Fiberglass cloth

[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

[9GT]

Draw with your blue or black Sharpie the shape and size required on heavy clear plastic about 8 mil. Lay your first over-sized layer of glass down and wet it out. Use a hair dryer to heat the epoxy & glass as you stipple with a brush,,,,or squeegee out the excess epoxy. You want all the glass wet out using the least amount of epoxy resin necessary to do so. Repeat for each layer. Use a hand held light to inspect each layer as you go to ensure the cloth is whetted out, no air bubbles, and no excess epoxy. Now when done with all your layers, cut out the shape you drew,,,,,,,you can see right through the properly wet out layers. Carry it over to whatever you are working on and wet that area out where you are going to apply your patch or whatever. (You did clean and sand that up REALLY good first with 36 grit Zircon cloth backed paper 'til it was dull and no shine ,,,,,,right?) Lay your piece in position and carefully peel off the clear plastic,,,,use a pick and paint brush to assist in peeling and pushing, stipple the patch on. Now if you want a REALLY nice transition finish,,, you will have some peel-ply fabric to lay over the patch and surrounding area. I peel-ply everything I do. Stipple that on with epoxy and heat from your hair dryer. Leave the edges of the peel-ply with no epoxy. Now leave it be until FULLY cured. When cured, grab a corner of the peel-ply and strip it off. You will be amazed at the perfect looking and structural sound patch or joint you just completed.

[WingedFrog]

Helpfull instructions for fiberglass greens like me, thanks 9GT. However I have no idea what peel ply-fabric is. Can you elaborate?
Thanks

[az_gila]

Originally Posted by WingedFrog

Helpfull instructions for fiberglass greens like me, thanks 9GT. However I have no idea what peel ply-fabric is. Can you elaborate?
Thanks

It's just dacron fabric...

http://www.aircraftspruce.com/catalo...es/peelply.php

[Mike S]

Peel ply is a material like polyester dress lining, it is used to give a smoother finish to a layup, or to create a bondable surface on a layup.

Peel ply does not stay in the layup, you "peel" it off after the resin hardens. The surface left will be flatter overall, but have small "teeth" in it. The surface is easy to finish with minimum sanding, or is ready for another layup without sanding.

Here is some good info.

http://www.clcboats.com/shoptips/epo...se-fabric.html

[Mark Henderson]

Peel Ply is a smooth dacron fabric that is used to get a smooth top layer. Aircraft Spruce sells it.http://www.aircraftspruce.com/catalo...es/peelply.php It's cheap and works great. My only tip on the fiberglass is get your contour shaped correctly. Fill in the areas where the cloth "drapes" over the canopy frame with extra foam and sand to where it is the final contour. Mine was close, but not exact. I spent ten times more effort sanding an filling later than it would have taken to get it right in the first place.

[KRAUSEGB]

Thanks guys--Now it is time to "get-er done"

[9GT]

One more thing I forgot to mention is that the fibers of the cloth must be straight. That's EZ with UNI (one direction) cloth where the strands are straight and are held together with thin woven fiber strands. This provides strength in one direction only unless you put the next layer at a 45* to the first and so on. The other most common weave is BID (bi-directional) where the strands are woven at a 45* already. Here is where its hard to hold a shape you cut out as it stretches and distorts easily,,,,hence using the plastic to help hold its shape. Its really important that the fiber strands are straight with BID to maintain its structural strength. BID is generally used for taping joints and for curves, as it shapes easily and will stay where you put it. You also alternate the direction of the weave with each layer....think "X" pattern. Now if you have a compound curve or shape you are trying to glass and the UNI does not want to stay put,,,,lifts up in areas or forms air bubbles,,,,,some times the Peel-ply will hold it down, especially if you are using a light weight peel-ply. If it does not,,,,,take a clean piece of clear kitchen saran wrap and cover everything working out all the air. It does a really good job of holding the glass work down. Its a PITA to remove afterword's though so use it only when needed.

[Mike S]

Originally Posted by 9GT

The other most common weave is BID (bi-directional) where the strands are woven at a 45* already.

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.

[erich weaver]

fiberglass tutorial with pictures and material list:

http://www.rvpilot.com/Fiberglass/fiberglass.html

erich