Custom Fighters - Custom Streetfighter Motorcycle Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
1,593 Posts
Discussion Starter · #1 ·
I need to bond fiberglass to plastic (dirtbike fuel tank) Do any of you guys have experience with bonding fiberglass to something other than fiberglass, be it metal, carbon fiber or plastic?
I think I am set on using an adhesive made by Fusor but they make several different adhesives for fiberglass and plastic.. I am not sure which one to use.
 

·
Registered
Joined
·
1,593 Posts
Discussion Starter · #5 ·

·
Perpetual Project
Joined
·
3,695 Posts
I've made 2 pieces of bodywork that were fiberglass and plastic. First experience was not so good, second experience has proven fine.

Trick: make sure the plastic is WELL scarified in the area where the fiberglass will contact it. Use a very rough sandpaper.

My first project didn't work the greatest originally because I was trying to get a flat piece of fiberglass to adhere to a piece of flat painted plastic. It bonded for a while, but developed cracks pretty quickly and started to peal from the plastic. I'm gradually redoing the piece a different way to correct it.

My second attempt -where I sanded all the contact surfaces very well- has turned out great and is lasting fine. Its tricky getting the seam where the fiberglass and plasic meet to be perfectly smooth, it takes a lot of sanding down to very fine grits, so make sure you have enough layers of resin down; you don't want to sand into your fabric, it'll leave raised fabric paterns on your finsished product.
 

·
Registered
Joined
·
97 Posts
When I modified the headlight that's currently on my bike I had to make a fiberglass piece to attach to the headlight's mini-fairing in order for it to fit over my stock guage cluster. The original part of the fairing is ABS plastic, after after sanding it with 120 grit sand paper to rough it up I was able to bond the fiberglass to it using 6 minute epoxy. As candyman said, make sure you rough up the plastic pretty good or it won't bond. Also, make sure you use the least amount of epoxy you can, anything that oozes out will have to be sanded in order to create a seamless transition.

If you're mating surfaces aren't perfect you can use some Bondo to smooth things out. Just remember that the fiberglass, Bondo, and plastic will expand and contract at different rates when exposed to the same temperature. This may result in some cracking in the long term. I haven't had any problems yet, but it's something to consider.

Here's a pic of the finished headlight:

http://i183.photobucket.com/albums/x157/IndySV1K/My Bike/Picture004.jpg

I've trimmed it a little since this was taken.
 

·
Perpetual Project
Joined
·
3,695 Posts
With respect, I would highly caution against the use of Bondo filler except for the tiniest pinholes. Bondo is much to soft and britle, if you use it in any kind of quantity it will just crack from vibrations if nothing else. A lesson learned by me, for you. I tried it on some of my first attempts at fiberglassing but it failed miserably. On my current projects I don't use a drop of it. Your result will look much better if you focus on getting a smooth, even coat of resin for your finished layer.
 

·
Registered
Joined
·
1,593 Posts
Discussion Starter · #9 ·
Thanks guys for the info, the parts are slowly rolling in. Hopefully I'll have everything here this weekend to get a start on it.
 

·
Ebay PosterChild
Joined
·
981 Posts
you really cant bond the 2 since plastic is so full of static but like candyman said scuff the shit out of it gouge it you dare but other then that i dunno my a-pillar in my car failled after 3 months in the heat
 

·
Registered
Joined
·
1,593 Posts
Discussion Starter · #11 ·
this is what i have so far, the dummy tank hasn't shown up yet. hopefully tomorrow. I've got the fiberglass copy of the bottom of the xr tank done.
[/QUOTE]

this is what it looked like originally
 

·
GURU
Joined
·
8,827 Posts
one thing that i think has been overlooked is the porosity of the plastic. You know the graphics that go on your gas tank and how they have a bunch of tiny holes in them. This is because the gas fumes"vent" through the plastics. Id say you could get them to stick but i seriously doubt it will stay very long. The stock xr tank should have been steel right. You dont really need the louvers since your riding on the street and its aircooled. i think youd be okay without them. Are you trying to fit a cr tank on there? should be fun since it drops in a twin spar frame. Maybe you can get a 96 and older cr tank to stradle your frame rail.
 

·
94900RR
Joined
·
9 Posts
Plexus adhesive !!! Where can I get this? I would love to give it a try. I have a large amount of glass to ABS that I need to do. Do you know any tricks to working with this kind of adhesive, and what is the name? Thanks!!
 
1 - 17 of 17 Posts
Top