Fiberglass cloth

[RV7Guy]

1) Make your patterns. If you can do them in something like cardboard or poster board, even better.

2) Get some 3M77 contact spray from Home Depot/Lowes etc.

3) LIGHTLY spray the pattern and lay on waxed paper.

4) LIGHTLY spray the waxed paper and lay an oversized piece of the glass cloth over the pattern. With this method, using a 45 degree cut isn't absolutely necessary.

5) Cut the glass to the pattern. You'll find it very easy to cut now. Keep the waxed paper on the glass.

6) Lay the cut piece on a larger piece of waxed paper.

7) wet out the cloth with the epoxy.

8) Apply to where you want it. The waxed paper will come off easily.

9) Apply ply peel and press into the cloth.

[9GT]

Originally Posted by Mike S

Nope.

BID is woven at 90*.

It is often cut so the weave lays at 45* on the work, this gives an amazing amount of ability to fit on compound curve parts.

U R right,,,,,,

[D&M Dan]

Thank You RV7Guy. The wax paper method for cutting the cloth and setting in place worked great.

I sprayed a little quick stick on the wax paper, cut to shape, wet the cloth, Put another piece of wax paper on top and squeeged out the excess resin.Set the cloth in place and peeled the wax paper off.
Thanks again

[vernhendershott]

Hi Folks,

This is a RV-12 thread and most of the sage advice is not the way it needs to be done on the RV-12.

This is one of the areas that Van's plans is very well thought out, follow the plans, do it Van's way and it will work out just fine.

As to the earlier question about using the pattern, it may take two people (three hands holding things in place and one hand rolling the cutter) to keep the fiberglass held down firmly as you cut and it is very important to have a sharp blade. Use the larger plastic cutting board with grid lines so that you can line up the fiberglass straight and keep it that way. Yes the fiber glass may stretch a little but Van's has you making extra area everywhere except the line on the windshield so get it right and try to keep the rest so that you have the planned excess area on all the other lines. When you are done it is easy to cut off the excess to the trim line on the template.

Van's system of placing the first layer on wet and the rest dry and wetting them out in place works very well just follow the instructions.

I have found it helpful to have ten (10) sheets of cardboard with a piece of wax paper ready for each one, number then 1-L to 5-L and 1-R to 5-R so that you can slid the cut piece from the cutting board to the wax paper on the cardboard (you got some nice large sheets in the Van's crates) this reduces the handling and stretching. The first piece can be wet out right on the wax paper and moved on it to the aircraft for placement. Follow the instructions and let the first layer tack up and then proceed with the other layers and the cross strips which can be cut to width and laid out folded in half on a cardboard numbered 1 to 10 so that you can be ready to place them in the proper order.

The one variation on Van's plans I have found is that I get nicer edges on the windshield by using the 4 inch wide fiberglass tape from Aircraft Spruce as it has a very nice factory edge on one side that will lay down very nicely as the first layer and it is much easier to cut the small widths required if you take a 3 foot long tape and fold it in half so that the finished edge is even then use a metal yard stick to hold down the width you need and run the roller cutter right along the metal edge.

This has served me well on the 5 RV-12 canopies I have done so far.

Good luck.

Best regards,
Vern

[D&M Dan]

Thanks Vern, but there is more than one way to skin a cat. I also used the 4" cloth across the center. Just felt RV7guys idea worked well for me.
What ever works is the right way to go.

By the way, I still have all the cloth I cut Van's way for other projects.

[RVadmirer]

Not sure wax paper is such a good idea. Don't hear much mention of it in the composite world. If the wax gets into the epoxy you've contaminated the work. With wax it would then not be the best surface to either do more layups or filler or paint. Clear plastic works very well for all the things discussed above and doesn't have any coating that might be a problem. Then peel ply finishes up the layup leaving a smooth surface ready for further work.
The 45° cut is important, when required, for more than convenience.
Just some thoughts....discard at will....

[BigJohn]

......... marry a quilter!

[PEGASUS]

Originally Posted by KRAUSEGB

Has anyone had trouble cutting the fiberglass cloth to the patterns required.
Using the suggested roller cutter, the fabric stretches so when I finish the pattern, it doesn?t fit the original?
How accurate does it have to be?

Gary

Gary

Go to a fabric store ask for a wheel cutter pad.
The fiberglass will cut edge clean, use a sharp wheel.

Pegasus
Queen Creek, Az.

[DanH]

Been using the same OLFA rotary knife almost 20 years (with a blade change or two): http://www.aircraftspruce.com/catalo...izzacutter.php

The slick-face plywood Vans uses for crates makes a fine cutting board. My former favorite was formica. I don't recall a real problem with the pizza cutter pushing fabric around on any surface.

Most fabric cuts are made with excess and trimmed after placement and wetting. You want a good pair of pointy all-steel barber shears. If the task calls for a precisely sized section of glass, wet out, draw dimensions, and cut between plastic. Point is, you rarely need to cut perfectly accurate lines in dry fabric. When you do it's almost always a straight line and you run the pizza cutter along a heavy gauge straight edge.....which clamps the fabric to the table. I use a 48" aluminum rule 1/8" thick.

Wax paper won't hurt anything, but you can see through clear 4 mil plastic.

There is no application for UNI fabric on any RV. Use plain weave BID for flat or single-curve surfaces. Use a harness weave BID for compound curvatures. Fabric information this thread:

http://www.vansairforce.com/communit...ad.php?t=41375

[RVadmirer]

Originally Posted by DanH

Wax paper won't hurt anything, but you can see through clear 4 mil plastic.

Gotta respectively disagree with you Dan. The only composite guru that ever suggested using wax paper was Nat Puffer and he modified his recommendation in the following Builder Hint:

Newsletter# 50 / July 1995
from Builder Hints...

Taping joints. For Structural reasons, all joints should be taped with 2 plies of BID 2' wide (1" on each surface) cut on the bias (45 degrees) unless otherwise specified. After application, the tape should be peel-plied. One recommended way to accomplish this is to wet out 2 plies of BID on wax paper or Saran wrap, cut into strips, apply over joints, remove the wax paper or Saran wrap, cover with peel ply and wet out same. Wax paper should only be used with discretion. It should not be left in place while the epoxy cures, because wax will be left behind, and it should only be used on those joints which will not be later covered with additional layups. Glass layups. Remember, BID is always cut on the bias and overlapped l' in every direction, but UND is overlapped only in the direction of the major fibers.

Rutan said never use it.

The heat from layups in warm weather can melt wax into the layup and make further attachment of anything poor. And you can't use a hairdryer on the layup under wax paper as many of us do to to finish the squegee process and minimize epoxy and weight.