makenmend Posted January 5, 2014 Report Share Posted January 5, 2014 that's the route I took, easier I think. Tabbed the keel completely as well. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 5, 2014 Author Report Share Posted January 5, 2014 Uh oh... Came back to the taped seams and when cutting the overhanging bit of tape, I noticed it pull out away from the joint some. With some firm tugging I was able to rip a strip all the way up the transom. We taped this the afternoon of NYE with temps probably around 60 but dropping as the sun left the greenhouse. To keep things as warm as possible through night we left 2 grow lights on which have worked well for the interior of the hull. When I came back the next morning to fill the weave, I noticed that the stuff with the least direct light exposure was still a bit gooey. That's my best guest to the problem: not warm enough for a proper cure. It looks like we will be stripping all the tape, sanding back to bare wood, and starting over again. Any thoughts? Quote Link to comment Share on other sites More sharing options...
mattp Posted January 5, 2014 Author Report Share Posted January 5, 2014 My assumption is that a properly cured fiberglass epoxy joint should be harder to strip off than wallpaper. If I were strong enough to peel the tape, I would expect chunks of plywood to come off with it. Anybody disagree with this? Quote Link to comment Share on other sites More sharing options...
LennieG Posted January 5, 2014 Report Share Posted January 5, 2014 I am far from an expert, but it seems like either a temperature issue, or bad mix ratio of epoxy, or not stirred enough. Appreciate your pace and progress never the less. I am on "vacation" from boat building until later this week but enjoying your build and posts. Good luck getting through this issue. Quote Link to comment Share on other sites More sharing options...
Miyot Posted January 5, 2014 Report Share Posted January 5, 2014 I had a similar problem while doing an inside panel. I had never, and I mean never had a problem like this before. Most areas were perfectly cured and one quite large spot was still gooey. I was using west system slow hardener which is quite clear. After some serious thinking I did remember putting down my resin after pumping out the proper strokes and quickly doing another small job before returning to my glass work. I had forgotten to add the hardener, stirred the resin without the hardener and applied it. Needless to say I had to redo the entire panel. I stripped off the glass, scraped to bare wood and then sanded with 80 grit. The next try was perfect and I've never had another problem. Just goes to show. You must not loose your track of thought. Keep track of your number of pumps, make sure your pumps are delivering the right amount and stir thoroughly. I did have to replace my main resin pump during my project. I started getting quite a few bubbles in my resin, changed the pump and resolved the problem. When I glassed the outside of the boat it was summer and I used the Slow Tropical hardener. This took several days to reach full hardness. My assumption is that a properly cured fiberglass epoxy joint should be harder to strip off than wallpaper. If I were strong enough to peel the tape, I would expect chunks of plywood to come off with it. Anybody disagree with this? I agree. Unless the epoxy had not reached full cure. All according to the type of hardener being used and the temps involved. I've seen temps change enough during the cure phase that another 24 hrs brought about the cure I thought should have come sooner. 10 - 20 degrees can make a big difference in cure time even when your lower temps fall well within the epoxy's suitable working limits. Quote Link to comment Share on other sites More sharing options...
Dnjost Posted January 5, 2014 Report Share Posted January 5, 2014 I have had similar issues due to the following (not all at the same time). not adequately removing blush from previously cured surface. water and a scrunge work well. roughing up the bonding surface with 80 grit prior to mating new surface not mixing epoxy correctly (too much resin to hardener) using cheap epoxy. Staying with WEST for now after a brief experiment with Systems Three (both are good, but I get more consistent results using the WEST). moisture forming on the resin surface during cure due to changes in the weather. Nothing terminal, just scrape, prime and do over. in golf, it would be a mulligan. Doesn't get reported on the score card. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 5, 2014 Author Report Share Posted January 5, 2014 I don't think the ratios were wrong because we were working in small batches and I think if the ratio was off, it would have had a more drastic effect. The cured epoxy has the same feel and appearance as the other bits I have done. It sands the same as well. When I peel it off, it has a bit more than the resistance of pulling duct tape off of a sticky roll. Around the corners I have to scrape it off with a chisel. What's left is a weave textured layer of hardened epoxy, not bare wood. Quote Link to comment Share on other sites More sharing options...
Miyot Posted January 6, 2014 Report Share Posted January 6, 2014 I don't think the ratios were wrong because we were working in small batches and I think if the ratio was off, it would have had a more drastic effect. The cured epoxy has the same feel and appearance as the other bits I have done. It sands the same as well.When I peel it off, it has a bit more than the resistance of pulling duct tape off of a sticky roll. Around the corners I have to scrape it off with a chisel. What's left is a weave textured layer of hardened epoxy, not bare wood. How long did you let it cure before pulling on it? Did you wet out the ply before laying on the cloth and if so did you let the resin cure before applying the cloth? I have heard of bad batches of epoxy but have never seen it myself. Also is the cloth compatible with epoxy, as some kinds of glass are not, which can cause adhesion problems. Very odd. Hope you get it figured out Quote Link to comment Share on other sites More sharing options...
mattp Posted January 6, 2014 Author Report Share Posted January 6, 2014 I don't think the ratios were wrong because we were working in small batches and I think if the ratio was off, it would have had a more drastic effect. The cured epoxy has the same feel and appearance as the other bits I have done. It sands the same as well.When I peel it off, it has a bit more than the resistance of pulling duct tape off of a sticky roll. Around the corners I have to scrape it off with a chisel. What's left is a weave textured layer of hardened epoxy, not bare wood. How long did you let it cure before pulling on it? Did you wet out the ply before laying on the cloth and if so did you let the resin cure before applying the cloth? I have heard of bad batches of epoxy but have never seen it myself. Also is the cloth compatible with epoxy, as some kinds of glass are not, which can cause adhesion problems. Very odd. Hope you get it figured outGlass applied Dec. 31 and wet out to fill weave again on morning of Jan. 1. First noticed pull off yesterday on Jan 4 and again today, Jan. 5. Being in a greenhouse, the temperatures fluctuate from about 40F at night to about 70F on sunny days. The first night under very warm grow lights.We wet the seam first then immediately applied and wet out the tape. The cloth is 3" wide 10 Oz. fiberglass tape.Is it possible that I am not being patient enough with the cool weather and the epoxy is not FULLY cured yet? Quote Link to comment Share on other sites More sharing options...
