Fiberglass

See our FAQ and tutorials before posting.
cape_fisherman
Active Poster
Active Poster
Posts: 298
Joined: Tue Oct 07, 2014 11:04 pm
Location: Mount Pleasant, SC

Re: Fiberglass

Post by cape_fisherman »

I believe there is a simple misunderstanding. If y'all could calm down & research a tad more, you're 'argument' wouldn't be needed.

CSM, as a stand alone product, typically has styrene binders that dissolve when polyester or vinylester resins are applied. It basically 'melts' apart and conforms to what you're applying it to...sort of. Epoxy will not dissolve the styrene binder and makes it sort of useless. HOWEVER, there IS a CSM product available that has a powder binder instead of the more common styrene binder. The powder binder IS compatible with epoxy.

Now on to 1708 (and 1208 for that matter). The 08s do indeed have CSM attached to one side. They do. That's what the "08" is...CSM. With that said, the 08s DO NOT have any binders because they are stitched. They are held together with the stitching, and binders are not needed. Because of this, the 08s are compatible with epoxy, poly, and vinylester.

1700(1200) is the product that does not include CSM...and typically a better choice when using epoxy.



TomW1
Very Active Poster
Very Active Poster
Posts: 3522
Joined: Sun Apr 19, 2015 10:57 pm
Location: Bryson City, NC

Re: Fiberglass

Post by TomW1 »

Thanks cape fisherman. I agree no more comments from me.
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

fallguy1000
Very Active Poster
Very Active Poster
Posts: 6940
Joined: Tue Jan 12, 2010 12:25 am

Re: Fiberglass

Post by fallguy1000 »

No attempt to argue cf. I even apologized in advance for my tone AND asked for edification.

The other thing I did wrong here was the math. The stuff is 0.75 oz per square foot or 6.75 ounces per square yard. I am not sure why they use the 08 numbering. I tend to treat the 8 as 8 ounces in my pea brain.

I have used actual csm with epoxy. The epoxy does not need to break down the binders for certain applications. For other applications; the binder breaking allows for greater movement of the glass and is essential.

If one scours the interwebs for details on how 1708 is made; it is rather hard to find. There is some way the chopped strand mat is held together to end up attached to the db. I will see if it is stitched. I never noticed stitching thru and thru.

I have used some 1708 that is rather stiff and makes funny noises. It is either a coating applied to the entire fabric or something used to hold the mat portion together. Not sure which. And it is not all the time.

All trying to be straight is all.

I used veil on two of the Skoota hull panels. It was csm. Epoxy does not care. The veil layer did not accomplish my wishes. I have a whole roll of it if anyone knows wjat to do with it! It was like $450. I used maybe 70 feet of ?100 or 200 yards.
My boat build is here -------->

viewtopic.php?f=12&t=62495

cape_fisherman
Active Poster
Active Poster
Posts: 298
Joined: Tue Oct 07, 2014 11:04 pm
Location: Mount Pleasant, SC

Re: Fiberglass

Post by cape_fisherman »

See below ... ...
Last edited by cape_fisherman on Sat Feb 20, 2021 11:55 am, edited 1 time in total.

cape_fisherman
Active Poster
Active Poster
Posts: 298
Joined: Tue Oct 07, 2014 11:04 pm
Location: Mount Pleasant, SC

Re: Fiberglass

Post by cape_fisherman »

Not sure how easy, or difficult, the stitching is to see here...

Image

Image

piperdown
Very Active Poster
Very Active Poster
Posts: 1166
Joined: Fri Jun 22, 2018 12:35 pm
Location: Kansas

Re: Fiberglass

Post by piperdown »

^^^^ That's the stuff Tom (thb) sent me to help build thickness for the rocker I had. It's stitched like that. And it takes a TON of epoxy to wet out!
Eric (aka, piperdown)

"Give an Irishman lager for a month and he's a dead man. An Irishman's stomach is lined with copper, and the beer corrodes it. But whiskey polishes the copper and is the saving of him." --> Mark Twain

fallguy1000
Very Active Poster
Very Active Poster
Posts: 6940
Joined: Tue Jan 12, 2010 12:25 am

Re: Fiberglass

Post by fallguy1000 »

Maybe they spray a bit of binder to hold it until stitched and that is the scrunching noise I hear.
My boat build is here -------->

viewtopic.php?f=12&t=62495

cape_fisherman
Active Poster
Active Poster
Posts: 298
Joined: Tue Oct 07, 2014 11:04 pm
Location: Mount Pleasant, SC

Re: Fiberglass

Post by cape_fisherman »

piperdown wrote: Sat Feb 20, 2021 3:19 pm And it takes a TON of epoxy to wet out!
Which is why builders I know don't use it. Takes twice the amount of epoxy for not even half the amount of strength. A friend of mine that builds custom sportfishers out of wood & epoxy doesn't have a single yard of 1708 in his shop. He's a 1700 guy through & through.

jacquesmm
Site Admin
Site Admin
Posts: 27775
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA
Contact:

Re: Fiberglass

Post by jacquesmm »

There may be a problem with terminology here. In this discussion, CSM stands for Chopped Strand Mat not that Chloro something stuff.
CSM is normally the chopped fiber that comes out of a chop gun used in fiberglass boat production but it also exist as a fabric in which all those glass strands are kept together with a binder. Some people call the fabric version, it is correct if you want but many more just call it mat.
The binder can be of different types and yes, some are very stiff.
1208, 1708 etc. are made with mat stitched to the biaxial.
I very rarely specify it because as Fallguy writes, it soaks up resin without adding much strength. However, when a laminate is sufficiently strong but not stiff enough, I need to increase that stiffness by making it thicker and that is where 1708 comes into play. It is cheap and bulky, it makes that panel stiffer.
The 1708 sold by Jeff, is compatible with epoxy.
Jacques Mertens - Designer
http://boatbuildercentral.com

User avatar
Evan_Gatehouse
Very Active Poster
Very Active Poster
Posts: 3130
Joined: Tue Aug 27, 2002 1:00 am
Location: Vancouver, BC, Canada

Re: Fiberglass

Post by Evan_Gatehouse »

1708 = 17 oz biaxial + 8 oz CSM stitched together. That's the definition of the stuff. It always have CSM.

Most 1708 has a binder compatible with epoxy these days.
designer: FB11/GV10,11,13/ HMD18/
SK17,MM21/MT24

Post Reply

Who is online

Users browsing this forum: No registered users and 7 guests