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jesusgatos 03-21-2011 02:49 PM

learning how to work with composites
Learned a lot about making composite parts from reading all of ebrabaek's tutorials. Thanks again for sharing all this with us.
And I found another good thread about making a carbon fiber tank on the bay area riders forum. I don't know him, but I guess his name is Chris Baker and I found all the stuff he posted to be very helpful too. This thread -> How to make carbon fiber parts links to some of his youtube videos.

notmybikemodelname's super light F650-R project thread contains some good info too. tmotten got inspired and started working on his own bike. Looks like he's doing a great job.

Composites 101: Composites, Fiberglass, etc.
More fun with carbon/kevlar
Flexible fiber glass?
working with carbon fiber?
fiberglass fabricating ?'s
XR 650 R Rally Fairing for acerbis sahara tank
DR650 rally fairing
KLR headlight / fairing project
Repairing ABS fairings and Parts etc
Fabricating custom fairings
Any Carbon/Kevlar Skinning experience in the group? How to Make Carbon Fiber Parts

If you guys have any other good links (projects, sources for materials, etc.), feel free to post them and I'll add them to this list.

And lets see some more projects. Would love to see what other people are working on.

Seth S 03-21-2011 02:53 PM

Make sure you have proper ventilation and the correct respirators. A lot of the chemicals used in the layup process is nasty nasty stuff.

jesusgatos 03-21-2011 03:04 PM

Got a long list of composite dirtbike parts that I'd like to make, but have been busy working on other projects. My youngest brother Robo-Boogie was home for spring-break last week though, so we spent a couple days working together a few small projects. He's got a bit more experience working with this stuff; started when he got into riding jetskis and now he's going to school up at Chico, working on a manufacturing technology degree. So it was really helpful to have him around.

First thing we did was drive up to Svendsen's Marine Supply to buy some materials. Got some lightweight, medium weight and heavy mat, along with resin and some expanding foam.

jesusgatos 03-21-2011 03:15 PM

We decided to start with a new shock guard for my XR650R. Robo-Boogie made a really nice carbon/kevlar one for his CRF250X a while ago. It's held up really well and looked like a pretty easy part to reproduce, so it was an obvious choice for my first project.

The shock guard that I took off my bike is on the left and the new stock replacement shock guard that I purchased is on the right. Back tire just shredded it, so had to keep trimming it shorter.. and shorter.. and shorter.

Here's a pic of the carbon/kevlar shock guard that Robo-Boogie made for his bike, and you can see the ratty old shock guard on my 650 in the background.

jesusgatos 03-21-2011 03:22 PM

Applied some mold-release compound, laid down a thin coat of resin, and then the first layer of fiberglass (the lightweight stuff).

We only applied two layers of thin mat, and then taped-up a vacuum-bag. We didn't have a proper vacuum pump on-hand, and we weren't sure our shop-vac would create enough vacuum to get the mat to conform to some of the more irregular surfaces (like the area around the mounting bosses), so we decided to pack it in sand.

jesusgatos 03-21-2011 03:31 PM

This is what it looked like when we pulled it out of the sandbox.

But instead of releasing the shock guard from the mold, we laid-up another layer of fiberglass. The heavy matt didn't conform to the compound curves very well, so I ended up cutting in into smaller strips.

Let that dry and then pulled the shock guard. Made a pretty good mold, and we only lost a little bit of detail around the edges in a few spots.

So this morning I taped the shock guard back into the mold and poured some more resin to fill those spots where there were some small gaps. Not sure how well that's going to work...

akarob 03-21-2011 03:46 PM

I have a vacuum pump at work and I've done some basic fiberglass work before. I really should get into this as well.

Good for you, getting it done!

jesusgatos 03-21-2011 03:59 PM

The other project we started working on is a KTM headlight mask. Wanted to make something that we can cut to fit another, better headlight. So the first thing to do was make a mold of the headlight mask and headlight. Tried taping over the headlight, then filling the gaps with bondo, but that just made a mess. There was no way to maintain the contours of the stock headlight because I couldn't tell how thick the bondo was anywhere until I sanded all the way through it.

So I chipped off the bondo, pulled the tape, and filled the gaps with silicone caulking. After that dried, I applied some mold-release compound.

Laying-up the first layer of fiberglass was pretty challenging, mostly because of the mounting boss for the brake cable guide. I'm planning on modifying that mounting boss to make it easier to make, but wanted to start with an accurate reproduction of the stock headlight mask.

This morning I laid-up some lightweight mat in the mold and then backed that with some heavier mat. This first mold is a throwaway part, so left it pretty thin (fiberglass + resin = $$$). But was concerned about it turning out wonky parts, so laid it in the sandbox. Seemed to support the mold pretty well and I didn't have any sand fall into the mold, but it probably would have been a good idea to cover the sand with saran wrap or a garbage bag or something.

jesusgatos 03-21-2011 04:01 PM

If this part turns out halfway decent, I'll start re-shaping and modifying the headlight mask, and then make another mold. Haven't decided what headlight I want to use yet, and need to start looking into that.

jesusgatos 03-22-2011 05:20 PM

Spent a bit of time last night reading through notmybikemodelname's thread about his super light F650-R. Lots of good info.

