markfitz Posted January 11, 2005 Report Share Posted January 11, 2005 OK, last night we dry fit our fiberglass cloth, and attempted to apply epoxy to one half of the bottom. From what I can tell, the cloth RAKA sent to us is too thick. It was brutal to get it to wet out properly, and even when it did, in areas like the sharp transition from bottom to side, it had a tendency to be fine, and then gradually form an air bubble. It was like the epoxy couldn't hold the cloth down sufficiently. We did the best we could, but on the bottom especially, the surface looks pretty uneven. We applied with a roller and a plastic body filler spatula to push the epoxy down into the weave...but I think there are some areas where the cloth may have either too much or too little epoxy under it. What is the best course of action? Do we keep putting on more coats until the weave is completely filled? Do we need to sand between coats?? If this were lacquer, I would simply build up the finish until it's thick enough to sand out the imperfections without sanding through the finish. Will this strategy work here? Also, looking for suggestions to make the other side easier....would thinning the epoxy help or hurt? I was thinking it would help the wetout process, but also might not hold the cloth down to the hull as well as heavier stuff. Plus I have no idea what to thin it with. Help!! Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 11, 2005 Report Share Posted January 11, 2005 OK, I'll take a stab at this. Do we keep putting on more coats until the weave is completely filled? Only if the cloth is sufficiently adhered to the substrate. It always take multiple coats to fill the weave, but don't waste the time doing so unless teh cloth is properly adhered. Do we need to sand between coats?? Yes, unless you catch it while it is still green. If you get another coat on in about 24 hours, you won't ned to sand. And remember to remove any blush 'prior' to sanding. If this were lacquer, I would simply build up the finish until it's thick enough to sand out the imperfections without sanding through the finish. Will this strategy work here? Basically yes, see answer to number one. Also, looking for suggestions to make the other side easier....would thinning the epoxy help or hurt? Try to lay the cloth on the bias, or lay the weave diagonally on the hull. Cloth will take greater curves if it is layed on the bias. There is a fine line between too much epoxy and too little when wetting it out. You want to the cloth to touch the substrate and not be floating in epoxy. at the same time, it need to be thoughly wet, if not it will look dry or kind of white. Short answers but I hope these may help. Quote Link to comment Share on other sites More sharing options...
Arnie Eaton Posted January 11, 2005 Report Share Posted January 11, 2005 On the other side, I would put a layer of epoxy down first and then lay the cloth over it. Use a squeege to smooth out the cloth. Use more epoxy over the cloth if needed.Let this set up and then apply as many coats as needed to fill the weave, letting the epoxy set between coats. Be sure to cut the cloth to fit before applying the epoxy, makes for better work. Should you have bubbles (after the epoxy sets up) cut the glass bubble out and then fit a new pc of glass and epoxy it in place. Good luck and be sure to ask if you get confused. No such thing as a foolist question. Quote Link to comment Share on other sites More sharing options...
markfitz Posted January 11, 2005 Author Report Share Posted January 11, 2005 We had given the entire boat a coating of epoxy a week ago, on the bare wood. We figured this would help avoid the wood sucking the epoxy out of the cloth. So this weeks extravaganza was after it had already been sanded once and the dust cleaned off. I Didn't know that about the diagonal. I don't know if we could have done that with this size cloth - but good to know. After searching on some other epoxy threads here, I think we should have heated it up first too, to thin it out some. Using the foam roller on the sides seemed to create wrinkles in the cloth, and sometime even peel the cloth up. In some small areas, i think the cloth may actually be "floating" in epoxy, if that makes sense. Like it raised up from the wood as it was applied. Thanks for all the advice.. Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 11, 2005 Report Share Posted January 11, 2005 Laying the cloth on the bias is a real saver. As for heating it, unless it is extremely cold I wouldn't bother with it, as when it contacts the cold substrate, you are back to the same temperature anyway. I have used Raka's epoxy and really like the way it wets out cloth. Double check with Larry and make sure you got the cloth you asked for. Arnie's suggestion is also a good one, though I like to lay the cloth dry and get all of the wrinkles out of it first. Pre-coating is an option; I have heard pro and cons both ways though I don't. I also had a problem as you describe with the roller wrinkling the cloth. I gave up and used only a squeegee and a slotted roller for applying cloth. A bit of a pain on the verticles but it turned out well. Quote Link to comment Share on other sites More sharing options...
