No matter how much research I do into this, I can't seem to find much information on fiberglassing a wooden hull. 1. I know I have heard of people using 6 oz. fiberglass cloth, does that sound about right? How many layers do you think are called for? 2. When I went to the local marine store, they sold the resin with a substance called "flag." Is this the hardener I keep hearing about? 3. For complicated parts like bows, should I cut separate small strips and do it in parts, or do it with one big piece?
I am now looking online for materials, the local marine store was going to charge ~$60 just for a yard of 6 oz fiberglass and some epoxy, these prices seem to be much better. These are what I have found: http://www.hobbylinc.com/htm/hca/hcahcar5010.htm http://www.hobbylinc.com/htm/paa/paapt40.htm I suppose I would do two layers?
go to your local marina (or hobby store) and pick up a couple of packs of 5oz cloth ($3bucks/pack last time I bought it) also if you're putting it over a wood hull one layer should do it on the outside (2 if you really feel its needed) and coat the inside with a liberal dose of epoxy and that should be plenty strong. It also depends on how you built the hull. how did you BTW?
Although I want to build real scale battleships eventually, what I am doing now is just an RC pool toy for the kids at the local pool (last summer was a submarine ) The hull is a pentagon shape with a funny sort of bow and a block stern, two props one rudder and some simple water cannons. I hope that answers your question
6oz seems a little heavy to me. I would go with nothing heavier than 2oz. 1 oz cloth should work also. A local hobby shop should have a package of the stuff. One package is more than enough to do a hull. All you need is a single layer. There are two ways to stick it to the ship; CA glue or a resin. I've done both. The CA method works well if you can handle the fumes. You must use the thin CA type of glue. A person may think that a lot of CA is needed, but surprisingly little is actually used since the stuff wicks through the cloth and spreads out. I tend to use this method for small repairs (I don't like the fumes that much ... heh). NOTE: do not use CA on foam unless it is foam safe CA!! For big jobs, I like to use West Systems Expoxy resin. It's a two part resin that takes a while to harden but gives a very hard durable finish when dry. I normally spray a light mist of contact cement on the hull to hold the cloth in place, then brush on the resin. Make sure the resin goes through the cloth! After the cloth is painted on, take an old credit card and scrape the excess epoxy off to minimize soft spots and to give a nice even finish. let dry, then primer. Fiberglassing a wood hull is easier than it sounds. Really!
Ok, about how much epoxy do I need to buy? The ship is only 33 inches long, I don't want to buy $30 of epoxy when $10 would do the trick. For a hull that size do you think I would need a whole quart?
An alternate source for resin is the two part polyurethane sold in arts & craft stores. The stuff is normally used for table tops, plaques, or anything that needs a thick coat of varnish. The small size costs around $12 and will do a large ship. For a small ship, you can use the extra to waterproof the interior wood.
I really recommend you stick to a Marine made Epoxy system. Delmaination is a ugly thing and when exposed to water a poor done fiberglass job can delimanite. Excuse the spelling there. I am tired and Spell checker is not helping.
I'd recommend that you go with a West Systems (or equivalent) epoxy and 2oz S-glass fabric. You'll avoid the mess associated with using fiberglass mat and West Systems epoxy is specifically designed for marine applications.
When you say fabric, you mean the stuff thats actually woven togeather, as opposed to just being a jumble of semi-fabric like threads? I saw that jumble of threads stuff and immediately decided to avoid it
Need to be clear. the woven make is a final layer. the Mat is a good layer or two for strength purposes. you will find most all fiberglass products have weave just under the gelcoat and the mat in several layers with maybe another layer of weave to make a clean finish.
One further suggestion. Always test your materials before you put it on your ship, as not all mat will wet out well with epoxies. I have come across some matt that would not wet out well and generally was a big mess, while others would. As far as strength, a woven cloth will always be stronger than mat for similar thicknesses. One of the tricks with composites for strength is to maximize the fibrous content with a properly wetted epoxy. The fibers are the strong part and the alignemnt, length, etc. of them along with the quantity governs strength. Mats always use more epoxy. I can highly recommend west systems epoxy. It is the best stuff I have ever used.
