Yep that is my thought all of the ideas look good. I think the heat shrink tubing is going to be a simple method for my immediate needs compared to the long range of the project.

How are you coming on your boat?

Filling and fairing. Fairing and filling!

My shoulders hurt!

Progress is on the website; teamvmg.weebly.com

I've done this on a smaller scale (1" OD) but used Latex tubing as the inflation medium. It's inexpensive, inflates easily, stretches a TON, the pneumatic fittings are very cheap, and epoxy doesn't stick (very well) to the latex tubing.

True and I agree 100%. Except, the vacuum has advantages with respect to removal of water vapour etc. The ideal is actually to do both (like the aerospace autoclave operators do). Create a vacuum and then apply additional pressure. This can be achieved in this case by putting your whole setup in a sausage back as well. The once everything is set up you "suck and blow".

Paul,
Do you mind giving a few more details on how you get the lay up and bagging materials set up in the tube?
Thanks,

I am also interested in more information on how you set it up.

Mike,
I understand your desire to make all the parts for your project, but this is the one part thats easy and relatively cheap to buy off the rack is carbon tubes. Its going to be highly stressed part, so it needs to be perfect, and you need to be weight sensitive because its hanging off the front of your boat. If you buy the beam tubes, the forespar and the boom, you would save on shipping.

Tubes are the one part I would BUY. Save yourself the headache and call Forte. www.forterts.com

You probably could find someone going south and have them strap it their roof racks.

+ 1
Makes perfect sense to me.

But thats the bit that kept me awake at nights trying to figure it out!

The trick was to wrap everything around a 2" mandrel [pipe] in reverse order [Starting with vac bag and ending with lay-up, poke it inside the 4" tube and then get it to stick/expand to fit. the 2" tube then is pulled out.

You can just see the 2" tube with the disposables already around it in the picture on the website.

I did it in about 3 hits because the pre-wetted carbon is very clingy and difficult to expand if too much is laid up at once.

This is a pretty half-arsed garden shed method and would never get used in any sort of production, but suits the one off approach.
Contrary to what others state, a large chunk of money was saved by doing this, that then went to pay for other parts of the build.

Paul f32#81

teamvmg.weebly.com

The savings are highly dependent on the cost of your own working (and thinking) time.

Time which you dont sum up and multiply with $$ anyway when doing something worthwhile. I work to live, not the other way around.

Has anyone tried resin infusion with this method? As long as you can find a way to stop the joins in the mould becoming race tracks it should provide a good product with the advantage of giving you unlimited time to get everything set up perfect.

No mould involved, just a pipe. infusion would work well, just that it would help if the carbon fiber is a bit tacky somehow to hold in place when positioned.

The pipe is the mould. With what I understand of your current system, when you set the up the infusion you would probably end up with resin running up the join in the pipe instead of through the fibres. This would result in a lot of dry areas. Having said that it would be relatively easy to set up your bag so the resin would go in one gap, through the fibres and then out the other gab. I might do an experiment at some stage.

There are spray adhesives that are used to hold fibres in location while setting up.

Whats your recommendation on the spray adhesive? I'm just about to do a small tube
regards

Thanks for all of input! I’ve been off line the last few days working on the boat burning midnight oil.

I received the woven braided tubing very interesting material. I have not made a final decision on the molding method yet. The braided tube will give me a continuous weave that will expand or contract and keep the fibers in the correct orientation.

Any way that is the fun part about boat building is figuring thing out and coming up with ingenious ways to solve the problems.

Go out and buy it pre-made has never been cheaper! Plus that spoils the fun.

I’ll let you know how my method works, and it is a precursor for building the beams, which will be a unique shape. I had the engineering performed on the beam shape and it proves out structurally stiffer then a circle or teardrop.

I've never found setup time much of a problem.I only lay a thin layer of resin over each layer of uni carbon with a squeegee and rely on the pressure to push the resin through the fibres for saturation. Drop it in the mould, fold the layers over the bag put the top on and inflate.
Super slow hardener or a simple oven and pre-preg would be a nice way of providing setup time on big jobs.

What keeps the fibers in line? I found that uni wrapped in a cylinder shape want to stretch and not keep the fibers in proper orientation. I’ve also seen a problem with wrinkles I suppose enough pressure will resolve that issue but that tends to mess with fiber orientation also. Carbon is all about the proper fiber orientation.

I lay the uni in the orientation that I need over a light layer of plain weave glass cloth. It could be plain weave carbon but when Uni carbon is way cheaper than plain weave carbon the uni carbon and glass combo gives best value, given the plain weave is mainly for handling.

Because I only lay the resin with a light touch to the squeegee on to of the surface of the uni it does not move around. All laid up on flat surface and then it moves together because of the plain weave. I've had no issue with fibre orientation.

Good idea.