Fiberglass?

[Mike Goodwin]

I just finished a weekend of working with Dynel instead of fiberglass .
Covering the bottom of the 22' Sam Devlin designed tugboat that I'm building.
This stuff, dynel , has it all over fiberglass cloth.
It is lighter by 2/3 's and stronger by a factor of 6 or 8 .
It conforms to curved surfaces better too .
PLUS , it doesn't make you itch and scratch .
I got it in 54" wide roll .
Dynel is polypropylene cloth BTW.

[Tony G]

Mike,

That Dynel sounds pretty interesting. What's the catch? Outrageous cost? Not compatable with readily available epoxies or resins? Only available to trained, certified, card carrying professionals?

You gotta' admit, it sounds too good to be true.

[Mike Goodwin]

No catch , I paid around $6 yd . Equal fiberglass is over $9 yd.
It does saturate a little slower than E-glass and you have to paint it , no varnish .
Works great with cheap epoxy $35 gal .
Only negative is, it uses about 10 to 15% more epoxy , which per square yd. works out to aprox. 1.5 oz extra.

[ebb]

Hunnert years ago I used Dynel as the last layer in a polyester resin glass fabric overlay of a planked hull. I was adding 'abrasion resistence' to my first layup job. Was impressed with the pitch, as I thought glass was pretty indestructable. Back then.
To date this, isophthalic resins had just come on the market, or just had become available at Abe Schuster's. Can't remember what the 55gal drum cost, was it $325? Outrageous!
Dynel was my first order from Defender (shows how long they have been around!) and back then was known as a polyester fabric.
Dynel disappeared for awhile, must be back with a new mother polymer.

Oh, and used Dynel with Arabol on the foredeck over raw fir plywood. Never had a problem.

[Mike Goodwin]

I used to buy poly resin for $5 per gallon ( gas was only $0.19 gal. too ) , back in the 60's making surfboards and glassing tired old wooden Sunfish sailboards and skiffs . I even repaired my 1947 Chevy with the stuff .

The original Dynel was by Union Carbide , they quit making it years ago . The new stuff is even better . Mind you there are several versions out there , get the one with these specs;

54" wide roll
30x30, 660 denier 2-ply twisted yarn, 5 oz plain weave

The other stuff is much harder to work with and uses lots more resin per sq. yd.

[Tony G]

...sounds like the ticket for vacuum bagging being needs a little extra resin...