Fiberglass cloth is a woven material available in various sizes to allow custom strength, thickness, and weight in projects. Fiberglass cloth provides great strength and durability when layered with a resin to form a hardened composite.
Fiberglass cloth has many advantages:
Fiberglass cloth has greater tensile strength than steel wire of the same diameter.
Excellent fire and heat resistance
Thermal conductivity (making it useful for insulation applications) and chemical resistance properties similar to glass
Durable and economical
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JD - Can I get 14 yd's of 4 oz fiberglass on a roll from you?Bob
They are precut in 3, 10, or 25 yard rolls.
Kevin: I have replaced the floor decking in our ski boatand I want to make it waterproof before I put down the carpet. Is 4oz cloth strong enough to do this or do I need 6oz cloth? I am using west system epoxy resins and hardners
I would use 6oz. More durable and less likely to crack if there is any flex at all in the deck.
Presuming you are just sealing over removeable wood decking, its the resin not the cloth that'll be waterproof. 4" will hold more resin horizaontally, so better, a bit thinner vertically so less good. I'd use the resin liberally making sure its completely wetted out so water has less voids to run in when it does get in.
if it's for protection and not structural, 4 oz. will be good
I used the 4 ounce cloth to waterproof the plywood deck of the glen-l malahini boat I built and was very satisfied with the result. In my case I wanted a thin cloth that would add minimal weight and not show the texture (top deck was stained).
safe for potable water?
I don't know Sorry I use it for building kayaks
don't know used 4oz cloth to build stand up paddle boards
how much epoxy does it take to do a job for 10 yards of 50" wide 4 oz fiberglass?
One gallon will cover 15 square yards so figure it out. I like three coats on a boat. I can no longer build boats but I always bought by the gallon knowing I would use it sooner or later.
I like to spread the first layer using the "dry" method-put the cloth down and gently spread the epoxy with a 4-6" "squeegee ". I think the job described would use between 1/2 gallon and one gal. I'd probably recommend 1 gallon of epoxy and the corresponding amount of hardener, e.g., 1/2 gal of system 3 w/ 1 gal of system 3 epoxy. That's for two coats. You might get by with 1/2 gallon- If you have to buy more it's more expensive for the smaller amounts. Also I'd get medium drying or slow drying hardener as you don't want it to set up too quickly. If you're in a hot climate I'd recommend slow. Hope this helps! wstm- email me any time.On Apr 7, 2014, at 7:46 PM, Jamestown Distributors wrote:
I use the 4 oz. glass with West System's epoxy to build strip canoes. A 10' solo boat takes about 10 yards of cloth and I use about a gallon and a quarter of epoxy and hardener. That gives me three thin coats on the outside and two on the inside. The inside is "non-skid" with the weave of the cloth still visible.
About 1 gallon. You're using a little over 120 SF of material. Some people figure about 1 oz/SF. And a gallon is 128 oz. That would be the total amount including resin andhardener.
Assuming you are using a wet layup I would start with double the weight of the cloth. If vacuum bagging much less. So you have 56 oz of cloth I would buy 112 oz of resin about a gallon. This is only a general rule I would use for a wet lay up which allows for mixing loss. If you are going over a porous rough surface you may need more. Most importantly try to buy your product elsewhere. Jamestown distributors has used deceptive sales tactics with me and ignored my request to resolve the problem. I no longer do business with them. Hope this helps.
I m repairing a 4" long crack in a fiberglass bath tub. Plan on beveling out the crack , sanding and cleaning then using fiberglass and "Resin or Epoxy?" to lay in several layers of increasing smaller piece of cloth in the crack. What is the difference between resin and epoxy and what thickness cloth would be best. The crack is just where the tub curves up to the side so I want it to be strong. Todd
A couple of issues. First, if you are using the West system, it is a 2 part resin and hardener. You would mix the resin with the hardener in a predefined ratio which would result in the fluid mixture that you would use to soak the fiberglass mat. You won't need much resin and hardner for a 4 inch crack so you might want to use the G/5 5 minute adhesive with is also a two part resin and hardner but comes in much smaller 4 oz bottles. In any case, you would then make the repair, fair the repaired area and then probably paint over it. I'm not certain of the compatibility of the West system or G5 with the "fiberglass" that your tub is made of. You should make certain that the West system epoxy or G5 and the fiberglass in your tub are compatible. Secondly, I'm not sure how strong the fix will be if you fill the tub with water and have someone in the tub. This could result in more weight than your repair could take. It's a gamble, but it might work. Good luck.
