Proper glass materials for boat repair W/Pics

[Yacht Dr.]

Hello Iboaters New and Vets

I would like to take this opportunity to guide us through what our Fiberglass really is and what its for.

Many of us readers often come across threads or posts regarding " Just use poly and CLOTH with mat " or " Just use epoxy and CLOTH and no mat " and " Use mat and 1708 with X resin ".

The thing is .. more times then not .. the use of the word " Cloth " could be misleading.

Here is some pics and explanations ..Pics are above the text referance.

http://i699.photobucket.com/albums/vv352/YachtDr/Glass Materials/DSC03798_640_480.jpg

This Pic shows an over all shot of 5 different glass types ( well 4 with one modded Ill explain later in the thread ) . 3 of the 5 are Common glass types in building And repairs .. the other 2 are not typically used.

http://i699.photobucket.com/albums/vv352/YachtDr/Glass Materials/DSC03799_640_480.jpg

This Pic shows actually 2 different ( but from the same material ) glass types.

Its called Woven Roving. For our research we will typically buy in 17 oz or 21 oz ( with mat backed if you like ).

* This Roving Must be used with 1.5 oz mat on Both sides of application *

"Roving Roving" has been the Industry standard for both boat builds and repairs from the inception of production of boat building. Its Strong and has many uses including Stringer/hull/transom/tabbing ( very versatile in conforming against odd shapes ) .. basically the workhorse of boat construction.

The little short strands that you see is called "Unidirectional" Fiberglass ( One direction ).
* Hint * I take the Roving and cut squares ..then carefully unthread the Roving to make my own unidirectional for RADIUS builds. * Hint *

Now on to the Mat ..

http://i699.photobucket.com/albums/vv352/YachtDr/Glass Materials/DSC03802_640_480.jpg

This is what we mean by Fiberglass Mat. This pic is 1.5 oz mat but you can buy .75 oz or 2 oz. ( you can also buy mat for Epoxy that looks more like filter media for your house heater )

Most of us know what mat is. Notice how you see the Tearing of the mat. 90% of the time I hand Tear my mat and not Cut it. Only for larger glassing schedules do I cut it.

Moving on to 1708..

http://i699.photobucket.com/albums/vv352/YachtDr/Glass Materials/DSC03801_640_480.jpg

1708 Is an angled woven fiberglass material ( with mat backed .. so no more glass,mat,glass,mat,glass schedule normally in the past had to be done ) that has proven useful in builds and repairs alike.
It can be used for basically Anything for Build or Repairs ..

One Caveat is that it only Moves in one direction ( stretches ). So if you need the material to kinda "move" around that corner or multi-radius .. you Might be in trouble with air bubbles ( This does not happen with Roving Roving because of its 90 deg. pattern which it can "move/stretch" in almost all directions ).

Another Caveat is when you want to "prewet" your pre-cut 1708 on cardboard..it can change its shape longer and thinner. * HINT * after you cut your 1708 1" masking tape across several times to help hold it in shape..after placing the tape will peel off easy *hint*.

Now onto the Cloth..

http://i699.photobucket.com/albums/vv352/YachtDr/Glass Materials/DSC03800_640_480.jpg

Typically this is called "finish cloth" or " veil cloth ". This is sold ( IMO Wrongly ) to the general public in packs of "fiberglass repair kit".

This stuff is basically Useless on boats ! I cannot stress enough how This material should not be used in our boat builds or repairs.

Unless you are making RC boats stay away from this Cloth.

Iboats..When you read a post or thread that suggests "Cloth" please dont construe that as meaning you can goto your body store and pic up a few packs of "cloth". I think for the most part ( unless its specifically stated using finish cloth ) we mean " Material ". Structural Glass like Roving or 1708 .. or biax etc.

I Sincerely hope this helps misunderstandings in future or past threads or posts..

YD.

PS. Hope this sticks .. : ) ..

 

[retiredfornow]

Re: Proper glass materials for boat repair W/Pics

Thanks, that helps a lot. You ought to have this thread as a "sticky" on top, and add to it the proper resins, etc. and whatever is needed.

 

[ondarvr]

Re: Proper glass materials for boat repair W/Pics

I agree, there can be a great deal of confusion when it comes to the terms people use to describe each type of glass. Using the correct terms for each type of glass can make it much easier to understand how and where to use each one.



