Fiberglass on Chines

Fiberglassing over plywood and one-off fiberglass methods. See: "Boatbuilding Methods", in the left-hand column of the Home page.

Moderator: ttownshaw

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Fiberglass on Chines

Post by Baron » Sat Feb 01, 2020 9:30 pm

How many ounce biaxial and also regular fiberglass can bend easily over sharp chines? I’ve never used heavier than 10 ounce regular weave. I’d like a bit heavier on the bottom and up 6” on the sides. Same for tape......how heavy.

JimmY
Posts: 895
Joined: Sat Jul 30, 2016 11:08 am
Location: Brighton, MI

Re: Fiberglass on Chines

Post by JimmY » Sun Feb 02, 2020 6:15 am

On my boat, I used 7 oz. (Glen L kit) and it bent fine over about a 1/8" radius (pencil). If the weave is on the bias (45 degrees to chine) it may lay down better, and you will have the advantage of all the fibers crossing the edge.

Do you want to keep the chine as sharp as possible? If so, you can always round over the chine, glass it, and then build it back up with epoxy and fillers. Use one of the chopped fiberglass fillers for toughness. I used regular microballoons to get my transom edge sharp after glassing and it is holding up fine on a Squirt.

If you are looking for toughness on a working boat, you may want to leave the chine rounded over to keep a sharp edge from being damaged.
-Jim
Nothing says poor craftsmanship like wrinkles in your duct tape!

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Sun Feb 02, 2020 7:14 am

Jimmy thanks for the info. I love your quote at the bottom. Our son is an engineer and we knew he was going somewhere when at 7 or 8 he gave his mother a nice birdhouse mad entirely of duct tape.
I use a pretty large radius on the chines, perhaps 1/4 - 1/2”. I might even go bigger on the next boat as it helps when banging around on rocky shorelines.
30 ounces on the bottom +/- is the goal and I want it to go 6 or 8 “ up the sides. I see that there is much heavier cloth available than my normal 6,7 or 10 ounce. For instance 12-18 and more. But will it bend over the chines and still drape well across multiple edges like the lighter cloth does? Or will it be full of puckers and air pockets and the nightmares they create.
Would I be better to use 6ounce multiple times.

TomB
Posts: 707
Joined: Wed Jan 18, 2017 4:07 pm
Location: Holland, MI

Re: Fiberglass on Chines

Post by TomB » Sun Feb 02, 2020 9:33 am

Baron wrote:
Sun Feb 02, 2020 7:14 am
Or will it be full of puckers and air pockets and the nightmares they create.
Would I be better to use 6ounce multiple times.
I'd hate to try and fix the nightmare you described, so my vote would be for the sure thing, multiple layers.

Tom

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Sun Feb 02, 2020 12:39 pm

I wonder if when using the really heavy cloth if the resin stays put of does it run out of the weave?

JimmY
Posts: 895
Joined: Sat Jul 30, 2016 11:08 am
Location: Brighton, MI

Re: Fiberglass on Chines

Post by JimmY » Sun Feb 02, 2020 6:44 pm

I second the comment on heavy cloth being difficult to keep wetted out and in place. I used System 3 silver tip epoxies, and you can recoat without sanding within 24 hours. So, you could lay 3 or 4 layers of cloth in short order.
-Jim
Nothing says poor craftsmanship like wrinkles in your duct tape!

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Sun Feb 02, 2020 9:12 pm

Well then I guess Ill not use the heavier stuff. Thanks helping me brainstorm a bit.

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Mon Feb 17, 2020 9:09 am

In you opinion is biaxial cloth worth the extra cost on simple boats such as the Pacific Dorys. I will be putting a glass schedule together for the little Hunk and while I don't want to blow money I also don't want to skimp. I ordered the plans yesterday and hope to have them in a week or so. Do the plans detail the fiberglass lay-up and perhaps ways to beef it up?

hoodman
Posts: 2285
Joined: Thu Nov 10, 2011 8:48 am
Location: Lafayette, IN

Re: Fiberglass on Chines

Post by hoodman » Wed Feb 19, 2020 7:51 pm

What is the reasoning for using the super heavy cloth? You'd be better off using thicker plywood. (If strength is your concern).
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Wed Feb 19, 2020 9:42 pm

Hi Matt,
I will be using this boat allot in beaching scenarios where it is common to have some aggregate rock in the surf and furthermore it will be in contact with larger rocks upon occasion. What is a sturdy layup for abrasion protection for the bottom?
Will the plans spec what I'm to use?

User avatar
Bill Edmundson
Posts: 11766
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Fiberglass on Chines

Post by Bill Edmundson » Thu Feb 20, 2020 6:38 am

Try Dynel fabric. It is far far better for abrasion than glass! https://www.jamestowndistributors.com/u ... $253EDynel

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Thu Feb 20, 2020 7:27 am

Have you used it? Ruell parker used it in his Sharpies.

User avatar
Bill Edmundson
Posts: 11766
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Fiberglass on Chines

Post by Bill Edmundson » Thu Feb 20, 2020 8:11 am

Baron

Yes, I have. I did a test panel with glass on one side and dynel on the other. I took a firebrick on edge and rubbed each side. I went through the glass in 15-20 strokes. I stopped on the dynel side somewhere over 100. There is another fabric that is supposed to be even stronger. I think it's something like xynel. I haven't used it. The stem of the Tahoe rubbed the trailer launching and recovering and would go through the glass. There hasn't been any problem since I put dynel on it. Dynel is not for brightwork. It lays up kind of milky white.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Thu Feb 20, 2020 8:58 am

That is an excellent testimonial, the Tahoe that is.

On the Jamestown site they mentioned not to use on stitch and glue hulls. I guess it’s not rigid enough to support joints. My boat will be a framed boat. Raka marine epoxy carries Xynole and Dynel in 4 ounce.

I was hoping to get some stiffness out of the glass but abrasion resistance is the most important.

One of the above calls Dynel “poor mans Kevlar”.

I wonder if the drapability is good enough that seams would not need taping.
Don

Baron
Posts: 137
Joined: Mon Jan 01, 2018 6:33 pm
Location: Easton, PA

Re: Fiberglass on Chines

Post by Baron » Thu Feb 20, 2020 9:31 am


Post Reply

Return to “Fiberglass”