markfitz Posted January 11, 2005 Author Report Share Posted January 11, 2005 What is a slotted roller? This cloth looked pretty heavy. In the video that came with the plans, it seems much more 'formable' and thin than what we had. For instance, where the side hits the bottom rub rail....in the video, he'd dry fit it down, and it would stay in that 90 degree angle. Ours kept popping out. My father is checking with Larry to make sure he got the right stuff. As for heating, I can't see it buying us much, you're right. The garage is heated, and the epoxy stored inside, so it's at least 60 degrees or so. I noticed when squeegieing it around (is that a word?)the epoxy seemed to turn creamy white. I assume this is blush, or tiny air bubbles. I think this was due to moving the squeegie around too quickly, because were were paranoid it was going to set up too fast. Like my old college prof used to say, "There is no such thing as a stupid question. Just stupid people who ask questions." Quote Link to comment Share on other sites More sharing options...
JMetzner Posted January 11, 2005 Report Share Posted January 11, 2005 Mark, What weight fiberglass cloth did you get from RAKA? I used their material and epoxy for my weekender and didn't have these kinds of problems. I used their 5 oz. fiberglass cloth. The web page said it was rated stronger than the normal 6 oz., which I believe is what the plans call for. My fabric draped very well and tucked in around the rubrail on the dry fit just like on the video. --John M. Fairbanks, AK. (-39F this morning, no whining about how cold it is from you guys down there in the lower 49) Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 11, 2005 Report Share Posted January 11, 2005 If this link works, it will show a sample of the roller I am refering to. Slotted Roller Turning creamy is indeed whipping air into the mixture. Not to worry as most if not all of it will dissipate. remeber, epoxy has a very long open time (as long as it is not in the pot) and thus you have plenty of time to work it (I did the same thing first time out). Blush is a waxy or greasy film that forms on the cures epoxy. It is caused by the amines that are used in the curing process. If you re-coat within a reasonable period you won't have to worry about it. Personally, I have not encountered any blush with the Raka products, though I usually wash it all down with lacquer thinner prior to additional coats if I have let it cure for many days. One more thing..............I am the only one who asks stupid questions!!! :) Quote Link to comment Share on other sites More sharing options...
Frank Hagan Posted January 11, 2005 Report Share Posted January 11, 2005 I noticed when squeegieing it around (is that a word?)the epoxy seemed to turn creamy white. I assume this is blush' date=' or tiny air bubbles. I think this was due to moving the squeegie around too quickly, because were were paranoid it was going to set up too fast. [/quote'] You mentioned that you had epoxied and then sanded the surface ... the white color you see might be suspended epoxy particles. I always got that with subsequent coats after sanding. If the glass is intact, with solid epoxy under it, you can just continue to fill the weave (unless its raised up so far that you will have an unsightly "bump" there). If there's an air bubble, you have to remove it (condensation will form in it and rot the wood underneath). Take a surform shaper or rasp and remove it. Don't worry about patching a small area smaller than a half-dollar with more glass cloth ... just sand the edges of the "hole" in the glass and fill with epoxy. You can do the same with any areas where the glass is too high and forms a "bump". On these boats, the glass serves two main purposes ... prevent fir plywood from "checking" and to provide some abrasion resistance. The strength it adds is secondary and not really that important to the construction of the boat (the plywood structure is already strong enough). So you don't have to worry about small places that don't have the glass. In other words, you don't have to be anal retentive about covering every square centimeter of the plywood with glass. You do want to fill the weave completely, as the "pattern" of the glass will show through if there isn't a thick enough coating of epoxy over it. If you plan to finish the hull in a dark color, this is especially important, as they tend to heat up more, and the greater heat makes the pattern show through more. On the foam rollers ... if you are using the 1/4" foam rollers from Home Depot or Lowes ... stop! They won't work, even though they say "for epoxy" on them. The nap is too thick, and you'll get lifting, bubbles, etc. You can get foam rollers from West Marine or Boat US stores that have very little foam on them ... about 1/8" or less. RAKA also sells these. These work fine. Some places sell what looks like a roller cover without anything on it ... just a resin impregnated cardboard tube. These work well also. I liked to use a spreader to lay down the first coat that adhered the cloth, then multiple roller coats (5 or 6) to fill the weave and have very little sanding. If you re-coat within 24 - 30 hours, with RAKA epoxy, you don't have to worry about washing off any amine blush. You won't have any ... no sanding, no washing, just roller on another coat. Quote Link to comment Share on other sites More sharing options...