Shopper:The 4 OZ cloth should work fine, the best way to cut the small strips you want without fraying is with a "Friskars rotary cutter" # 1993575 at Joanns. I would recommend epoxy over Resin. Epoxy is a little more flexible, does not form a film when curing and be easier to feather out. Also most paints will bond to Epoxy better.
Todd; Resin is one of the parts to the epoxy. The other is the hardner. 2 are mixed and applied to the cloth and will harden.Be sure the repair area is clean and dry. Apply the mixed epoxy, then the cloth. Saturate the cloth with more epoxy and it will become transparent. Keep in mind the hardened epoxy will be tough to sand so as it hardens, try and smooth it out as it sets. Let it dry for the recommended time. The finish coat of epoxy can be thickened with a sanding filler (reddish color, but easy to sand). Take the time to prep the area before painting. The prep work is the key to a good finish.hope this helps
I have used the West system epoxy and resin on a hole on the bottom of a fiberglass tub for a quick repair. I lightly sanded the fiberglass until I was sure all the shiny colored resin was dull. It has lasted two years of daily use with no problems. Now about your repair of a side crack with the 4oz cloth. If the tub hasn't separated at the crack then you should be able to do the same as above except use the cloth to give it strength. Otherwise if it is separated, then you would need the cloth on both inside and outside which would be difficult to do if the tub is installed
First I would use epoxy over resin as it is strong and will last longer. I guess almost any size would work but I would probably use 4 oz. cloth. In strip as you indicated..good luck.
Todd:Fairing glass cloth can be an effort in futility but can be done with care. I would recommend using West System (or System Three) Epoxy with their fairing compound to fill the void instead of using cloth. The 4 oz woven fabric will work quite well as long as the substrate is solid but it doesn't like to bridge gaps. If you can get to the outside of the crack, overlay a piece of cloth for tensile strength, fill the void inside with fairing compound, and cover with another piece of cloth. Use Epoxy instead of Polyester resin, the epoxy will bond, the resin will flake off over time. Hope this helps.
Haven't done fiberglass bathtub repairs. So, my .02 worth:1. Get your materials together.2. Sand the crack thoroughly.3. Coat the crack with epoxy, 5 or 15 minute epoxy would be good 4. Put a small piece (sliver) of fiberglass cloth in the bottom of crack & coat with just enough epoxy so the clothbecomes transparent. Use a plastic squeege to smooth. 5. If necessary, put another piece of fiberglass cloth on top of the first layer & coat with epoxy & smooth.6. Allow to cure and give a final sanding.
I need fiberglass cloth (non-woven is fine)that is fairly open weave if woven. The glass must NOT be coated or otherwise treated with resin. Do you have anything that fits my needs?
It depends on what you want to do with it. I use the cloth to make deck delimitation repairs. Generally I remove the old laminate that has become detached from the structure and replace it with the correct thickness cloth. I wet it with West System 2 part epoxy and place it in the space that was previously prepared. Then it's simply a matter of filling in the voids (several sang ins) and then painting it and applying non-skid grid. I use bi-directional cloth for additional strength.More information would be needed on your specific applications to better answer your question.
I am using this cloth to cover plywood to make a panel for my boat. What resin would you recommend? I assume West System is ok?Also, i selected this cloth, because i'm more concerned about the finish of the panel than strength. Please let me know if you recommend a different cloth or mat for a good finish. Thanks!Ed
Ed,4 ounce cloth with 2-3 applications of epoxy resin should do just fine. The idea is to fill the weave of the cloth without putting on too much resin that will only add weight and expense. A light sanding between applications of resin is advisable to facilitate adhesion between coats of resin. Finish off your work with a couple of coats of marine varnish that has UV inhibitors. Epoxy resin will deteriorate when exposed to direct sunlight for any length of time. The varnish will protect the epoxy from deterioration.Any of the major brands of epoxy sold for marine use can be used. I have used MAS, West and System Three resins with good success.
Yes West System clear works but I prefer System 3. My experience is System 3 does not "blush" and West tends to. You might also be aware that epoxy does not resist heat such as around an engine bay. Here I would a vinyl esther resin. Almost all racing hydroplanes use a layer of 3 or 4 oz glass over the mahogany ply. We then use automotive clear coat over that for scratch resistance. Here I prefer the Dupont system.
