lightweight fiberglass trial

sluggo · Post by **sluggo** » Sun Mar 02, 2008 2:56 pm

I did my first test with Style 1678 fiberglass this weekend.
The glass was purchased from Thayercraft Industries, it is very inexpensive at just over $1/yard! The details of the cloth are: 3.2oz, 0.1mm thick, 60x58 thread count, 210x200 lb/in breaking strength. In comparison, style 7533 (typical 6oz boat cloth) is 6oz, 0.2mm thick and 220x220 lb/in breaking strength. In other words, this cloth is almost 1/2 the weight, 1/2 the thickness and about the same strength. Even if doubled up on a kayak, the cost would be about $30/boat (for my canoe).

For some detailed info on cloths, check out
Hexcel's website

It wets out clear but it is definitely more difficult or finicky to make sure the epoxy wets it out. I had a few spots that ended up not clear, these were where I doubled up on the cloth. The photos below show the fiberglass, the wetout, 1 fill coat, a few spots not clear, and the layer thickness.

If you have any questions let me know.

Glen Smith · Post by **Glen Smith** » Sun Mar 02, 2008 3:18 pm

I would like to point out one major problem with Thayercraft. They will not ship to Canada. I wanted to order a roll of that same cloth but they said that they were not set up to make shipments outside of the USA. Bummer!

Adamv · Post by **Adamv** » Sun Mar 02, 2008 3:32 pm

Sluggo,

I'm interested to hear about your tests with the Thayercraft fiberglass. I'd be particularly interested in how the lighter cloth translates to overall weight savings on the hull. Not only is the cloth itself lighter, but it seems to me that it would hold less epoxy as well and be lighter for that reason too. Also, how does its strength compare with 6 oz cloth, and how does it compare if the 3.2 oz cloth is doubled? Let us know if you conduct any tests to determine this.

Adam

Larry in Champaign · Post by **Larry in Champaign** » Sun Mar 02, 2008 8:43 pm

Here is shot of my canoe following final sanding. I just finished sponging off the dust when I took this shot. There are four layers of 1678 on the bottom and up the sides of the bow and stern. From the feature stipes up to the sheer there are two layers with three bias layers on the stems. Use a fiberglass roller between wet out and squeegee to pop the bubbles. The cloth drapes very well, even around my 3"+ recurved tumblehome. The fiberglass roller is the key to a good [easy] wet out!

Good luck,

Larry

sluggo · Post by **sluggo** » Mon Mar 03, 2008 3:21 pm

Looks awesome Larry! Well obviously it can be done then eh.

I have a few questions for you...
Did you put two layers of cloth on each side of the hull and have them overlap to the opposite side up to the feature strips? Did you have to cut and remove a bunch of the material at the stems or did you cut slits so that it folded over and around the stems? And finally, did you use a brush, roller or squeegee to spread epoxy on the wetout? I've used rollers in the past but I noticed that there is the tendancy for the roller to move the cloth around a bit. Having never wetout two layers of cloth at once, I wonder if the roller would cause a problem. I also plan on pre-coating the wood first to help with the wetout.

cheers!

Karl Huebner · Post by **Karl Huebner** » Mon Mar 03, 2008 4:31 pm

Larry, it sure looks good - great. I wish I could be the artist you guys are.

Guessing, how much weight do you think this adds? That seems to be a lot of layers!

Larry in Champaign · Post by **Larry in Champaign** » Mon Mar 03, 2008 9:20 pm

I used a brush for wet out spreading 12oz of epoxy from sheer to sheer amidship and then rolled out the bubbles. After repeating this wet out / roller process adjacent to the first, I squeegeed the first section and then wet out the other adjacent side. I continued this leap-frogging procedure, back and forth, till I reached the ends. I formed the cloth to the hull prior to wet out and I didn't have to deal with wrinkles during the wet out. I did pre-coat on this canoe. I gave it a light wet sanding, still within the US Composites 635/556 slow drying time, before laying the cloth. I hope these photos help answer your questions.

This shot shows 2 layers of cloth overlapped to the waterline.

Here are all four layers. The second two layers overlap the first two by about 2-3”.

Wet out dry but tacky with bias strips applied.

Various fiberglass rollers - I used the long skinny one in the upper left for the wet out.

Best guess for the extra two layers? Maybe 4 pounds. I wanted two layers coming up the recurved sheer. Overkill? Maybe. Maybe I’ll find the guts to go light on the next one.

Larry