adla Posted January 11, 2005 Report Share Posted January 11, 2005 epoxy cures through an exothermic chemical reaction - (it gets warm on its own) i wouldn't add heat to thin it...that will set it off faster. a. Quote Link to comment Share on other sites More sharing options...
Charlie Jones Posted January 12, 2005 Report Share Posted January 12, 2005 If the temps are around 60, I WOULD warm the epoxy. That's too cold for it to flow nicely. Even when it's slightly above 60 when I'm using epoxy, I'll warm the mixing container as I'm stirring by directing a blow dryer down into the container. Sure, it'll cool as it is applied, but so will UNWARMED epoxy. Better to have it warmed a bit. Besides that, when the temps do start cooling here, I store my epoxy in an old chest freezer and hang a 60 watt bulb in ther so the epoxy is at or above 70 degrees. Works a lot better that way and it's easier to mix and easier to mix in additives. I always precoat and lightly sand plywood surfaces prior to glassing. Keeps the wood from sucking epoxy away. If you are having trouble with the glass pulling and puckering when you roll it, try rolling in one direction only, then pick the roller up, move it back up next to the first pass and roll again. Squeegees do work much better on horizontal surfaces, but I roll epoxy on verticals, then use the squeegee to push it into the cloth. I find that it makes a whole lot less mess that way. By the way, when you squeegee, you should act like you are trying to scrape the top off the glass- not hard enough to show white strands, but hard enough to move all excess epoxy- the surface should look quite dry, but not have any white strands showing. Takes a time or two, then you get to be a pro;) Quote Link to comment Share on other sites More sharing options...
adla Posted January 12, 2005 Report Share Posted January 12, 2005 Charlie - You are a pro. And you do beautiful work...IMHO people that don't have at least a first or second time experience with epoxy should stick to the product guidelines...knowing how much and when isn't easily conveyed in email or message boards. Heat is how and why epoxy kicks....I could give anyone i know a seat on my piano bench (the instrument) show what notes are what (the tools) and give em a sheet of music (silence)....but some things just come with practice. epoxy is hardly something i would recomend manipulating with heat to someone who hasn't had it kick on them unexpectedly or even not at all...once or twice. This is a great board...the best...sorry i am typing like good ol'capn' Jake (little time) and Charlie, I think you're the best....it pains me to disagree with u. i was a "pro" (or at least sallaried) and worked in a "chop" shop for Years (7+) and saw a lot of interesting fiberglass and epoxy techniques....we never fiberglassed on wood so that it would stick there...(nor were we building boats -just little crappy things and horses and ponds and stuff)..um and stay so i can see how the project can get away from some people. I think the light touch and let it do its thing approach is best.....i glassed the bottom of my boat :oops: without gloves here ---> http://adlacearl.com/v-web/gallery/Morgaine pages 2,3,4...and while i agree that temp is important i also know that charlie and i both use west system 105 epoxy and 206 slow hardner....it may behave differently than RakKka :? a. Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 12, 2005 Report Share Posted January 12, 2005 If the temps are around 60, I WOULD warm the epoxy That's only because you are tired of the snow, isn't it? ;) I am kidding! As you see Mark, varied opinions and all of them work. It comes down to what works for you in the end. As has been said, practice will make you play like a virtuoso! Quote Link to comment Share on other sites More sharing options...
