Hello from Washington state, USA!

First Stop Introductions
#1

Hello,
I have been ‘lurking’ here for a while, but thought I should take a moment to offer a proper introduction. I have a good friend who works with composites in the aerospace industry, and through many examples that he has shown me, I have seen the benefits of various composite parts. I can’t seem to leave anything alone, and at some point I began thinking up ways of making my snowmobile both lighter and stronger. After machining various titanium parts to replace steel, my thoughts eventually drifted towards the even greater weight savings possible with composites. From there, I came up with the ‘crazy’ idea of making a carbon fiber tunnel for the snowmobile, which would offer a significant weight savings. I only say it’s a ‘crazy’ idea because the number of carbon fiber/composite projects I have done at that time was exactly…zero. So, it seemed like a bit of a stretch, but I enjoy a challenge and am learning as I go, with much thanks to the vast knowledge available (and generosity of those who share it!) from the members of this site. I can only hope to someday be able to help others with questions they may have, knowing what it is like.

I picked up books 1-3 of John Wanberg’s “Composite Garage” series, and read them cover to cover, fascinated with all the new information I was learning. My professional background is in manufacturing, primarily precision machining of aerospace parts, so the topic of composites has been something relatively ‘foreign’ to me, at least in the technical aspect of it. I have decided to build a mold for the tunnel, even though there is a chance that I will only ever make one actual tunnel from it. Or maybe someone else becomes interested and I make a few, time will tell.

At this point, I have nearly completed the plug, and though it is not ‘pretty,’ I do think it will function as needed, and (hopefully) allow an accurate mold to be made. One of the biggest ‘problems’ I have had to overcome is my own preference for accuracy, coming from a background of machining metals. I have had to remind myself many times that certain things do not have to be perfectly square, a radius doesn’t NEED to be exact, etc. It has been a great learning experience for me so far, and I really don’t think I’ll be ‘done’ with composites when the tunnel is finished…somehow, I think this is just the beginning, which leaves me even more excited for what the future will bring!

So that’s me, and why I am here, in a nutshell. I don’t know that I have much knowledge to share that is of any value to anyone at this time as I am still learning more each day, but I do look forward to reading about and sharing new techniques all the time. Lastly, I wanted to give a HUGE thanks to all of those who have shared their knowledge and taken the time to help those (like me) who may not yet know or understand how things are to be done. I am pretty sure I’ll have a ton of questions one of these days, and would like to say thanks in advance! With that said, I would also like to add that I do try to use the ‘search’ feature to find my answers first (maybe I’m just stubborn), but sometimes there simply is no answer available for the exact question, or scenario I am in.

Thank you for taking the time to read through this, and I look forward to participating in many helpful, interesting conversations here in the future!

-Charlie

#2

cool, sounds like you’ve got a good start!

Welcome, look forward to hearing more about your projects.

#3

Thanks for your post, and more importantly, thank you for sharing your knowledge with others! I have read countless posts of yours and inevitably learned from you. I keep feeling like I’m getting closer to finishing this project, but then I have to stop and laugh at myself a bit, since I realize I still have a long ways to go. Probably the biggest challenges so far have been trying to find ways to ‘protect’ the plug from being dissolved by adhesives, bondo, gelcoat, etc. That, and not having a proper workshop. And there was that incident where I read the wrong data sheet and mixed some epoxy and hardener at a 1:1 ratio, not realizing my error until the next day when it had not cured.
:frowning:

Regardless, I’m still moving along, and feeling pretty confident that the plug will be done within a couple of weeks, or sooner. I’ve attached a few pictures to give a better idea of what it is I’m working on. Despite the many different splotches of colors, the surface is actually very smooth and straight. The various colors are the result of using bondo, spackling paste, paint, etc. while countouring, filling, and shaping the plug. I would have liked to have painted it all one color before coating it with the Smooth-On “Epsilon” epoxy, but found that the epoxy adheres to the foam much better than to painted foam.

The first picture is just doing a bit of mock up of the fuel tank and upper frame to make sure everything sat in the proper relation to each other. The second and third photos are more recent, with the flange attached to the plug and with a coat of Smooth-On’s Epsilon epoxy (to protect the foam from the tooling gelcoat).

#4

hey, nice looking so far. I take it you’re working with eps foam then? That stuff is nice cause it’s cheap but also a pain for the reason you listed. Just use what you got i guess? Though i find with composites, if you try to be cheap then, it invariably causes a lot more work and time and wasted materials. Sometimes I feel like I should just buy a gallon of resin and just mix the whole thing and throw it in the trash to avoid all of the frustration… lol… takes a lot of patience. At this point i’m trying to just do things as best as possible. I’ve also taken the step into using prepreg instead of infusion or wet layup which has only made things a bit more complicated… it never ends.

Well glad I could be of some help. I’m slowly moving my way toward knowing what i’m doing. A lot of it is just having the right tools, equipment, materials and shop.

that Smooth-On “Epsilon” epoxy looks interesting.

Keep it up, there is a light at the end of the tunnel! :smiley: