Fabricating custom fairings

I want to make a custom fairing for my 98 Tiger. Something like this:






I want it to look good and not " a hack job", my question is does anybody know how to do mock ups for projects like this?? I guessing I could maybe start with cardboard but is there any other techniques that work well?

There are some other threads (not exactly sure if they are in Garage, but most likely) on this same topic. Maybe they can kick start your ideas...

Yes, cardboard is a good cheap place to start - others have done this as well.

Good luck

Let google do the search work for you:

http://www.google.com/search?num=100&hl=en&lr=&safe=off&q=site%3Awww.advrider.com+motorcycle&btnG=Search#sclient=psy&hl=en&lr=&safe=off&q=site:www.advrider.com+fairing+build&aq=f&aqi=&aql=&oq=&pbx=1&bav=on.1,or.&fp=a2885925ea8ae0

You always use foam. Carve it, sand it, and file it to shape. Then seal it well and use it to make your mold. Alot of work but it can be done. Are you using fiberglass or trying to vacuum form plastic?

yep, foam & glass. You need high density foam like Divinicell if you use polyester resin... lesser foams dissolve. You can use any old thing if you buy epoxie... but 5x the money.

very nice work on the XT, and great ideas from you guys too.

Check out this thread for inspiration and info:
http://www.advrider.com/forums/showthread.php?t=592734

Get a big piece of styrofoam, draw the 2d shape at the front. Draw the 3d shape at the top and remember how the 2 meet and start cutting with a kitchen knife and saw and shaping with a wood grate (bit like a cheese grater) and rough sand paper. Cover it in epoxy resin and start sanding. When you've done that remember to show the progress.

where do yo get styrofoam stock like that?

Florists foam, the green stuff.

Easier to work and shape.
Guys I know that do a lot of fiberglass fab have found a source for the two stage chemicals and create their own.

Once you have the shape, make a mold. (as in what do you do if you crash it and need to make another)

Sand the mold to get it as smooth as you want it and lay in the glass...

Lot of steps in between but you get the idea.

oh yeah, use an electric carving knife to take it down until smaller tools are required.

+1 on the electric knife. Also, you can get thin foam, like 1/4" and bend the arc you like, hot glue a dowel to the back to hold the shape and do the layup. When it cures, hot glue the wings, etc on until you have your final form. I built a couple hovercraft like that. Nice to have a mold, but it's extra work. The upside is that if you like the shape & need more for other bikes it's done... or at least a good place to start from.

BTW, epoxy resin will stick to polyester, but not the other way around, it will not make a permanent bond that you can trust.

If you want it to look really professional, I think you should invest the time in making a plug, then a mold.

A plug can be made from a variety of materials:
- styrofoam is a good choice if there are going to be lots of curves (remember polyester resin will dissolve most styrofoam)
- wafer board is good if there will be lots of straight edges
- other media like wood, aluminum, steel can all be used to make your plug - these have the disadvantage of requiring much more time to make, but if you want a permanent plug that can be used to make more than one mold, the more durable, the better.

Here is a plug I made from wafer board and duct tape:


Your plug will be the exact replica of what you want the shell of your fairing to look like. Your plug should be as smooth and blemish-free as you want your final product. Grade-A plug yields Grade-A mold that yields Grade-A product. By far, the most labor intensive part is making the plug perfectly symmetric and blemish free.

Once you have a plug, you can either layer your glass (or whatever composite you choose) directly over the top, or make a mold from which you can make multiple fairings in the future. Regardless, if you want to re-use your plug, I recommend you take the same plug material and try a variety of mold-release agents on that material before committing to layering glass or making a mold.

This is my plug after covering it with Bondo and spending hours with a sander:


If you are making a mold, you will need to invest in some gelcoat. I recommend spending some extra $$ up front and getting "tooling" gel coat. The tooling gel coat is stronger and will last longer. For a fairing the size in the photo you posted, I would expect about a gallon of gelcoat for the proper thickness.

This is my mold after pulling out the plug:


You can see that it is kinda rough...that is because I didn't use a proper mold release agent. The plug was destroyed after removing it, and I had to spend more hours with the sander.

