Joe Westrich

My Feedback: (95)

Ok, recently I just asked about Kevlar cloth and got a little education on it. I am now going to 2oz fiberglass, but I just had one more question. What would be the difference between single weave and double weave cloth? What would be the best for our RC application? I have fiberglassed a few airframes before, so I'm not new. I just want a better education.

Thanks!

Bob_B

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Joe i have never used heavier tha 3/4 ounce cloth for finishing. Why 2ounce cloth?

Joe Westrich

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50+ lb jet with a P200

I use 3/4 on my 1/5 prop warbirds

I may go lighter than 2oz on the tail surfaces

thunderchief

Joe, Check out this web site for cloth selection. They are out side of Dayton. If you use 2 oz I would consider vacuum bagging it.
Glenn

http://www.fibreglast.com/

invertmast

My Feedback: (23)

I have never heare of single weave and double weave.. You typically have

Unidirectional
Tow
Plain weave
4HS (crowsfoot)
8HS

Thayercraft.com has good info on glass, along with good prices

Robrow

I think double=Twill where the warp fibres go over/under two of the weft, better drapability for getting into awkward corners and conforming to compound curves, etc. It has a front and back.

Rob.

invertmast

My Feedback: (23)

Oh ok, i forgot about twill weave

sidgates

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I have gotten better answers about cloth, resin and mold making on this thread
http://www.rcuniverse.com/forum/forumid_97/tt.htm

Joe Westrich

My Feedback: (95)

That's kind of what I was looking at. Why the different formats and what applications would they be used for?

Joe Westrich

My Feedback: (95)

A friend told me of that site too.

Is it manageable without vacuum bagging it. I don't have one.

thunderchief

Sure, you can treat 2 oz cloth just like you would 3/4 oz or 1/2 oz cloth. When I lay up a mold my first layer is always a 2 oz layer of cloth because it is very easy to work with. It just takes more resin to fill the weave then 3/4 oz..
Glenn

invertmast

My Feedback: (23)

Uni-directional is a fabric that has all of the glass strands going in one direction. This works well for needing strength in one direction only (spar caps for instance).
Tow is a non woven cord

Plain weave can be easy to work (conforms easier) with if it is loosely woven.. If its tightly woven (which is what I would suggest for glassing) it doesn't conform as well, but requires less filling of the weave. It also provides a consistent surface due to how it is woven.

4HS and 8HS is a bit stronger (less thread crimp) and offers greater conform-ability than plain woven fabric. I've never heard of anyone using this outside of a molded part.

Twill is kind of in between Plain and 4HS and 8HS in how it is woven. Typically when you see a "pretty" Carbon Fiber part, it is a twill weave carbon.

sidgates

My Feedback: (2)

I use 2oz or 3.2oz crowfoot for my first layer in a mold. Below is a quote from WyoWindWorks on crowfoot.


Style 120 and 220 are good choices. The 120 will be slightly more flexible while the 220 is a little stronger. Either will work well.

Crowfoot is the same as a Harness Satin 4. The yarns go over 3, under 1, over 3, under 1, etc. This weave allows the fabric to be more conforming than a plain weave. It also allows the yarns to lay flatter. This is theoretically stronger since the frequency in the crimp of the fiber is reduced.

mr_matt

My Feedback: (10)

How would he vacuum bag? Isn't this going to cover the outside of a wood structure?

invertmast

My Feedback: (23)

You either vacuum bag with a foam core wing, or in a mold. Theres really no good way of vacuum bagging any other type of build structure

thunderchief

Right,, to vacuum bag it would have to be a foam wing. Vaccuum would probably damage a build up part
Glenn

sidgates

My Feedback: (2)

I don't find any need to vacuum bag when doing one layer of cloth on a sheeted surface..

mr_matt

My Feedback: (10)

Exactly

invertmast

My Feedback: (23)

If you use some waxed mylar sheet (.014" thick) you can paint the mylars, the put a layer of wet out glass or carbon on the mylars. Then blot up the excess resin with a paper towel, then while wet you can vacuum bag this to a wing or tail surface. Once it cures, the mylars peel away leaving a painted part. This only works in simple surfaces though. Any compound curves makes it impossible to do.