Last post was:

Originally Posted by notmybikemodelname (Post 15479831)
When laminating with epoxy, you should do all of the lam at once. If you don't you have to sand the pasrt before finishing. When laminating with polyester you can and should do multiple layers to keep the shrinkage down, but only if you're not using a finsih resin or adding surfacing agent. If you do, then you need to sand the surfaces before lam'ing again as surfacing agent will act like mold release and your part will delaminate.:lol3

Figures I'd find that thread right after I'd poured some more resin to try and fill some holes in the shock guard mold. Didn't bond at all in most places, but bonded well enough in other spots that I think I have to start all over. Bah.

jesusgatos 03-22-2011 05:27 PM

Poured some foam into the headlight mask that I laid-up yesterday, hoping to stiffen-up the part enough that it would hold it's shape. Not so much. The marine supply place only had 2lb foam and it's pretty soft. The whole thing is flimsy enough that it's not symmetrical. The definition/detail is pretty good though. More wasted time/materials, but I'm figuring it out...

Notes for next time:
1) should have all my materials cut ahead of time
2) trying to save materials/money is wasting materials/money & time

jesusgatos 03-22-2011 10:48 PM

Robo-Boogie is back at school, but I talked to him about all this and then he talked to his composites professor. Says his professor is going to help him out, and suggested that they make aluminum dies for the molds (cast out of urethane RTV or plaster of paris). Sounds interesting. But that kind of takes me out of the loop. So I'm going to focus on designing/shaping parts and Robo's going to make the parts. Told me he'll take lots of pics and post up all the details here if anybody is interested...

Started messing with some handguards today. Got a pretty good idea of what I want to end up with. Will continue working on this tomorrow.

jesusgatos 03-23-2011 07:53 PM

The big idea with these handguards was to make a 'basket' on the bottom that should keep hands/wrists from getting tangled-up in the handguards in a crash. So I wanted to wrap them under the bars and back as far as possible, but without interfering with anything. Spent a few hours today hollowing-out the new handguards to check the fit. Took these pics of myself sitting/standing on the bike as far forward as I could possibly get. Clearance was good everywhere, and I figured out that I could extend the bottom back even a little bit further (on the inside) without causing any problems.

Taped-up another paper basket and poured some more foam. Unlike the fiberglass resin, this stuff bonds to itself really well. Filled the whole thing up since I was finished checking the fit and the hollowed-out foam was really flimsy.

Raised the front/top edge a little bit and then slathered-on a layer of bondo. Going to do a little bit more shaping and styling tomorrow.

ebrabaek 03-24-2011 01:12 PM

Wow....... First I want to compliment you on your ingenuity, and determination.......I know of many people that would have ditched the project after the first ups.......:clap.... That said I would like to add a few observations. Generally speaking.....Unless you have sharp 90 deg. can make the fabric mold nicely with a little persuasion. There is nothing wrong with vacuum bagging....But I usually end up spending more time in prep....and cosmetic fixing after wards.... So I usually saves this method for the twisted crazy pieces. What you have here does not warrant vacuum bagging. It does how ever require several fermented malt and hops beverages to keep the temperament in check and to be able to see clearly through the tunnel staring at the light making sure it`s not a freight train.:D. The thin glass mat you used is not very cooperative. many will tell you it is because of it`s thin weaving.... and some of that is correct in theory......But what they don`t tell you is that it does not stretch well as a fabric in whole. So as you see it.... it will lay down very good in one direction....But as soon as you begin to mess with the next corner....It`l yank and pull like mad in the areas your`ve already layed down. You would notice this a lot if you would compare a similar thick piece of plain weave Carbon fiber..... It`l conform much better.... Twill weave....even better.
Also if you have issues wait to lay the first piece of cloth down until the resin is tacky.... Use it like flypaper to hold it in place.... You will be surprised to as how effective that is. Bad thing..... One layer at a time.:wink:
The polyurethane foam is a kick to work, and see the mix expand..... But requires a lot of post work with fillers and re-do`s...... As long as you are using epoxy.....try to use this.....

Enough for many projects....and you can just "melt away" the remaining foam with acetone....:evil Then you just sand the piece to your liking before layup. The resin has a hard time with grapping the polyurethane foam as well.....whereas it`l grap the above foam nicely. Just a side note..... Not all epoxy`s are equal.... Some are better than others.......Not just in strength....but workability....transparency...etc. Remember to give the pieces a uv clear coat protection, before they get bombarded by the sun.
After seeing your project being a few days old.... I have no doubt that you will succeed in making exactly what you want. Very nice....:freaky



jesusgatos 03-24-2011 06:35 PM

Hi Erling-

Thanks for posting. I've read all your composite threads and found them to be very helpful.

Understand exactly what you're saying about the materials I was using. What would you suggest using for making plugs and molds for parts like these?

I was laying-up the fiberglass before the resin got tacky at first because I was afraid about working time - thought it might start to dry/harden before I was finished. Have had that problem with bondo and found it to be very frustrating. But quickly realized that this isn't much of a problem with the materials I'm using, and things started going a lot better once I figured that out. Think the biggest mistake I've made so far though has been not cutting all my materials ahead of time. Was wasting a lot of time and making an awful mess cutting materials on-the-fly.

Have a bunch of that insulating foam here (but it's the white EPS stuff) in different thicknesses, but seemed like it would have been a major pain in the arse to try and cut those pieces to fit the handlebars and handguards. Am sure that will be really useful for other projects though.

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