?Cloth? is frequently used in almost a generic way to describe almost any type of glass, but it referrers to one type of glass with a fairly fine weave. This product is rarely used with polyester resin when building boats, but is often called boat cloth. It is frequently used with epoxy and works very well when used with it. It?s not used with polyester because for it?s cost and how it needs to be used it makes an expensive and heavy laminate. The reason is that a layer of CSM (chopped strand mat) needs to be used between each layer of cloth, and mat has the least amount of strength and requires the greatest amount resin, this combined with cloth?s very light weight (light weight, equals less strength per layer, so more layers are needed) the laminate is comparatively weak, heavy and costly.

This is not the case with epoxy, so the cloth can be used by itself, this can yield a light and strong laminate.

Woven roving looks like cloth?s bigger brother and like YD said, has been the workhorse of the industry for decades. It has the lowest cost of the woven or stitched fabrics and is easy to work with, which makes it a good product.

Biax has two layers of non woven unidirectional glass laid at 45 degree angles and then stitched together, it may have a thin layer of glass stitched to it also. This is a stronger way to use glass because when woven the bends can create weak points, this results in lighter laminate for the same strength, but it may flex more because it will be thinner.

Unidirectional glass is only one layer of the same type of glass that is used in the biax product, it is made up of individual bundles of strands laid down side by side and stitched to each other.

Continuous strand, or gun roving, is a bundle of individual strands that comes in a ball, although its not really shaped like a ball, it pulls off the ball like a rope, only its not woven or braided like a rope, the strands are parallel to each other.

Mat is the fuzzy stuff with strands laid in a random pattern, it builds bulk, helps with the bond to the substrate and between each layer of woven or stitched fabric.

Using the correct terms for each type of glass can make it much easier understand how and where to use each of them.


This information is supplied in the sticky at the top of the page in greater detail.

http://forums.iboats.com/showthread.php?t=286013

 

[Woodonglass]

Re: Proper glass materials for boat repair W/Pics

And the New E-Glass Cloth and S-2 Glass cloth make light weight and Super strong Laminates when using epoxy as your resin. Not sure why those were not mentioned. www.uscomposites.com gives very good descriptions of ALL the various types of resins, mats and Woven Rovings, and Cloths and what each specifically are used for. It would behove all New members to check out their site to get a basic education on all the different types of materials available.

 

[Yacht Dr.]

Re: Proper glass materials for boat repair W/Pics

Using the correct terms for each type of glass can make it much easier understand how and where to use each of them.

This information is supplied in the sticky at the top of the page in greater detail.

http://forums.iboats.com/showthread.php?t=286013

Yes sir .. but that thread is locked.

And the New E-Glass Cloth and S-2 Glass cloth make light weight and Super strong Laminates when using epoxy as your resin. Not sure why those were not mentioned. www.uscomposites.com gives very good descriptions of ALL the various types of resins, mats and Woven Rovings, and Cloths and what each specifically are used for. It would behove all New members to check out their site to get a basic education on all the different types of materials available.

Whats "New" about E-Glass or S Glass ?? Did you have a specific product in mind that you recommend using ?

ALL of the glass posted in my pics are "E-Glass".

As far as "S(2)-Glass" .. I have used that while working for LoPresti. But we are not building Airplanes or UFO's. Not normally used in boat building or for repairs m8.

YD.

PS. I Personally thought that my OP was well thought out and presented

 

[Yacht Dr.]

Re: Proper glass materials for boat repair W/Pics

If you Really want to study up on Glass and supporting resins you should Read ..

http://www.marinecomposites.com/PDF_Files/G_Composite_Materials.pdf

This is one of the best compilations I have read.

But basically for Us Iboaters you only need 1708 ( or 18 oz woving )/1.5oz mat/Lam poly resin and cabosil. I can fix Anything ( poly based ) with those 3 things. Sure you can experiment with different glasses and resins..let us know how that turns out for ya.

US comp has Many Many different products which for some might be overwhelming. Remember folks..they sell glass/resins for Auto/Aero/Boat/RC/Bathtubs/phone cases/bikes on and on etc. You have to know which one is best for your application.

Because Iboats Resto forum is Mainly Boats..trust the guys who do this for a living ( or don't ).

Peace Out YD.

PS. Guys..Glassing is simple..repairs are simple..materials are Simple. Do one or 2 of them... you will get the idea.