Kevlar vs. Carbon Fiber vs. Fiberglass

[Rick Iverson]

Gents:

Long ago, I purchased and will install a late model diffuser onto my mid year VD.

The diffuser’s upper leading edge has a thin metal strip that attaches to the belly pan side pod floors. On mine, it has a two (2) inch separation (tear) on one side.

My thoughts are to clean the entire fore area with hot soapy water, lightly apply an epoxy to secure the split, then bond both upper and lower surfaces amply with a cloth/epoxy resin/catalyst combination.

Your thoughts on kevlar vs carbon fiber vs fiberglass? I know the drill on licked by the wind. Comments, please.

[proutyc]

If it was me Rick I'd clean it as you have mentioned but Id recommend either a structural epoxy adhesive something like West 404 or 406. Once repaired could you make a large envelope bag to apply vacuum pressure for a stronger bond?

[Rick Silver]

I dont think you are allowed to use carbon fiber on a diffuser repair. And kevlar does not make sense here. So just use fiberglass woven roving material with a good epoxy resin and it will be fine.

[Tim Minor]

I agree with Rick,Carbon Fiber is not legal matt with cloth and vacuum bag should be fine
Tim

[lucky13]

What everyone else said about carbon fiber v. Fiberglass. Depending on what the crack looks like, be careful with the soapy water too if you have exposed cloth, especially Kevlar.

[proutyc]

As members have pointed out, the use of some composites aren't allowed. There is a fibreglass known as S-Glass. This is a structural cloth. It is more expensive than E-Glass but has a strength much closer to the materials that are not allowed for use.

Thanks

[Rick Iverson]

Chris:

Can you recommend a weight? Thin is good.

As members have pointed out, the use of some composites aren't allowed. There is a fibreglass known as S-Glass. This is a structural cloth. It is more expensive than E-Glass but has a strength much closer to the materials that are not allowed for use.

Thanks

[10rmotor]

I don't know about the hot soapy water for cleaning. Maybe as a first pass clean. In aerospace we use acetone for a degreaser, followed up with IPA and a short 10-15 time period for it to flash off.

[CGOffroad]

Chris:

Can you recommend a weight? Thin is good.

Selection in S-Glass is a bit more limited than E-Glass. Here are the most common selections you will find. Scroll toward the bottom of this page and you will find the S-Glass. If you have some weights of cloth already at your shop, you can compare to what weight you have on hand and make a decision for what to use. Or, you may decide to just keep it simple and use what you already have in stock.

https://www.uscomposites.com/cloth.html

[Steve Demeter]

Good information to keep handy. Thanks

[Lee Johnson]

Chris:

Can you recommend a weight? Thin is good.

Rick -- I've had good dealings with the following suppliers. You will have to read details on their websites to see just what they have that might suit your needs. Regardless of the fabric material, twill (or satin, or bi-directional) weave will have better conformability to compound curves than the equivalent in plain weave

https://www.fibreglast.com/

https://compositeenvisions.com/

https://sollercompositesllc.com/ {they don't show fiberglass fabrics, but carry more exotic fabrics including hybrids like carbon-Kevlar

Lee