W DAVID RICHARDSON
The west system used with the cloth will work for strength and will be virtually invisible when done. You should epoxy both sides of the plywood to keep it from warping, then apply the fiberglass cloth the next day. I hope this helps!Wayne
The 4oz cloth becomes invisable under a coat of West System of 105 and 205. It makes a very slick and clear finish. A light sanding and it can be painted
What size and type of boat are you building or repairing ? Where will the panel be positioned ? How is the boat being used ?West System is fine to use.
4 ounce per yard fiberglass cloth is virtually invisible over wood when properly wetted out. I have used West System epoxy to build wood-framed boats with an exterior fiberglass coating and have been very happy with it. West System epoxy does not cure quite as clear and colorless as some others, such as System 3 epoxy, according to some wooden boat builders, but the difference in pictures I have seen posted on the web has been minimal.
west system is good, but my last boat used mas epoxie which worked very well,a little pricer but worth it.4 oz. cloth still has good strength and wets in nice.
I'm a carpenter, and have built two sets of rail truck boxes to hold my tools, both with 3/4 ac plywood covered with fiberglass set in West System. On my first set I used 6 oz, and after about 5 yrs. of heavy use, they are still going strong, on a friends work truck. On my second set I used 4 oz., and it has cracked in spots, and doesn't seem to have the durability needed, allowing for water penetration into the plywood. The benefit was that the weave depth was shallower, so they were quicker to finish. Hope this helps.
Hi ! Which way is it , I want some thin cloth . Is the lower the oz. the thinner ?
Hi Greg,I think you've already figured it out, the lower the weight in ounces, the thinner the cloth. Most of the cloth JD carries is appropriate for boat building. If you need a very fine cloth (say 1/2 oz. or such) you might try a shop that sells r/c boats and airplanes.I hope that helps, Ray
I can not remember.
Short answer is yes.....lower oz. means oz per unit area.....per square foot, I think.
Yes Greg, the lower the ounce number the less (thinner material) per yard and takes much less resin to fill the weave
The lower oz the thinner! I used 4oz for a feather weight canoe. Please note that the thinner you make it the lesser strength.
I belive the lower the number the lighter the weight. 4oz wets good, becoming clear, and is plenty strong.
I want to buid a cedar strip canoe. What do I need for a 17' 36" beam? It will be glassed inside and out.
First build the boat; then measure the girth if you can use one piece per side that makes things pretty easy. If you are In Maine, perhaps I can give you a hand. Dave
David,It depends a bit on how the canoe will be used. For general purposes, for a tandem canoe, I'd recommend 2 layers of 4 oz.cloth (inside and out, in the "football" area (basically, that would be the area below the waterline. Foe areas above the waterline, a single layer, inside and out would be sufficient.If the canoe will be used a bit less gently, you could follow the same procedure, using 6 oz. cloth. Unless the boat will be used in heavy rapids, there is likely no reason to go any heavier. Conversely, it the boat will only receive gentle usage (day trips on calm lakes) a single layer of 6 oz. inside and out (skipping the extra layer in the football area) might be sufficient.I'd be pleased to elaborate more if you have specific questions.Marc OrnsteinDogpaddle Canoe WorksCustom Canoe Paddles and Woodstrip Canoes
What are you asking ??? Is 4 oz. cloth suitable? Answer....... YesHow much cloth do you need ? Answer....that's your problem.I would not recommend glassing the inside. Coat the inside with epoxy resin. And use epoxy resin for the outside work. Wood likes to expand and contract. If you capture it between two layers of fiberglass cloth you are asking for trouble.........right here in River City.
I would use 4 oz cloth on the inside but I might consider a heavier cloth for the outside. Keep in mind this adds weight to a light canoe.
Hi Dave,I built two wooden boats and fiber glassed them both. I used epoxy cloth on the outside and penetrating epoxy on the inside. I had too many frames to try to us cloth on the inside. Epoxy works much better than polyester as it sticks to the wood much better. I never mixed much epoxy at a time, just many plastic cups. 14 years later they are both as good as the day they were built.Dave
I have a very old fiberglass canoe that has several small holes and the gel coat is cracked all over. I want to repair the holes and re gel coat the entire canoe. since it is so old I was wondering if it would be best to put a single layer of fiberglass cloth over the entire canoe just to give it extra strength? and if so which cloth would be best. The canoe is approximately 14 feet long, 3 feet wide at the middle, and has a depth of 15 inches.
that is a good idea. but make shure to remove all the old paint and rough up the gell coat.
one layer of 4 oz. cloth would add strength and durability. It would not add that much weight either. I would rough up the entire surface with course sand paper and use epoxy resin.
