Fiberglass information

[WallacE]

Anyone have any tips/advice on fiberglass moulding??? I am looking to make a new rear fairing-I do not like the way the back fairing meets up with the side fairings, I want a smoother transition. I googled it and found info on there, I was just wondering if anyone here had any advice.

Also does anyone know of anyone with a spare rear fairing for an 06 Kat, or a front headlight assembly I would post a WTB ad, but don't have 50 posts yet and need to get going on the big mods-Thanks in advance.

[BigFish]

For your specific project:

I would suggest:
1) buy a block of styrofoam
2) cut it so it fits your bike,
3) sand it so that it is shaped as you would like it to be shaped
4) cover the finished shape with something, otherwise the resin will eat and distort most styrofoams. (glad pres'n'seal, painters tape, or elmers glue will all work for this)
5) Cover the nearby areas and those below with a vinyl sheet or several layers of newspaper to prevent contact with dripping resin.
6) Cut one piece of fiberglass to the right shape
7) spread some resin over the shape created in 3 and protected in 4
8) lay down pre-cut fiberglass and spread some extra resin over the fiberglass so that it is saturated
9) let dry, then sand the layer so it is mostly flat
10) cut 2-4 pieces of fiberglass and lay them down using steps 7 & 8
11) let dry, then sand, sand, sand and paint. For an even paint job start with 220 grit, then 320, then 400, then 600, then 1000

Other thoughts
I use "Glad press'n'seal" when making fiberglass molds of things. It is slightly porous though so don't put it on anything that would be chemically burned by fiberglass (paint, etc).

The cheaper stuff is actually better if you want something that sticks to itself and some plastics.

If you want it to be translucent with color add some pigment to it. Some surf shops and art supply stores will have these. Outside of San Diego I can't name a good source for these. It seems like the sort of thing that Dickblicks.com should carry though....if you want a solid color there are additives that will accomplish that too.

I like to use plastic butter knives to apply the stuff.

Always, always, always sand and clean an area to which you are applying fiberglass.

[WallacE]

Appreciate the info...what about the bolt holes lining up??? I guess that I will just wing it when I get there-I am sure it is gonna take a couple of trys until I get the shape and durability that I want, but hey thats what the winter is for right

[WallacE]

For your specific project:

I would suggest:
1) buy a block of styrofoam
2) cut it so it fits your bike,
3) sand it so that it is shaped as you would like it to be shaped
4) cover the finished shape with something, otherwise the resin will eat and distort most styrofoams. (glad pres'n'seal, painters tape, or elmers glue will all work for this)
5) Cover the nearby areas and those below with a vinyl sheet or several layers of newspaper to prevent contact with dripping resin.
6) Cut one piece of fiberglass to the right shape
7) spread some resin over the shape created in 3 and protected in 4
8) lay down pre-cut fiberglass and spread some extra resin over the fiberglass so that it is saturated
9) let dry, then sand the layer so it is mostly flat
10) cut 2-4 pieces of fiberglass and lay them down using steps 7 & 8
11) let dry, then sand, sand, sand and paint. For an even paint job start with 220 grit, then 320, then 400, then 600, then 1000

Other thoughts
I use "Glad press'n'seal" when making fiberglass molds of things. It is slightly porous though so don't put it on anything that would be chemically burned by fiberglass (paint, etc).

The cheaper stuff is actually better if you want something that sticks to itself and some plastics.

If you want it to be translucent with color add some pigment to it. Some surf shops and art supply stores will have these. Outside of San Diego I can't name a good source for these. It seems like the sort of thing that Dickblicks.com should carry though....if you want a solid color there are additives that will accomplish that too.

I like to use plastic butter knives to apply the stuff.

Always, always, always sand and clean an area to which you are applying fiberglass.

so when you say "precut" should i just cut it in strips and do a paper mache type of thing? Do you think that would work?

[BigFish]

so when you say "precut" should i just cut it in strips and do a paper mache type of thing?

