum cleaner in the other! :lol: I would prefer not to build a bike in the middle of my living quarters, but at the moment it would take far too long to finish it if I only worked on it in the workshop three hours every tuesday. I'll just do the rough shaping of the foam at home, then all the fiberglass work, the sanding and pretty much everything else on the bike will be done at the workshop. Actually I can't wait to get it out of here and be able to move around without bumping into it all the time. :roll:
 

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