markfitz Posted January 12, 2005 Author Report Share Posted January 12, 2005 I don't know for a fact that is what we received, since I don't have anything to compare it to. I've done fiberglass repair work on my old canoe and old car when I was a teenager, and this cloth seemed about the same as what came in that Bondo kit. I will try warming the epoxy a bit. I am fairly certain I can tell when it's about to kick. I used the same epoxy in the heat of summer, so I assume that it won't be any faster than than how it was on a 92 degree day... Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 12, 2005 Report Share Posted January 12, 2005 Most of the Bondo repair kits came with a fairly heavy cloth in them. Heavier than 6 oz anyway..... Quote Link to comment Share on other sites More sharing options...
Charlie Jones Posted January 12, 2005 Report Share Posted January 12, 2005 Thank you Adla, for the kind words. I'm not really advocating someone manipulate the epoxy. But even the Gouegeon's recommend having epoxy near 70 degrees when working with it. In their book "The Gougeon Brothers on Boat Construction" they go into detail on building a box with a lightbulb to hold epoxy at warmer temps. When it gets cold, like down in the low 60s, it thickens to the point that it is difficult to work, PARTICULARLY when wetting out glass cloth. So I mentioned what I do with mine. And I highly recommend it. Certainly it's very difficult to convey techniques in print, without many many words and even photos. One of the reasons I (and others) use a series of pics when showing a technique. Can't argue with that at all. But there is no sense handicapping yourself when working on something that is already a big job, like glassing the hull. Once you've done one, you see what and how to do it. Til then, I just try to help a bit to make it easier. By the way- you do pretty nice work yourself gal. Quote Link to comment Share on other sites More sharing options...
capt jake Posted January 12, 2005 Report Share Posted January 12, 2005 Adla, nice pictoral!! I hadn't seen it before. Nice video including 'The old guy'. ;) BTW, Mark, where are you located?? Quote Link to comment Share on other sites More sharing options...
markfitz Posted January 12, 2005 Author Report Share Posted January 12, 2005 I'm in upstate NY, near Saratoga....My father will be rolling on the third coat today - (btw, using the 1/8" foam rollers purchased from Larry) and he said the second coat seemed to even things out quite a bit. I'm sure the second half will go better. The inside and decking should be a lot of fun....... Quote Link to comment Share on other sites More sharing options...
vk1nf Posted January 16, 2005 Report Share Posted January 16, 2005 I use a roller sleeve specifically designed for epoxy and other resins - it's a very short-nibbed, nylon bristle roller called a FIBERTEX (or FIRBETEK) - comes in regular roller size. but can be easily hacksawed to fit any roller. While I use it as a one-shot, it can be held in acetone between coats if you can stand having acetone around. It doesn't shed anything, soak up resin, or tend to lift things, and I think the short bristles help lay glass tape by penetrating the tape's weave. Manufacted by PINTAR, costs about $4 per sleeve here (Newfoundland.) Quote Link to comment Share on other sites More sharing options...
Tom Lathrop Posted January 16, 2005 Report Share Posted January 16, 2005 If the glass seems to be "floating", you have put on too much resin and need to squeegee it around. It is too dificult to roll epoxy on without getting too much on in some areas so a squeegee (a rubber one is best) should be used to put on the minimum required to completely wet the cloth and the surface below. There is way too much concern about bubbles in the resin. I defy anyone to mix epoxy and apply it without creating air bubbles. The only time they are a concern to me is if they are in the finish coat. Think about it. Lots of boat construction materials are purposely full of air. Foam, Nomex, microbaloons, balsa, etc., etc. Air ok, water bad! Protect it and seal it and it will be fine. Keeping epoxy in a box that is heated with a small light bulb is a good idea in colder times. Makes pouring or mixing easier and prevents crystalization of the resin. I store the containers of epoxy in use in a wooden cabinet with a 40 watt bulb. Smoothing out the dry glass cloth over the hull is best done with a wide soft brush to avoid the snags that happen when you try to move it around with your hands. I have a draftsmans brush that works great. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.