It will be stronger and less prone to cracking if you have one solid piece of fiberglass for each layer. This is only possible with certain shapes however. For something exceptionally curvy you will need to use strips. Cutting the exact shape and size needed is as much art as science, but you'll get it fairly quickly. In general you're better off cutting a little too big and wasting some material than having too little. I tend to have a 1-3 inch overlap with my fiberglass matte depending upon the shape.

I am sure it is gonna take a couple of trys until I get the shape and durability that I want, but hey thats what the winter is for right

You can practice this with paper. Outline your hand on a piece of paper. Next draw a line that is at least 3 inches away from the line you just drew at every point. Cut along that line. You should now have a piece of paper that covers your hand with a 1 - 2 inch excess. Fiberglass has a degree of stretch unlike paper though (except it doesn't rebound like spandex does) so it will be more forgiving than the paper would be.

3 layers minimum should be used. The flatter the shape, and the more paper mache style strips you use (these are contradictory, I know) the more layers will be needed for strength. If you use paper mache style strips, go vertical for one layer and horizontal the next. This will ensure that the fault lines will not line up for each layer.

Appreciate the info...what about the bolt holes lining up???

I've tried two different methods:
1) you can put a bolt or dowel through the area where the bolt goes, and wrap the bolt/dowel with 3+ layers of painters tape. Use more if you want the hole to be much larger than the bolt. In order for this to work you'd have to be building the fiberglass on the bike. When I did this the holes didn't line up and I wound up cleaning the holes with a dremel.
2) You can make the shape and drill it later. Fiberglass cracks easily though. This can be minimized by applying minimal pressure while drilling, and starting with a very small drill bit in the center of where the hole will be. Then repeat with drill bits of increasing sizes until the hole is the proper size.

[WallacE]

So i picked up some styrofoam from a local arts and crafts store...and the resin and what not from Lowe's. So far I have about 40 invested, i am going to try the cowl first and see if i can get the principles down first. I am gonna try and get an extra rear fairing and use that one. I know that the stuff from Lowe's is not the best, but I am not the best at it, figure I will use this as a practice round.

[BigFish]

I just noticed your pic. You're not going to build Picasso art into the curves of your bike are you?

[WallacE]

OK...so does anyone know where I can get an outline of the post Kat...I know that there is one on here somewhere-I have tried the search function, but if someone has a quick link that would be great

[airforceranger49]

honestly bro... i wouldnt use fiberglass for an entire section on a bike... mainly due to its tendancy to crack. for smaller pieces/parts of a fairing, fiberglass will work ok... but over bigger sections (unless you use ALOT of layers) it will tend to build stress cracks.... my suggestion for something like this would be vaccum formed ABS. you can google it... making a vaccum former is pretty easy, and you can make mold after mold after mold with it.

[loudnlow7484]

honestly bro... i wouldnt use fiberglass for an entire section on a bike... mainly due to its tendancy to crack. for smaller pieces/parts of a fairing, fiberglass will work ok... but over bigger sections (unless you use ALOT of layers) it will tend to build stress cracks.... my suggestion for something like this would be vaccum formed ABS. you can google it... making a vaccum former is pretty easy, and you can make mold after mold after mold with it.

I prefer fiberglass for pretty much everything. If you do it right, it's incredibly strong. Plus I love how it smells. Wear a dust mask when you sand it, though..... if you breath in a lot of that crap, you'll have a nasty cough for months afterwards.

1 tip for strength of large flat areas..... Once you have it all molded out, if you feel like you need more strength in a big flat area, lay down strips of rope (maybe 3/8" thick rope) spaced 1 1/2"-2" apart along the back of it, and do another layer or two over top of that. Fiberglass is a lot stronger when it is curved, so the wavy effect you'll get will really add to the strength a lot more than just a couple more layers of mat would.

[loudnlow7484]

For strength in glassfibre moldings add a layer of core mat in key area's, eg 2 layers of 600w mat laminated flat will bend but not break easily where as the same 2 layers with core mat between will be a struggle to bend & will take really serious abuse before breaking completely

tone

are you talking about the honeycomb mat? Where the f* do you get that stuff?!?!?! I found it about 6 years back at a marina, and it was great stuff, but I've never been able to find it again.

[T McCall]

All your fiberglass needs including " how to's": fiberglast.com