Saturday, October 3, 2009

Bulkhead #4 and First Gluing Disaster

Jeezum Crow.

First, I've been having problems on the employment front that has been keeping me out of the workshop. Today, I'm feeling good, confident, it's raining, I've got nothing else going on, so I roll into the shop and quickly pound out the framing for BH4. Then, I decide to start my first gluing.

Holy Baloney, what a disaster the whole thing turned into. First, I cover most everything with plastic. I set up my pumps, prime them, get my yogurt cups, my ziploc bags to deliver my epoxy to the wood Storer-style, etc etc etc. I got medium speed epoxy, so I'm feeling pretty good and I go ahead and throw in a mess of pumps to the appropriate 2:1 ratio for the "Marinepoxy" brand that I'm using. I decided to start out as clean as possible with the Duckflat method mentioned on Storer's website, ie. mix everything in the ziploc bag. So I pour in the resin and hardener, I "massage" the bag to mix, then I start dumping some silica into it. For this part, I placed the bag over a yogurt cup. Interestingly enough, the level of epoxy in the bag continued to get lower and lower as I mixed in silica. A hole mysteriously appeared at the bottom. If this was a self-inflicted hole or a heat-inflicted hole, I don't know. Whilst I was investigating the bag dropped into the cup. At this point the mix just freaking took off temperature wise. "Whoa Nelly!" Batch One, done. I sat it aside and kept an eye on it so it didn't combust on my workbench.

Discouraged but not out, I mix up batch Two. This time, screw it, I'm mixing in a cup, and I'll pour into a ziploc bag. The mixing goes well, I dump in the silica, that goes well. It's thick, but not super thick, definitely not peanut butter thick, but the temperature was starting to rise, and I wanted the epoxy delivered on the wood before it took off like the previous attempt. So into the bag, I cut the corner and that stuff just started pouring out all over the place. Then the bag got super hot, I dropped it, kicked it aside and starting grabbing the top and bottom frames for BH1. I placed them accordingly and clamped them down, but they started swimming all over the epoxy and wouldn't sit still. Epoxy was oozing out of every seam all over the place, I was watching two batches now for tell-tale smoking and potential combustion, and I was worried like the dickens that my frames were going to set akimbo.

Son of a bitch! Everything is somewhat quieted down now, and things are positioned somewhat where I want them, but not as perfect as I imagined. I'm not down with the ziploc bag idea with the speed at which the epoxy starts to hyperventilate. I've got to spread it over a larger area to mix and then either pour into a bag or distribute it over the surfaces with a different method. I'm going to try the sidearms tonight just for fun, but after I calm down.

Edit: Some ideas on gluing better.

Mark the centerlines on the top and bottom frames to line up with the centerline on the BH in case everything goes to hell in a handbasket and the sidearms are removed.

Mix smaller batches, as in 2 pumps to 1 pump. Just keep it small and work from there.

2 comments:

  1. Man, that sucks.

    Seems to be going off much too quickly. The only time I've had epoxy go off that fast was on a 105 degree day working in the sun.

    Let me ask a really dumb question - and please don't be offended. Are you mixing 2 parts resin to 1 part hardener? It almost sounds like you may have the ratio turned around.

    I do work with very small batches, too. My resin/hardener is a 2:1 ratio and most times I measure out what amounts to less than a single pump of resin. Adding silica ought to increase the volume of the mixture.

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  2. I've got the ratio correct 2resin/1hardener, maybe it was just too many pumps in too small a container. I'm about to go back and try the sidearms with just 2 pumps of resin.

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