Designer Posted January 6, 2014 Report Share Posted January 6, 2014 I would not be in a hurry to blame the epoxy. I have recently had the same issue in cooler weather where the epoxy had not fully cured and my impatience got the better of me, I peeled off some glass just like the picture above and it came off without much effort, scaring me. In one instance during a multi layer glue-up, some plastic release turned back under the glass giving a good purchase to peel off the semi cured epoxied glass. I re-did the job and monitored the other parts glassed with the same mix and found that after a few days they had very good peel strength. Quote Link to comment Share on other sites More sharing options...
Oyster Posted January 6, 2014 Report Share Posted January 6, 2014 Finishing cloth can also be a bit finicky over some woods. I have had instances when I was working with marginal amount of resin left and attempted to scrimp a bit of wet out that finish cloth peeled off. . What I concluded when the finish cloth did pull off a bit starting along the edges was that the wood pulled resin out of the glass and essentially starved the glass and bond, which allows for the glass to be peeled off. food for thought... Quote Link to comment Share on other sites More sharing options...
Howard Posted January 6, 2014 Report Share Posted January 6, 2014 Matt: It would appear to me your assessment is correct. It sounds very much like your epoxy was still "green" and not cured enough. It can feel and look hard as though it has cured, yet isn't. You really notice it on a stressed joint if you pull off the clamps or wire stitching too soon, as a gap forms or the taped joint slides or lamination pops open. Curious what epoxy and speed of hardener you were using, and what temp the resin was when you mixed and applied it. The latter is an often overlooked factor that may have more influence than we know. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 6, 2014 Author Report Share Posted January 6, 2014 Thanks for all of the replies. I am hoping for the "still green" scenario. We will give it a few days and tug on a different strip. Quote Link to comment Share on other sites More sharing options...
Hirilonde Posted January 6, 2014 Report Share Posted January 6, 2014 I re-did the job and monitored the other parts glassed with the same mix and found that after a few days they had very good peel strength. I never really made a point of monitoring my epoxy work like this but I have found that epoxy done in low temperatures can take many days to achieve the same cure as occurs in 4-6 hours during warm temps. I don't know that any of us have enough information to say just what did happen mattp, but if I had to bet I would bet on simply did not finish curing due to temperature. I have done some very cold epoxy work and have found that if I wait long enough, or until a period of warm has occurred it always seems to come out fine. Some say that epoxy work done in cold temperatures will never reach the strength of work done in warm temps. I can't say this is true or not. I only know that I have never had issues in any temperature so long as I wait long enough or for a warm period. As a matter of fact, during particularly warm weather I put both parts of my epoxy on ice and mix them cold on site to extend pot life. This has never caused issues either. Quote Link to comment Share on other sites More sharing options...
PAR Posted January 7, 2014 Report Share Posted January 7, 2014 Epoxy curing is a pure chemical reaction, so if you do it in cold temperatures, it will eventually cure, once the temperatures come up long enough to permit the cure to finish. I know northern builders that do a bunch of work, knowing nothing is cured. In late winter, they often have a false spring and the roll the project outside, in the sun and let all the last few months of work "kick off". I use heaters to make goo cure in cold weather. Rig a tarp over the boat or work and place a non-flame heater (oil filed electric ones at Wal-Mart for 15 bucks). Leave it like this for several hours and you've got cooked goo. I've replaced transoms and soles in 20' powerboats, still on their trailers, using this method in freezing overnight temperatures. Of course, freezing overnight temperatures is a relative term her in Florida, where it might go down to freezing for a few hours on an exceptionally cold morning (like tonight), but the process still works up the in the great white north, it just takes longer. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 11, 2014 Author Report Share Posted January 11, 2014 These comments are reassuring and informative. Thank you. Tomorrow should be sunny and in the 50's which means mid seventies in the green-boat-house. A good day, we think, for fiberglass sheathing! Meanwhile in the satellite shop (my house), progress is made on rudder components: Quote Link to comment Share on other sites More sharing options...
Scott Dunsworth Posted January 12, 2014 Report Share Posted January 12, 2014 Exactly what I was thinking Oyster!!!! Quote Link to comment Share on other sites More sharing options...
Dnjost Posted January 12, 2014 Report Share Posted January 12, 2014 I like the idea of having a radius on the inside bottom corner of the filler block. It should help prolong the life of the downhaul. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 12, 2014 Author Report Share Posted January 12, 2014 My thinking with that radius was for an uphaul but probably the better way is to just keep the line outside. Of course, it would be difficult to add the radius later. Quote Link to comment Share on other sites More sharing options...
mattp Posted January 13, 2014 Author Report Share Posted January 13, 2014 Fiberglass day! I didn't get a picture of the tarp heating tent for overnight curing. Quote Link to comment Share on other sites More sharing options...
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