My CF/Kevlar gas tank

General Composites Discussions Showcase
#1

I began this project about 6 months ago and picked at it little by little. I took this from a steel gas tank, creating my own plug, making a production mold after some modifications of the plug, and finally to production. I have probably 100 hours of labor into it from concept to creation but since this is my very first serious CF piece, I am extremely happy with the outcome.

The bulk of the tank is going to be painted (race team colors) so I was fortunate in that I didnt have to be terribly picky about where my visible seams were but there will be two visible carbon “rally stripes” down the center of the tank.

All in all I am very happy. There are a few minor blemishes where I got a bubble in the epoxy and the seam from the two halves of the top mold is visible however it will be covered with paint so I am not too concerned.

The tank schedule is CF/CF/CF/Kev/Kev/Kev/CF/CF/CF. I wanted to ensure that this thing was going to hold up should I have an abrupt meeting with the pavement. It is my belief that the Kevlar will help to keep any abrasion damage from rupturing the shell.

Anyway, couldnt have done it without the the knowledge and help from CompositesCentral so a sincere thanks to you all for what is the first but surely not the last composite piece that I make.

#2

That Looks brilliant.

How did you joint the two halfs in the end? was it a stepped lap joint? what did you use to bond it together? and im guessing you hsve filled the tank with the fuel tank sealer liquid to make it ‘water tight’ or should that be ‘fuel tight’ lol. have you tested it yet?

#3

The production mold is in 3 parts: a bottom and two top halves which I bolt together. Makes for easy removal once cured however it does leave a small seam right down the center of the tank. I sanded it flush but it is still slightly visible however it is going to be painted there by design so it shouldnt be visible at all.

I bonded the tank with thickened epoxy top to bottom, ran a bead of loctite structural epoxy around the mating surfaces as well. The entire inside of the tank is coated with several coats of POR15 fuel tank sealer.

I have had fuel in it and no leaks but it hasnt been under pressure yet.

#4

i like the seams alot

#5

Mmmmmm… a Ducati Monster tank eh? One of my goals is to produce a CF tank for my 748s. Any chance you could post some pics of the molds?

#6

You beat me to it! Im in the process now of doing the same thing to my Tuono after reading the thread on the BARF forum. And it looks like Im also using the same CF/Kevlar mix. Mind you, I made up a test strip about 1" wide to test fuel compatibillity and I ended up using 10 layers compacted. Man, that`s not thick!

Nice job!

Ray

#7

I am sorry I dont think I have any pics of the production molds, but I have the splash mold pics which I used to make the plug, they are pretty close to the produciton molds, just shaped slightly differently. These are “raw” molds and havent even been cleaned yet so please be forgiving =)

Bottom mold:

Top Mold halves:

The plug:

Underside of the plug during the reshaping/filling/sanding (and sanding, and sanding, and sanding) phase:

and the final piece after paint

#8

hi mate im sure i followed a thread you did? on a bike forum. are these parts vacum bagged or infused?? im intrested how you joined the 3 seperate parts once been made

regards

#9

One question,

this tank as I understand is full composite tank and you use epoxy resin? Epoxy is not good friend for gas tanks, the only strong resin for this specific project is Vinyl resin. Vinyl Resin has much better specifications for such applications.

#10

The parts are vacuum bagged however the production tank is 2 parts, top and bottom. They were bonded with thickened epoxy as n well as a structural epoxy for reinforcement.

The entire tank has multiple coats of a rubberized fuel cell sealant on the inside so I am not terribly concerned about using epoxy during construction.

#11

:cool::cool:

#12

beauty! please keep updated about the performance of the POR coating. Thanks!

#13

It has been in production for several race weekends now, probably a total of about 20 hours on the track and not a single issue. I should also add that I am running VP C12 gasoline (110 octane) that is known to be brutal on tanks and liners but so far, so good. I should add that it has had fuel in it now for about 2 months straight.

#14

does that fuel have etoh added?