There have been several mentions of west epoxy and mat in this thread. They should never be used together. Mat is made with a binder to hold the loose strands together until wet out with resin. The binder is designed to dissolve in Polyester resin and it helps promote saturation of the mat by the polyester resin. This does not happen with epoxy. There are some mats and fabmats made to work with epoxy, but they are rare and hard to find. In polyester the mat is the adhesive layer and the roving or cloth is the strength layer. Epoxy is already adhesive and you only need the cloth to provide the strength.
DAVIS BOAT WORKS
This would indeed be an appropriate way to refurbish the hull. I'd begin by sanding away most of the existing gel coat. Use proper dust masks to protect yourself while sanding. You'll be able to tell when most has been removed, since the underlying color of the fiberglass hull will begin to show through. I'd suggest doing the last bit of sanding by hand, using a fairing board and 60-80 grit paper. This will help to level the surface and eliminate high and low spots.Grind out the areas surrounding any holes and patch with pieces of FG cloth and resin. Sand the patches flush with the rest of the hull. I won't go into the full patching procedure, here. There is much info. about that elsewhere. After vacuuming off the hull and wiping it down with lacquer thinner (do outside), lay on the new cloth as neatly as possible. If possible, do it with a single piece. You'll need to slit the cloth at the stems. Apply the epoxy resin, working from the center towards the ends and from the"keel" line towards the sheer, working out any wrinkles along the way.When applying the epoxy, working with a helper is much easier than working alone. Use a slow setting, low blush resin. My preference is West System resin with #207 hardener. There are other excellent alternatives. Follow the West System instructions. Apply a second / 3rd coat as necessary to fill the weave of the cloth. Once the final coat of resin has cured, wet sand beginning with #180 grit paper and working up through at least #300. Choose your preferred paint/primer and apply according to the manufacturer's directions. Marc OrnsteinDogpaddle Canoe WorksCustom Canoe Paddles and Woodstrip Canoes
Yes that would be a good idea. It would not only fix the holes, or cover the fix you put on, but also stop all the cracking. I built both a rudder and a centerboard this year and used the lightest cloth I could get, 4 OZ. I think. It worked well. Also use epoxy not polyester, it holds on to older work much better.I built a 25 foot Glen-L plywood sailboat and did all of it with epoxy; 15 years later it is still perfect and strong.Thanks!Dave
I greatly appreciate the advice it was exactly what I needed! I was wondering if I need to re gel coat or if I can just paint the entire canoe with a few coats, and what about the inside of the canoe, just paint or a gel coat?
Have done about a dozen canoes. Use the 4 ounce fiberglass matt. Cover entire canoe with epoxy, set full matt, another layer of epoxy, and put a diagonal piece of matt in center bottom of canoe. More epoxy and sand out. last matt is normall 4'x4'. this seems to give maximum strength.
I used the 4 oz. fiberglass cloth and Total Boat Epoxy Resin & Hardener to fiberglass a canoe paddle I made. The fiberglass cloth wet out beautifully and wrapped around the edges of the paddle with no problem.
Good product and good service.
Cover inside and outside of new 12' strip plank kayak Wee Lassie.
New Haven, VT
I was surprised how the product was shipped (rolled) this made lay out and cutting so much neater. this glass is working very well for my hobby project.
North Charleston SC
The product was great! Exactly what I needed with great quality. The only thing that would stop me from buying from Jamestown again was that my credit card had two pending transactions placed on it for a month for a single purchase. Eventually I was only charged once, but the two pending transactions still lowered my available credit allowance. I don't understand why they placed two pending transactions on my account and when I wrote to them asking for clarificaiton I did not receive a response.
25 yards of 4oz. cloth
Smooth cover over cedar strip single scull.
Fox Lake. Wisconsin
I would by this product again
High Quality fiber cloth, I use it for my wooden kayak projects.
Product came rolled up, so there were no creases Was easy to apply.So far I have applied the fiberglass cloth to the exterior of a wood strip canoe. It went on smoothly. I still have the interior to do.
The 4 oz cloth worked very well, although I wish the same (small) quantity of material were available rolled rather than folded.