I recommend you at least consider a fairing made from multiple pieces. The reason for this is that if the shape is complicated, and you are using a mold, "pulling" the product may be challenging. This was another mistake I made. My last mold had to be completely destroyed in order to get the final part out. Although it looks very simple, when I tried to "pull" it, all the angles that go toward the center of the product make the "pull" much harder.

I don't want to discourage you, but if you have no experience doing this, then you should expect to spend lots more than you planned. Mistakes are costly when fabbing composites, as they often require a complete redo.

So this is sounding like its not a cheap adventure. I was thinking maybe a $100 - $200, but what you guys have shown looks like its costs a but load.

+1 on making a plug!

I think that once you have acquired the skills, a good mold, and some other equipment, then the cost of supplies like resin, gelcoat, and fiberglass is lots less than $100 per fairing. Like almost all things, the cost is in the Research and Development.

I'm embarrassed to admit this, and I admit I have a problem, but I have spent a couple thousand dollars over the past year, and have yet to turn out anything of really good quality yet. If I were charging for my time, I would have tens of thousands of dollars invested by now.

In hindsight, if I wanted to do it well, do it quickly, for the least amount of money, and be able to make many copies, I would take my plans to a machinist who could mill me an aluminum or hard plastic plug(s) to my design. It would be a big expense up front, but would save thousands on labor and supplies in the long run.

"So this is sounding like its not a cheap adventure. I was thinking maybe a $100 - $200, but what you guys have shown looks like its costs a but load."

don't have to be.... polyester resin is about $40 a gallon at Hm Depot, Schcuks, etc. If you don't want to use Bondo (about $10-15 a can), you can make your own filler with Cabosil which is available from stores that specialize in fiberglass products... it's only a couple bucks a pound (ground up fiberglass). A yard of 6 oz cloth is about $10 at 60" wide. Thats all you need to produce a one time part. I like the pasteboard idea.... cut shapes, glue with a hot glue gun, wax the crap out of the surface & start laying up.

Poly resin stinks bad, suggest a respirator for sure. And a box of nitrile gloves. And a half gal of lacquer thinner, acetone, or MEK.

I reckon it was cheap as for me. I had a lot of help from NMMBN who is a pro at this. I'm just a DIY clown with 2 left hands. There is a thread about it in thumpers. The process is pretty simple. I filled up the car twice with sheets of off cuts from a sign maker. Free. Downside of this was I needed to buy cans of styrofoam safe glue which isn't cheap where I am. Most glues are polyester based and will desolve the foam which is also polyester based. Look up styrofoam on wikipedia.

Make the plug as accurate as possible so that it actually looks like the final part. This way the mold won't require sanding. It's a lot easier to sand the plug exact because it's the actual shape where as the mold is the inverted shape.

With foam you get a lightweight plug which helps positioning it on the bike. You can also use clay, but you should be able to do it with foam. Cover it in epoxy resin with microbaloons which will make it into a thick putty. I only used 1l of it. The baloons expand it massively.Put it on to fill the gauges and sand it smooth up to 120 grid. You can also fill in other bits with body filler so long it's not in contact with the foam. Body filler is polyester based but is quick to set. Epoxy require curing overnight, but filler about 10-20min. I'd get an orbital sander, but still hand sand it for the final smoothness. Than spray it with primer/filler and sand with wet and dry. Haven't done this bit yet.

For the body I'm using clay over masking tape and block of foam to fill the voids and holes. Drill holes into the foam to give the clay something to bond to. There are good youtube videos of the car pro's to show you how it's done. There is never only 1 way to do it and you can be creative with your methods, but I recommend spending all the time on the plug and less on the mold. It should be finished by the time you get to molding it. That's why you use gell coat. Shouldn't require sanding.

This was about 2 hours of clay work.

this is really cool stuff. I guess I'll have to get some time and start figuring this out.

This Tiger's stock fairing curves back over the instruments so everything is hard to see standing. Plus the wind is deflected right at my chin so its very noisy. I think the line of the bike would be better looking with the rally style fairing I showed earlier. This would also add more room for gadgets.